Merritt Island National Wildlife Refuge

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threatened species occurs on John F. Kennedy. Space. Center/Merritt. Island. National. Wildlife. Refuge. ... recovery strategy was developed, based on studies of Florida. Scrub-Jays and scrub vegetation. ..... Administration. (NASA),. U.S. Fish.
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NASA-TM-111676

A Conservation Strategy for the Florida Scrub-Jay on John F. Kennedy Space Center/ Merritt Island National Wildlife Refuge: An Initial Scientific Basis for Recovery

D. R. Breininger, F. Adrian

April

V. L. Larson,

and H. Hill,

1996

Jr.

R. Schaub,

B. W. Duncan,

P. A. Schmalzer,

D. M. Oddy,

R. B. Smith,

NASA-TM-111676

A Conservation Strategy for the Florida Scrub -- Jay on John F. Kennedy Space Center/ Merritt Island National Wildlife Refuge: An Initial Scientific Basis for Recovery

D. R. Breininger, V. L. Larson, R. Schaub, B. W. Duncan, P. A. Schmalzer, D. M. Oddy, R. B. Smith Dynamac Corporation, NASA Biomedical Operations Office John F. Kennedy Space Center, Florida F. Adrian and H. Hill, Jr. U.S. Fish and Wildlife Service, Merritt Titusville, Horida

Island National Wildlife Refuge

National Aeronautics and Space AdmLrus"tration John F. Kennedy Space Center, Kennedy Space Center, Florida

April

1996

32899-0001

Abstract

The ecosystem

fire.

F. Kennedy trends

on reproduction

been

Analyses declining

scrub,

of the largest

Population

1995.

(Aphelocoma

of Florida

One

on John

Refuge. data

Scrub-Jay

integrity

frequent occurs

Florida

were

for 30 years. declined

10 years,

management

simulations

suggest

the jay population responsible natural

fire regimes.

recovery scrub

to persist.

for declining

strategy

vegetation.

science

principles

to restore

habitat,

habitat

A reserve for scrub

quality.

Site-specific

fire alone

can not reverse on studies

was formulated The

mechanical areas

tree

greatly

from optimal

with

the disruption

the trajectories. Scrub-Jays

of A

and

on conservation

cutting

for severely

degraded

for population

for

structure,

frequent

rapid

in

and computer

emphasizes

can produce

2

40%

strategy

will need to be developed, suitable

by another

of Florida based

has

suggested

of vegetation

are associated

ecosystems.

strategies conditions

trajectories

based

large

deviate

1988 -

suitability

Data

suitability,

design

but includes across

cannot

Landscape

was developed,

Pine thinning

to achieve

suitability

and field

from

simulations

and will decline

species

Wildlife

collected

intensified.

requires

modeling

that habitat

and computer

is not greatly

Prescribed

areas.

modified

data

of

threatened

population

indicated

that

National

Scrub-Jays

by at least 40%

that habitat

Island

using

of Florida

Field

that the population

of this federally

predicted

photography

is an indicator

ecosystem

Center/Merritt

and survival

if habitat

an endangered

populations

Space

of historical

coerulescens)

increases monitored,

persistence.

fire

in habitat and

Table

of Contents

Abstract

2

List of Tables

5 6

List of Figures Executive

8

Summary

13

Acknowledgments 1.0

14

Introduction

1.1

Optimal

Florida

Scrub-Jay

1.1.1 1.1.2

Landscape Characteristics Focal Habitat Patches

1.1.3

Matrix

1.2 2.0

Past

2.1

Risk

Management

Happy

Creek

2.2.3

Titan Complex Shiloh and Haulover

and

National

Estimated Extinction

Population Risk Change

Canal

31

Seashore

33 34

and Declines

2.3.3

Loss

of Natural

Happy

33

Declines

Replacement of Scrub Increased Forestation

Habitat

24

Risks

3O

2.3.1 2.3.2

2.3.4.2

Extinction

29

Canaveral

Landscape

21

26

in Habitat

with Urban

Openings

2.3.4 Historic Landscape 2.3.4.1 Tel 4

2.4

Status

21

2.2.2

2.3

and Habitat

Assessments Trajectories

2.2.7

20

Overview

Population

Population 2.2.1 Tel 4

2.2.6

19 19

Scrub-Jay

2.2

2.2.4 2.2.5

17

Habitat

Habitat

Florida

15

Habitat

36 36

Areas

38 Among

Scrub

Oaks

38 39

Change

40 44

Creek

Restoration

Suitability

and Population

Recovery

3

52

3.0 Strategic

Recovery

Plan

58

3.1

58

Criteria of Reserve Design 3.1.1 Provide for a Large Population 3.1.2 Maintain the Northern and Southern 3.1.3

Maintain

3.1.4

Minimize

Edge

by Keeping

3.1.5

Maximize

Well

Drained

3.1.6

Keep

3.1.7

Maximize

3.2

the Population

Patches

Habitat

Biogeographical

3.2.1

Population

3.2.2

Linkages

3.3 Restoration

in Close

60

Wide

but Maintain

the Necessary

and Minimize

Restoration

Costs

Degraded

63

Burning

69

Techniques

70 72

Habitat

3.7

Ecosystem

3.8

Long-term

Habitat

and Restoration

72

Costs

75

Inventory

Shiloh

3.6

62 63

Quality

3.5.1

61

69

Burning

Population

Matrix

62

Proximity

Activities

Restoration

Appendix

60

67

3.3.2

3.5

Landscapes

Centers

and

3.4.1

Areas

of the Population

Considerations

Mechanical

Habitat

Extent Contiguous

Reserve

Scrub

Quality

3.3.1

3.4

in Large,

59 59

and Haulover

Population

76

Inventory

79

Management

80

Management

82

Monitoring

A: Description

of the John

F. Kennedy

Space

Center

85

A.1 Landscape A.2 Climate

85

A.3 History A.4 Habitat

86

86 87

Descriptions

89

Appendix

B:

Fire

Appendix

C:

Ecosystem

Integrity

Appendix

D:

Population

Risk

Appendix

E:

Other

Literature

Management

Florida

and Biological

Diversity

91 94

Model

Scrub-Jay

Studies

Cited

95 97

4

List of Tables

Table

1. Current

Scrub

Reserve

Table

2.

Scrub

Reserve

Table

3.

Shiloh

land cover Units

Disturbed

Scrub

and corridors

and degraded

Units

Florida

(SRUs)

composition

(SRUs)

Scrub-Jay

Reserve

habitat

and corridors

groups

(hectares)

of the

between

SRUs.

(hectares)

within

between

SRUs.

and habitat

Unit and Haulover

by burn unit

corridor.

5

64

72

in the 78

List of Figures Figure

1.

Boundaries

Merritt

Island

of John

National

F. Kennedy

Wildlife

Refuge,

Canaveral

Figure

2.

Florida

Scrub-Jay

study

Figure

3.

Florida

Scrub-Jay

population

Figure

4.

Population

Figure

Figure

trajectories

data

6.

from

data

Haulover

Seashore,

A) Titan

launch

complexes,

of population

probabilities

Figure

8.

Comparative

extinction

Figure

9.

Historical

success

reproductive

National

Comparative

25

habitat. and

28

Creek.

and C) Canaveral

7.

and

Archbold

reproductive

using

Figure

success

B) unburned

A) Tel 4 and B) Happy

from

23

model.

reproductive

using

trajectories

areas,

22 risk

and

trajectories

Population

survival

National

areas.

using

A) optimal

Population

survival

Canaveral

including

Air Station.

data from

5.

Center,

16

and Cape

survival

Space

success B) Shiloh

and and 32

Seashore.

35

declines.

37

risk estimates.

landscapes

mapped

using

aerial

photographs

at Tel 4. Figure

10.

41 The

Kennedy Figure

11.

Space Forest

Tel 4 study Figure

12.

The

Kennedy Figure

13.

14.

15.

Kennedy

The

dynamics

on previously Space

of forest

site on

cleared

areas

in the 43

Center.

in the Tel

4 study

site on 45

Center. landscape

dynamics Space

patterns

mapped

using

aerial 46

Creek. of open

scrub

in the Happy

Creek

study

site 48

Center.

dynamics

Space

in the Tel 4 study

42

site on Kennedy

at Happy

The

scrub

Center.

Historical

on Kennedy Figure

of open

establishment

Space

photographs Figure

dynamics

of forest

in the Happy

Creek

study

site on 5O

Center.

6

Figure 16. Forest establishment on previously cleared areas in the Happy Creek study site on Kennedy Space Center.

51

Figure 17. Influence of habitat, helpers, and epidemics on population trajectories in habitat capable of supporting 700 53

breeding pairs after restoration. Figure 18. Reduction of extinction risk associated with restoration.

54

Figure 19. Influence of initial population size and habitat suitability 56

on extinction risk. Figure 20. Influence of initial population size and hurricanes on

57

extinction risk in optimal habitat. Figure 21. Potential scrub habitat on John F. Kennedy Space Center/Merritt Island National Wildlife Refuge, Cape Canaveral Air Station, and adjacent lands.

65

Figure 22. Scrub Reserve Units (SRUs) and corridors.

66

Figure 23. Disturbed and degraded scrub.

74

Figure 24. Bald Eagle nest sites on John F. Kennedy Space Center/Merritt Island National Wildlife Refuge.

7

81

Executive

The peninsular

Florida

Scrub-Jay

(Aphelocoma

portion

of Florida.

It was listed

Fish and Wildlife species John

Service

imperiled

status

F. Kennedy

Space

remaining

population

managed Some

habitat

Canaveral

Canaveral/Merritt

The

Scrub-Jay

to formulate scrub

for the Florida inventories required

are needed

KSC/MINWR the scrub

Florida

recovery

provides

recovery

Scrub-Jay

to as the Cape

review

recovery

to KSC/MINWR.

in the and 2)

towards

and the

and biological Detailed

plans,

Implementation

population

with

on KSC/MINWR,

site-specific

will lead

by the

for a large

the decline

and recovery.

efforts.

(MINWR).

of the jay population

a detailed

is

is contiguous

is specific

quality

habitat

(CNS)

has potential

decline

this document

and survival

jays on KSC/MINWR,

quantify

population

resulted

in declining

habitat

towards

on

basis

habitat

but are not

of the stabilizing

and will improve

the

the overall

quality

of

ecosystem.

Reproductive banded

many

population

1 ) to describe

habitat

to develop

from

are:

population

Seashore

document

Scrub

Refuge

can be referred

and scrub

document

Scrub-Jay

recommendations

This

KSC

Wildlife

also

for this

for one of the three

National

which

reasons

Most

National

areas

ecosystem.

strategy

The

to initiate

(CCAS), These

population

habitat

KSC/MINWR

of this document

a general

ecosystem.

The

population.

purposes

Island

by the U.S.

degradation.

Scrub-Jay.

as Canaveral

(NPS).

Island

and habitat

only in the

species

The primary

provides

of the Florida

as Merritt

occurs

as a threatened

in 1987.

(KSC)

Air Station

Scrub-Jay

Florida

Center

managed

Service

coerulescens)

are loss of habitat

cores

is also

Park

the Cape Florida

(USFWS)

by the USFWS

National

Summary

models

trends Florida

data,

were

seven

incorporated

and extinction Scrub-Jay

and photointerpretation

from

risks. habitat

years

of study of color

into a population Landscape suitability

of historical

changes were

and recent

risk

model

that

evaluated photography.

using

to

Most of the KSC/MINWR Florida Scrub-Jay population has been declining for at least 10 years and is expected to decline by 40% within The

KSC/MINWR

population

and population Scrub-Jay scrub

trajectories

species. fires

species

Nearly to maintain

( Gopherus

coupen),

Florida

Loggerhead

Extinction

of these

regional,

and global

Prior

Shrike

species

with short

agricultural

practices

resulted

established

in many

agricultural

becoming 1960s.

forests The

1960s

and most

seedlings loads

open

this time,

sandy

increased.

became

frequent

Fires

established

increased,

resulting

fires

areas

would

Frog

(Rana

capito

species.

impact

on local,

is the largest

kept KSC/MINWR

of marshes

differed

were

from

fire patterns.

led to increased

Fire suppression patches

in scrub

no longer

in high densities in the potential

of scrub

became

caused

occurred

pine mortality, in areas

sites

burned

poorly,

agencies

in the

habitat during

Shrub

the became

height

and pine

with soil disturbance.

for catastrophic

the

by having

and marsh

closed.

became

However,

areas

by federal

Early

species

abandoned.

Disturbed

program

many

plant

undisturbed

of KSC/MINWR

an open

and scrub.

Native

after they

of the space

During

Gopher

corias

coast.

areas

and facilities.

habitat

(Drymarchon

KSC/MINWR

in soil disturbance.

to acquisition

by roads

pine densities

Fuel

prior

because

no scrub

on the Gopher

and other

concern

characteristic

that influenced

and 1970s.

forests,

vegetation

development

fragmentation

Atlantic

and composition

fuels

impacts

Snake

Florida other

and marshes;

negative

Florida

The

require

long unburned

Indigo

if habitat

for many

concern

scrub

ludovicianus),

diversity

quality.

to prefer

floridanus),

settlement,

landscape

discontinuous

Eastern

of conservation

Florida's

structure

within

10 years.

in 50 years,

conditions

of conservation

will have

(Lanius

biological

along

habitat

are known

(Podomys

extinction

of poor habitat

conditions

forestation

to European

vegetation

species

polyphemus),

aesopus),

reserve

because

suitable

Mouse

with

of suitable

concern

Continued

Tortoise

species all scrub

of conservation

conditions.

scrub

continue

is an indicator

frequent

is endangered

the next

fires

under

and

certain weather conditions. As a result of these changes, fuel structures developed that would most likely burn only under extreme conditions. Prescribed fire management has been conducted through the 1980's and 1990's, but has not reestablished habitat conditions that can sustain Florida Scrub-Jay populations. Smoke management, safety considerations, and meteorological conditions limited the range of conditions suitable for burning. Fires will not return most forested areas to scrub or marsh. Prescribed fires alone have not returned scrub to optimal habitat suitability. Florida Scrub-Jay populations continue to decline in scrub landscapes fragmented by forests or other areas of tall shrubs. Florida ScrubJays require a complex mosaic of openings among scrub oaks. Natural openings among scrub oaks do not remain long after fire in most areas that have been subject to fire suppression. Man-made edges provide suitable habitat for jays but do not adequately replace natural openings because they can be systematically searched by predators. Other management tools are suggested to improve scrub habitat quality. Several experimental restoration efforts have been conducted, and their results have been promising. These efforts have primarily involved the mechanical cutting of trees followed by prescribed fire. Restoration efforts need to be implemented on a larger scale. Many years of study have quantified relationships among fire, vegetation, habitat structure, habitat use, and reproductive success and survival of Florida Scrub-Jays. These findings indicate that the continued decline in habitat suitability can be reversed with intensive management. Reversing landscape and population trajectories resulting from practices of the past half century requires a long-term commitment. Habitats for population persistence must be recently burned (less than 15 years from the last fire) and must represent wide vistas where most Florida 10

Scrub-Jay territories are surrounded by other territories. Four major landscapes, designated as scrub reserve units (SRUs), should be restored and managed as optimal habitat. These SRUs are Shiloh, Happy Creek, Schwartz Road (south of the Vehicle Assembly Building), and the Southern Pinelands (south of the KSC/MINWR Industrial Area). Because Florida Scrub-Jays have limited dispersal and are vulnerable to predation when they are outside of optimal habitat, corridor regions are identified within the KSC/MINWR population SRUs and between CCAS. No large scrub areas on the Florida mainland can be connected to KSC/MINWR. The CCAS population has undergone a severe decline, but it represents a potential large population center. All corridors within the Cape Canaveral/Merritt Island ecosystem need habitat restoration. The scrub within the SRUs and corridors is approximately 7,000 ha. This could result in a population of 700 Florida Scrub-Jay territories if all habitat could be restored to optimal suitability. Recovery to this population size can only occur if reproductive success exceeds the mortality rate over many decades. Studies show that all conditions must be optimal for Florida Scrub-Jay reproductive success to exceed or equal mortality rates. Achieving optimal habitat conditions quickly by extensive restoration is unlikely. Therefore, it is important to manage for a large population size in order to attain low extinction risk. Questions remain about the exact habitat and landscape requirements essential for population persistence. Some habitat has become so degraded that it will be uneconomical or impossible to restore to optimal conditions. Much habitat that is not restored will have negative impacts on the surrounding scrub by limiting the dispersal abilities of jays and their ability to detect predators. Thus, restoration of the population to 700 territories is likely to be a lengthy process involving adaptive management practices. Restoration of fire frequencies need to be adapted to site-specific fire history, past soil disturbance, and the amount and distribution of accumulated underground biomass. Restoration efforts need to include frequent burning for 11

at least 10 years and the additional mechanical treatment of forests. It is important not to burn all scrub within a unit at once in order to provide cover, acorns, and nest sites for resident jays. Prescribed fires need to occur under narrow meteorological conditions, for smoke and safety reasons, so that multiple fires may be needed within some units to accomplish objectives. Generally, most burn units (BUs) within the core reserve need to have 20-40% of the area burned every one to three years depending on the extent of habitat degradation within the BUs. A less frequent fire management regime can probably be used once the initial intensive treatments have been completed. Mechanical tree cutting is needed for oaks that have grown too large and pines that have grown too dense. Careful logging of pines along man-made edges and other disturbed suitability.

The

mechanical

Intensive needed

used

as models

population

for finely

recovery.

Jay population range

quickly

of habitat

conditions

The greatest

additional

prescribed

burning

equipment

and personnel

team

is needed

supervise

burns

the KSC/MINWR

for at least

whose

leaders

whenever population

This

must

can

needed

and the Florida techniques

be

for Scrub-

and the

the frequency

be supplemented cutting

burns

and operations endangered

12

landscapes

persistence.

for the mechanical

will become

will be optimal

habitat

is to increase

plan and evaluate

weather

to achieve

the management

10 years.

needed

and monitoring

of vegetation

needed

in habitat

improvement.

experimental

for population

effort

slower

of the remaining

monitoring

essential

may yield

These

restoration

to establish

improvements

it will be difficult

in most areas. tuned

in rapid

techniques

because

Continued

is essential

of oaks

restoration

landscapes,

conditions

can result

cutting

and expedited

in several

habitat

areas

permit.

with the

of trees.

on a daily Without

with extinction.

of

A burning

basis such

and efforts,

Acknowledgments

This Operations J. Barkaszi,

study

was funded

Office

at KSC/MINWR.

M. Burgman,

Knott

III, C. Hall,

Stith,

H. Swain,

by NASA,

R. Hight, J. Thaxton,

R. Bowman, R. Hinkle, O. Tilley,

administered

We thank

B. Summerfield,

R. Farinetti, M. McCarthy, B. Toland,

13

by the Biomedical

S. Ferson, E. Menges,

R. Akcakaya, J. Fitzpatrick, M. O' Connell,

and G. Woolfenden.

M. W. B.

1.0

The breeding

Florida

bird,

endemic

(Woolfenden America's than

Scrub-Jay

of North

America's

habitation.

Stith

exceed

core

an area

Typically,

monogamous

meters

et al. 1995,

for males

parents

than

Breeders

the year

burned

in press).

Most

respectively.

one year,

"helping"

and care for subsequent

offspring

once

upland

et al. in that

probability

their

of

entire

lives

and Fitzpatrick

within 1984,

by permanently 1984,

are within

1991;

300 and 1000

usually

to detect

as

et al. 1991 ).

spend

Young

Space

populations

a high

Fitzpatrick

dispersals

and

(Fitzpatrick

is defended

and

due

is designated

(Woolfenden

scrub

like

Florida

for agriculture

range-wide

provide

to more

Scrub,

across

on Kennedy

(Fitzpatrick

(Woolfenden

and females,

for greater

the territory,

pairs

is imperiled

are contiguous

properly

is one of North

important

(KSC/MINWR)

populations

are territorial.

all periodically

breeding

Refuge

species

et al. 1994 a).

population

populations

throughout

Scrub-Jay

in an ecosystem

for the species

Such

threatened

and its destruction

Wildlife

is managed

Scrub-Jays

Florida

(Breininger

Scrub-Jay

Core

is a cooperative

listed

habitats,

regimes,

Florida

that is defended

Breininger

fire

pairs.

The

It lives

fire-maintained

et al. in press).

Florida

1991).

concern

populations

if the habitat

coerulescens)

is a federally

birds.

National

400 territorial

survival,

1991).

The

Island

one of the three press,

1984,

of natural

Center/Merritt

that

of conservation

to the disruption human

to Florida,

habitat-specific

100 species

many

(Aphelocoma

and Fitzpatrick most

Introduction

remain

and mob

(Woolfenden

with their

predators,

defend

and Fitzpatrick

1984).

Scrub islands

and along

Florida, 1991, Here

dominated most

of the Atlantic

but are now among Larson

scrub

1992, includes

natural

Bergen native

communities

Coastal

Ridge

the most endangered 1994, shrub

14

of eastern

communities

Cox et al. 1994, communities

on east coast

Swain

dominated

barrier

mainland (Snodgrass

et al.

et al. in preparation). by saw palmetto

and

mesic shrubs on poorly drained soils and dominated by scrub oaks on well drained soils (Schmalzer and Hinkle 1992 a, b). Natural fires burned frequently in these landscapes and maintained their habitat structure and species composition (Vogl 1973; Campbell and Christman 1982; Means and Campbell 1981; Mushinsky 1985; Abrahamson and Hartnett 1990; Myers 1990; Schmalzer and Hinkle 1992 a, b; Breininger and Smith 1992). All other species of conservation concern that depend on scrub (e.g., Gopher Tortoise, Eastern Indigo Snake, Florida Mouse) also require frequent fires (Speake et al. 1978; Layne 1990; Auffenberg and Franz 1982; et al. 1991 b, 1994 a, 1994 b; Ostertag and Menges 1994, Hawkes and Menges 1995). Many of these species are threatened with regional extirpation management only

large

occur

of the few remaining remaining

on federal

subregion

properties

include

1, Appendix

habitat

This

Service

and CNS quality

(Swain

(USFWS),

lands

and a declining

that extend

and Labisky Coast

and Space

significant

Florida

scrub

1991 ). The subregion

tracts

in the

and private

lands

considered

Federal

Air Station

(CCAS),

beyond

KSC/MINWR which

Administration Park

population

Scrub-Jay

and

Smaller

KSC/MINWR

and the National

also have

restoration

et al. in preparation).

emphasizes

Aeronautics

Park

Canaveral

(CNS)

document

the Atlantic

State

Cape

Seashore

of National

and Wildlife

County

(Noss

et al. in press).

Dickinson

KSC/MINWR,

National A).

jurisdiction

CCAS

on Jonathan

reserves

within

(Fitzpatrick

in Brevard

of Canaveral

of scrub

properties

occur

for acquisition

tracts

large

without

Service

(Figure

is under

(NASA),

U.S.

(NPS).

Other

potential,

population

and areas

but have

Fish

poor

(Percival

et al.

learned

at the

1995).

1.1

Optimal

Florida

Much

of what

Archbold central

Biological Florida.

Scrub-Jay

is known Station

Applied

Habitat

about

scrub

(Archbold),

and theoretical

ecology

located studies

15

has been

on the Lake have

been

Wales conducted

Ridge at

in

I

0

5

10

km

Figure

":'!'i:::.

1. Boundaries

National Wildlife Air Station.

of John

Refuge,

F. Kennedy

Canaveral

Space

National

16

Center,

Seashore,

including

Merritt

and Cape

Canaveral

Island

Archbold

for more

Scrub-Jay burned

habitat

at once

fire regime

similarities

in scrub

are also only

1.1.1

after

landscape

avoid

Fitzpatrick

tree

with 1984,

cover)

jays

that was unburned

for

water

table,

This

more

mainland

scrubs

(Schmalzer

a, 1995).

Although

there

Ridge

are

and KSC/MINWR,

and 10 years

of habitat

most

there

of KSC/MINWR of applied

has

studies

here.

where

Florida

(Woolfenden

1974,

1974,

et al. 1995).

Scrub-Jays

1984).

are common,

(Woolfenden

typically

hawks

vulnerable

and Sharp-shinned

al. in press).

pines

Breininger

by Florida

and Fitzpatrick

scattered

et al. 1995),

(McGowan

are especially

1984,

can be

Florida

Scrub-

although

Woolfenden

they and

et al. 1995).

avoid

woodland

10 ha in size within

preferred

(Woolfenden

Breininger

average

and Fitzpatrick

high pine densities

(Breininger

Scrub-Jays

cooperil]

for

the dynamics

typically

(Woolfenden

Scrub-Jays

spot and evade adult

territories

attributes

Florida

enough

than

to predict

is

but is not frequent

matrix

Wales

not all habitat 1991).

scrub

et al. 1991

for Florida

and Fitzpatrick

has a higher

of management

in landscapes

areas

Ridge

where

scrub

on the Lake

as low and open

occur

Woolfenden

management

Characteristics

habitat

described Jays

15 years

Scrub-Jay

undisturbed The

b; Breininger

ecology

years

KSC/MINWR

drained

Our ability

Landscape

Florida

poorly

optimal

8-20

Wales

KSC/MINWR

1992

distinctions.

begun

et al. 1991,

not to restore

and a more 1987,

every

for the Lake

20 years.

and Hinkle

At Archbold,

burning

(Fitzpatrick

at least

than

nutrients,

25 years.

includes

is suitable

KSC/MINWR, greater

than

Scrub-Jay Woolfenden

areas

because

(i.e.,

there

accipiters).

and Woolfenden to accipiters Hawk

near forests

[A. striatus])

mortality

results

and Fitzpatrick

17

than

they have

reduced

Accipiters

are predators

1989) (i.e.,

(greater

and evidence

Cooper's

Hawk

on KSC/MINWR mostly

from

1984).

Florida

65%

abilities

suggests

to

on that

[Accipiter (Breininger

et

predation Scrub-Jays

not

only do not use pine forests (Cox 1984) but avoid Blue Jays (Cyanocitta which

are competitors

1991).

Blue Jays

near forests

are common

but are rare

and Schmalzer

Nest

1990,

et al. 1992).

allows

in recently

Scrub-Jays

dominated

Vegetation

to monitor

for Florida

Scrub-Jays

may not be effective

found

the nest

(Lohrer

and Fitzpatrick predators

1980,

1984).

(Francis

et al. 1989).

(Masticophis

flagellum)

adult

Scrub-Jays

Florida

of recently terrestrial

The woodlands

burned

burned open

providing

and

Breininger

et al. 1980,

Terrestrial

predators

Indigo

Snakes)

1990,

(recently

burned)

scrub

refuge

once

and the activities.

1980,

(e.g.,

of foraging

Eastern

1989),

has

Woolfenden

Coachwhip

are important

the detection

Florida

the predator

the course

and Woolfenden

may also facilitate

(Schaub

Webber

may alter

Scrub-Jay's

scrub

in their

predators

mobbing

(McGowan

scrub

while

at deterring

and Eastern

cover)

1990,

the Florida

to be inconspicuous

However,

20% tree

1984,

1992).

by frequently

Patterson

Fitzpatrick

(Breininger

that characterizes

Scrub-Jays

than

influencing

a large area

opportunity

scrub

and Smith

factor

and

(greater

burned

is a primary

for landscapes

(Woolfenden

in woodlands

Breininger

predation

preference Schaub

and nest predators

cristata)

predators

on

and the openness

and avoidance

of

predators.

fragmentation

of scrub

and forests.

suppression,

Disturbances

and other

edges

of habitat

within

habitat

landscapes related

disruptions

fragments

fragments

(Breininger

et al. 1995).

tall shrubs,

no longer

of natural

unsuitable

results to human

for jays. influence

Landscapes,

fragmented

Florida

Scrub-Jays

18

Forests

have not only

the suitability

large

fire

made

many

replace of nearby

by woodlands, to scan

of

development,

fire patterns

but negatively

allow

in an increase

areas

forests,

scrub habitat and

for predators.

1.1.2

Focal

Habitat

Optimal 1984;

Patches

Florida

Woolfenden

Scrub-Jay

habitat

and Fitzpatrick

al. 1995;

Duncan

following

attributes:

1984,

et al. 1995 a) occurs

a) 10-30%

(Westcott 1991;

1970;

Breininger

as patches

of the area comprised

1992

(focal

of bare sand

Woolfenden

b; Breininger

habitat)

or sparse

1974;

with

Cox et

the

herbaceous

vegetation,

b) greater

than

( Quercus

spp.),

c) a shrub

height

d) less than

e) greater

Scrub-Jays

within

represents condition

100 m from

increasing

condition

a territory

the potential

Patches

photographs

remained

unburned

Most patches (Serenoa

focal time

Habitat

potential

Florida within

Lyonia

of having

oaks

enough

by defending

patches 1984).

and Fitzpatrick

Oak scrub in optimal

Breininger

depending

on the time

since

little oak scrub

on Merritt

Island

(see

Scrub-Jay

1984,

large

in optimal

but not all of it is necessarily

that very

a matrix

fires

and Fitzpatrick

vary in quality

lucida)

of scrub

and

to frequent

(Woolfenden

Matrix

repens,

adapted

habitat,

suggest

comprised

a forest.

for long periods

of oak scrub

cover,

(Woolfenden

of oak scrub

Historical

1.1.3.

have

layer

cm,

the probability

at the same

1995).

of 120-170

15% pine canopy

than

Florida territories

50% of the shrub

Section

habitat

of little-used

and swale

19

et al. fire.

2.3).

on KSC/MINWR habitat

marshes

occurs

as

of palmetto-lyonia

(Breininger

et al. 1995).

These native matrix habitats provide prey for Florida Scrub-Jays and habitat for other species of conservation concern (Moler and Franz 1987, Breininger et al. 1994 a, b). The flammability of native matrix habitats is important for spreading fires into oak scrub that often burns poorly (Webber 1935). Saw palmetto, gallberry holly and marshes, oaks

(llex glabra), are more

(Abrahamson

Schmalzer

b, Abrahamson

Fish Crows

(Corvus

15 years),

native

and Smith

1992).

matrix

Past

disrupt

Logging, KSC/MINWR (Appendix the land

Scrub-Jays,

prior

ownership

MINWR

and CNS

prescribed

occurred

Fire

USFWS

(Adrian

1992).

fuel

Ioadings

to manage suppressing

wildfires.

another

primary

Farinetti

1995).

Ioadings

has been Initially, to reduce Habitat

objective

habitats

in most

Myers

with

scrub

1990,

habitat

Scrub-Jays,

regularly

such as

burned

and Fitzpatrick

1991,

into woodlands

the habitat

(every

suitability

3-

Breininger

and forests

and forests

when

are not

of nearby

scrub,

et al. 1994).

and agriculture and USFWS were

suppression

and fuel

fire program

than

Overview

to NASA

The

rapidly

1990,

woodlands

(Schmalzer

land clearing,

in the 1960s.

few wildfires

These

more

of Florida

develop

decrease

Management

ditching,

B).

often

of fire regimes.

fire patterns

Habitat

predators

(Woolfenden

habitats

fuel

matrix

that are rare

habitats

Matrix

for Florida

and further

adds

saw palmetto-lyonia

1992 a).

of native

ossifragus),

is a disruption

suitable

areas

dominate

and Hartnett

and Hinkle

or replacement

and industrial

which

and accumulate

et al. 1991 ; Schmalzer

fragments

1.2

flammable

1984

Degradation

there

and grasses,

objective

the hazards

and

and

1990s

of prescribed

and costs

for a variety

prescribed

2O

NASA

to dangerous

in the 1980s

the primary

of the current

after

in the 1960s

accumulated

conducted

natural

habitat

on

and NPS jurisdiction

established

occurred

management,

altered

associated of species,

fire program

purchased 1970s

when

levels.

A

by the burning

was

with has become

(Adrian

and

2.0

Detailed

Florida

data

are available

from

several

(Figure

1995,

sites in press,

spatial from dating

from

xeric

the existing

Scrub-Jay

long-term

2.1

than

study

Scrub-Jays

et al. 1994; data).

changes

from

Breininger

Remote

in habitat

on sequences

based

population

Much

et al.

sensing

and

and landscapes

of aerial

photography

that based

on the acreage

of 700-800

of the scrub

especially

population

has become,

of natural

north

families

potential.

size on KSC/MINWR

1989,

or is in transition

Canal

to,

Consequently,

(Section

Documented have

could

(Breininger

fire regimes.

of Haulover

on habitat

of scrub,

3.5),

is

declines

occurred

in

in several

sites.

Risk Assessments

Population reproductive for Florida detail

to quantify

of the disruption

population,

smaller

Florida

because

Florida

densities

2.3).

Scrub-Jay a).

Smith

Status

and territory

banded

unpublished

on KSC/MINWR,

et. al. 1991

hammock

much

(Section

habitat

for a Florida

Breininger

Schaub

that are identifiable

the 1940s

survival,

of color

et al. 1993;

used

and Habitat

success,

of study

2) (Larson

are being

Potential provide

3-8 years

features

Population

on reproductive

in preparation;

analyses those

Scrub-Jay

risk

success

models

and survival

Scrub-Jays

in Appendix

incorporates and presence

from

of helpers.

sets that had insufficient breeders. breeders

This

second

(breeders

with

future

in Figure

Breininger

independent Another sample ("simple") helpers

trends

(Burgman

is summarized

D (and see

stages

predict

model

model

et al. 1993).

The

through

to distinguish distinguished

21

"primary"

without

data

model

The model

breeder

experience,

for KSC/MINWR

novice

from

data

experienced

only two classes helpers).

on

in greater

ms.).

adult,

was developed

and breeders

using

3 and is presented

et al. unpublished young

sizes

in populations

of

"!

0 Figure

2. Florida

Seashore, Shuttle

3

6 Scrub-Jay

HC-Happy Launch

...........

Creek,

study areas. SLF- Shuttle

Complexes.

22

CNS-Canaveral Landing

Facility,

National LC39-

Figure 3. Florida Scrub-Jay features of Florida Scrub-Jay

population risk model. The model incorporates sociobiology. The model implements Monte Carlo

simulations

and variances

using

of six stages fledglings based

Scrub-Jay.

and two helper

on habitat

breeders novice

the means

the Florida

stages;

acreage;

after one year breeders

breeder

mortality;

of breeding;

5) older

first year

helpers;

breeding

vacancies

2) there

3) novice

is dependent

of reproductive

Model

is a ceiling

breeders

that

helpers

are unfilled

have

on the number become

chance

that survive

can become

by helpers;

7) the number

include

of breeders experienced

of nonbreeders

of breeding

the first

and survival

1) nonbreeders

survive

4) the number

on the number

6) fledglings

success

assumptions:

becoming

vacancies

attributed

to breed,

followed

first

breeders

year

of nonbreeders

to

by if is

dependent on the survival of nonbreeders that have

of nonbreeders from the previous years, the number no chance to breed because there area no vacancies,

the survival

and the ceiling

of fledglings,

habitat.

The dotted

survival

and transitions

lines

represent from

on the total

reproduction

one stage

number

of helpers

and the solid

lines

represent

to another.

f

'

\

/

f

Experienced breeders

/ /

/

l

_

xperienced breeders

helpers

/ without

-1 with

helpers__

/,'

_

Novice breeders

Older helpers

\ First Fledglings

helpers

23

I

based

_,'

on

Both models perform fecundity ceilings,

are sampled attributed

breeders

2.2

from

to strict

and helpers

Population

model

was

data).

Ten

years

and Fitzpatrick

KSC/MINWR

data.

used

The in Figure Fitzpatrick burned matched without

to predict

population

1984,

primary

habitat

showed

mortality

during

mortality

of adults

and Fitzpatrick

Consequently,

per year

(Woolfenden

at Archbold

populations

at

The

simple

Archbold

model

habitat

trends

(Woolfenden

Reproductive in optimal 1984).

Archbold

A severe

the epidemic estimate

and Fitzpatrick

1991,

and

periodically

success

and resulted

survived

was

is presented

in the optimal,

at Archbold

24

Smith

to simulate

4A.

a reasonable

et al. 1993;

for

and Fitzpatrick

few juveniles

on data

comparison

rate (;_)=1.00)

of study

based

a standard

population

Figure

of

ms.; R. Schaub

collected

Populations

decline

one of 20 years

is 0.05

used

on optimal

growth

and helpers;

data

based

a slight

number

of habitat.

(Larson

unpublished

and CNS.

et al. 1991).

on the total

trajectories

complexes.

to observed

Population

Risks

at Shiloh

(Woolfenden

1984).

was

and

data.

on the amount

provide

and Titan

trajectory

(population

catastrophes

1991)

model

Creek,

Fitzpatrick

are placed

population

in press,

mortality

empirical

sites on KSC/MINWR

4A and is very similar 1991,

where

upon

based

of demographic

populations

occurred

probability

The

Tel 4, Happy

to simulate

used

et al. 1995,

(Woolfenden

Archbold,

behavior,

and Extinction

five study

Breininger

unpublished

territorial

simulations based

and are ultimately

at Archbold,

et al. 1994;

Carlo

distributions

Trajectories

The risk collected

Monte

exactly habitat

epidemic in high (Woolfenden

of epidemic Fitzpatrick

et al.

Figure 4. Population trajectories using reproductive success and survival data from A) optimal and B) unburned Archbold habitat. Mean and standard deviations of 1000 simulations represented. Assumes that epidemics occur with a yearly probability of 0.05. Other catastrophic events are excluded.

A. Optimal 8OO 7OO N_ c

6OO o-

5OO 4OO 3OO

0 O..1_

2OO 100 0 0

10

20

30

40

30

40

50

Years

800 7OO .N .,.-

6OO

c o

5OO

{3. c_

4OO 0 _I_. Q v

3OO 2OO 100 0 0

10

20 Years

25

50

1991).

A slight

decrease

or catastrophes

in population

are incorporated

It is not appropriate decline

based

assessments population

growth

to predict

for periods

changes

(;_ = 1.00),

longer

than

growth

analyses

rates

or lower

optimal

was maintained

otherwise

noted),

acknowledging

The for 25-40

The

years

decline

at Archbold

and extinction

throughout

Brevard

(Fitzpatrick

et al. 1991).

2.2.1

in an exactly

assessments data.

rates

or decrease.

result

populations

from

Extensive

throughout

ms.).

typically

Very

slight

1.00

result

need

in

in vital

prediction

for

The epidemic

the remaining

that the frequency

stable

increase

population

et al. unpublished

risk

sensitivity

that a few percent in a stable

will

analyses

of epidemics

(unless

may be higher

(Woolfenden

County

using

of Florida (Swain

associated

with habitat

and Fitzpatrick

vital rates

within

Scrub-Jays

unburned

1991 ) was also such

habitat

in unburned

et al. in preparation)

(Figure

habitat

4B).

occurs

and statewide

Tel 4

The

Tel 4 site (Figure

fire suppression forests

developed

burned

five times

keeping

risk

et al. 1993).

Few population

empirical

and extirpation

with the simulations

decline

that results

epidemics

modeled.

population

consistent

Scrub-Jay

and survival)

showed

when

(Burgman

trajectory.

but population

(Breininger

of 0.05

than

data

success

frequency

or lower

in the above

frequency

habitat

model

Florida

the available

model

epidemic

Archbold

that

that increase

of the population

is common

a population

empirical

in vital (reproductive

population

rates

decline

long term rate

into

to conclude

on the slight have

trajectories

shrubs

period

and did not lose

in several since from

2) was burned

1979.

exceeding

areas

once

openings used

Prescribed optimal

by at least

26

among

scrub

for agriculture.

burns height

one wildfire

at Tel 4 were and maintaining

during

oaks, The

the

although

study

effective openings

area at among

scrub oaks in most areas (Duncan et al. 1995 b, Duncan et al. in press). The Tel 4 study site was adjacent to private lands where scrub has undergone habitat destruction and fire exclusion. The population trajectory, using the primary model, for Tel 4 suggested a 25% decline within 10 years (Figure 5A). A decrease in the number of territories or birds has not been documented (Breininger et al. in press). The decline in the Tel 4 trajectory was sensitive to model assumptions in contrast with other trajectories below. The Tel 4 study site has higher habitat suitability for Florida Scrub-Jays than most areas on KSC/MINWR because there are few tall shrubs and an abundance of openings. Population dynamics within subpopulations are dependent on demography in nearby subpopulations and the dispersal of individuals from other subpopulations. Population declines are not always obvious in subpopulations where mortality exceeds reproductive success, if these populations have higher habitat suitability than their surroundings (e.g., Pulliam 1988, Howe et al. 1991, Pulliam et al. 1992, Dunning et al. 1992). Therefore, extinction risk is not always realized until extinction is inevitable (Howe et al. 1991, Pulliam and Danielson 1991). High immigration of Florida Scrub-Jays resulted in abnormally high Florida Scrub-Jay densities that may have lowered survival (see Watkinson and Sutherland 1995). Most immigrants appeared to be from adjacent private property where habitat has been destroyed for housing or has remained unburned for long periods (Breininger et al. in press). The data suggested that a density dependence relationship (at least at very high jay densities) may influence survival at Tel 4 but more data are needed to confirm this relationship.

27

Figure 5. Population trajectories using reproductive success and survival data from A) Tel 4 and B) Happy Creek. Mean and standard deviations of 1000 simulations represented. Assumes that epidemics occur with a yearly probability of 0.05. Other catastrophic events are excluded.

800

A. Tel 4

7O0 N "_ E

o

._ (_ {3L

o)

600 500

E

o

_5

400

'--

300

a_ _

200 100 0

• --

0

10

20

30

40

50

40

50

Years

B.

8OO

Happy

Creek

700 ,_ ._

600

500

400 300 n°_'-_

200 100 0 0

10

20

30 Years

28

Some evidence also suggested a negative influence of helper densities on breeder survival at Archbold (Woolfenden and Fitzpatrick 1984). Density dependence of survival rates could have been incorporated into the model. But logistic and similar density dependence formulations should not be used without strong evidence for such forms of density dependence because they can seriously underestimate extinction risk (Ginzburg et al. 1990). Sensitivity analyses of these density dependence models (i.e., Beverton-Holt, logistic or Ricker equations) confirmed that extinction risk was underestimated for habitat conditions (and associated vital rates) where failed

long term outside

improvements

stability KSC/MINWR

Immigration

attributed success

Tel 4 that could et al. 1995

a).

edges

adjacent

Happy

population site was

populations

attributed

readily

such

Island

these

by tree cutting.

have

Restoration

by Florida

resulted is needed

Scrub-Jays

in

suitability

et al. 1995;

and 1950's

et al.

Variation

in habitat

(Breininger

(Swain

persistence.

is temporary.

to variations

for

population

20 pairs

for population

areas

in the 1940's

are needed

Scrub-Jay

is less than

by restoration

competition

areas

Florida

little chance

leaving

has been

or else

sites,

at Duncan in many in

will continue

for

as Tel 4.

Creek

Happy centers

subjected

sequences

to jays

have

that can be restored

landscapes

The

jays

be altered

The

on Merritt

Soil disturbances

the few quality

Creek,

property

and these

demographic

at Tel 4 and in surrounding

of the Tel 4 population.

in preparation),

2.2.2

Scrub-Jay

to persist.

Habitat

forest

Florida

Creek

(Figure

on KSC/MINWR to 20 years

(1943-1979)

and the

area

landscape

2) is one of the largest (Breininger

et al. 1991

of fire suppression

showed became

that natural increasingly

29

before

openings forested.

potential a). The

Happy

Creek

1979.

Photographic

disappeared

from

The

study

area

Happy burned

five times since 1979. Prescribed burns at Happy Creek have not effectively reduced shrub height in many areas and natural openings have not returned (Schmalzer and Hinkle 1992 a). The population trajectory for Happy Creek suggested a decline by 50% within 10 years (Figure 5B). Sensitivity analyses indicated that minor changes in demographic data or epidemic frequency have little influence on the trajectory. Actual declines in mean family sizes and territory densities have been observed (Breininger et al. in press). Conspicuously, poor reproductive success represents one causative factor in the population decline (Breininger et al. in press). The loss of natural openings among scrub oaks, increase of tall shrubs, and the replacement of marsh and scrub by forest has been characteristic of this landscape for nearly 20 years. The population decline in the Happy Creek area has probably been occurring for decades. Although most Happy Creek scrub is of low to moderate quality, it is in better condition than many other areas on KSC/MINWR. Therefore, a decline at Happy Creek might have been masked by immigration until there were no more immigrants, if color banding studies had not been conducted. 2.2.3

Titan

Study

Complex

areas

surrounding

a history

of fire suppression

occurred

but they were

areas. Jays

There (Larson

natural became

et al. 1993). among

a woodland

for greater

launch

(Figure

2) have

had

A few unplanned

fires

rapidly

and these

fires

large

little or no evidence

for launch

impacts

Photographic scrub

than

complexes

35 years.

extinguished

has been

openings

the Titan

sequences

oaks disappeared

or forest.

30

did not burn

(1943-1989) and most

to Florida showed

of the landscape

Scrubthat

The population trajectory for Titan launch complexes suggested a population decline by of 50% within 10 years (Figure 6A). Sensitivity analyses indicated that minor changes in demographic data have little influence on the trajectory. Actual declines in Florida Scrub-Jay population have occurred (Larson et al. 1993, D. Oddy, unpublished data). Declines have probably occurred for longer periods than have occurred at Tel 4 and Happy Creek. The Titan launch complexes occur along a narrow stretch of coastal habitats that connect KSC/MINWR and CCAS. The population on CCAS is more vulnerable to extinction due to a long history of fire suppression. Ongoing studies indicate that the CCAS population is only a portion of its potential and that reproductive success and breeder survival on CCAS is especially poor (Percival et al. 1995). 2.2.4

Shiloh

This for longer Much

Haulover

landscape periods

scrub

years.

and

in these

sequences

within

potential

3.5).

10 years have

(Figure

Declines

have

6B).

Actual

Florida

This

agricultural

disturbance practices.

for greater

areas.

than

35

Photographic

disappeared

suggested

unpublished

Scrub-Jay

occurred

and most

of

decline

by

years.

31

data).

is less than periods

area of scrub

has been

largely

a population

in Florida

population

for longer

is a large

area

openings

declines

a) but the population

There

large

soils

or forest.

and Haulover

probably

Creek.

CNS jurisdiction.

that natural

(R. Schaub

a large

et al. 1991

Tel 4 and Happy under

for Shiloh

to greater

of fire suppression

but they did not burn

a woodland

occurred

subject

due to earlier

had a history

showed

became

to support

(Breininger

areas

2) had been landscapes

occurred

The trajectory

population

most

(1943-1979)

the landscape

25%

(Figure

than

A few fires

Canal

Scrub-Jay The

Shiloh

area

has

on KSC/MINWR 1/2 its potential than north

unburned

have

(Section

occurred

at

of KSC/MINWR for greater

than

35

Figure 6. Population trajectories using reproductive success and survival data from A) Titan launch Canaveral National

complexes, Seashore.

simulations represented. of 0.05. Other catastrophic ._. N

Assumes events

that epidemics are excluded.

occur

with

800

.h

"_ __ E O

B) Shiloh and Haulover areas, Mean and standard deviations

600

O)

_5

400

h_

200

D

o

13.-.....

0 0

"_" N

B. Shiloh

800

30

and Haulover

40

Canal

50

Area

600

_)

_5 a.

20 Years

.__

,-- _ 0

10

400

G)

o _ 13_.-.

200 0 0











10

20

30

40

50

Years

800

Canaveral

National

Seashore

N E O

¢_" {:t)

60O 4OO

Q- Q) O l._ I::L -_

200 0 0

10

20

30 Years

32

40

50

and C) of 1000 a yearly

probability

2.2.5

Canaveral

This

National

landscape

and habitat

Florida

fragments.

Much

than

USFWS

The

Florida

are also

in these Many

fires

trajectory

6C).

Scrub-Jay

construction

occurred

to road

mortality

burned

of this study

suggested

a population

have

indicated

(Smith

(Smith

in these

large

et

habitat for

areas

under

area.

decline

by 25% within

that minor

on the trajectory.

occurred

disturbance

of fire suppression

but they

analyses

soils

of NPS facilities

had a history

little influence

population

to greater

and south

Sensitivity

data have

subject

subject

areas

to the north

population

demographic

due to recent

scrub

35 years.

(Figure

2) had been

Scrub-Jays

jurisdiction

10 years

(Figure

fragmentation

al. 1994).

greater

Seashore

changes

Actual

declines

et al. 1994,

in in

unpublished

data).

2.2.6

Estimated

Recent Jays

Population

studies

have

on all nonfederal

levels

(Fitzpatrick

the KSC/MINWR

Declines

identified

properties

at local

et al. in press). population

at such

to document

changes

monitoring

has focused

on detailed,

of the KSC/MINWR

indicate

that

occupied

Florida

Breininger

pers.

The vital KSC/MINWR for KSC/MINWR.

highly

never

Scrub-Jay

been

made

and the available size (Appendix

reliable

Numerous,

no longer

Florida

et al. in preparation)

have

accuracy,

landscape.

Florida

(Swain

in population

Scrub-Jays

in 1978 when

all of the remaining

Attempts

insufficient

portion

nearly

data

occupy

many

studies

began

and state to estimate

estimates E).

collection

qualitative

Scrub-

are

Ecological for only

a

observations

areas

that were

at KSC/MINWR

(D.

obs.)

rates from

population

long term study to estimate

The same

vital

different

rates

sites

can be applied

probabilities

and model

33

to the

of population

that were

used

decline

for the above

population trajectories were applied to estimate the probabilities of different rates of decline at the end of 10 years, a procedure referred to as terminal percent decline (Ferson 1991). Although the actual decline in the KSC/MINWR population is impossible to determine, one can use the results of such analyses to estimate the probabilities and magnitudes of the decline. Terminal

percent

decline

that all KSC/MINWR

study

10 years

The

(Figure

optimal

7).

habitat

in ten years historical

mapping

Schmalzer

et al. 1994)

population (Section

than

Hinkle

has declined 3.5).

KSC/MINWR

It is not possible

may only

be approximately

Extinction

Extinction probability

decline

The

Creek

1980,

been

longer

landscapes

probably

as an assumption

10 years. potential

decline

in decline

1981,

1991 a;

responsible

50% from its habitat

in

Ongoing

Breininger

than

20%

decline

areas.

et al. 1988,

the actual

than

of a 40%

and Titan

conditions

than

70% probability

population probability

(Stout

occurring

than

of greater

that the habitat

400 breeding

for the The at Shiloh

for the entire

had different

suggests

the current

extinction

risk which

rates

of

population

pairs.

Risk

risk

is often

that a population

during

represent

a 40%

collection

to estimate

different

Using

once

have

population;

20%.

1992 a, b; Breininger

by more

decline.

2.2.7

less than

suggest

decline

of at least a 20%

data

1987,

a greater

a decline

70% for Happy

and habitat

and

Scrub-Jay

was

indicated

experienced

probability

greater

Schmalzer

Florida

areas

at Archbold

was

results

a specified

the probability

presented

as quasi

will fall below

period

a threshold

of time (Ginzburg

of falling

below

et al. 1992).

a threshold

34

population

population

is the

size at least Here,

risk curves

size at least

Figure 7. Comparative probabilities of population declines. The percent decline is the percent of the population that declined at the end of a 10 year period. The curves resulted from 1000 simulations beginning with a population size of 700 breeding pairs. Assumes that epidemics occur with a yearly probability

of 0.05.

Other

catastrophic

events

are excluded.

1.00 •--e---

Optimal

_x---.Tel 0.80

•-_-

(Archbold)

4 Happy

Creek

_Titan o

0.60 O

.13 ..(3

0.40

o

0.20

0.00 0

20 Percent

40 decline

35

80

60 after

10 year

period

100

once during a 50 year period, a realistic management time frame. Demography from three study areas was used in three simulations to provide several estimates of risk for the entire KSC/MINWR population. The quasi extinction probabilities for the Happy Creek and Titan areas (Figure 8) suggest that the KSC/MINWR population has a greater than a 95% probability of declining from 400 to 50 breeding pairs below from

10 pairs other

1991).

and Titan

2.3

2.3.1

in optimal

populations

The

period.

appear

to almost

(Fitzpatrick below

et al. 1991, 10 pairs

Florida

Scrub-Jay

invariably

Woolfenden

within

50 years

populations

go extinct

if isolated

and Fitzpatrick is 50% for Happy

Creek

areas.

Landscape

Change

Replacement

KSC/MINWR

of Scrub

and CCAS

now urban miles

south

urban

areas.

population

1992).

Today,

populations

within

area

the only

on the mainland

areas

been

the mainland

on Merritt

mainland

viability.

36

habitat

south

barrier

of CCAS

was contiguous

at Oak quality There

connection, conservation

are

for

is in agriculture

of KSC/MINWR

and of poor

for scrub

areas

once

occurs

on

on the outer

of this habitat

near the KSC/MINWR

due to low population

Most

Island

et al. in preparation).

recommended

habitat

contiguous

connection

fragmented

(Swain

Scrub-Jay

Inlet.

Now most

Florida

Suitability

Areas

was once

potential

to the

Scrub-Jays have

Habitat

is extremely

pine densities

Urban

as Sebastian

of KSC/MINWR.

Scrub-Jay that

with

in Habitat

shows that Florida

as far south

(Larson

many

and Declines

photography

to at least

and high

a 50 year

habitat

risk of falling

Historical

island

within

or

Florida

Hill but the habitat due to infrequent

fire

are few Florida and little to no on that area

of

Figure 8. Comparative extinction risk estimates. The risk curves represent the probability of falling below different threshold population sizes any time during a 50 year period. These threshold populations range from zero (extinction) to 400 breeding pairs, the beginning population size. Curves represent 1000 simulations and assume enough habitat to support a population of 400 breeding pairs. Assumes that epidemics occur with a yearly probability of 0.05. Other catastrophic events are excluded.

N

_

1.00

c" 0

13.

o 0..

0.80

"0 0

c-

0.60

0

"Q

Optimal 0.40

C

--x--

Tel 4

. ,L.

Happy

(Archbold)

Creek

Titan O

=

0.20

.13 O

0.00 0

50

100 Threshold

150 population

37

200

250

size (breeding

300 pairs)

350

4OO

2.3.2

Increased

Forestation

Pine densities year

period

fire

the landscape,

with severe

soils

been

areas

willow

(Salix

marshes

where

there

1985).

no longer

2.3.3

Loss

suppression returned 1981;

Much

prior

and do not persist

around

often scrub

Among

pines

burn for days, on KSC/MINWR

itself

areas

1990).

or where

especially

wax myrtle rubrum),

the soils

invaded

(Schmalzer

influences

marsh

(Myrica

have

in hydrology

by fragmenting

in areas

so that

and Schmalzer

marshes

Scrub

during

to 1978.

long after

and Hinkle

in many

fragments

flammable

17 years

surrounding

a previously

vegetation

open

so that

areas.

disappeared

that occurred

are abundant Snags

Openings

openings

Schmalzer

replaces

into surrounding

of Natural

Natural

and pine flatwoods,

a 20

fragmentation

(Acer

of swale

after

discontinuities

of fire or alterations

invasion

Even

not reestablish

(Breininger habitat

size during

to increase

in fuels

and red maple

is exclusion

vegetation

carry

does

Hardwoods,

caroliniana),

to 1978.

continues

often

within

disturbed.

scrub

Woody

fires

occur

tree

and habitat

oak forests

The woody

particularly

landscape.

palmetto

become

mechanically

and Hinkle

cover

and this results

and forests

cerifera),

habitats,

Saw

disturbance,

Pine woodlands have

forest

reached

prior

due to soil disturbance

et al. 1994).

disturbed

that occurred

management,

(Schmalzer

many

and scrub oaks

of fire suppression

of prescribed within

increased

1987,

Oaks

the 20 year

Natural

fires,

openings

except

sometimes

of fire

in scrub

in some

1992 a; Schmalzer

and snags

period

pinelands

et al. 1994).

on KSC/MINWR

(Breininger

weeks

creating

has always

after fires,

lacked

pines

have

not

(Breininger Openings 1992).

openings.

but historically

had many

openings.

Natural fire patterns

fire pattern achieved

and frequency

by management

within

the landscape

techniques.

Most

38

differed

natural

fires

from

the

occurred

during the growing season, and vegetation is adapted to growing season fires (Robbins and Myers 1992). Many prescribed fires have occurred in winter may explain oak cover

why natural as effectively

Furthermore, Different holly,

types

patches

burned

into wide

flammability openings

among

burn

Fire

across

large

fire to provide

scrub

Accounts

of scrub

of historic

on KSC/MINWR results

openings Scrub

(a major

oaks food

more

the fires often photography especially

need

without

having

that fire

stopped

due to low

cover

frequent

the edges

of saw

Ioadings

making

excessive

fires

to be at a sufficient

source),

than

indicate

shows

fuel

gallberry

frequently

along

in continuous

in oak scrub

palmetto,

fire patterns

oaks where aerial

and summer.

The

burned

do not reduce

et al. 1995).

winter

flammability.

probably

Historical

oaks

for long

(Breininger

located

Historic

The

along

edges

it that

age from the last

from predators,

and nest

Tel 4, Happy

sites

Scrub-Jay

they

used

be "mortality (Yosef

1990).

Florida

et al. 1990,

that can These

Scrub-Jays Fitzpatrick

by Florida

traps"

are et al. 1991 ).

Scrub-Jays

because

they can

be

1994).

Change

Creek

landuse/landcover because

where

(Dreschel

could

in openings

and Schmalzer

roadsides

by predators

Landscape

result

may be extensively

edges

searched

(Breininger

vehicles

1981 ), these

systematically

soil disturbances

periods

by motor

man-made

long-term

different

oak scrub

mechanical

killed

Although

selected

have

suppression

acorns

are often

frequently

historical

during

fires

Scrub-Jays.

openings

2.3.4

differ

areas.

Extensive, degrade

of fuels

1935).

to reestablish

for Florida

patterns

patches

scrub

palmetto-lyonia difficult

(Glitzenstein

oak.

(Webber

Winter

fires

within

of scrub

not returned.

season

of vegetation matrix

have

as growing

the moisture

and grass

wide

openings

which

span

study

and Shiloh

analysis much sites,

study

areas

on KSC/MINWR.

of the geographic

and represent

39

a wide

were

selected

These range range

areas

for were

of KSC/MINWR, of historical

are

landuse on KSC/MINWR. Aerial photographs from 1943, 1951, 1958, 1969, 1979, and 1989 were used to map a time series of landuse/landcover changes. Landuse/landcover categories were mapped and digitized into ARC/INFO. Coverages were registered, overlaid, and acreage's of landcover types were determined. These results will be discussed sections sites

for the Tel 4 and Happy

is currently

2.3.4.1

underway

Study

sites.

and is not presented

in the following

Work

on the Shiloh

study

here.

Tel 4

Since

the 1940's

and an increase Forest

cover

and then

landuse present.

and

(Figure

10).

in the scrub a wildfire

began

burned

management prescribed but have

until

of open area

to 1.6%

to 30.7%

in 1969

scrub

(Figure

9).

in 1969,

was at its maximum

large facilities

grazing habitat

in 1943,

and

the land

In 1977 during

the extent

in the scrub

before

4O

have

(Figure

were

range 1960's

of fire suppression, prescribed

fire

the implementation slowly

in the form

also

and the openings

the fire suppression

of soil disturbance

in the Tel 4 area

1970's,

After

with

in the early

into effect,

In the late

Other

herbaceous

open

this period

on KSC/MINWR openings

areas

by encouraging

went

ranching.

of crop farming

remained

purchased

the Tel 4 area.

1943 was

amount

fire suppression

management,

the ranch

it decreased

The

NASA

to disappear. through

were

it increased

scrub

and a limited

cover.

this point,

not yet reached

There

area;

in the Tel 4 area during

was implemented fire

in the Tel 4 study

Open

fire to improve

woody

continuing After

area;

as citrus

used

reducing

management

of the study in 1989.

landuse

such

Ranchers

growth

cover

in the amount

in 1989.

dominant

practices

1.3%

of the study

to 7.7%

a decrease

of forest

to 21.8%

10.4%

The

has been

in the amount

decreased

increased

there

in 1943 was

representing

support

Creek

and presented

began

of to return

period. of clearings

11 ). These

cleared

to areas

Figure 9. Historical landscape trends mapped using aerial

photographs

for Tel

4.

- o - Forest Open

2OO

scrub

--..n---

Closed

-

Marsh

•-

scrub

2.

150

100 iii



O-



.

I

m

m

,,0

0

50

-

0 1943

I

! 1951

1958

1969 Year

41

1979

1989

m OpenScrub 1943 m open Scrub 1969 m OpenScrub 1989 m open Scrub 1943& 1969 m OpenScrub 1943& 1989 [-Q OpenScrub 1969& 1989 m OpenScrub 1943& 1969& 1989

Uete_

Figure 10, The dynamics of open scrub in the Tel 4 study site on KennedySpace Center.

42

Cleared 1943-1989 Cleared-forested1969 Cleared-forested1989 Cleared-forested1969& 1989

Metem

Figure 11. Forest establishment on previously cleared areas in the Tel 4 study site on Kennedy Space Center, Redareas were cleared between 1943and 1989but were not forested in 1989. Green areas were cleared between1943and 1958and were forested in 1969.Blue areas were cleared between1943and 1979and were forested in 1989.Yellowareas were cleared between 1943and 1958and were forested in 1969and 1989,

43

were

abandoned

land.

Slash

areas. pines

pine (Pinus

With

rapidly

management

across

areas

it burned

area

during

restored

Tel 4 habitat

areas,

Prescribed

fire

by slash

cover.

Logging

restore

these

In 1943, increased

cleared understory, fire

but is unlikely

to

mechanical

other

under

period,

a native

many

areas

understory

Scrub-Jay

the

Fire

and thinning

the overstory.

cleared

area clearly

is able to carry

and recolonized

into the tall pine

pines

is required

which

reduced

understory.

(killing)

on scrub

in the scrub

burning

fire has also

not extend

in thinning treatment

prescribed

that were

does

on KSC/MINWR

and openings

As a result,

the canopy

practices

areas

to reduce

in addition

shows

forest

to fire to

the implications

with

a pine

inhabits

this

overstory dynamic

of

and the habitat

type.

Creek

Creek

gained

forest

cover and

of the Happy

Creek

study

to a maximum

of the Happy

the

Prescribed

additional

Prescribed

with

The Tel 4 study

for the Florida

5.2%

12).

of pine forests

many

lost.

areas

and mechanical

Happy

from

are ineffective

areas.

Happy

of 2.7%

over

land management

2.3.4.2

(Figure

type without

to optimal.

A flammable

so that fires

implications

differs

penetrating

canopy

different

purchased

and the lack of a flammable

native

has not restored

pines.

NASA

the abandoned

the Tel 4 landscape

not completely

cover

into these

in effect

after

vegetated

the fire suppression

were

of forest

densely

the rate of spread

oak vegetation

amount

abandonment

et al. in press).

The Tel 4 study

much

total

back to their

(Duncan

because

elliottil)

has reduced

these

treatment

until

fire suppression

spread

return

gradually

Creek

in 1969

of 18.2%

study site,

and increased

site was forest

in 1989.

increased slightly

lost openings

Open to 14.0%

to 3.3%

44

scrub

cover. in 1943

in 1951,

in 1989.

in scrub (Figure Forest

cover

comprised

decreased

13).

7.7%

to a low

Forest 1943 Forest 1969 m Forest 1989 m Forest 1948& 1969 D

Forest 1969& 1989

m Forest 1943& 1969& 1989

L Neters

Figure 12. The dynamics of forest in the Tel 4 study site on KennedySpace Center,

45

Figure Happy

13.

Historical

landscape

trends

mapped

using

aerial

photographs

for

Creek.

- o - Forest

Open

Scrub

Closed

" •"

Scrub

Marsh

400

300

tt_

200

,,0

100

.....

O'"

.....

_.:.2 " --

&

1958

1969

&

I

0 1943

1951

Year

46

1979

1989

Landuse less uniform intensely fields

practices

than

at Tel 4.

managed

(Duncan

extensive 1958.

have

The Happy difference

xeric

than

few pine differently needles

trees.

openings

openings

above monthly

mesic

were

many

were

scrub

mapped

Creek

corner

are much

while

oak scrub.

just prior

carry

broader

Another and more

in Happy

Creek

Tel 4 is dominated

pines

oaks

to

subdivision

aspects.

type

Another

fires

was

the land.

vegetation

of scrub

Many

rainfall

the fire under

period

during

1950.

probably

were

most

Robbins

and Myers

from

is by

important

and Happy through

Creek

has

the landscapes

and high flammability

Historical

climate

but, far below An ignition

Prior

1992).

imagery

records

Slight

is much

of pine

document

14).

July,

(lightning

strike

or man

dry periods

to moderate

47

August

fires

(Davidson increases

Scrub for a hot fire the

as a year with and September

induced)

in the above period,

but

just before

1950

June,

sometime

imagery,

evidence

average

conditions

during

(Figure

from a fire that occurred

to the fire suppression

extensive

from the 1943

fire and there

resulted

extreme

mapped

the 1951

openings

measurements.

started

openings

to time since

was taken. average

ridges

differences,

and farming

at Happy

Tel 4 in other

site has abundant

of these

homesteads

were

to be

was for a housing

vegetation

xeric

1950's

1935).

are related

to 1951.

imagery

sand

due to the low flammability (Webber

from

dominant

interspersed

Because

network,

and

did not appear

disturbance

differs

Creek's

is that the Tel 4 study

There

prior

with

Creek

had not purchased

landscape

interspersed

1940's

in the northwestern

with road

at Tel 4. The

with

vegetation

difference

more

ridges

largest

if NASA

is that Happy

oak scrub

mesic

Creek

the

a few scattered

that took place

built

during

land at Happy

The

complete

been

Creek

contained

et al. in press).

This clearing,

extensive

Most

and only

land clearing

that would

main

at Happy

probably

four

month

in xeric

scrub

and Bratton and decreases

1986, in open

Kilometers

6

o_



Open Scrub 1943



Open Scrub 1951

11o •

Open Scrub 1989

[]

Open Scrub 1943, 1951and 1989

Figure 14, The dynamics of open scrub in the Happy Creek study site on Kennedy Space Center.

48

space,

attributed

(Schmalzer and

to time since

and Hinkle

1958 were

The

in the amount

1960's,

fires

had

any conditions,

and other

have

openings

are far below

through

the landscape,

extreme

conditions.

edges

between

Forest occurring

the extent often

closed

cover

scrub

increased

from

found

on poorly

hardwoods Without

compete

with hardwoods.

through

through

frequent

these

the established

of the hardwood not slowed burned cover

high

in these

drained

sites

slightly

altered

drained

Most

of forest

intensity

into

in a few forested

when

sandy

natural

fires

extreme

swales. areas

with simple

into surrounding were

established,

fires

under

Naturally

and sedges

simply

swept

trails.

15).

spread

fire under

prescribed

spread

Prescribed

Today's

(Figure

became

was

and occasionally

or open

grasses

but they

burning

are now associated

soils

under

by roads,

returned.

season

in the

landscape

prescribed

to 1989

hardwoods

hardwoods

the process

with

1943

of a large

Beginning

and 1951,

grass

Occasional

composition.

unable fires

carry

conditions

resprout

with

around

these

A 1993

to

can burn

little alteration forests

restoration

and significantly

has fire

reduced

tree

areas.

Disturbed

scrub,

Once

oaks.

openings

Creek

fire, the swale

areas.

1980's,

the growing

and mowed

in 1943

was fragmented

in 1943

at Happy

before

oaks.

by fire suppression.

found

during

Openings

swales.

poorly

initiated

habitats

1958 was the start scrub

but few natural

trends

scrub

the KSC/MINWR

In the early

Creek

not reversed

surrounding

Creek

scrub

that

the landscape

firebreaks.

at Happy

shows

to burn across

after

within

at Happy

that surrounded

Creek

little chance

are expected

Openings

of openings

especially

implemented fires

mosaic

for Happy

decline

facilities,

1992 a, b).

a complex

imagery

the last fire,

sites

have

have

generally

composition.

revegetates

disturbed

often

been

returned

vegetated to scrub

by forests

or an oak scrub

Saw

palmetto,

which

areas

poorly

(Breininger

49

(Figure

carries

fires

16).

woodland through

and Schmalzer

Well with

oak 1990).

KilomeLers

6

o_



Forest 1943



Forest 1989

[]

Forest 1943and 1989

Figure 15, The dynamics of forest in the Happy Creek study site on Kennedy Space Center.

5O

Kilometers

6

o'.5

1.b



Cleared 1943 - 1989



Cleared-Forested 1989

Figure 16. Forest establishmenton previouslycleared areas in the Happy Creekstudy site on KennedySpaceCenter, Redareas were cleared between 1943and 1989but were not forestedin 1989.Green areas were cleared between1943and 1989and were forested in 1989,

51

The

relative

abundance

and Schmalzer perhaps

1990).

because

Happy

Creek,

of hardwood These

hydric trees,

_Unlike

suppression

Tel 4. Winter openings

2.4

and mesic

burned

length

(e.g.,

landscape

have

for recovery

rapidly

even

after

hurricanes)

to occur. a large

will be longer

and have

of breeding

restored

areas,

helping

breeders

Restoration population

does

approach

optimal

enhance

(Woolfenden

less

(Figure

chance

quickly. as well

will decrease

increase,

conditions

(Figure

providing 18).

52

upon

than

of natural

stochastic

which

must

numbers 17).

The

for successful Continued

they

the demographic

not rapidly

a longer

Creek.

will rebound population recovery,

decline

breeders

of breeders

by

1991).

extinction

risk

that most

Simulations

even

habitat

using

if

of helpers.

are potential

success

be

population

as the number

because

and Fitzpatrick

of the habitat

with

suitability

at Happy

population

effort

pairs,

to the population

and they

that

restoration

the number

patterns,

an abundance

suitability,

will reduce

Combined

in habitat

and habitat

is not implemented

of fire

effects.

depends

restoration

are important

period

recovery

aggressive

Helpers

a longer

Recovery

It is unlikely

scale

types

and swamps.

marshes.

forestation

At

by many

to swale

reduction

and Population

seeds.

of forests

not reestablished further

of pine

and vegetation

(Breininger

to clearings,

colonized

degradation

in a greater

not prevented

epidemics,

period

through

habitat

from

fires

were

characteristic

went

areas

differently

source

areas

of time for population

optimal

recovery

Creek

in disturbed

responded

in comparison

resulted

Restoration

The events

poorly

prescribed

and have

Habitat

by those

resulting period

differs

nearby

disturbed

had additional

discontinuities

also

was an abundant

especially

which

oaks

Tel 4 vegetation

Tel 4, Happy

suppression,

fire

The

there

hardwoods

fuels

of scrub

if the begins

empirical

to

for

Figure 17. Influence of habitat, helpers, and epidemics on population trajectories in habitat capable of supporting 700 breeding pairs after restoration. Assumes that habitat is restored to optimal or moderate suitability. Reproductive success and survival rates for optimal habitat derived from Woolfenden and Fitzpatrick (1984). Moderately suitable habitat vital rates were approximately midway between optimal and unburned habitat.

--e- Vital rates for optimal habitat, no catastrophes, helpers present in initial population. Vital

rates

for optimal

yearly probability restoration. -x--Vital

rates

epidemics present

of 0.05,

for habitat occur

in initial

habitat,

epidemics

no helpers

with

moderate

with a yearly

occur

present

habitat

probability

with

a

prior to

suitability,

of 0.05,

helpers

population.

8°°t 7OO

I.-

O. O) C

6O0

5OO ..Q v

40O

N cO

3OO

°p

"1 O 13_

2OO 100 0 0

10

20

30

Years

53

40

50

Figure 18. Reduction of extinction risk associated with restoration. Curves represent 1000 simulations beginning with a population size of 400 breeding pairs and assuming enough habitat to support a population of 700 breeding pairs. The risk curves represent the probability of falling below threshold population sizes any time during a 50 year period. The Happy Creek trajectory assumes currently

that reproductive occur at Happy

assumes

improvements

survival

rates

that optimal epidemics excluded.

remain habitat

occur

success and survival Creek. The moderately in habitat

5% below conditions

with a yearly

quality

but that

optimal. follow

remain the same as those suitable habitat trajectory reproductive

The optimal

a restoration

probability

0.05.

program. Other

success

habitat

trajectory Assumes

catastrophic

that

and assumes that

events

are

1 0.9 0.8 .B u .m

O

- ,L - Happy

0.7 0.6

rex--

Creek

(Optimal)

Archbold

Moderate

suitability

(-

.o

0.5

..I...i

t3 c"

°m

x iii

0.4 0.3 0.2 0.1 0 0

50

100 Threshold

150 population

54

200

250 size (breeding

300 pairs)

350

4OO

data

showed

that habitat

population

extinction

of KSC/MINWR

Even within

50 years

is inevitable

Florida

1% in optimal

habitat

habitat

optimal

Therefore,

habitat

low extinction

second

hurricane

of nearly

800 breeding habitat,

islands

A direct

19).

and that characteristic

to become

Extinction for large

probabilities

large

in A

an extinction

risk of

catastrophes).

by extensive

for a large

extinct

populations.

to have

and other

quickly

to manage

restoration

population

to the coastal

for a population

pairs

is unlikely.

size in order

result

could

to attain

given

5 storms

hurricanes

hit near Merritt

(Breininger

et al. unpublished

might

is nearly

Island/Cape

ms.).

(Figure

3 storms

Buckley,

Schuh,

& Jernigan,

contiguous

for 47 km.

ms.).

55

Total

storm

and all could

to inundate

during

size

surge

Half of the scrub

be needed

Canaveral

the maximum

risk of 1% in

20).

simulated.

is a

A population

an extinction

than

by category (Post,

5 storm

that scrub

to have

mortality

be inundated

of KSC/MINWR

size that approaches

are considered

in greater

hit by a category

proximity

et al. unpublished

is needed

hurricanes

by category

KSC/MINWR

remains

are likely

low only

hurricanes

size (Breininger

when

could

inundated

suitability

is essential

conditions

to manage

population

barrier

pairs

risk attributed

potential

inundation

persistence

risk.

reason

optimal

(Figure

are relatively

(without

it is important

The

habitat

populations

habitat

size of 400 breeding

Achieving

for population

if poor

Scrub-Jay

in poor quality

suitable

population

be optimal

scrub.

large

moderately

must

on

be

Inc.,

1990).

all of No catastrophic

the last 100 years

Figure 19. Influence of initial population size and habitat suitability on extinction risk. Quasi extinction probability refers to the chance that a population will decline below 10 pairs, a population size that usually involves extinction. Assumes that epidemics occur with a yearly probability of 0.05. Other catastrophic events are excluded.

-x-

Poor

quality

Moderate Optimal

quality quality

1.00

0.80 ..Q (0 JE)

o,9 t-J

0.60

tO O t..I-.,

X

0.40

(0

O

0.20

0.00 0

100

200 Initial

300 population

56

400 size (breeding

500 pairs)

600

700

Figure 20. Influence of initial population size optimal

habitat.

Quasi

extinction

population

will decline

extinction.

The frequency

yearly 63%

probablity mortality

1.00

below

probability

10 pairs,

of epidemics

of a catastrophic rate of all Florida

refers

on extinction

to the chance

a population

that

size that usually

is assumed

hurricane Scrub

and hurricanes

to be 0.01

involves The

resulting

Jays.

-

0.80

0.60

+

With

hurricane

+

No hurricane

mortality mortality

C

0.40

g, 0.20

0.00 0

1 O0

200 Initial

300 population

400

500

600

size (breeding

pairs)

5?

in

a

to be 0.05 per year.

is assumed

risk

700

800

in a

3.0 Strategic

One overall of 400-800 maintain

Florida the

with the goals

management

conservation

concern

high fuel

an interim

3.1

period

Criteria

Most persistence, habitat

Knowledge

will require

of extensive

of Reserve

Florida

restoration,

prescribed

be subdivided

based

and the potential restoration. on economic

will need

for habitat

proximity

to urban

estimated

based

A coarse

Sections

on current

and industrial on average

existing

information.

potential

reserves

of conservation use of prescribed

for species

fire safety

that result

that this effort

adaptive

fire

of

hazards

require

be

management

activities

existing

using

2.4 and 3.3).

undertaken

and ecological habitat

been

monitoring.

during

with

58

suitability,

sizes

based

and can be

can be developed

habitat

need

habitat.

of existing

soils,

habitat

be formulated

population

strategy

reserve

fine scale

fire management,

size and available

vegetation,

detailed

once

mechanical

can then

Expected

prepared

fires,

habitat

and without

designs

for population

Landscapes

potential

restoration,

areas.

prescribed

to prioritize

suitability,

reserve

only

condition

An adaptive,

to be established

territory

have

be in optimal

achieved

and conservation

Maps using

The

habitat

parallel

must

for mechanical

reserve

scrub

following

management

detailed

estimates

management.

numerous

habitat

burning,

Alternative,

of species

that is

Design

(see

process

ecosystem

and resources

and this is not readily

implementation

of the scrub

is to

restoration.

Scrub-Jay

is degraded

objective

needs

refinement

a core population

Another

C) and eliminate

successive

Recovery

habitat

of fuels

(Appendix

is to achieve

habitat.

tool will manage

Ioadings.

and involve

principles.

The

Plan

plan

and diversity

of KSC/MINWR.

coincide

phased

in optimal

integrity

as a primary

from

of this recovery

Scrub-Jays

biological

characteristic concern

objective

Recovery

landscapes

with and

and land use maps

to

(Huckle et al. 1974, Breininger et al. 1991 a, Larson 1992). Several principles for reserve designs can be immediately adapted using basic conservation science (Thomas et al. 1990, Noss 1991, Murphy 1992, Brussard and Murphy 1992, Murphy and Noon 1992, Noss and Cooperider 1994). Many of these principles apply to Florida Scrub-Jay conservation planning at state (Fitzpatrick et al. in press) and local (Brevard County) planning levels (R. Bowman, Archbold, unpublished, Swain et al. in preparation). 3.1.1

Provide

for a Large

A large

population

focused

on meeting

press).

Reproductive

precariously Florida exists

from should

include

3.1.2

Maintain

The vulnerable (i.e.,

must

the existing Even

impacts

the population

trajectories

landscapes.

the Northern

proximity

(Weiss program

on the population.

water

makes

and Murphy

1993).

and national

defense

and enhancing

decreases

The

combination

for a larger

population 59

resulting restoration

the population

this The

The topography region

potentially

location

makes

and nature

the population

the geographical

the risk of single

devastating

of KSC/MINWR,

CNS,

overall.

of the

Population

ms.).

table)

Maintaining

Scrub-Jays

makes

et al. unpublished

and shallow events

coast

of the

all habitat

much

Consequently,

Extent

to the Atlantic

(Breininger

for the space

provides

and Southem

of habitat

to return

changes,

scrub

of Florida

populations

given

by

Uncertainty

management

all major

to catastrophes.

distribution

decline

are

occupied

persistence.

be

et al. in

Scrub-Jays

size and the ability

with immediate

should

(Fitzpatrick

most habitat

for population

population

Efforts

of Florida

so that

the last half-century.

to climatic

vulnerable

rates

within

very low elevation

of operations

quality

of extinction.

populations

change

to hurricanes

vulnerable

and mortality

be optimal

may temporarily

landscape

for core

with habitat

conditions.

population

the probability

guidelines

success

balanced

concerning

to optimal

reduces

state

Scrub-Jays

Population

Evidence

and CCAS

suggests

that

demography varies among landscapes (Breininger et al. 1995); thus, some landscapes may be particularly important as population sources in comparison to other landscapes. This may relate to landscape configurations, predator populations, or other environmental factors. For these reasons, it is imperative to maintain the maximum north-south distribution of the population and the links to the Cape Canaveral population. 3.1.3

Maintain

Large

habitat

Scrub-Jays, adjacent

the Population

suitability sentinel

system

that

warnings

allow

Florida

1984,

then

(B. Stith,

unpublished

the best

3.1.4

when

formation Geological

data).

including

minimize

the amount

Margules

1993).

generally

north

by poor

by Keeping

of longitudinal

features

not forests, open

quality

surroundings habitat,

in large,

(Woolfenden have with

forests,

contiguous

have

landscapes

long distances

in their

developed

and

et al. 1991 ). Nonbreeders

Populations

of Merritt

formations

families,

from

habitat

a keenly

(McGowan

Large,

are often

greater

less risky

or development landscapes

thus

for long term survival.

Edge

geology

predators

vacancies

surrounded

chance

Minimize

The

breeding

by other

of Florida

Scrub-Jay

have

as hawks

numbers patches

on Florida

are nearby.

1991 ; Fitzpatrick

to detect

dispersal

such

hawks

to detect

fragmented

Scrub-Jays

surrounded

woodland

Scrub-Jays

Small,

Florida

Landscapes

the largest

influence

predators

Families

when

to maintain

a negative

for detecting

and Fitzpatrick opportunity

have

Contiguous

are equal.

et al. 1995).

1989).

early

are likely

factors

(Breininger

Woolfenden

have

patches

if all other to forests

in Large,

Island

ridges have

forests

of habitat

also

Orientation

Areas

and Cape

population

each

has resulted

parallel

In order

patch 6O

of other

to maximize

areas

should

landscape

total area

be elliptical

of the patches

as wide

in the

to the coastline.

the position

of the long axes

making

Wide

Canaveral

mostly

influenced

and roads.

of edge,

to south,

Reserve

(Sisk

should

as possible

and and

be

east to west.

Minimizing edge will reduce the number of territories along busy roads that are likely to have high mortality and will often be population sinks (Fitzpatrick et al. 1991, Dreschel et al. 1990). The proximity of scrub patches to forests should also be minimized, because populations near forests are subject to nest and adult predation. A long north-south axis maintains continuity across the KSC/MINWR population, and a wide east-west axis minimizes edge effects. 3.1.5

Maximize

Most drained

soils

occurred

et al. 1991

Nearly

interspersion

scrub

of woodlands,

and habitat

Scrub-Jays.

areas

soils

Matrix

of scrub areas

on well

(Woolfenden

population

and

in the mid-

on KSC/MINWR

components forests

for other

and other

species

they

due to low flammability which

and accumulate

a, b).

dominate

fuel

more

and Hartnett 1992

a, b).

for spreading

edges

Fires

prey

(Breininger

1990,

Thus, fires

burn

(Webber

than Myers

well

drained

marshes scrub

influence.

Native

for Florida

into wide

patches

of scrub

and marshes, oaks

the flammability into oak dominated

Schmalzer of native areas

1984

et al. 1991, matrix

habitats

that often

1987; oaks

gallberry

are more

(Abrahamson

matrix

Scrub-Jays

and Franz

Saw palmetto,

are

and serve

(Moler

1990,

61

landscapes

and swale

species

1935).

scrub

the

concern

palmetto-lyonia

rapidly

scrub

within

of negative

provide

that

minimize

areas

surround

of conservation

often

and grasses,

drained

that should

because

should

and industrial

Poorly

et al. 1994

important

consists

Scrub-Jay

management

forests,

Breininger

and Hinkle

the Necessary

drained

80% of the Florida

and habitat

are important

Abrahamson

on poorly

design

between

stop

habitat

300 m of well drained

landscape

habitats

Scrub-Jay

within

to Florida

as buffers

but Maintain

a).

Reserve

native

Scrub

Florida

with adjacent

1984).

important

Drained

high quality

Fitzpatrick 1980s

Well

burn

holly,

flammable a, b Schmalzer is poorly.

3.1.6

Keep

Patches

Contiguity Florida Stith

in Close

is important

Scrub-Jays

moving

unpublished

possible Small

data).

without

gaps,

woodlands, jays.

and poses

extreme Some

maintain

linkages

increase

Early

optimal

requirements continual accumulate. habitat

ecosystem Florida concern

(B. as

of water. for

is improbable

be as narrow

of habitat

as

will be required

to

quality

process

will

have ms).

the High

survival

of successful

and

restoration

decreases.

should focus Scrub-Jay

in the selected

Management

by managing

Breininger

on vegetation

species

occurs

required of Bald 62

finer

evaluate

scale

habitat will need

and populations the

of conservation

between

for

b).

efforts

in

and

1992

Recovery

to continually

overlap

and conditions

landscapes

persistence.

to other

the decline

landscapes

to identify

as data

will need

on reversing

in all major

1991,

will be needed

population

Much

quality

its associated

and risks

and Fitzpatrick

strategies

Costs

et al. unpublished

size and

costs

and modification

C).

corridors

(Breininger

population

this process

for long term

(Appendix

should

habitat

(Woolfenden

Scrub-Jays

habitat

bodies

or forests

of the highest

Restoration

processes.

of water

regions

populations

management

bodies

high

of

the risk of mortality

Restoration

of the Florida

The

is very

or large

increase

Mortality

be as contiguous

and Minimize

success

evaluation

should

Quality

as habitat

during

habitats

areas

in suitable

of restoration

habitat

Monitoring

large

risk.

all patches.

maximize

stable

non-scrub

development,

and urban

objectives

demographic establishing

as forests,

of persistence

success.

dispersal

the reserve

and less optimal

within

will

within

Gaps

Habitat

probability

reproductive efforts

risks.

it minimizes

mostly

across

among

Populations

quality

such

narrow

Maximize

habitat

through

Scrub

Dispersal

possible.

greatest

because

agriculture,

dispersing

3.1.7

Proximity

concern

conditions

for other

species

Eagle

(Haliaeetus

importance

optimal

of and for

of conservation leucocephalus)

nesting habitat requires additional considerations and priorities that need to be incorporated into alternative reserve designs. 3.2

Biogeographical

3.2.1

Population

Recent dominated reserve

habitat

units

(Table

landscapes

were Much

other

1, Figures areas

et al. 1991

700 territories,

Historical

forests.

(Larson

These

(Breininger

territory.

aerial

of poorly

landscapes soils

Canaveral

but it has been

photography

shows

may serve

marshes,

scrub

and few soils,

while

soils

in a

of well drained

et al. 1991

on mostly

of fire suppression.

Canaveral

for each

by well drained

scrub

of

show that these

Breininger

by coastal

for the

a population

is needed

conditions

patches

as scrub

potential

provide

openings,

et al. 1974,

to 40 years

Cape

could

is dominated

was dominated

that

many

include

(Huckle

subject

areas

and edaphic with

landscapes

habitat

10 ha of scrub

photographs

landscape

four

22) which

the highest

These

assuming

of the Shiloh

identified

21, Figure

a).

by scrub

drained

1992)

have

dominated

KSC/MINWR

Cape soils,

mapping

(SRUs).

approximately

matrix

Centers

by scrub

population

most

Considerations

well

drained

Historical

had many

openings

supported

much

a).

aerial

and few

trees.

The

adjacent

well drained

scrub

destruction.

Scrub

long unburned

Florida than

is no realistic

those

on KSC/MINWR

mainland

from

on the Florida

present,

mainland

(Snodgrass potential

Merritt mainland

to link mainland expanses

and the extent

(Swain

was decimated

now occurs

et al. 1991,

due to wide Island

originally

but this scrub

on the Florida

habitat

There

mainland

Larson Florida of open

of scrub

et al. in preparation).

63

more

by habitat

as patches 1992,

Bergen

Scrub-Jay water

extensive

of mostly 1994).

populations

that separate

destruction

with the

and degradation

o

0

=-

o

II r_

8

CO

"5

#

_o 8

o_

o "o

_g

_m

mn, I-CO

64

Figure 21. Potential scrub habitat on John F. Kennedy Center/Merritt Island National Wildlife Refuge, Cape Air Station

and adjacent

lands.

65

Space Canaveral

\

km 0

Figure

22.

3

Scrub

SRU: 1-Shiloh, Corridors:

6

reserve II- Happy

a-Haulover,

units Creek, b-Banana

(SRUs)

and corridors.

III-Schwartz Creek,

Road,

c-Cape

66

Roman

numerals

and IV-Southern

Canaveral,

indicate pinelands.

and d-Industrial

Area.

cores.

3.2.2

Linkages

A narrow Space

corridor

Shuttle

Complexes

(i.e.,

exists

a vital

link between

is also

important

of occupied

LC39A

and LC39B)

between

KSC/MINWR

SRUs

linkages

scrub

between

most

northern

the Happy

Creek

area

with the Shiloh

open

water,

crossed

immediately several made

south

occasions

Canal

(R. Schaub

personal

Much

birds.

the canal

for urban

acquired

soil disturbance

expanses

of severely

freezes, grape 1994),

groves have

vines

not native

The Happy

most

Creek

and cabbage

scrub

plants.

corridor

area to the Schwartz

fragmented

3.5).

These

and shrub

Several

palms

to establish Road

67

were

not

the

are known

by citrus occurred

ceased

land clearing

habitat

on

to

data).

development

by native

spp.),

difficult

dispersals

with

to be farmed.

crossings likely

of

the area

the canal

long distance

urban

scrub

dominated

crossing

through

expanse

occupying

These

connects

Movement

and were

has been

associated

22).

attempt

(Section

Although

continue

become (Vitis

corridor

degraded

seen

unpublished

development

the land.

been

is

require

which

is a 90 m wide

observation).

three

(R. Schaub

purchase,

the citrus

Also,

corridor

Scrub-Jays

or as a dispersal

of the Haulover

land cleared NASA

defense

have

This

22); this corridor

on KSC/MINWR

(Figure

which

Florida

of Haulover

of young

crossed

Canal

et al. 1993).

concern.

is the Haulover

landscape

the

and LC41)

(Figure

of conservation

of these

Haulover

(Larson

units

surrounding

LC40

and CCAS

reserve

by a drawbridge.

for territorial

wanderings have

crossing

habitat

(i.e.,

and CCAS

scrub

The

requires

and Titan

species

restoration.

this area

Scrub-Jay

on KSC/MINWR

for other

Several

Florida

groves,

has resulted and brush abandoned

and introduced (Sabal

involves

landscape.

after

grasses

palmetto)

and

before NASA's in land.

Most

after

hard

and forbs,

(Schmalzer

the connection Movement

groves

et al.

of the

between

these

of

areas involves crossing about 3.5 km of peripheral impoundments, open water of Banana Creek, and industry associated with the LC39 area (Figure 22). The landscape to the west of SR 3 includes Banana Creek that is hundreds of meters wide and is bordered by wide marshes on either side. The only possible connections occur along the crawlerway, barge canal, islands, and peninsulas that extend into Banana Creek. The best connection between Schwartz Road and the Southern Pinelands occurs near the western shore of the Banana River through an area of scrub that has been unburned for greater than 20 years and is outside BUs (Figure 22). The only unavoidable discontinuity is the busy, two lane NASA Parkway (SR 405) and its grassy edges. The connection between these two major landscapes could be widened readily by pine thinning and burning in areas outside BUs north and south of NASA Parkway. Although risky, dispersal can occur across four lane roadways (i.e., SR 405) and industrial areas dominated by buildings, landscaped trees and shrubs, parking lots, and large grassy areas. Potential for a permanent connection between KSC/MINWRJCCAS/CNS and Florida Scrub-Jay populations outside the federal boundaries is unlikely. There are less than 20 territories remaining on Merritt Island near the south boundary of KSC/MINWR (Swain et al. in preparation). These territories occur in small patches of habitat with no hope of population persistence except for those adjacent to the Southern Pineland area. Some scrub adjacent to the Southern Pinelands has been purchased by the Brevard County Environmentally Endangered Lands Program as the Kabboord Sanctuary, and it could support several territories. The other scattered territories on Merritt Island have been excluded from the reserve design for the Brevard County Habitat Conservation Plan (Swain et al. in preparation).

68

3.3

Restoration

Activities

Small

habitat

scale

implemented scrub

restoration

(Schmalzer

vegetation

not be known

for decades, groves

mechanical

treatment

landscape

techniques

should

mechanical

techniques

which

required

in many

trees

should

techniques

areas,

territories

efforts

not reestablish

xeric

woodlands

efforts

will

in include

into an open

scrub

Scrub-Jays.

to be greatly

increased.

in soil disturbance Although

and in areas

planting

of these

restoration

BUs or other

edges

include

Other

can be accomplished

along

and

on fire with cautious

1990).

by fire within

will be useful

scrub will

fire needs

may result

planned

efforts

of Florida

rely mostly

much

be thinned

that

to convert

and Schmalzer

been

The success

efforts.

of prescribed

Restoration

(Breininger

groves.

intensive

and burning

application

of fuels

citrus

to support

have

Experimental

but it is clear

without

suitable

The

et al. 1994).

in abandoned

abandoned

efforts

use of

and a discontinuity

mechanical using burn

techniques

prescribed

areas.

that have

fire.

are Pine

Mechanical had extensive

soil

disturbance.

3.3.1

Mechanical

and

Mechanical and other

tree

cutting

at these

cutter,

unpublished).

produced

that

et al. 1994).

Brown

treated

techniques

vegetation

(Schmalzer

with

but the oaks,

Techniques

have

have

sites.

the Brown

been

grown

tree cutter

in several

techniques

landscapes

have

and other and prescribed

resulting and other

been

shrubs fire.

in an increase shrubs

69

to cut oaks

by burning have

and V blade.

responses

saw palmettos,

saw palmettos,

cutting

K-G blade,

Vegetation

soil disturbance

used

too tall to be restored

Experimental

rollerchopper,

Oaks,

more

Burning

involved

Burning promising

resprouted Some

the

has followed (P. Schmalzer in areas

techniques

in herbaceous

are recovering.

alone

weeds,

Florida Scrub-Jays have actively used restored areas for foraging, caching acorns, and even nesting within 18 months postfire. However, most restored areas have been too small relative to the overall landscape and the period after restoration too short to judge demographic success. Given the large size of Florida Scrub-Jay territories, it is clear that restoration activities must occur across entire landscapes. 3.3.2

Restoration

Burning

Many

can be restored

areas

with spatially

explicit

objectives.

burning

every

8-20

Menges

et al. in prep.).

KSC/MINWR

shrub

height.

desired

a 15 year

Prescribed burning

These

within

cycle

fire for scrub more

should

prescriptions

management

for Lake

mean

scrub

smaller

on standard

mainland.

fire and

existing

is

et al. 1991,

pine trees

intense

and

scrub

considered

to thin

than

ridge

restoration

on the Florida

be used

frequency

(Fitzpatrick

than

may require areas

Wales

habitat

frequently

drained

for restoration

fire at an increased

A standard

of excessively

fires

conducted

with

will require

the maintenance prescribed

years

by using

for

Initial

and reduce may need

to be

BUs to achieve

results.

"Hard" should

fire lines

be made

undesirable openings

fuel

are needed

to minimize

can be searched

fire

soil disturbance

discontinuities

is preferable

to control

systematically

edges,

in some

that has been

and subsequent

to artificial

spread

forestation.

such

by predators

associated A natural

as fire breaks of Florida

areas.

Efforts with mosaic

and roadsides,

Scrub-Jay

nests

of that

and

adults.

Seasonal summer Myers

fires 1992).

pinelands

variation

to mimic The

in prescribed

historical

recovery

by allowing

snags

fire

fire patterns

of open

space

and downed

7O

involving will

also

the

increased

be needed

can be performed trees

to burn.

use of (Robbins

more

However,

easily allowing

and in these

to burn creates potential smoke problems for roadways, urban areas, NASA, and CCAS operations. The recovery of openings in scrub may be difficult herbicides.

A long term

openings. reduce

to establish

Initial

frequent

biomass

needs

to be dead

between

four

for oak scrub

between

burns

Extremely conducted These

Florida

get them

(less

need

Many

oaks

areas

especially

when

in

at least three

minimum

to

time

burning.

200 ha), burns

landscapes

(e.g.,

conditions

should

Happy

success

stature

be

Creek).

and investigate

to burn the same

at sufficient

burn

This

for reproductive

are not intended

obs.)

and at least

using

than

optimal

essential

is important

Thus,

openings

small

in enough

(F. Adrian

are required.

to

exact

fine

to exceed patches

each

and age for acorns,

poorly

so that repeated

considering

the operational

fires

are needed

complexities

to

of

management.

A variety restoration intense

to restore

of ignition

fires. head

Ignition

fires

implemented.

devices

to create

are needed

ground

palmetto

or

to reestablish

reserves

pers.

It

techniques

years

to live fuels

difficult.

that 25% of the above

palmetto

towards

needs

Scrub-Jays

to burn,

fire

in a few experimental

burns

and cover.

ratio of dead

sparse

restoration

for 10-15

with abundant

usually

restoration

Yearly

nesting,

with

the speed

year

can expedite habitat

in areas

mechanical

carbohydrate

It appears

is more

will be needed

2-4 years)

for effective

specific,

each

mortality.

smoke

burns

limits

The

to burn.

two years years

(every

to return.

able to get areas

time.

fires

pine trees

without

approach

of underground

for openings

being

quickly

experimental

the accumulation

patches

scale

openings

without

strips

Narrow

stripped, scrub.

or a heli-torch

and prescriptions

of mechanically

that can penetrate

overgrown (DAIDs)

techniques

flank Aerial

should

chopped

fine fuels

tall, long unburned fires ignition,

can produce using

may be necessary

71

be used

to produce

oak patches the fire intensity

delayed

aerial

for burning

in early

have

been

required

incendiary

patches

that are

not easily accessible or pose a safety threat due to fuel loads or burning conditions. A heli-torch would be more effective than DAIDs at igniting areas that do not carry fire because of fuel discontinuity (Adrian and Farinetti 1995). 3.4

Habitat

only

Quality

Detailed

mapping

in long term

study

al. 1995 a), although KSC/MINWR

a, Larson

1992).

are being

varies

term

(Provancha

et al. 1986,

demographic

(Breininger

local

efforts

throughout in which

KSC/MINWR.

Habitat habitat

to identify areas

soils, fire history, development.

large

areas

Duncan

Breininger

Scrubsuccess

in preparation; that

modeling (Duncan

for

et al. 1991

Florida

effort

et

developed

demographic

intensive

suitability

been

banded

Scrub-Jay

require

Habitat over

on color

et al. 1995,

(Section

2, Figure

and Restoration quality

Duncan

is not

is approaching

et al. 1995

a

a,

23).

BUs and along edges

inventories

have

3.5) to assess quality

Degradation

been

and severe

of woodlands

and more detailed

of habitat

Costs

of disturbance

the presence

These

Initial analyses

and forests

Florida

have

performed

et al. in preparation).

Preliminary

inventories

scale

it can be applied

Degraded

resolution

how

data

has been

in preparation;

habitat

conditions

These

quality

of potential

with landscape

Breininger

(Table

maps

habitat

et al. 1995,

to evaluate

feasible

3.4.1

(Breininger

landscape

Long

Scrub-Jay

used

et alo 1995 a).

phase

areas several

the entire

Jays

of Florida

57%

is widespread

of BUs, facilities,

often do not burn effectively

because

72

using

and the proximity

of

with population

structure

present

today.

of the scrub is degraded

in areas

and forests.

at coarse

degradation

can be coupled

the metapopulation that

habitat

and forests,

studies

indicate

conducted

Edges

excluded

from

of BUs, facilities,

of their fuels

structure

or

.8o E

8

3

n,'

o'3 c

"5

c-

_5 e4

1--00

73

i.

km 0 Figure units,

23.

Disturbed

(2) within

or forested

3

land,

6

_.

and degraded

300 meters or (4) within

scrub.

of facilities, regions

7 Defined (3) within

of scrub

74

:| as scrub: 100 meters

having

a dense

:.._ I (1) outside of urban Florida

of bum land

slash

pine canopy.

deliberate

fire suppression

hazardous. estimate

These

mechanical

difficult

to initiate

Areas

dominated

sales.

However,

monitoring

costs

within

costs

can

hectares

associated further

Most

costs

thinning

the proposed

require

increased

fire frequency

cover.

This

is approximately

There willows Many

and wax myrtle

hammocks, because edge

habitat

3.5

within impact

3080

habitats

have fragmented

Population

Scrub-Jay

KSC/MINWR.

The

wide

timber and

cutting

The exact

are difficult

of oaks number

of

to determine

that is not severely openings

degraded

and decrease

will

tree

and 306 ha of marshes

become

landscape,

populations

hammocks.

need

population

restoration

by

activities.

Some

extensive

centers

occupied

fire and cutting

with too much

forest

to be successful.

Inventory

150 families

center

using

mechanical

fire and other

have

potential

Approximately

(Figure

of the trees.

ha.

habitat

in the native

for Florida

investigation quality,

marsh/swale

assessments,

reserve

that need frequent

not present they

will be

implementing,

actions

fires to produce

are 571 ha of disturbed

historical

treatment

with time and equipment. restoration

to

fire with or

areas

activities

for planning, The

frequent

of these

by logging

can be used

to the population.

that need

mechanical

operations.

habitat

critical

in most

prior

may be considered

inventories.

within

scrub

scrub

fires

incurred

with specific

scrub

initial

be thinned

associated

habitat

and corridors

without

are also

of commercial many

The

control

by pines

will incur

SRUs

fire or smoke

and degraded

ha of degraded

treatment. and/or

where

of disturbed

is at least 4100

without

without

inventories

restoration

There

near facilities

study

restoration 2).

Because

territory

of Florida areas

Scrub-Jays

include

activities,

and long-term

of the extent

censusing

territories

investigation

monitored

for short-term

(e.g.,

and variation

has not previously 75

are under

3-8 years)

in scrub

conducted.

habitat As habitat

quality and population estimates continue to decline, center wide surveys of jay territories

are needed.

Secondary areas

efforts

of poor

will focus

quality

The overall accurately

censuses

should

on territories

that exist

have

used

accuracy

to survey

(Fitzpatrick

et al. in press).

that that Florida

Scrub-Jays

occupy

Florida

that all habitat Scrub-Jay

The number initiation

3.5.1

territorial

of territorial

and

Scrub-Jay

Florida

scrub

was a visual

biologists

surveying

and other

were

remain

with a resident

adjacent

group.

During

territorial

calls

After

finding

both

biologists

allowed

calls

m from while

the adjacent were

biologists

Inventory while

satisfied

to be aware

unpublished

often

away

that they of group

on the

occupation

occupying

territories

activities

group, under

groups.

(e.g.,

direction

calls

for the

began

kept under

within

that one

searched

from the group

two

of territorial

required

biologist

were

Because

to have

protocols

had separate

76

data).

of the resident

groups

for the Shiloh

to a playbacks

the second

both

based

necessary

the second

the position

group,

occupancy.

habitat

was conducted

to respond

moving

that imply

of

Inventory

Scrub-Jays

group

is

1984)o

Florida slow

Scrub-Jay

and the playback

to be estimated

behaviors

more

on KSC/MINWR,

need

(R. Schaub

the inventory,

at 50-70

territorial

and in

to be considered

for determining

it was

observation).

biologist

playing

SRUs.

regions

Florida

methods

barrier,

often

soils

searches

inventory

in 1995

together.

personal

provide

Scrub-Jay

overgrown

(R. Schaub

Visual

Population

corridor

scrub

drained

and Fitzpatrick

Haulover

tall, unburned

within

population

to the statewide

territories

disputes,

and Haulover

A complete SRU

calls

(Woolfenden

Shiloh

linkage

One difference

poorly

be surveyed.

of Florida

and ownership

within

areas

the KSC/MINWR

comparable

project

requiring

first target

habitat.

approach

should

mapping

Territory

playing

the

and continued observation.

observation Two-way

until radios

and distance

of

travel). Repeated visits were made at sites where no Florida Scrub-Jays were detected. Estimates of the potential population size (breeding pairs) were made from inventories of potential habitat, which includes available scrub, disturbed shrub and brush, abandoned citrus groves, and conifer plantations that are contiguous with scrub cover types. These later cover types are considered potential habitat because they have the potential to be restored. An additional estimate was made of the historical population size based on potential habitat and active citrus groves that are contiguous with potential habitat. Comparisons of field inventories and estimates based on habitat indicate that the population has declined severely throughout the Shiloh SRU. The number of breeding pairs in the Shiloh SRU is at 40% carrying capacity (total number of breeding pairs based on potential habitat), with some burn units at less than 25% capacity (Table 3). Much of the available habitat (at 46% capacity) is also unoccupied because of fire suppression and forestation. There is little active citrus in this area. Restoration of available scrub, without the more difficult restoration of disturbed areas (disturbed shrub and brush, abandoned citrus and pine plantations), could provide habitat for 87 territories. Analysis of data from the Haulover corridor suggested a high density of Florida Scrub-Jay groups relative to the amount of available scrub (Table 3). However, many of the Florida Scrub-Jay groups in this region occupied disturbed shrub and brush (where the dominant vegetation includes cabbage palms, wax myrtle, and Brazilian pepper). These disturbed areas resulted from land clearing associated with residential development prior to NASA acquisition. Much of the current scrub is excessively overgrown and not occupied by ScrubJays. Although the disturbed areas have low suitability, they contain some scrub oaks, patches of low growing vegetation, and open sandy areas. These later

77

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