C. Stuart Houston and Marc J. Bechard ... um (USNM), and the British Museum .... Pre-1960 nest sites in Area C have been omitted to avoid clutter. northwest of ...
POPULATION
Decline
STUDY
of the Ferruginous
Hawk
in Saskatchewan This specieshas disappearedfrom much of its former range, and occupies other portions in diminishednumbers C. Stuart Houston
INTRODUCTION
HEFERRUGINOUS HAWK (Buteo rega-
and Marc
J. Bechard
chiefly in the southern and western fringesof the province.
Assiniboia
lis), North America's largestButeo, IS listed as the only raptor among 12 avlanspeciesthat are primarilyendemic to grassland andhencerestrictedin range (Mengel 1970). Swainson'sHawk (Buteo swainsoni), the Northern Harrier (Ctrcus cyaneus), the Prairie Falcon (Falco mexicanus),the MississippiKite (ktinia mississippiensis), the Burrowing Owl (Athenecunicularia), and the Short-
Historic Nesting Information
earedOwl (Asiofiammeus) are listedby Mengel amongthe 25 secondary,more widespread, avian grassland species.
um (USNM), and the British Museum (BM), respectively.The locationof these nestswas given by Blakiston(1861) as
Since the native prairie was settledand broken by the plow, the Ferruginous Hawk hasdisappearedfrom much of its original range and occupiesother portions in diminished numbers (Snow
"between
1976, Lokemoen and Duebbert 1976,
Powersand Craig 1976, Fitzner et al. 1977, Tate and Tate 1980). Beforetheturnof the centurythe FermginousHawk nestedregularly, even commonly,on the Great Plainsnorthto southern Alberta and southern Saskatchewan and east to southwestern Manitoba
andnortheastern NorthDakota.Today,it no longernestsin the two latter regions (Stewart 1975, Bechard 1981). To trace its decline within Saskatchewan, we studiednest-siterecordsleft by explorers, oologists,and early settlerswithin
whatwasbefore1905theterritoryof Assiniboia and is now southern Saskatch-
ewan.We comparedthemwith the distributionof currentlyactive nestsites, and found the presentpopulationto be restrlctedto relict tracts of pastureland,
166
It wasnotuntil the 1890sthateggcol-
lectorsbecameactivein the territoryof (Houston
and
Bechard
1982a).Luredby the unusualbeautyof Ferruginous Hawk eggs,and their high valuein trade,whichwasequalto thatof WhoopingCraneeggs,oologistsrecord-
' ' T HE FIRST EGGS ofthe Ferruginous Rough-leg brought to scientific notice" (Bendire 1892) were collected
ed locations of several dozen nests. Fer-
by ThomasBlakiston,magneticobserver
ruginousHawk nestswere then common
with Palliser's
throughout almostthe entireterritoryof
British
North
American
ExploringExpedition,while on a buffalo hunt in 1858. Eggs from two setswere sent to the United States National Muse-
north and south branches
of
SaskatchewanRiver," by the USNM card catalogueas "plains of the Saskatchewan"and by the BM catalogue,
quite erroneously,as "Fort Carlton." Fortunatelya letterfrom Blakistonin the
Assiniboia, from 49 ø north to 51058'
Althoughmuseumdata and firsthand reportsdo not permit quantitativeestimates of pre-settlementpopulations, when comparedwith currentlyactive nestsitesthey do showthe varyingdegreesof declineof theFerruginous Hawk in threeareas(SeeFig. 1): Area A (now vacated);Area B (where numbershave
fallen drastically);and Area C (where reasonable numbersstill remain).
Jonespapersin the Nova Scotiaarchives hasbeenlocatedandpublished(Houston 1976), allowing us to pinpointthe exact
A. Vacatedrange
location of these nests.
no FerruginousHawk nests have been foundin Area A for 40 years.In the Anerley Lakes area, where Blakistoncol-
These historically important nests werenearly100milessouthof FortCarlton, along the southshoreof the most westerlyof thethreeAnerleylakes,three mileseastof the presentvillageof Dinsmore, Saskatchewan(Fig. 1). The first nest, foundon April 29, 1858, was in a treeonly ten feet abovethe waterof Anerley Lake and containedfive eggs.The secondnest,foundthe next day, was 20 feet up in an aspenand containedfour eggs, one of which was illustratedin Plate 9 of Bendire's two-volume Life Histories of North American Birds (1892).
Apartfroma singleknownexception,
lectedthe first Ferruginous Hawk eggs, recentvisitshavefailedto locatea single pair. The lastconfirmednestin the adjacent Coteau Hills, about 12 miles south
and three miles east of Anerley, was foundin 1940 by F.J.H. Fredeen•ers comm.).
The most northwesterlynestswere foundby the late R. D. Symons•ers comm.) in 1928 and 1929; all were
groundnestson steephillsides:in Buzzard Coulee, two miles south of Lone Rock; in Blackfoot Coulee, ten miles
AmericanBirds, March-April 1984
I
5301 ""'"'•.,,• '
I.,. 53
1928
I
! !
s
1929
:::::::::::::::::::::::::::::::::::
:::::::::::::::::::::::::::::::::::
• • ... ,•. •
I*•
:::::::::::::::::::::::::::::::::
-"-."x ß %_/ ?
©•%© / %ß ./
Hit[,....•-•
ß • Hills '
ß
[] $wi•,
. •I
/
' '
•.....'
AREA B
"
ß .'.
.
ß
ß
,I
\
./
Quill Lakes
•
ß
/ •
a,
•\\
rorkton
•189S
.•
1.o
19olß
,.:.o - a,....... 1945 Kegtiaa []
\ •,.9,-9,
old W•ves "•". Lake % -'"'/ / "
•..•
\ MOose Mtn. ß1939
ß
'"
•-• AREA A
•--"
'--....--.'• AREAC
.....................................................
ß• /•/.\
&&& /
%.•...__ ---
.
/
Coteau
I, \
Cyp ....
ß,7/
ß
I •
;"
-.
ß / \,-...
I
ßß
1,o2-o, /."\ // ß \\/ \ 191o.17 ^,, ½..•/
%
,,0'.*•
:'
ß ß ßMuddy
\
[]
Figure1.NestsitesoftheFerruginous HawkinSaskatchewan from1858tothepresent. Dotsrepresent nests since1960,andtriangles indicate nests prtorto 1960;opensquares are towns.Pre-1960nestsitesin AreaC havebeenomittedto avoidclutter. northwest of Marsden; and in the Ear
show that there were at least five sets of
Hdls, seven miles south of Unity. At Carlton, the northernmostedge of the fire-sweptgrasslandsin buffalo days, FerruginousHawks nestedat least until 1939, whenFarley Mowat (Houstonand Street 1959) made 17 sightingsof indivtdual birds, comparedto 37 of Red-
eggstakenbetween 1910 and 1917 near Big Quill Lake, where Bent observed ninebirdssoaringin late May 1917 over burntprairie (Bent 1937, Houston1959). At nearbyKutawaganLake, P.A. Tavcrnersawoneor two FerruginousHawks
tinled and 42 of Swainson's
evidently found a dozen nestssouth of
Hawks.
At
Saskatoon on May 5, 1902, R.T. Congdonfounda nestwith threeeggs(Congdon 1903), andonMay 1, 1903,G. Harris founda nestwith five eggs,nine feet up •n a willow (Western Foundationof Vertebrate Zoology). The records of R M Barnes,W. Clark, and A.C. Bent
Volrune 38, Number 2
eachdayin mid-June[920. WalterRainc Yorkton between June 5 and 13, 1901
and Atkinson found it "regularly and commonlynotedfromjust westof Yorkton" throughSaskatoonand Edmonton
was still "fairly commonin open country" (Houston1949), but the lastdeftrote nest record was from
the Louis
K•rk
farm, eight miles northof Neudorf in the late 1930s.
At Indian Head, William Spreadborough found two nestsin 1892 (Macoun andMacoun 1909) andGeorgeLang listed it as "moderatelycommon" as late as 1929 (Callin 1980). In 1895, Edward Arnold made a trip of 30 miles from the
westendof PasquaLake to the southern edgeof the TouchwoodHills, and found
(Macoun and Macoun 1909).
ten Ferruginousnestsin threedays(Ar-
When Mrs. Isabel Priestly arrived at Yorkton in 1935, the FerruginousHawk
nold 1895, Arnold 1896, Houston and
Bechard1982b). No breedingpairshave
167
been found there since. The last recorded
nestin the Reginaarea was at Boggy Creek, where Doug Gilroy in 1945 describeda long-usednestthe size of a 45gallondram (Belcher 1980). Farthereast near Wauchope, H.H. Pittman photographeda giganticFerruginousnestin a willow in 1912 (Pittman 1915, 1956) and Marion Nixon had a nest in 1939 (Nixon 1939). In the extreme southeast corner of Sas-
katchewan near Gainsborough and Northgate,GeorgeWitheyandG. Abbey crossed the border from North Dakota to
collectover20 setsof eggsbetween1925 and 1930.The lastpair in the areanested on a hugepile of stickson a stonepile alongthe edge of GainsboroughCreek untilabout1960(Trevlyn Reynolds,fide Vere Hunt Scott in litt. September8, 1971). Figure 2. Putting up a FerruginousHawk nestpla(forrnnear Kindersley,Saskatchewan.Photo/ C. S. Houston.
B. Areas of marked decline
In Area B, the numberof Ferruginous Hawk nestingshas declinedgreatly. On the South Saskatchewan
River
south of
White Bear, Sig Jordheim(pers. comm.) had four pairsnestingon steephillsides along four miles of river in 1931. By 1945 there were only two nestsleft, and in 1964 someoneshotthe nestingpair al the sole remainingnest, The amountof suitablegrasslandin the undulatingvalley breakshas not changed,but no nesl has been found since.
In the Lucky Lake area, Ferruginous Hawks became greatly reduced in the 1930sand disappearedas a nestingspeciesin the 1940s(Roy 1964). A tree-nest
attemptsouth of Lucky Lake in 1969 failed, but eachyeara pair nestson steep river valley slopesnear Matador (Maher 1974).
Todd's Carnegie Museum collecting party in 1932 found the Ferruginous Hawkfairly commonandoneof thecommonesthawk speciesbetweenElbow and Last Mountain Lake. Near Davidson, be-
tweenMay 18 and 21, they collectedsix setsof eggs,and on June8 they founda nestwith eggs near Elbow (Todd 1932, 1947). The most recent nest near David-
sonwasadjacentto pasturelandalongthe UpperArm River wheretheseniorauthor
bandedfour youngin 1972. Occasionalnestattemptswith a higher-than-averagefailure rate have been noted near Luseland 11980), west of Rosetown (1974-76 and 1982), easl of
Biggat (1982), north of Wiseton (1983), near Dundum (several years), northeast
168
of Saskatoonand east of Saskatoon 11960s,bothfailed).One or morepairs nestregularly,witha reasonable success rate,only in large(government) pastures suchasthosenearTugaske, eastof Simpson,nearGoodwater, nearCedoux,near Frobishcr, andnorthof Forget. C. Areaswithreasonable numbers
six successful pairsbeforewe installed six artificialnestplatformsin the more openportions of thepasture,andasmany asninesuccessful pairssince.Thisrepresentsa densityof oneFerruginous pair per4. I squaremilesbeforethepolesand onepairper 2.7 squaremilesafter the poles(1:7,1km2),perhaps the highest densityof this speciesever reported (Houston 1982).
In the southwestern comer
of Sas-
katchewan.where pasturesare almost continuous alongtheMontanaandAlber-
Extentof the declineand its probable causes
ta borders,a reasonablystablepopulation
of Ferruginous Hawks persists. W.A.
andJ.E. Bowmanmadetripsup Battle andWillowCreeksfromnearbyMontana in 1904,1915,and1917andcollected17 setsof eggs.J.E.Grantcollected fivesets between1907and 1911northof Maple Creek.In 1920,S.J. Darcuswasableto locate15nestingpairsin onesummerin the CypressHills (Ingersoll1920). At SkullCreekonthenorthedgeof thehills, SteveA. Mann (pets. comtn.)had two Ferruginous nestsonhis rancheachyear untilthemid-1930s,thenfor eightor ten yearshad only one pair, and thereafter none.Nestsextendeastalongthe Montanaborderasfar astheBig MuddyBadlands, where Bob McCall found sev6n
nestsin 1971 (pers. comm.). Along the Alberta boundary,a few largepastures still supportstablepopulationsof Ferruginous Hawks.The pasture near Kerroberthas three pairs of this hawk, but usuallyonly one pair is successful.In contrast,the 24-square-mile pasturenearKindersleyhad as manyas
"•ASEDONFHEPREVIOUSACCOUN I Jean makea "ballparkestimate"that theFerruginous Hawkpopulation in Saskatchewan hadby 1960dropped to 10%20ckof itspre-settlement levels.Thisestimateis basedon the following: i. Nearly40ckof thehawk'soriginalrangeis no longeroccupied; 2. Another 40% is now only sparselyoccupied,chiefly becausefew potentialnestsitesremainwith sufficientcontiguous grassland to supporta pair of Ferruginous Hawks;this area is amongthemostintensively culrivatedregionsin theworld,with about 70% of the land under cul-
tivation(Coupland1978); 3. In the remaining20% of the originalrangenear the Alberta and Montana borders, only abouthalf the landis cultivated; evenhere,a numberof previous sites, with nest trees and sufficientgrassland, arenolongeroc-
AmericanBirds,March-April 1984
foundsevennestsin 1905bul only three nestsin 1906. "illustratingthe prejudice of farmersand ranchmenagainsteven
largepartto a decreasein the numbersof
simplybecauseonly marginallandsnow remainuncultivated.As land pricesrise, as cattle pricesdrop disproportionately, asfarmerstry to cultivatea largerproportion of their holdings,and as mechanical rockpickingmachinesallow .cultivation of rocky grasslandfor the first time, less andlessacreageremainseachyearin native grassland.Even government pastures are being converted from native grassesto exotic grasses.with uncertain long-term effects. Not only do ground squirrel numbers decline noticeably when large tracts of grassland are plowed, but once the shortergrassesare replacedby taller graincropsthe remaining animalsare more easily concealed, oftenallowingthemto avoidcapture(Bechard 1982). Further, poisoning of ground squirrelswith arsenic and other chemicalshasbeensporadicand we have encountered the deathof nestlingbuteos
hawksshotin the past40 years.
in such areas.
Second,groundsquirrelsare the main preyof boththe FerruginousHawk and its more widely distributed relative,
Fifth. nestingsitesappearto be a limiting factor. With the exceptionof "badlands" in a few valleys in the southand west, where ground nests are built on steep hillsides, FerruginousHawks in
this most useful hawk" (Bent 1907,
1937).In 1924,H. HedlcyMitchell summarizedthe situationwhen he reported that FerruginousHawks were "unfortu-
nately becomingmore scarce yearly, withotherlargebeneficialhawks,owing to persistentpersecution by misguided settlers."
As lateasthe 1930s,bandingrecoveriesindicated a highmortalityrate,mainly from shooting.Near Rosebud,Alberta, Salt reported19% of 144 Ferruginous nestlingskilled in the first ten months Figure 3. Oneoffou?successful Ferruginous Hawk nest pla(forms near Kindersley,Saskatchewan.
Photo/C.
S. Houston.
(Salt & Wilk, 1958), whereas the senior
author'scomparablerecoveryrate has beenonly2% from534 nestlings banded in western Saskatchewan since 1968.
This changein recoveryrate is due in cupiedby FerruginousHawks. Why has the FerruginousHawk suffered such a decline? The answer does
notappearto berelatedto low reproductivesuccess. The Ferruginous Hawklays a relativelylargenumberof eggs,averaging up to four per nest(Davy 1930). In Saskatchewan, an averagepair raises threeyoungto dodging.The seniorauthor's data show600 youngbandedin
Swainson's Hawk (Buteo swa#isoni).
196 successful nests between 1969 and
The importance of Richardson's ground squirrel(Spermophilus richardsonii)for grassland buteosis suggested by its Alberta range being exactly coterminous with that of its chief predator.Swain-
1983,with a rateof 3.1 youngper suc-
sows Hawk (Wonders 1969). There was
cessfulnest (yearly range 2.5 to 4.5).
a crashof RichardsoWs groundsquirrel Thisfigureis slightlyabovetheaverage numbers throughout the southernprairie fledgingratesreportedfor Ferruginous provincesin the early 1940s, coincident Hawksin otherareaswherepopulations withthereturnof wetspringsaftera deccontinueto thrive (Smith and Murphy adeof drought;numbersof both Swain1978; Schmutz,Schmutz, and Boag son'sandFcrruginous Hawksdiminished 1980;BlairandSchitoskey1982;Gilmer noticcablysoon therafter. A noticeable and Stewart 1983).
The Ferruginous declineappearsto be
recovery in Swainson's Hawk numbers
graduallyoccurredafter 1950, although
related to at least five other factors. First.
not to previous levels.
it is obviousthat shootingand egg-collectingtooka heavytoll in the first decadesof settlement, contributing to a ma-
Third. as annual prairie fires were brought undercontrol,andaspenclumps
jor decline between 1880 and 1930.
regenerated throughout all of Area A and
FerruginousHawks were present"in
part of Area B (Archibold and Wilson 1980), thc Rcd-tailed Hawk (Buteo
gmat numbers" in 1893 between Wood
jamaicensis)graduallyspreadand in-
MountainandtheCypressHills, butwith "increasinghumanpopulationand con-
creased to become the dominant Buteo at
the expense of Swainson'sand particu-
Saskatchewan nest in trees. We know of
onlytwo nestson rock-piles,nearSmiley in the 1920s and Val Marie in the 1960s,
one on a telephonepole cross-armnear Findlaterin the 1930s, (Gwilym Jones, pers. comm.) andone on a haystacknear Estlin(Goclitz 1918). Originallywillows or aspens,untouchedby fire along the edgeriversand sloughs,were the typical nestsites.Thesewere later augmentedas shelterbelt
trees matured
in abandoned
farmsteads, typicallyabout40 yearsafter initial settlement.Today, however, with the bulldozing of shelterbelts,and the lossof treesto cattlerubbinganddebarking them and exposingtheir roots, the availabilityof nestsitesis againcritical, especiallyin large treelesspastures.For this masonwe have experimentedwith artificialnestpolesin two pastures,with encouragingsuccess;four of the first six poles were used successfullyby FcrruginousHawks (Houston 1982). Since the amountof nativegrasslandcontinues
stant persecutionthese hawks declined
larly of the FcrruginousHawk (Houston
quickly." particularlybetween1905 and 1913 (SpencerPearse,quotedby Brad-
andBeehard.1983). Althoughmanyof theseaspenclumpsare nowbeingbull-
shaw 1915). Laurence B. Potter con-
dozed. and Red-tailed Hawk
firmed that in 1905 "ten or a dozen of
may in turn decline somewhat,the new
platformsadded to large, treelesspasturesoffer the besthopefor maintaining FerruginousHawk populationsin Sas-
this fine hawk'snestsmight have been easily found in a day's walk; last year
treelessareasare convertedto cropland
katchewan.
[19291 in the same time and areas I was
son'sand nonefor FerruginousHawks.
rewardedby finding one nest." (Potter 1930). At CraneLake,just northof the
Fourth,plowingof the remainingnative grassland continues,thoughat a slowerpacethanearlierin the century,
CypressHills, A.C. Bentandhis party
Volume38, Number2
numbers
to diminish.
we feel that artificial
nest
which offers little attraction for SwainSUMMARY
IlE FERRUGINOUS 1tAWK hasexpe-
rienceda long-termdeclinethat be-
169
gan whenthe first settlersarrivedbefore the turnof the century.Nestingpairsare now absentthroughoutmuch of the presettlement breedingrange;todaya relict populationof perhaps10% of the original populationstill breedsin the province. Thesebirdsareableto find adequateprey only in the remaining large pastures whereRichardson's groundsquirrelsare abundant.With the increasingloss of suitablenesttrees,governmentagencies shouldrecognizethe importanceof their pasturesto this species,and take measures that will halt the decline of this beneficial hawk.
1908 Summer birds of southwestern Saskatchewanß Auk 25: 25-35ß
BLAIR, C.L.
and F. SCHITOSKEY,
CentralPlainsasan isolatingagent•n b•rd speciation.In: PleistoceneandRecentEn-
son Bull. 94: 46-54.
vironments
BLAKISTON,
T. 1861-1863ß On birds col-
ish North AmericaßIbis 3: 314-320, Ibis 4: 3-10, Ibis 5:39-87 and 121-155ß
and the American
Museum
of Natural
CONGDON, R.T. 1903. Saskatchewanbirds. 14: 569-620ß
R.T. 1978. Future land use on
Changeon the CanadianPlains, ed. W.A. DaviesßRegina:CanadianPlainsResearch Centerß
DAVY, G.L. 1930. Nestingof the Ferruginous RoughlegHawk in northernNorth Dakota. Oologist 47: 14-18. FITZNER, R.E., D. BERRY, L.L. BOYD, andC.A. RIECK. 1977. Nestingof Ferruton, 1974-75ß Condor 79: 245-249. GILMER, D.S. and R.E. STEWARTß 1983.
FerruginousHawk populationsandhabitat
use in North DakotaßJ. Wildl. Manage. 47: 146-157ß
GOEL1TZ,
W.A.
1918. The destruction of
1982. Artificial nestingplatformslbr FerruginousHawksßBlue Jay 40: 208213.
and M.R.
J. Botany 58:2031-2042ß M.J.
1981. Historical nest rec-
and M.J. BECHARD. 1982a. Oology on the northernplains:an historicalpreview. Blue Jay 40: 154-157ß 1982b. Edward Arnold,
WILSONß
1980. The naturalvegetationof Saskatchewanpriorto agriculturalsettlementß Can. BECHARD,
__.
enthusiastic
oologist.Blue Jay 40: 184-192. __.
1983. Trees and the Red-tailed Hawk in
southernSaskatchewanß Blue Jay 41: 99-
and C H
TROST. 1975. Populationstatusol the FerruginousHawk in southeasternIdaho
and northern Utah. pp. 151-157 In MURPHY, J.R., C.M. WHITE and B E
HARRELL feds.]. Populationstatusof Raptors.RaptorResearchReportNo 3 ROY, J.F. 1964. Birdsof theElbow. Regina, Sask. Nat. Hist. Soc. 33 pp. SALT, W.R.
and A.R. WILK.
1958 The
Birds of Alberta [First ed.]. Edmonton SCHMUTZ, D.A.
J.K.,
BOAG.
S.M.
SCHMUTZ
1075-1089.
SMITH, D.G. and J.R. MURPHY.
1978 B•-
ologyof the Ferruginous Hawk in central UtahßSociobiology3: 79-95. SNOW, C. 1974. Habitatmanagementseries for uniqueor endangered species.No 13 Ferruginous Hawk. Buteoregalis. Techmcal Note. Denver:U.S. Dept. of Interior, Bureauof Land Management.23 pp STEWART, R.E. 1975. BreedingB•rds of North Dakota. Fargo:Tri-College Center for Environmental Studies.295 pp TATE, J.D., JR. and D.J. TATE. 1982 The Blue List for 1982. Am. Birds 36
C.S. and M.G.
STREET.
and
1980. Coexistence of three
speciesof hawks(Buteospp.) in the pra•rie-parklandecotone. Can. J. Zool 58
109.
HOUSTON,
Tech
FieldsNat. 44: 147-149.
63: 215-241.
katchewanßBlue Jay 17: 93. ß1976. A bird-watcher'soutingin 1858.
__.
Biome
POWERS, L.R., R. HOWARD
1959. A.C. BenCs 1917 trip to Sas-
CITED
Grassland
Queen'sPrinter.511 pp.
C.S. 1949. The birds of the district, Saskatchewanß Can.
Field-Nat.
Dakota Ool-
IBP
Report 21. Fort Collins: Colorado State University. PITTMAN, H.H. November 20, 1915 A North American Hawk's nest. Counto Life 38: 695. __. 1956.Sandhillcranesin retrospectNature Magazine 49 (5): 237-239. POTTER, L.B. 1930. Bird-lifechanges•n 25 yearsin southwestern SaskatchewanCan
ewan. Auk 35: 238-240ß
HOUSTON, Yorkton
Sask. Histota' 29: 14-25.
O.W.
Colorado.
nestsby farming operationsin Saskatch-
ogists," by M.J. Bechard and C.S. Houston,in BlueJay 42, 1984, in press.
ARCHIBOLD,
ture. Saskatchewan Farmerß
ginousHawks(Buteoregalis)in Washing-
tion, Pierre,SouthDakota, providedinformation about G. Abbey. More detailedinformationon theearlystatusof the FerruginousHawk in North Dakota, and more detailed acknowledgments,
ARNOLD, E. 1895ßAn outingin Assiniboiaß Oologist12: 150-151, 161-163, 168-170. __. 1896. My 1895 Outing in Assiniboiaß Oologist 13: 19-21.
38:101-118
OLENDORFF, R.R. 1973. The ecologyof the nestingbirdsof prey of northeastern
burne of the Office of Cultural Preserva-
LITERATURE
H.H. 1924. Birds of Saskatch-
ewan. Can. Field-Nat.
GovernmentPrinter. 71 pp. CALLIN, E.M. 1980. Birds of the Qu'Appelle, 1857-1979. Regina: Sask. Nat. Hist. Soc., Spec. Publ. #13. 168 pp.
History, respectively. Junius R. Fish-
will be found in "North
Spec. Publ. 3, 278-340. MITCHELL,
NIXON, M. June15, 1939. Lookingat Na-
EARE INDEBTED toLloydKiffand
utinghistoricaldatain eggcollectionsof the NationalMuseumof NaturalHistory
Great Plmns
BRADSHAW, F. 1915. Reportof the Chief GameGuardianfor theyear1914.Regina:
the prairies,pp. 175-178.In: Nature and
nest sites. Thanks are also extended to James Dean and to John Bull for contrib-
of the Central
Universityof Kansas,Dept. of Geology,
lected and observed in the interior of Brit-
Transß Wisconsin Acad.
RaymondQuigley of the Western Foundationof VertebrateZoology for theirhelpin collectingdataon historical
MENGEL, R.M. 1970. The North American
1982. Breedingbiology and diet of the Ferruginous Hawk in SouthDakota.Wil-
COUPLAND,
ACKNOWLEDGMENTS
JR.
Tech Rep #58 SaskatoonUmvers•tyof Saskatchewan, 36 pp.
1959.
126-
135.
ordsfor the FerruginousHawk in Manito-
The Birds of the Saskatchewan River,
ba. Can. Fiehi-Nat.
Carlton to CumberlandßRegina: Sask.
TODD, W.E.C. 1932. Glimpsesof prmne bird lifeßCarnegieMagazine6:115-116
NaturalHistorySociety,Spec.Publ. #2.
__.
95: 467-468.
ß 1982. Effectof vegetativecoveron foragingsite selectionby Swainson'sHawk. Condor 84: 154-159ß
BELCHER, M. 1980. Birds of Regina, rev. ed., Regina,Sask.Nat. Hist. Soc., Spec.
Publ. #12. 151 pp. BENDIRE, C. 1892. Life Histories of North
AmericanBirds with specialreferenceto theirbreedinghabitsandeggs.SmithsonJanContributions to Knowledge,vol. 28: Washington:Govt. Printing Office. 446 PP.
BENT, A.C. 1907. Summer birds of southwestern Saskatchewanß Auk 24: 407-430.
170
205 pp.
1947. Notes on the birds of southern
Saskatchewan. Ann. CarnegieMu• 30
INGERSOLL,
E. December 6, 1920. Natural
History Club [letter from S.J. Darcus]. FamilyHerald and WeeklyStar, Montrealß LOKEMOEN,
J.H. and H.J. DUEBBERT.
383-421.
WONDERS, W.C.
1969. Atlas of Alberta
Edmonton:University of Alberta Press 162 pp.
1976. FcrruginousHawk nestingecology and raptorpopulationsin northernSouth Dakota. Condor 78: 464-470ß
MACOUN,
J. and J.M. MACOUN.
1909.
Catalogue of Canadian Birds. Ottawa: GovermnentPrintingBureauß761 pp. MAHER.
W.J.
1974. BIRDS:
If. Avifauna of
the Matador area. IBP Matador Project,
863 UniversityDr., Saskatoon, Sask. S7N OJ8 (Houston), Dept. of Biology,BoiseSt. Untv , 1910 Univ. Dr., Boise, ID 83725
(Bechard)
AmericanBirds, March-Aprfi 1984
