SUNY Plattsburgh
Digital Commons @ SUNY Plattsburgh Center for Earth and Environmental Science Student Posters
Center for Earth and Environmental Science
5-1-2014
Patterns of Nest Box Use Among Squirrels (Sciuridae) in Managed Forest Stands in Clinton County, New York Alex Sotola SUNY Plattsburgh
Jason Leewe SUNY Plattsburgh,
[email protected]
Follow this and additional works at: http://digitalcommons.plattsburgh.edu/cees_student_posters Recommended Citation Sotola, Alex and Leewe, Jason, "Patterns of Nest Box Use Among Squirrels (Sciuridae) in Managed Forest Stands in Clinton County, New York" (2014). Center for Earth and Environmental Science Student Posters. Book 10. http://digitalcommons.plattsburgh.edu/cees_student_posters/10
This Article is brought to you for free and open access by the Center for Earth and Environmental Science at Digital Commons @ SUNY Plattsburgh. It has been accepted for inclusion in Center for Earth and Environmental Science Student Posters by an authorized administrator of Digital Commons @ SUNY Plattsburgh.
Patterns of Nest Box Use Among Squirrels (Sciuridae) in Managed Forest Stands in Clinton County, New York Alex Sotola, Jason Leewe, and Dr. Danielle Garneau SUNY Plattsburgh, Center for Earth and Environmental Science ABSTRACT Both natural and artificial habitat enhancements can be the structural component that increases the fitness of squirrels (Sciuridae) and thus warrant study. These structures can provide useful demographic and community information about wildlife populations, such as occupancy rates, litter size, habitat preference, as well as species richness and abundance estimates. This artificial nest box study aims to investigate the nesting patterns of squirrels from late winter through early fall 2011 in managed mixed forest stands within Clinton County, New York. It is known that squirrels are very sensitive to forest disturbance, hence we compared sites of varying silvicutural impacts (e.g., managed for logging and maple sugaring versus a control). A total of 48 nest boxes (16 per site) were constructed, across 4 stands. Weekly measurements of abiotic variables were recorded and biotic variables were examined which included wildlife point counts and nest box occupancy. Occupancy may be a function of nest box height (~3.5m and ~5m), site-specific tree cavity/ snags/drey abundance, thus they were surveyed. Of nest boxes, approximately 81%, 44%, and 13% in the control, logged and maple sugar site, respectively, had visual confirmations of Glaucomys sabrinus (Northern flying squirrel), with one observation of Sciurus carolinensis (Red squirrels). The first noted incidence of nest box occupancy was observed on 20 March, 2011 approximately two weeks after erection at the control site. Additionally, approximately 79% of nest boxes show evidence of wildlife visitation (e.g., scat, crushed seeds, or nesting material), 87% of the high boxes versus 71% of the low boxes were utilized, and 17% of all occupancies contained multiple individuals. This survey provides additional multi-season occupancy data for an elusive mammal species under managed habitat regimes. We suggest forest managers, and conservation biologists alike, attempt to reduce the removal rate of snags and trees with cavities in their daily practices, as these features can enhance the nesting success of squirrels. Additionally, if faced with logging, managers should implement habitat enhancements (e.g., nest box addition) to offer long-term housing and protective refugia for squirrels.
INTRODUCTION • Our primary goal was to assess whether forest management (scale-dependent disturbance), in particular maple sugaring and silviculture (logging) sites, influences how squirrels and other wildlife use nest boxes. •
•
Squirrels and other arboreal mammals have been found using abandoned woodpecker cavities, standing dead snags, and are known to construct leaf-litter dreys for shelter from harsh abiotics (e.g., wind, rain, cold temperatures) and predators (Whittaker and Hamilton, 1998).
Figure 1. Reference site.
Figure 2. Sugar maple site.
Figure 3. Logged site.
Artificial nest boxes have been shown to increase small mammal populations and are important due to a shortage of large trees with sizeable cavities that the squirrels can use as nests (Lindenmayer et al., 2009).
Figure 9. Nest within wool bedding.
SITES: CLINTON CTY – CHAZY, NY (Fig. 4) Reference site (Figure 1) • Mixed forest has not been logged in many years! minimal anthropogenic disturbance • Reasonably biodiverse; understory has numerous seedlings and saplings Managed sugar maple site (Figure 2) • Mixed forest abounds with tubing for sap lines in maple sugar collection! common foot traffic • Sparse ground cover and trees Logged site (Figure 3) • Logged within the past 2-3 yrs (pers. com., Herb Boyce Northeast Forest Consultants), logging trails • Pines not logged ! pine seed trees common • Lower canopy possesses some ground cover
METHODS • Study duration: February - November 2011 • Sites (n = 3), 4 stands per site • Nest boxes were located away from roads and 20m apart, creating a 20m2 survey plot per stand (Lindenmayer et al., 2009). • 50% of the stands per site had nest boxes erected high (5m) and the other low (3.5m) (Risch and Brady, 1996). • Nest boxes were filled with sheep’s wool for bedding (Figure 9) (Macomb and Noble, 1981). • Weekly wildlife point counts and nest box occupancy surveys (ladder or iPhone telescoping pole) were performed weekly (Figure 10) • Occupancy was assumed if an animal was observed or animal sign was visible (e.g., nutshells, scat, nesting materials) (Figures 5, 9-11). • Motion cameras (Stealth Camera I540IR) were erected at each site to capture animal presence (Gommper et al. 2006). • The abundance of snags, dreys, and cavities were recorded (Lindenmeyer et al., 2009) and a composite score was calculated to compare with occupancy rates. • Abiotic factors (e.g., temperature (oC), wind speed (average mph), wind chill (oC), humidity (%), and barometric pressure (HG)) were measured weekly at each site.
Figure 11. Four flying squirrels in a box.
DISCUSSION
Hypothesis 1: Dominant species inhabiting artificial nest boxes would be red squirrels (Tamiasciurus hudsonicus) ! high nest boxes most often. Hypothesis 2: Presence of woodpecker cavities, as well as forest dreys, and snags should negatively affect the abundance of squirrels using artificial nest boxes. ! logged and sugar maple sites will have fewer natural nesting opportunities and higher rates of nest box occupancy.
Figure 10. Jason checking a box using the ladder.
Figure 4. New York state, the Adirondack Park, and common metropolitan areas in relation to the study site – Chazy, NY.
Figure 5. Two flying squirrels peering from a nest box.
RESULTS NEST BOX OCCUPANCY Occupancies: 98% flying squirrels, 2% red squirrels • Site influence (statistically significant, p=0.045) (Figure 6) • 82% Reference site (A) • 15% Logged site (B) A. • 3% Maple sugar site (C) • Nest box height influence (not statistically significant) (Figure 6 and 7) • 77% High (63% of the total 24 high boxes occupied) • 23% Low (29% of the total 24 low boxes occupied) B. • Sign presence (Figure 6) • 88% of the 24 high boxes had documented sign • 71% of the 24 low boxes had documented sign • Composite score influence (p = 0.27, Pearson’s r = 0.34) C. (Figure 8)
High Boxes (5m) Low Boxes (3.5m)
(March)
(June)
(Sept)
• Highest occupancy at reference site! refutes our hypothesis regarding lesser occupancies at managed sites • Flying and red squirrels occurred 98% and 2% of nest box occupancies, respectively. • Flying squirrels ! extremely sensitive to thinning and other disturbances • Less woody and herbaceous vegetation! reductions in habitat and food • Delay in occupancy at managed sites • Carey (2002) found flying squirrels were twice as abundant in old growth compared to thinned sites • Flaherty et al. (2008) found flying squirrels expand their range up to 150m in disturbed areas • Pyare and Longland (2002) found two specific nesting requirements 1) Distance to nearest tree! minimal 2) Percent canopy cover! more abundant and high canopy preference • Higher percentage of high nest boxes occupied • More gliding time • Higher in the canopy = more cover from branches • High boxes preferred for occupancy, although trend not present for observed sign. • Sign supported low box use! temporary shelters, spatial partitioning
FUTURE DIRECTIONS (Oct)
• Night surveys (night vision scopes)! missed occupancies by diurnally active red squirrels • DNA extraction/PCR of hair/scat from boxes to assess if northern or southern flying squirrels • Developing better management practices! benefits of nest boxes • Vary heights, limit distance to nearby trees, maintain dense canopy cover = refugia from predators
ACKNOWLEDGEMENTS
Occupancy Sign
Figure 6. Site-specific percent occupancy where A) reference, B) logged, and C) maple sugar site (C). Each bar signifies a different Julian day (day since January 1st).
A very special thank you to Dr. Kenneth Adams, Dr. Rachel Schultz, George Maynard, Will Goumas, Siobhan Levere, Alejandro Reyes, Erin Hayes-Pontius, Thomas Maynard, Steve Fessette, Steve Kramer, Kirk Beattie, Eileen Allen, Becky Kranitz (photo Credits), and the Center for Earth and Environmental Science. Funding provided by the Center for Earth & Environmental Science and the W.H. Miner Agricultural Institute.
Literature Cited
Figure 7. Height- (top) and site-specific (bottom) occupancy and sign
Figure 8. Scatterplot of the relationship between the calculated composite score (e.g., dreys, snags, cavities) and stand-specific occupancy.
Elzinga, C.L., Salzer, D.W., Willoughby, J.W., and Gibbs, J.P. 2001. Monitoring Plant and Animal Populations. Blackwell Science, Inc. Malden, MA. Fokidis, H.B. and Reisch, T.S. 2005. The Use of Nest Boxes to Sample Arboreal Vertebrates. Southeastern Naturalist 4(3): 447-458. Gompper, M.E., Kays, R.W., Ray, J.C., Lapoint, S.D., Bogan, D.A., and Cryan, J.R. 2006. Comparison of Noninvasive Techniques to Survey Carnivore Communities in Northeastern North America. Wildlife Society Bulletin 34(4): 1142-1151. Lindenmayer, D.B., Welsh, A., Donnelly, C., Crane, M., Michael, D., Macgregor, C., McBurney, L., Montague-Drake, R. and Gibbons, P. 2008. Are Nest Boxes a Viable Alternative Source of Cavities for Hollow-dependent Animals? Long-term Monitoring of Next Box Occupancy, Pest Use and Attrition. Biological Conservation 142(1): 33-42. McComb, W.C. and Noble, R.E. 1981. Nest-Box and Natural Cavity Use in Three Mid-South Forest Habitats. The Journal of Wildlife Management 45 (1): 93-101. Risch, T.S. and Brady, M.J. 1996. Trap Height and Capture Success of Arboreal Small Mammals: Evidence from Southern Flying Squirrels (Glaucomys volans). The American Midland Naturalist 136 (2): 346-351. Shuttleworth, C.M. 1999. The Use of Next Boxes by the Red Squirrel (Sciurus vulgaris) in a Coniferous Habitat. Mammal Review 29 (1): 61-66. Stone, K.D., Heidt, G.A., Baltosser, W.H. and Caster, P.T. 1996. Factors Affecting Nest Box Use by Southern Flying Squirrels (Glaucomys volans) and Gray Squirrels (Sciurus carolinensis). American Midland Naturalist 135(1): 9-13. Taulman, J.F. and Smith, K.G. 2004. Home Range and Habitat Selection of Southern Flying Squirrels in Fragmented Forests. Mammalian Biology 69(1): 11-27. Whitaker, J.O. and Hamilton, W.J. 1998. Mammals of the Eastern United States. 3rd Ed. Cornell University Press. Ithaca, New York.
