Short-term responses of tree squirrels to different-sized forest patches on new clearcuts in a fragmented forest landscape
Thomas P. Sullivan
A C and Druscilla S. Sullivan B
+ Author Affiliations
- Author Affiliations
A Department of Forest and Conservation Sciences, Faculty of Forestry, 2424 Main Mall, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
B Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, V0H 1Z8, Canada.
C Corresponding author. Email: tom.sullivan@ubc.ca
Wildlife Research 48(4) 366-375 https://doi.org/10.1071/WR20002
Submitted: 3 January 2020 Accepted: 14 November 2020 Published: 26 February 2021
Abstract
Context: Tree squirrels disappear when forests are clearcut. The American red squirrel (Tamiasciurus hudsonicus) and northern flying squirrel (Glaucomys sabrinus) may occupy retention forest patches on new clearcuts, but with conflicting results with respect to area, isolation, and edge effects of patches.
Aims: We tested the hypothesis that abundance, reproduction and body mass of T. hudsonicus and G. sabrinus populations would be greater in large than small patches of retention forest on new clearcuts.
Methods: We measured demographic responses of both sciurids from 2014 to 2016 in replicated (n = 4) treatments of four sizes (ha) of retention patches (means of 0.53, 1.50, 4.13 and 18.73) in south-central British Columbia, Canada.
Key results: Mean abundance of T. hudsonicus per sample line was similar among treatment sites, ranging from 0.7 to 1.7 (2014), 1.0 to 1.7 (2015) and 0.5 to 1.3 (2016). There was a positive linear relationship of mean abundance of red squirrels and increased basal area of conifers in the larger patches. Mean numbers of G. sabrinus were consistently highest in the 4.13 ha patch class in all years and appeared to decline over time in the other patches with fewest captures in the smallest patch size. There was a significant positive linear relationship between mean overall abundance of G. sabrinus and total density of overstorey trees.
Conclusions: Mean abundance, reproduction and body mass (red squirrels) of both sciurids were generally similar among patch sizes, and hence these results did not support the hypothesis.
Implications: Although our results were short-term, habitat quality was apparently sufficient to maintain the occurrence of T. hudsonicus across patch sizes ranging from 0.3 to 20.0 ha. Glaucomys sabrinus also occurred in several patches (13 of 16), albeit at low and variable numbers.
Keywords: abundance, clearcuts, conservation, forest patches, fragmentation, Glaucomys sabrinus, Tamiasciurus hudsonicus.
References
Bayne, E. M., and Hobson, K. A. (2000). Relative use of contiguous and fragmented boreal forest by red squirrels (Tamiasciurus hudsonicus). Canadian Journal of Zoology 78, 359–365.Bogdziewicz, M., and Zwolak, R. (2014). Responses of small mammals to clearcutting in temperate and boreal forests of Europe. European Journal of Forest Research 133, 1–11.
| Responses of small mammals to clearcutting in temperate and boreal forests of Europe.Crossref | GoogleScholarGoogle Scholar |
British Columbia Ministry of Forests and Ministry of Environment (BCMoF) (1995). ‘Riparian Management Area Guidebook.’ (Ministry of Forests: Victoria, BC, Canada.)
Carey, A. B. (2000). Effects of new forest management strategies on squirrel populations. Ecological Applications 10, 248–257.
| Effects of new forest management strategies on squirrel populations.Crossref | GoogleScholarGoogle Scholar |
Carey, A. B., Kershner, J., Biswell, B., and DeToledo, L. D. (1999). Ecological scale and forest development: squirrels, dietary fungi, and vascular plants in managed and unmanaged forests. Wildlife Monographs 142, 3–71.
Cazares, E., Luoma, D. L., Amaranthus, M. P., Chambers, C. L., and Lehmkuhl, J. F. (1999). Interaction of fungal sporocarp production with small mammal abundance and diet in Douglas-fir stands of the southern Cascade range. Northwest Science 73, 64–76.
Côté, M., and Ferron, J. (2001). Short-term use of different residual forest structures by three sciurid species in a clear-cut boreal landscape. Canadian Journal of Forest Research 31, 1805–1815.
| Short-term use of different residual forest structures by three sciurid species in a clear-cut boreal landscape.Crossref | GoogleScholarGoogle Scholar |
Englund, S. R., O’Brien, J. J., and Clark, D. B. (2000). Evaluation of digital and film hemispherical photography and spherical densiometry for measuring forest light environments. Canadian Journal of Forest Research 30, 1999–2005.
| Evaluation of digital and film hemispherical photography and spherical densiometry for measuring forest light environments.Crossref | GoogleScholarGoogle Scholar |
Fedrowitz, K., Koricheva, J., Baker, S. C., Lindenmayer, D. B., Palik, B., Rosenvald, R., Beese, W., Franklin, J. F., Kouki, J., Macdonald, E., Messier, C., Sverdrup-Thygeson, A., and Gustafsson, L. (2014). Can retention forestry help conserve biodiversity? A meta-analysis. Journal of Applied Ecology 51, 1669–1679.
| Can retention forestry help conserve biodiversity? A meta-analysis.Crossref | GoogleScholarGoogle Scholar |
Fisher, J. T., and Bradbury, S. M. (2006). Understorey protection harvest expedites recolonization of boreal forest stands by North American red squirrels. Forest Ecology and Management 234, 40–47.
| Understorey protection harvest expedites recolonization of boreal forest stands by North American red squirrels.Crossref | GoogleScholarGoogle Scholar |
Fisher, J. T., and Wilkinson, L. (2005). The response of mammals to forest fire and timber harvest in the North American boreal forest. Mammal Review 35, 51–81.
| The response of mammals to forest fire and timber harvest in the North American boreal forest.Crossref | GoogleScholarGoogle Scholar |
Fowler, J., Cohen, L., and Jarvis, P. (1998). ‘Practical Statistics for Field Biology.’ 2nd edn. (John Wiley and Sons.)
Franklin, J. F., Berb, D. R., Thornburgh, D. A., and Tappeiner, J. C. (1997). Alternative silvicultural approaches to timber harvesting: variable retention harvest systems. In ‘Creating a Forestry for the 21st Century: the Science of Ecosystem Management’. (Eds K. A. Kohm and J. F. Franklin.) pp. 111–139. (Island Press: Washington, DC, USA.)
Goheen, J. R., Swihart, R. K., Gehring, T. M., and Miller, S. (2003). Forces structuring tree squirrel communities in landscapes fragmented by agriculture: species differences in perceptions of forest connectivity and carrying capacity. Oikos 102, 95–103.
| Forces structuring tree squirrel communities in landscapes fragmented by agriculture: species differences in perceptions of forest connectivity and carrying capacity.Crossref | GoogleScholarGoogle Scholar |
Herbers, J., and Klenner, W. (2007). Effects of logging pattern and intensity on squirrel demography. The Journal of Wildlife Management 71, 2655–2663.
| Effects of logging pattern and intensity on squirrel demography.Crossref | GoogleScholarGoogle Scholar |
Holloway, G. L., and Malcolm, J. R. (2006). Sciurid habitat relationships in forests managed under selection and shelterwood silviculture in Ontario. The Journal of Wildlife Management 70, 1735–1745.
| Sciurid habitat relationships in forests managed under selection and shelterwood silviculture in Ontario.Crossref | GoogleScholarGoogle Scholar |
Holloway, G. L., Smith, W. P., Halpern, C. B., Gitzen, R. A., Maguire, C. C., and West, S. D. (2012). Influence of forest structure and experimental green-tree retention on northern flying squirrel (Glaucomys sabrinus) abundance. Forest Ecology and Management 285, 187–194.
| Influence of forest structure and experimental green-tree retention on northern flying squirrel (Glaucomys sabrinus) abundance.Crossref | GoogleScholarGoogle Scholar |
Huynh, H., and Feldt, L. S. (1976). Estimation of the Box correction for degrees of freedom from sample data in the randomized block and split-plot designs. Journal of Educational Statistics 1, 69–82.
| Estimation of the Box correction for degrees of freedom from sample data in the randomized block and split-plot designs.Crossref | GoogleScholarGoogle Scholar |
IBM Corporation (2017). ‘IBM SPSS Statistics for Windows. Version 25.0.’ (IBM Corporation: Armonk, NY, USA.)
Koprowski, J. L. (2005). The response of tree squirrels to fragmentation: a review and synthesis. Animal Conservation 8, 369–376.
| The response of tree squirrels to fragmentation: a review and synthesis.Crossref | GoogleScholarGoogle Scholar |
Krebs, C. J. (1999). ‘Ecological Methodology.’ (Addison Wesley Longman, Inc.)
Krebs, C. J., Boonstra, R., Gilbert, S., Reid, D., Kenney, A. J., and Hofer, E. J. (2011). Density estimation for small mammals from livetrapping grids: rodents in northern Canada. Journal of Mammalogy 92, 974–981.
| Density estimation for small mammals from livetrapping grids: rodents in northern Canada.Crossref | GoogleScholarGoogle Scholar |
Kuehl, R. C. (1994). ‘Statistical Principles of Research Design and Analysis.’ (Duxbury Press: Belmont, CA, USA.)
Littel, R. C. (1989). Statistical analysis of experiments with repeated measures. Horticultural Science 24, 36–40.
Martin, S. K. (1994). Feeding ecology of American martens and fishers. In ‘Martens, Sables, and Fishers. Biology and Conservation’. (Eds S. W. Buskirk, A. S. Harestad, M. G. Raphael, and R. A. Powell.) pp. 297–315. (Comstock Publishing Associates: Cornell University Press, Ithaca, NY, USA.)
Maser, C., Claridge, A. W., and Trappe, J. M. (2008). ‘Trees, Truffles, and Beasts: How Forests Function.’ (Rutgers University Press: Piscataway, NJ, USA.)
Meidinger, D., and Pojar, J. (1991). Ecosystems of British Columbia. Special Report Series No. 6. Research Branch, Ministry of Forests, Victoria, BC, Canada.
Nagorsen, D. W. (2005). ‘Rodents and Lagomorphs of British Columbia. The Mammals of British Columbia, Vol. 4.’ (Royal British Columbia Museum: Victoria, BC, Canada.)
Nupp, T. E., and Swihart, R. K. (2000). Landscape-level correlates of small mammal assemblages in forest fragments of farmland. Journal of Mammalogy 81, 512–526.
| Landscape-level correlates of small mammal assemblages in forest fragments of farmland.Crossref | GoogleScholarGoogle Scholar |
Patterson, J. E. H., and Malcolm, J. R. (2010). Landscape structure and local habitat characteristics as correlates of Glaucomys sabrinus and Tamiasciurus hudsonicus occurrence. Journal of Mammalogy 91, 642–653.
| Landscape structure and local habitat characteristics as correlates of Glaucomys sabrinus and Tamiasciurus hudsonicus occurrence.Crossref | GoogleScholarGoogle Scholar |
Potvin, F., and Bertrand, N. (2004). Leaving forest strips in large clearcut landscapes of boreal forest: a management scenario suitable for wildlife? Forestry Chronicle 80, 44–53.
| Leaving forest strips in large clearcut landscapes of boreal forest: a management scenario suitable for wildlife?Crossref | GoogleScholarGoogle Scholar |
Potvin, F., Courtois, R., and Belanger, L. (1999). Short-term response of wildlife to clearcutting in Quebec boreal forest: multi-scale effects and management implications. Canadian Journal of Forest Research 29, 1120–1127.
| Short-term response of wildlife to clearcutting in Quebec boreal forest: multi-scale effects and management implications.Crossref | GoogleScholarGoogle Scholar |
Priol, P., Mazerolle, M. J., Imbeau, L., Drapeau, P., Trudeau, C., and Ramiere, R. (2014). Using dynamic N-mixture models to test cavity limitation on northern flying squirrel demographic parameters using experimental nest box supplementation. Ecology and Evolution 4, 2165–2177.
| Using dynamic N-mixture models to test cavity limitation on northern flying squirrel demographic parameters using experimental nest box supplementation.Crossref | GoogleScholarGoogle Scholar | 25360258PubMed |
Ransome, D. B., Lindgren, P. M. F., Sullivan, D. S., and Sullivan, T. P. (2004). Long-term responses of ecosystem components to stand thinning in young lodgepole pine forest: I. Population dynamics of northern flying squirrels and red squirrels. Forest Ecology and Management 202, 355–367.
| Long-term responses of ecosystem components to stand thinning in young lodgepole pine forest: I. Population dynamics of northern flying squirrels and red squirrels.Crossref | GoogleScholarGoogle Scholar |
Rosenvald, R., and Lohmus, A. (2008). For what, when, and where is green-tree retention better than clearcutting? A review of biodiversity aspects. Forest Ecology and Management 255, 1–15.
| For what, when, and where is green-tree retention better than clearcutting? A review of biodiversity aspects.Crossref | GoogleScholarGoogle Scholar |
Saville, D. J. (1990). Multiple comparison procedures: the practical solution. The American Statistician 44, 174–180.
Seber, G. A. F. (1982). ‘The Estimation of Animal Abundance and Related Parameters.’ 2nd edn. (Charles Griffin: London, UK.)
Shanley, C. S., Pyare, S., and Smith, W. P. (2013). Response of an ecological indicator to landscape composition and structure: implications for functional units of temperate rainforest ecosystems. Ecological Indicators 24, 68–74.
| Response of an ecological indicator to landscape composition and structure: implications for functional units of temperate rainforest ecosystems.Crossref | GoogleScholarGoogle Scholar |
Smith, W. P. (2007). Ecology of Glaucomys sabrinus: habitat, demography, and community relations. Journal of Mammalogy 88, 862–881.
| Ecology of Glaucomys sabrinus: habitat, demography, and community relations.Crossref | GoogleScholarGoogle Scholar |
Smith, W. P., and Person, D. K. (2007). Estimated persistence of northern flying squirrel populations in temperate rain forest fragments of southeast Alaska. Biological Conservation 137, 626–636.
| Estimated persistence of northern flying squirrel populations in temperate rain forest fragments of southeast Alaska.Crossref | GoogleScholarGoogle Scholar |
Smith, W. P., Anthony, R. G., Waters, J. R., Dodd, N. L., and Zabel, C. J. (2003). Ecology and conservation of arboreal rodents of western coniferous forests. In ‘Mammal Community Dynamics. Management and Conservation in Forests of Western North America’. (Eds C. J. Zabel, and R. G. Anthony.) pp. 157–206. (Cambridge University Press: Cambridge, UK.)
Smith, W. P., Person, D. K., and Pyare, S. (2011). Source-sinks, metapopulations, and forest reserves: conserving northern flying squirrels in the temperate rainforests of Southeast Alaska. In ‘Sources, Sinks, and Sustainability across Landscapes’. (Eds J. Liu, V. Hull, A. T. Morzillo, and J. Wiens.) pp. 399–422. (Cambridge University Press: Cambridge, UK.)
Steele, M. A. (1998). Tamiasciurus hudsonicus. In ‘Mammalian Species No. 586’. (American Society of Mammalogists: Lawrence, KS, USA.)
Steventon, J. D. (2015). Arboreal squirrel abundance in response to a gradient of mountain pine beetle attack in sub-boreal forests. Journal of Ecosystems and Management 15, 1–12.
Sullivan, T. P., and Klenner, W. (2000). Response of northwestern chipmunks (Tamias amoenus) to variable habitat structure in young lodgepole pine forest. Canadian Journal of Zoology 78, 283–293.
| Response of northwestern chipmunks (Tamias amoenus) to variable habitat structure in young lodgepole pine forest.Crossref | GoogleScholarGoogle Scholar |
Sullivan, T. P., and Sullivan, D. S. (2020). Similarity in occupancy of different-sized forest patches by small mammals on clearcuts: conservation implications for red-backed voles and small mustelids. Mammal Research 65, 255–266.
| Similarity in occupancy of different-sized forest patches by small mammals on clearcuts: conservation implications for red-backed voles and small mustelids.Crossref | GoogleScholarGoogle Scholar |
Sullivan, T. P., Ransome, D. B., Sullivan, D. S., Lindgren, P. M. F., and Klenner, W. (2017). Tree squirrel abundance and demography in managed coniferous forests of British Columbia are within the range of natural fluctuations of old-growth stands. Canadian Journal of Forest Research 47, 565–582.
| Tree squirrel abundance and demography in managed coniferous forests of British Columbia are within the range of natural fluctuations of old-growth stands.Crossref | GoogleScholarGoogle Scholar |
Sutton, D. A. (1992). Tamias amoenus. Mammalian Species , 1–8.
| Tamias amoenus.Crossref | GoogleScholarGoogle Scholar |
Swihart, R. K., Goheen, J. R., Schnelker, S. A., and Rizkalla, C. E. (2007). Testing the generality of patch and landscape-level predictors of tree squirrel occurrence at a regional scale. Journal of Mammalogy 88, 564–572.
| Testing the generality of patch and landscape-level predictors of tree squirrel occurrence at a regional scale.Crossref | GoogleScholarGoogle Scholar |
Trudeau, C., Imbeau, L., Drapeau, P., and Mazerolle, M. J. (2012). Winter site occupancy patterns of the northern flying squirrel in boreal mixed-wood forests. Mammalian Biology 77, 258–263.
| Winter site occupancy patterns of the northern flying squirrel in boreal mixed-wood forests.Crossref | GoogleScholarGoogle Scholar |
Van Horne, B. (1983). Density as a misleading indicator of habitat quality. The Journal of Wildlife Management 47, 893–901.
| Density as a misleading indicator of habitat quality.Crossref | GoogleScholarGoogle Scholar |
Wauters, L. A., and Dhondt, A. A. (1989). Variation in length and body weight of red squirrel (Sciurus vulgaris) in two different habitats. Journal of Zoology 217, 93–106.
| Variation in length and body weight of red squirrel (Sciurus vulgaris) in two different habitats.Crossref | GoogleScholarGoogle Scholar |
Wells-Gosling, N., and Heaney, L. R. (1984). Glaucomys sabrinus. In ‘Mammalian Species No. 229’. (American Society of Mammalogists: Lawrence, KS, USA.)
Wheatley, M., Larsen, K. W., and Boutin, S. (2002). Does density reflect habitat quality for North American red squirrels during a spruce-cone failure? Journal of Mammalogy 83, 716–727.
| Does density reflect habitat quality for North American red squirrels during a spruce-cone failure?Crossref | GoogleScholarGoogle Scholar |
Wolff, J. O., and Zasada, J. C. (1975). Red squirrel response to clearcut and shelterwood systems in interior Alaska. USDA Forest Service Research Note PNW-255. USDA Forest Service, Portland, OR, USA.
Zar, J. H. (1999). ‘Biostatistical Analysis.’ (Prentice-Hall, Inc.: Englewood Cliffs, NJ, USA.)
