Mammalian Biology

, Volume 78, Issue 2, pp 79–86 | Cite as

Factors influencing forage selection by the North American beaver (Castor canadensis)

  • Travis G. GerwingEmail author
  • Chris J. Johnson
  • Cecilia Alström-Rapaport
Original Investigation


Across their range, a large number of biotic and abiotic factors are known to influence the choice of browse plant and the foraging behaviour of the North American beaver (Castor canadensis). We used generalized linear mixed-effects models to investigate sets of variables that may influence the foraging choices of beaver: forage species, distance of forage from water, forage density, and site. Communities across the study sites in central British Columbia, Canada, were dominated by Salix sitchensis, Salix lucida, and Alnus spp. Density had no impact on forage selection, while site, distance from water, and species identity all influenced the foraging decisions of beaver. We postulated that these factors may be ordered hierarchically: large-scale factors, such as site, followed by the medium-scale distance from water, and species of plant at the finest scale. Forage items in some sites had a higher probability of being browsed than in others, while in all sites the probability of being browsed decreased with increasing distance from water. Beaver appeared to be foraging as “picky” generalists; of the 9 plant species examined, 3 species of Salix (S. scouleriana, S. drummondiana and S. sitchensis) were selected by beaver, Salix bebbiana was avoided, and 5 species were neither selected for nor against. Browse selection within the genus Salix implied that beaver were able to differentiate among closely related species. Detailed information on forage selection is a crucial first step in designing and interpreting models that predict large-scale distributional patterns of beaver.


Beaver Castor canadensis Forage selection Mixed-effects models Riparian Salix 


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  1. Anderson, D., Burnham, K., Thompson, W., 2000. Null hypothesis testing: problems, prevalence, and an alternative. J. Wildlife Manage. 64, 912–923.CrossRefGoogle Scholar
  2. Baccus, J., Kainer, M., Small, M., 2007. Foraging Preferences by American Beavers Castor canadensis (Rodentia: Castoridae) on Central Texas Rivers. Texas J. Sci. 59, 243.Google Scholar
  3. Bailey, J., Schweitzer, J., Rehill, B., Lindroth, R., Martinsen, G., Whitham, T., 2004. Beavers as molecular geneticists: a genetic basis to the foraging of an ecosystem engineer. Ecology 85, 603–608.CrossRefGoogle Scholar
  4. Baker, B.W., Ducharme, H.C., Mitchell, D.C.S., Stanley, T.R., Peinetti, H.R., 2005. Interaction of beaver and elk herbivory reduces standing crop of willow. Ecol. Appl. 15, 110–118.CrossRefGoogle Scholar
  5. Basey, J.M., Jenkins, S.H., 1995. Influences of predation risk and energy maximization on food selection by beavers (Castor canadensis). Can. J. Zool. 73, 2197–2208.CrossRefGoogle Scholar
  6. Beier, P., Barrett, R.H., 1987. Beaver habitat use and impact in Truckee River Basin, California. J. Wildlife Manage. 51, 794–799.CrossRefGoogle Scholar
  7. Boyce, M., Vernier, P., Nielsen, S., Schmiegelow, F., 2002. Evaluating resource selection functions. Ecol. Model. 157, 281–300.CrossRefGoogle Scholar
  8. Brown, J., Heske, E., 1990. Control of a desert-grassland transition by a keystone rodent guild. Science 250, 1705.PubMedCrossRefPubMedCentralGoogle Scholar
  9. Burnham, K.P., Anderson, D.R., 2002. Model selection and multimodel inference: a practical information-theoretic approach. Springer Verlag New York, New York.Google Scholar
  10. Busher, P., 1996. Food caching behaviour of beavers (Castor canadensis): selection and use of woody species. Am. Midl. Nat. 135, 343–348.CrossRefGoogle Scholar
  11. Danilov, P., Kan’shiev, V.Y., 1983. The state of populations and ecological characteristics of European (Castor fiber L.) and Canadian (Castor canadensis Kuhl) beavers in the northwestern USSR. Acta Zool. Fenn. 174, 95–97.Google Scholar
  12. Dieter, C.D., Mccabe, T.R., 1989. Factors influencing beaver lodge-site selection on a prairie river. Am. Midl. Nat. 122, 408–411.CrossRefGoogle Scholar
  13. Donkor, N., Fryxell, J., 1999. Impact of beaver foraging on structure of lowland boreal forests of Algonquin Provincial Park, Ontario. For. Ecol. Manage. 118, 83–92.CrossRefGoogle Scholar
  14. Elith, J., Leathwick, J.R., 2009. Species distribution models: ecological explanations and prediction across space and time. Annu. Rev. Ecol. Evol. Syst. 40, 677–697.CrossRefGoogle Scholar
  15. Flecker, A., 1996. Ecosystem engineering by a dominant detritivore in a diverse tropical stream. Ecology 77, 1845–1854.CrossRefGoogle Scholar
  16. Fryxell, J., Doucet, C., 1993. Diet choice and the funcional response of beavers. Ecology, 1298–1306.Google Scholar
  17. Gallant, D., Bérubé, C., Tremblay, E., Vasseur, L., 2004. An extensive study of the foraging ecology of beavers (Castor canadensis) in relation to habitat quality. Can. J. Zool. 82, 922–933.CrossRefGoogle Scholar
  18. Gerwing, T.G., 2009. Reproductive Ecology of the Sitka Willow (Salix sitchensis). MSc, University of Northern British Columbia, Prince George, British Columbia.CrossRefGoogle Scholar
  19. Gillies, C., Hebblewhite, M., Nielsen, S., Krawchuk, M., Aldridge, C., Frair, J., Saher, D., Stevens, C., Jerde, C., 2006. Application of random effects to the study of resource selection by animals. J. Anim. Ecol. 75, 887–898.PubMedCrossRefPubMedCentralGoogle Scholar
  20. Haarberg, O., Rosell, F., 2006. Selective foraging on woody plant species by the Eurasian beaver (Castor fiber) in Telemark, Norway. J. Zool. 270, 201–208.CrossRefGoogle Scholar
  21. Hartman, G., 1996. Habitat selection by European beaver (Castor fiber) colonizing a boreal landscape. J. Zool. 240, 317–325.CrossRefGoogle Scholar
  22. Hebblewhite, M., Merrill, E., 2008. Modelling wildlife–human relationships for social species with mixed-effects resource selection models. J. Appl. Ecol. 45, 834–844.CrossRefGoogle Scholar
  23. Hebblewhite, M., Pletscher, D., Paquet, P., 2002. Elk population dynamics in areas with and without predation by recolonizing wolves in Banff National Park, Alberta. Can. J. Zool. 80, 789–799.CrossRefGoogle Scholar
  24. Hood, G., Bayley, S., 2008. The effects of high ungulate densities on foraging choices by beaver (Castor canadensis) in the mixed-wood boreal forest. Can. J. Zool. 86, 484–496.CrossRefGoogle Scholar
  25. Howard, R.J., Larson, J.S., 1985. A stream habitat classification system for beaver. J. Wildlife Manage. 49, 19–25.CrossRefGoogle Scholar
  26. Jenkins, S., 1979. Seasonal and year-to-year differences in food selection by beavers. Oecologia 44, 112–116.PubMedCrossRefPubMedCentralGoogle Scholar
  27. Jenkins, S., 1980. A size–distance relation in food selection by beavers. Ecology 61, 740–746.CrossRefGoogle Scholar
  28. Johnson, C., Parker, K., Heard, D., 2001. Foraging across a variable landscape: behavioural decisions made by woodland caribou at multiple spatial scales. Oecologia 127, 590–602.PubMedCrossRefPubMedCentralGoogle Scholar
  29. Johnson, C., Seip, D., Boyce, M., 2004. A quantitative approach to conservation planning: using resource selection functions to map the distribution of mountain caribou at multiple spatial scales. J. Appl. Ecol. 41, 238–251.CrossRefGoogle Scholar
  30. Johnson, D., 1980. The comparison of usage and availability measurements for evaluating resource preference. Ecology 61, 65–71.CrossRefGoogle Scholar
  31. Johnston, C.A., Naiman, R.J., 1990. Browse selection by beaver: effects on riparian forest composition. Can. J. For. Res. 20, 1036–1043.CrossRefGoogle Scholar
  32. Jones, J., 2001. Habitat selection studies in avian ecology: a critical review. Auk 118, 557–562.CrossRefGoogle Scholar
  33. Jones, K., Gilvear, D., Willby, N., Gaywood, M., 2009. Willow (Salix spp.) and aspen (Populus tremula) regrowth after felling by the Eurasian beaver (Castor fiber): implications for riparian woodland conservation in Scotland. Aquat. Conserv.: Mar. Freshw. Ecosyst. 19, 75–87.CrossRefGoogle Scholar
  34. Jungwirth, J., Dieter, C., Munsterman, A., 2005. Beaver (Castor canadensis) habitat use in Eastern South Dakota, 2001–2001. Proc. South Dakota Acad. Sci. 84, 243–251.Google Scholar
  35. Kindschy, R., 1985. Response of red willow to beaver use in southeastern Oregon. J. Wildlife Manage. 49, 26–28.CrossRefGoogle Scholar
  36. Masslich, W.J., Brotherson, J.D., Cates, R.G., 1988. Relationships of aspen (Populus tremuloides) to foraging patterns of beaver (Castor canadensis) in the Strawberry Valley of Central Utah. West. North Am. Nat. 48, 250–262.Google Scholar
  37. Mccomb, W.C., Sedell, J.R., Buchholz, T.D., 1990. Dam-site selection by beavers in an eastern Oregon basin. West. North Am. Nat. 50, 273–281.Google Scholar
  38. McGinley, M.A., Whitham, T.G., 1985. Central place foraging by beavers (Castor canadensis): a test of foraging predictions and the impact of selective feeding on the growth form of cottonwoods (Populus fremontii). Oecologia 66, 558–562.PubMedCrossRefPubMedCentralGoogle Scholar
  39. Menard, S.W., 2002. Applied Logistic Regression Analysis. Sage Publications, Inc., Thousand Oaks, CA.CrossRefGoogle Scholar
  40. Murray, K., Conner, M., 2009. Met hods to quantify variable importance: implications for the analysis of noisy ecological data. Ecology 90, 348–355.PubMedCrossRefPubMedCentralGoogle Scholar
  41. Naiman, R., Johnston, C., Kelley, J., 1988. Alteration of North American streams by beaver. Bioscience 38, 753–762.CrossRefGoogle Scholar
  42. Naiman, R., Melillo, J., Hobbie, J., 1986. Ecosystem alteration of boreal forest streams by beaver (Castor canadensis). Ecology 67, 1254–1269.CrossRefGoogle Scholar
  43. Nolet, B., Rosell, F., 1998. Comeback of the beaver Castor fiber: an overview of old and new conservation problems. Biol. Conserv. 83, 165–173.CrossRefGoogle Scholar
  44. Nolet, B.A., Hoekstra, A., Ottenheim, M.M., 1994. Selective foraging on woody species by the beaver Castor fiber, and its impact on a riparian willow forest. Biol. Conserv. 70, 117–128.CrossRefGoogle Scholar
  45. Orians, G.H., Pearson, N.E., 1979. On the theory of central place foraging. In: Analysis of Ecological Systems. Ohio State University Press, Columbus, pp. 155–177.Google Scholar
  46. Paine, R., 1969. A noteon trophic complexity and community stability. Am. Nat. 103, 91–93.CrossRefGoogle Scholar
  47. Pearce, J., Ferrier, S., 2000. Evaluating the predictive performance of habitat models developed using logistic regression. Ecol. Model. 133, 225–245.CrossRefGoogle Scholar
  48. Perry, G., Pianka, E., 1997. Animal foraging: past, present and future. Trends Ecol. Evol. 12, 360–364.PubMedCrossRefPubMedCentralGoogle Scholar
  49. Pinto, B., Santos, M., Rosell, F., 2009. Habitat selection of the Eurasian beaver (Castor fiber) near its carrying capacity: an example from Norway. Can. J. Zool. 87, 317–325.CrossRefGoogle Scholar
  50. Power, M., Tilman, D., Estes, J., Menge, B., Bond, W., Mills, L., Daily, G., Castilla, J., Lubchenco, J., Paine, R., 1996. Challenges in the quest for keystones. Bioscience 46, 609–620.CrossRefGoogle Scholar
  51. Pyke, G., 1984. Optimal foraging theory: a critical review. Annu. Rev. Ecol. Syst. 15, 523–575.CrossRefGoogle Scholar
  52. Raffel, T.R., Smith, N., Cortright, C., Gatz, A.J., 2009. Central place foraging by beavers (Castor canadensis) in a complex lake habitat. Am. Midl. Nat. 162, 62–73.CrossRefGoogle Scholar
  53. Roberts, T., Arner, D., 1984. Food habits of beaver in east-central Mississippi. J. Wildlife Manage. 48, 1414–1419.CrossRefGoogle Scholar
  54. Rosell, F., Bozser, O., Collen, P., Parker, H., 2005. Ecological impact of beavers Castor fiber and Castor canadensis and their ability to modify ecosystems. Mamm. Rev. 35, 248–276.CrossRefGoogle Scholar
  55. Rushton, S., Ormerod, S., Kerby, G., 2004. New paradigms for modelling species distributions? J. Appl. Ecol. 41, 193–200.CrossRefGoogle Scholar
  56. Stevens, C.E., Paszkowski, C.A., Foote, A.L., 2007. Beaver (Castor canadensis) as a surrogate species for conserving anuran amphibians on boreal streams in Alberta, Canada. Biol. Conserv. 134, 1–13.CrossRefGoogle Scholar
  57. Swets, J.A., 1988. Measuring the accuracy of diagnostic systems. Science 240, 1285.PubMedCrossRefPubMedCentralGoogle Scholar
  58. Veraart, A., Nolet, B., Rosell, F., De Vries, P., 2006. Simulated winter browsing may lead to induced susceptibility of willows to beavers in spring. Can. J. Zool. 84, 1733–1742.CrossRefGoogle Scholar
  59. Wheatley, M., Johnson, C.J., 2009. Factors limiting our understanding of ecological scale. Ecol. Complex. 6, 150–159.CrossRefGoogle Scholar
  60. Wright, J.P., Jones, C.G., Flecker, A.S., 2002. An ecosystem engineer, the beaver, increases species richness at the landscape scale. Oecologia 132, 96–101.PubMedCrossRefPubMedCentralGoogle Scholar

Copyright information

© Deutsche Gesellschaft für Säugetierkunde 2013

Authors and Affiliations

  • Travis G. Gerwing
    • 1
    Email author
  • Chris J. Johnson
    • 1
  • Cecilia Alström-Rapaport
    • 1
  1. 1.Ecosystem Science and Management ProgramUniversity of Northern British ColumbiaPrince GeorgeCanada

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