Polar Biology

, Volume 36, Issue 2, pp 169–176 | Cite as

Directness of resource use metrics affects predictions of bear body fat gain

  • Christopher R. Ayers
  • Jerrold L. Belant
  • Joshua J. Millspaugh
Original Paper

Abstract

Many North American ursids rely on an annual hyperphagic period to obtain fat reserves necessary for winter survival and reproduction. Identifying causes of variation in body fat gain may improve understanding of how bear resource use affects body condition. We used data from southcentral Alaska to model changes in percentage body fat of adult female American black bears (Ursus americanus) in 1998 and 2000 and brown bears (Ursus arctos) in 2000. We used year, proportion of radio locations in different habitats, distance to streams containing salmon (Onchorynchus spp.), and degree of radio location clustering as predictors for black bears and elevation, distance to streams containing salmon, and degree of radio location clustering as predictors for brown bears. Degree of location clustering was the only predictor variable supported by parameter coefficients in black bear models, supporting our hypothesis that metrics of energetics perform better as predictors of body condition than habitat use. With every unit increase in location clustering black bear body fat increased 2 %. No predictor variables influenced variation in brown bear change in body fat. Some variables previously found useful for predicting bear presence (e.g., habitat) were not useful in predicting changes in body fat, an important biological outcome for these species. Rather than assuming fitness benefits of habitat-level selection, we recommend including metrics of energetics that might more directly influence biological outcomes.

Keywords

Bears Body condition Habitat Resource use Salmon Ursus spp. 

References

  1. Aldridge CL, Boyce MS (2008) Accounting for fitness: combining survival and selection when assessing wildlife-habitat relationships. Isr J Ecol Evol 54:389–419CrossRefGoogle Scholar
  2. Beeman LE, Pelton MR (1980) Seasonal foods and feeding ecology of black bears in the smoky mountains. Bears Their Biol Manag 4:141–147CrossRefGoogle Scholar
  3. Belant JL, Follmann EH (2002) Sampling considerations for American black and brown bear home range and habitat use. Ursus 13:299–315Google Scholar
  4. Belant JL, Kielland K, Follmann EH, Adams LG (2006) Interspecific resource partitioning in sympatric ursids. Ecol Appl 16:2333–2343PubMedCrossRefGoogle Scholar
  5. Belant JL, Griffith B, Zhang Y, Follmann EH, Adams LG (2010) Population-level resource selection by sympatric brown and American black bears in Alaska. Polar Biol 33:31–40CrossRefGoogle Scholar
  6. Blouin-Demers G, Weatherhead PJ (2008) Habitat use is linked to components of fitness through the temperature-dependence of performance in ratsnakes (Elaphe obsolete). Isr J Ecol Evol 54:361–372CrossRefGoogle Scholar
  7. Bonal R, Aparicio JM (2008) Evidence of prey depletion around lesser kestrel Falco naumanni colonies and its short term negative consequences. J Avian Biol 39:189–197CrossRefGoogle Scholar
  8. Both C, Visser ME (2000) Breeding territory size affects fitness: an experimental study on competition at the individual level. J Anim Ecol 69:1021–1030CrossRefGoogle Scholar
  9. Brown JH, Marquet PA, Taper ML (1993) Evolution of body size: consequences of an energetic definition of fitness. Am Nat 142:573–584PubMedCrossRefGoogle Scholar
  10. Burnham KP, Anderson DR (2002) Model selection and multimodel inference: a practical information-theoretic approach, 2nd edn. Springer, New YorkGoogle Scholar
  11. Buskirk SW, Millspaugh JJ (2006) Metrics for studies of resource selection. J Wild Manag 30:358–366CrossRefGoogle Scholar
  12. Ens BJ, Weissing FJ, Drent RH (1995) The despotic distribution and deferred maturity: two sides of the same coin. Am Nat 146:625–650CrossRefGoogle Scholar
  13. Ezenwa VO, Jolles AE, O’Brien MP (2009) A reliable body condition scoring technique for estimating condition in African buffalo. Afr J Ecol 47:476–481CrossRefGoogle Scholar
  14. Farley SD, Robbins CT (1994) Development of two methods to estimate body composition of bears. Can J Zool 72:220–226CrossRefGoogle Scholar
  15. Fortin JK, Farley SD, Rode KD, Robbins CT (2007) Dietary and spatial overlap between sympatric ursids relative to salmon use. Ursus 18:19–29CrossRefGoogle Scholar
  16. Fretwell SD (1972) Populations in a seasonal environment. Princeton University Press, PrincetonGoogle Scholar
  17. Futuyma DJ (1998) Evolutionary biology, 3rd edn. Sinauer Associates, SunderlandGoogle Scholar
  18. Gaillard J-M, Hebblewhite M, Loison A, Fuller M, Powell R, Basille M, Van Moorter B (2010) Habitat-performance relationships: finding the right metric at a given spatial scale. Philos Trans R Soc B 365:2255–2265CrossRefGoogle Scholar
  19. Graves TA, Waller JS (2006) Understanding the causes of missed global positioning system telemetry fixes. J Wild Manag 70:844–851CrossRefGoogle Scholar
  20. Haase P (1995) Spatial pattern analysis in ecology based on Ripley’s K-function: introduction and methods of edge correction. J Veg Sci 6:575–582CrossRefGoogle Scholar
  21. Harlow HJ, Lohuis T, Grogan RG, Beck TDI (2002) Body mass and lipid changes by hibernating reproductive and nonreproductive black bears (Ursus americanus). J Mammal 83:1020–1025CrossRefGoogle Scholar
  22. Hilderbrand GV, Farley SD, Robbins CT (1998) Predicting body condition of bears via two field methods. J Wild Manag 62:406–409CrossRefGoogle Scholar
  23. Hilderbrand GV, Schwartz CC, Robbins CT, Jacoby ME, Hanley TA, Arthur SM, Servheen C (1999) The importance of meat, particularly salmon, to body size, population productivity, and conservation of North American brown bears. Can J Zool 77:132–138CrossRefGoogle Scholar
  24. Hilderbrand GV, Schwartz CC, Robbins CT, Hanley TA (2000) Effect of hibernation and reproductive status on body mass and condition of coastal brown bears. J Wild Manag 64:178–183CrossRefGoogle Scholar
  25. Homyack JA (2010) Evaluating habitat quality of vertebrates using conservation physiology tools. Wild Res 37:332–342CrossRefGoogle Scholar
  26. Jacoby ME, Hilderbrand GV, Servheen C, Schwartz CC, Arthur SM, Hanley TA, Robbins CT, Michener R (1999) Trophic relations of brown and black bears in several western North American ecosystems. J Wild Manag 63:921–929CrossRefGoogle Scholar
  27. Johnson CJ, Seip DR (2008) Relationship between resource selection, distribution, and abundance: a test with implications to theory and conservation. Pop Ecol 50:145–157CrossRefGoogle Scholar
  28. Kertson BN, Marzluff JM (2011) Improving studies of resource selection by understanding resource use. Environ Conserv 38:18–27CrossRefGoogle Scholar
  29. Klinka DR, Reimchen TE (2009) Darkness, twilight, and daylight foraging success of bears (Ursus americanus) on salmon in coastal British Columbia. J Mammal 90:144–149CrossRefGoogle Scholar
  30. Libal NS, Belant JL, Leopold BD, Wang G, Owen PA (2011) Despotism and risk of infanticide influence grizzly bear den-site selection. Public Libr Sci One. doi:10.1371/journal.pone.0024133 Google Scholar
  31. MacArthur RH, Pianka ER (1966) On optimal use of a patchy environment. Am Nat 100:603–609CrossRefGoogle Scholar
  32. Maletzke BT, Koehler GM, Wielgus RB, Aubry KB, Evans MA (2007) Habitat conditions associated with lynx hunting behavior during winter in northern Washington. J Wild Manag 72:1473–1478Google Scholar
  33. Marcoux M, Larocque G, Auger-Méthé M, Dutilleul P, Humphries MM (2010) Statistical analysis of animal observations and associated marks distributed in time using Ripley’s functions. Anim Behav 80(2):329–337Google Scholar
  34. Mautz WW, Fair J (1980) Energy expenditure and heart rate for activities of white-tailed deer. J Wild Manag 44:333–342CrossRefGoogle Scholar
  35. McLellan BN (1993) Competition between black and grizzly bears as a natural population regulating factor. Proc West Black Bear Workshop 4:111–116Google Scholar
  36. McLellan BN (2011) Implications of a high-energy and low-energy diet on the body composition, fitness, and competitive abilities of black (Ursus americanus) and grizzly (Ursus arctos) bears. Can J Zool 89:546–558CrossRefGoogle Scholar
  37. McLoughlin PD, Boyce MS, Coulson T, Clutton-Brock T (2006) Lifetime reproductive success and density-dependent, multi-variable resource selection. Proc R Soc 273:1449–1454CrossRefGoogle Scholar
  38. McLoughlin PD, Gaillard JM, Boyce MS, Bonenfant C, Messier F, Duncan P, Delorme D, Van Moorter B, Said S, Klein F (2007) Lifetime reproductive success and composition of the home range in a large herbivore. Ecology 88:3192–3201PubMedCrossRefGoogle Scholar
  39. Moorter BV, Visscher DR, Jerde CL, Frair JL, Merrill EH (2010) Identifying movement states from location data using cluster analysis. J Wild Manag 74:588–594CrossRefGoogle Scholar
  40. Powell RA, Zimmerman JW, Seaman DE (1997) Important components of habitat for black bears. In: Putnam RJ (ed) Ecology and behaviour of North American black bears: home ranges, habitat and social organization. Chapman and Hall, London, pp 68–73Google Scholar
  41. R Development Core Team (2010) R: a language and environment for statistical computing. Vienna R Foundation for Statistical Computing. http://www.R-project.org. Accessed 20 May 2012
  42. Ricklefs RE, Miller GL (2000) Ecology. W. H. Freeman and Company, New YorkGoogle Scholar
  43. Ripley BD (1976) The second-order analysis of stationary processes. J Appl Probab 13:255–266CrossRefGoogle Scholar
  44. Solomon ME (1949) The natural control of animal populations. J Anim Ecol 18:1–35CrossRefGoogle Scholar
  45. Suring LH, Farley SD, Hilderbrand GV, Goldstein MI, Howlin S, Erickson P (2006) Patterns of landscape use by female brown bears on the Kenai Peninsula, Alaska. J Wild Manag 70:1580–1587CrossRefGoogle Scholar
  46. Taylor WP, Reynolds HV III, Ballard WB (1989) Immobilization of grizzly bears with tiletamine hydrochloride and zolazepam hydrochloride. J Wild Manag 53:978–981CrossRefGoogle Scholar
  47. Thomas DLE, Taylor J (2006) Study designs and tests for comparing resource use and availability II. J Wild Manag 70:324–336CrossRefGoogle Scholar
  48. Wallace RA (1973) The ecology and evolution of animal behavior. Goodyear, Pacific PalisadesGoogle Scholar
  49. Webb SL, Riffell SK, Gee KL, Demarais S (2009) Using fractal analyses to characterize movement paths of white-tailed deer and response to spatial scale. J Wild Manag 90:1210–1217Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Christopher R. Ayers
    • 1
  • Jerrold L. Belant
    • 1
  • Joshua J. Millspaugh
    • 2
  1. 1.Carnivore Ecology Laboratory, Forest and Wildlife Research CenterMississippi State UniversityMississippi StateUSA
  2. 2.Department of Fisheries and Wildlife SciencesUniversity of MissouriColumbiaUSA

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