Polar Biology

, Volume 41, Issue 4, pp 763–772 | Cite as

Dietary plasticity in a nutrient-rich system does not influence brown bear (Ursus arctos) body condition or denning

  • Lindsey S. Mangipane
  • Jerrold L. Belant
  • Diana J. R. Lafferty
  • David D. Gustine
  • Tim L. Hiller
  • Michael E. Colvin
  • Buck A. Mangipane
  • Grant V. Hilderbrand
Original Paper


Behavioral differences within a population can allow use of a greater range of resources among individuals. The brown bear (Ursus arctos) is a generalist omnivore that occupies diverse habitats and displays considerable plasticity in food use. We evaluated whether brown bear foraging that resulted in deviations from a proposed optimal diet influenced body condition and, in turn, denning duration in Lake Clark National Park and Preserve, Alaska. To assess assimilated diet, we used sectioned guard hair samples (n = 23) collected in autumn to determine stable carbon and nitrogen isotope ratios. To index proportional contributions of meat and vegetation to assimilated diets, we compared the carbon (δ13C) and nitrogen (δ15N) values of hair samples with the values identified for major food categories. We then compared percentage body fat and body mass in relation to the proportion of assimilated meat in the diet using linear models. We also examined the influence of autumn percentage body fat and mass on denning duration. Percentage body fat was not influenced by the proportion of assimilated meat in the diet. Additionally, percentage body fat and body mass did not influence denning duration. However, body mass of bears assimilating proportionately more meat was greater than bears assimilating less meat. Our results provide support for previous findings that larger bears consume higher amounts of protein to maintain their body size and therefore forage further from the proposed optimal diet. Additionally, our results demonstrate that individuals can achieve similar biological outcomes (e.g., percentage body fat) despite variable foraging strategies, suggesting that individuals within generalist populations may confer an adaptive advantage through behavioral plasticity.


Behavioral plasticity Body condition Brown bear Diet Stable isotopes Ursus arctos 



We thank the National Park Service for funding this project (Grant Number P15AC01024). We also thank Mississippi State University and the U.S. Geological Survey for their support. We thank Matthew Rogers for analyzing hair samples, Tewosret Vaughn for formatting assistance, Layne Adams for editorial comments, and Regan Sarwas for Geographic Information System (GIS) assistance. We thank pilots Troy Cambier, Rich Richotte, Don Welty, Andy Greenblatt, Matt Keller, and Lynn Ellis for making capture efforts possible. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US Government.


This study was funded by the National Park Service (Grant Number P15AC01024).


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2017

Authors and Affiliations

  • Lindsey S. Mangipane
    • 1
  • Jerrold L. Belant
    • 1
  • Diana J. R. Lafferty
    • 2
  • David D. Gustine
    • 3
    • 6
  • Tim L. Hiller
    • 4
    • 7
  • Michael E. Colvin
    • 4
  • Buck A. Mangipane
    • 5
  • Grant V. Hilderbrand
    • 6
  1. 1.Carnivore Ecology Laboratory, Forest and Wildlife Research CenterMississippi State UniversityStarkvilleUSA
  2. 2.Department of BiologyNorthern Michigan UniversityMarquetteUSA
  3. 3.National Park ServiceGrand Teton National ParkMooseUSA
  4. 4.Department of Wildlife, Fisheries, and AquacultureMississippi State UniversityStarkvilleUSA
  5. 5.National Park ServiceLake Clark National Park and PreservePort AlsworthUSA
  6. 6.U.S. Geological Survey, Alaska Science CenterAnchorageUSA
  7. 7.Wildlife Ecology InstituteStarkvilleUSA

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