Vol. 22 (1998)
Grand Teton Np Report

Body Mass and Lipid Changes by Hibernating Reproductive and Nonreproductive Black Bears

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  • Henry J. Harlow,
  • Thomas Lohuis,
  • Daniel B. Tinker,
  • Ronald G. Grogan,
  • Thomas D.I. Beck
Henry J. Harlow
University of Wyoming
Thomas Lohuis
University of Wyoming
Daniel B. Tinker
Western Carolina University
Ronald G. Grogan
Wyoming Game and Fish Department
Thomas D.I. Beck
Colorado Division of Wildlife
DOI: https://doi.org/10.13001/uwnpsrc.1998.3353

Published 1998-01-01

Abstract

Black bears have delayed implantation with fetal development and lactation energy demands during a period of maternal hibernation and starvation. Pregnant females in a state of diapause had about 23% greater fat depots than non­reproductive females going into hibernation. Fat provided 92% of the total energy for lactation and gestation. Rates of fat loss were 27% and protein loss 58% higher for reproductive females compared to non-reproductive females. The cost of winter reproduction to include gestation and lactation was 1432 kj/day to produce two cubs. While reproduction required elevated protein breakdown, the overall loss was relatively small, perhaps due to a short gestation period and urea recycling.

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