Document Type
Article
Publication Date
2022
DOI
10.1007/s00300-022-03066-9
Publication Title
Polar Biology
Volume
45
Issue
8
Pages
1351-1362
Abstract
Polar bears (Ursus maritimus) in the southern Beaufort Sea experience long annual periods when preferred seal prey are scarce or are unavailable. Consumption of bowhead whale (Balaena mysticetus) carcasses from native Alaskan subsistence hunting is increasingly common for onshore polar bears, yet the energetic consequences of this consumption remain unclear. We use data on bears captured repeatedly over periods that encompassed autumn and winter, combined with calculations, to show that adult female bears likely consume an average of at least 4 seal equivalents during both autumn and winter periods and that considerable variation in energy intake exists across individual bears. We further show that subsistence-caught whale carcasses provide an upper threshold of > 4000 seal equivalents, which could potentially meet mean consumption needs of ~ 80% of the southern Beaufort Sea bear subpopulation during autumn and winter periods. Finally, we modify an existing model to show that observed mass changes over autumn and winter could substantially alter spring foraging habitat choice by females with cubs and the chance that a female with reduced energy reserves would abort a pregnancy or abandon cubs in favor of increasing her own survival; these behaviors could potentially influence population vital rates. Our study highlights the importance of mass dynamics over the autumn and winter months, points to the need for additional data on foraging and energetics over this period, and indicates that the recent declines in polar bear body condition in some subpopulations could have complex effects on reproduction.
Rights
This article is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.
Data Availability
Article states: "The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request."
Corresponding author: Blaine D. Griffen (ORCID: 0000-0002-8126-6323)
Original Publication Citation
Griffen, B. D., Whiteman, J. P., & Pullan, S. (2022). Significance of autumn and winter food consumption for reproduction by southern Beaufort Sea polar bears, Ursus maritimus. Polar Biology, 45(8), 1351-1362. https://doi.org/10.1007/s00300-022-03066-9
Repository Citation
Griffen, Blaine D.; Whiteman, John P.; and Pullan, Sariah, "Significance of Autumn and Winter Food Consumption for Reproduction by Southern Beaufort Sea Polar Bears, Ursus Maritimus" (2022). Biological Sciences Faculty Publications. 490.
https://digitalcommons.odu.edu/biology_fac_pubs/490
ORCID
0000-0002-3348-9274 (Whiteman)