The Energetic Value of Land-Based Foods in Western Hudson Bayand Their Potential to Alleviate Energy Deficits of Starving Adult Male Polar Bears
Climate change is predicted to expand the ice-free season in western Hudson Bay and when it grows to 180 days, 28–48% of adult male polar bears are projected to starve unless nutritional deficits can be offset by foods consumed on land. We updated a dynamic energy budget model developed by Molnar et...
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ftcityunivny:oai:academicworks.cuny.edu:cc_pubs-1714 2023-05-15T15:53:32+02:00 The Energetic Value of Land-Based Foods in Western Hudson Bayand Their Potential to Alleviate Energy Deficits of Starving Adult Male Polar Bears Gormezano, Linda J. Rockwell, Robert F. 2015-06-10T07:00:00Z application/pdf https://academicworks.cuny.edu/cc_pubs/644 https://academicworks.cuny.edu/cgi/viewcontent.cgi?article=1714&context=cc_pubs English eng CUNY Academic Works https://academicworks.cuny.edu/cc_pubs/644 https://academicworks.cuny.edu/cgi/viewcontent.cgi?article=1714&context=cc_pubs Publications and Research Environmental Sciences Other Animal Sciences article 2015 ftcityunivny 2021-04-10T19:02:04Z Climate change is predicted to expand the ice-free season in western Hudson Bay and when it grows to 180 days, 28–48% of adult male polar bears are projected to starve unless nutritional deficits can be offset by foods consumed on land. We updated a dynamic energy budget model developed by Molnar et al. to allow influx of additional energy from novel terrestrial foods (lesser snow geese, eggs, caribou) that polar bears currently consume as part of a mixed diet while on land. We calculated the units of each prey, alone and in combination, needed to alleviate these lethal energy deficits under conditions of resting or limited movement (2 km d-1) prior to starvation. We further considered the total energy available from each sex and age class of each animal prey over the period they would overlap land-bound polar bears and calculated the maximum number of starving adult males that could be sustained on each food during the ice-free season. Our results suggest that the net energy from land-based food, after subtracting costs of limited movement to obtain it, could eliminate all projected nutritional deficits of starving adult male polar bears and likely other demographic groups as well. The hunting tactics employed, success rates as well as behavior and abundance of each prey will determine the realized energetic values for individual polar bears. Although climate change may cause a phenological mismatch between polar bears and their historical ice-based prey, it may simultaneously yield a new match with certain land-based foods. If polar bears can transition their foraging behavior to effectively exploit these resources, predictions for starvation-related mortality may be overestimated for western Hudson Bay. We also discuss potential complications with stable-carbon isotope studies to evaluate utilization of land-based foods by polar bears including metabolic effects of capture-related stress and consuming a mixed diet. Article in Journal/Newspaper caribou Hudson Bay City University of New York: CUNY Academic Works Hudson Hudson Bay Molnar ENVELOPE(-66.982,-66.982,-66.177,-66.177) |
institution |
Open Polar |
collection |
City University of New York: CUNY Academic Works |
op_collection_id |
ftcityunivny |
language |
English |
topic |
Environmental Sciences Other Animal Sciences |
spellingShingle |
Environmental Sciences Other Animal Sciences Gormezano, Linda J. Rockwell, Robert F. The Energetic Value of Land-Based Foods in Western Hudson Bayand Their Potential to Alleviate Energy Deficits of Starving Adult Male Polar Bears |
topic_facet |
Environmental Sciences Other Animal Sciences |
description |
Climate change is predicted to expand the ice-free season in western Hudson Bay and when it grows to 180 days, 28–48% of adult male polar bears are projected to starve unless nutritional deficits can be offset by foods consumed on land. We updated a dynamic energy budget model developed by Molnar et al. to allow influx of additional energy from novel terrestrial foods (lesser snow geese, eggs, caribou) that polar bears currently consume as part of a mixed diet while on land. We calculated the units of each prey, alone and in combination, needed to alleviate these lethal energy deficits under conditions of resting or limited movement (2 km d-1) prior to starvation. We further considered the total energy available from each sex and age class of each animal prey over the period they would overlap land-bound polar bears and calculated the maximum number of starving adult males that could be sustained on each food during the ice-free season. Our results suggest that the net energy from land-based food, after subtracting costs of limited movement to obtain it, could eliminate all projected nutritional deficits of starving adult male polar bears and likely other demographic groups as well. The hunting tactics employed, success rates as well as behavior and abundance of each prey will determine the realized energetic values for individual polar bears. Although climate change may cause a phenological mismatch between polar bears and their historical ice-based prey, it may simultaneously yield a new match with certain land-based foods. If polar bears can transition their foraging behavior to effectively exploit these resources, predictions for starvation-related mortality may be overestimated for western Hudson Bay. We also discuss potential complications with stable-carbon isotope studies to evaluate utilization of land-based foods by polar bears including metabolic effects of capture-related stress and consuming a mixed diet. |
format |
Article in Journal/Newspaper |
author |
Gormezano, Linda J. Rockwell, Robert F. |
author_facet |
Gormezano, Linda J. Rockwell, Robert F. |
author_sort |
Gormezano, Linda J. |
title |
The Energetic Value of Land-Based Foods in Western Hudson Bayand Their Potential to Alleviate Energy Deficits of Starving Adult Male Polar Bears |
title_short |
The Energetic Value of Land-Based Foods in Western Hudson Bayand Their Potential to Alleviate Energy Deficits of Starving Adult Male Polar Bears |
title_full |
The Energetic Value of Land-Based Foods in Western Hudson Bayand Their Potential to Alleviate Energy Deficits of Starving Adult Male Polar Bears |
title_fullStr |
The Energetic Value of Land-Based Foods in Western Hudson Bayand Their Potential to Alleviate Energy Deficits of Starving Adult Male Polar Bears |
title_full_unstemmed |
The Energetic Value of Land-Based Foods in Western Hudson Bayand Their Potential to Alleviate Energy Deficits of Starving Adult Male Polar Bears |
title_sort |
energetic value of land-based foods in western hudson bayand their potential to alleviate energy deficits of starving adult male polar bears |
publisher |
CUNY Academic Works |
publishDate |
2015 |
url |
https://academicworks.cuny.edu/cc_pubs/644 https://academicworks.cuny.edu/cgi/viewcontent.cgi?article=1714&context=cc_pubs |
long_lat |
ENVELOPE(-66.982,-66.982,-66.177,-66.177) |
geographic |
Hudson Hudson Bay Molnar |
geographic_facet |
Hudson Hudson Bay Molnar |
genre |
caribou Hudson Bay |
genre_facet |
caribou Hudson Bay |
op_source |
Publications and Research |
op_relation |
https://academicworks.cuny.edu/cc_pubs/644 https://academicworks.cuny.edu/cgi/viewcontent.cgi?article=1714&context=cc_pubs |
_version_ |
1766388642410921984 |