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Published on: November 11, 2021
Simulating polar bear energetics during a seasonal fast using a mechanistic model
Paul D Mathewson1, Warren P Porter
1Nelson Institute for Environmental Studies, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
Plos One
|September 11, 2013
Summary
This study validates the Niche Mapper™ model for polar bear (Ursus maritimus) energetics during fasting. The model accurately predicts survival rates, highlighting climate change impacts on polar bear populations.
Area of Science:
- Ecology
- Physiology
- Climate Change Biology
Background:
- Polar bears (Ursus maritimus) face fasting challenges during ice-free periods.
- Accurate modeling of polar bear energetics is crucial for predicting climate change impacts.
Purpose of the Study:
- To assess the accuracy of the Niche Mapper™ mechanistic model in simulating polar bear energetics during fasting.
- To evaluate the model's utility in predicting climate change effects on polar bear survival.
Main Methods:
- Utilized a steady-state heat balance approach within the Niche Mapper™ model.
- Simulated energetics and weight loss for adult, non-denning polar bears during 120- and 180-day fasts.
- Incorporated microclimate conditions and variation in animal properties.
Main Results:
- Model predictions for weight loss during a 120-day fast aligned with empirical data.
- Niche Mapper™ predicted survival for most bears during a 120-day fast under current conditions.
- A 180-day fast predicted up to 18% male mortality, with increased thermoregulation costs.
Conclusions:
- Niche Mapper™ is a valuable tool for assessing climate change impacts on polar bear energetics and survival.
- Environmental conditions and thermoregulation significantly influence survival during prolonged fasting.
- The generic nature of Niche Mapper™ allows for energetic predictions in other climate-threatened species.
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