Habitat degradation affects the summer activity of polar bears
Understanding behavioral responses of species to environmental change is critical to forecasting population-level effects. Although climate change is significantly impacting species’ distributions, few studies have examined associated changes in behavior. Polar bear (Ursus maritimus) subpopulations have varied in their near-term responses to sea ice decline. We examined behavioral responses of two adjacent subpopulations to changes in habitat availability during the annual sea ice minimum using activity data. Location and activity sensor data collected from 1989 to 2014 for 202 adult female polar bears in the Southern Beaufort Sea (SB) and Chukchi Sea (CS) subpopulations were used to compare activity in three habitat types varying in prey availability: (1) land; (2) ice over shallow, biologically productive waters; and (3) ice over deeper, less productive waters. Bears varied activity across and within habitats with the highest activity at 50–75% sea ice concentration over shallow waters. On land, SB bears exhibited variable but relatively high activity associated with the use of subsistence-harvested bowhead whale carcasses, whereas CS bears exhibited low activity consistent with minimal feeding. Both subpopulations had fewer observations in their preferred shallow-water sea ice habitats in recent years, corresponding with declines in availability of this substrate. The substantially higher use of marginal habitats by SB bears is an additional mechanism potentially explaining why this subpopulation has experienced negative effects of sea ice loss compared to the still-productive CS subpopulation. Variability in activity among, and within, habitats suggests that bears alter their behavior in response to habitat conditions, presumably in an attempt to balance prey availability with energy costs.
Citation Information
| Publication Year | 2017 |
|---|---|
| Title | Habitat degradation affects the summer activity of polar bears |
| DOI | 10.1007/s00442-017-3839-y |
| Authors | Jasmine V. Ware, Karyn D. Rode, Jeffrey F. Bromaghin, David C. Douglas, Ryan H. Wilson, Eric V. Regehr, Steven C. Amstrup, George M. Durner, Anthony M. Pagano, Jay Olson, Charles T. Robbins, Heiko T Jansen |
| Publication Type | Article |
| Publication Subtype | Journal Article |
| Series Title | Oecologia |
| Index ID | 70187710 |
| Record Source | USGS Publications Warehouse |
| USGS Organization | Alaska Science Center Biology MFEB |
Related Content
Summer Activity Sensor Data from Collars Deployed on Female Polar Bears in the Chukchi Sea 1989 to 1995 and Southern Beaufort Sea 1989 to 2014
Related Content
- Data
Summer Activity Sensor Data from Collars Deployed on Female Polar Bears in the Chukchi Sea 1989 to 1995 and Southern Beaufort Sea 1989 to 2014
These are data collected from two types of activity sensors housed within collars deployed on female polar bears in the Chukchi and southern Beaufort Seas during the months of July through October between 1989 and 2014. Mercury tip-switches were deployed 1989 to 2009 and accelerometers were deployed 2009-2014. Activity sensor readings were related to habitats used by polar bears as described in th - Connect