Skip to Main Content
Spatially explicit carrying capacity estimates to inform species specific recovery objectives: Grizzly bear (Ursus arctos) recovery in the North CascadesAuthor(s): Andrea L. Lyons; William L. Gaines; Peter H. Singleton; Wayne F. Kasworm; Michael F. Proctor; James Begley
Source: Biological Conservation. 222: 21-32.
Publication Series: Scientific Journal (JRNL)
Station: Pacific Northwest Research Station
Download Publication (3.0 MB)
DescriptionThe worldwide decline of large carnivores is concerning, particularly given the important roles they play in shaping ecosystems and conserving biodiversity. Estimating the capacity of an ecosystem to support a large carnivore population is essential for establishing reasonable and quantifiable recovery goals, determining how population recovery may rely on connectivity, and determining the feasibility of investing limited public resources toward recovery. We present a case study that synthesized advances in habitat selection and spatiallyexplicit individual-based population modeling, while integrating habitat data, human activities, demographic parameters and complex life histories to estimate grizzly bear carrying capacity in the North Cascades Ecosystem in Washington. Because access management plays such a critical role in wildlife conservation, we also quantified road influence on carrying capacity. Carrying capacity estimatesranged from 83 to 402 female grizzly bears. As expected, larger home ranges resulted in smaller populations and roads decreased habitat effectiveness by over 30%. Because carrying capacity was estimated with a static habitat map, the output is best interpreted as an index of habitat carrying capacity under current conditions. The mid-range scenario results of 139 females, or a total population of 278 bears, represented the most plausible scenario for this ecosystem. Grizzly bear distribution generally corresponded to areas with higher quality habitat and less road influence near the central region of the ecosystem. Our results reaffirm the North Cascades Ecosystem's capacity to support a robust grizzly bear population. Our approach, however, can assist managers anywhere ecosystem-specific information is limited. This approach may be useful to land and wildlife managers as they consider grizzly bear population recovery objectives and make important decisions relative to the conservation of wildlife populations worldwide.
- Visit PNW's Publication Request Page to request a hard copy of this publication.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationLyons, Andrea L.; Gaines, William L.; Singleton, Peter H.; Kasworm, Wayne F.; Proctor, Michael F.; Begley, James. 2018. Spatially explicit carrying capacity estimates to inform species specific recovery objectives: Grizzly bear (Ursus arctos) recovery in the North Cascades. Biological Conservation. 222: 21-32. https://doi.org/10.1016/j.biocon.2018.03.027.
KeywordsCarrying capacity, individual-based population modeling, habitat selection, carnivore, grizzly bear.
- Scale dependence in habitat selection: The case of the endangered brown bear (Ursus arctos) in the Cantabrian Range (NW Spain)
- Connecting endangered brown bear subpopulations in the Cantabrian Range (north-western Spain)
- Using bear rub tree data and spatial capture-recapture models to estimate trend in a brown bear population
XML: View XML