Genetic analysis of individual origins supports isolation of grizzly bears in the Greater Yellowstone Ecosystem
Haroldson MA, Schwartz CC, Kendall KC, Gunther KA, Moody DS, Frey K, Paetkau D. 2010. Genetic analysis of individual origins supports isolation of grizzly bears in the Greater Yellowstone Ecosystem. Ursus. 21(1):1-13
The Greater Yellowstone Ecosystem (GYE) supports the southernmost of the 2 largest remaining grizzly bear (Ursus arctos) populations in the contiguous United States. Sincethe mid-1980s, this population has increased in numbers and expanded in range. However,concerns for its long-term genetic health remain because of its presumed continued isolation. Totest the power of genetic methods for detecting immigrants, we generated 16-locus microsatellitegenotypes for 424 individual grizzly bears sampled in the GYE during 1983–2007. Genotypingsuccess was high (90%) and varied by sample type, with poorest success (40%) for hair collectedfrom mortalities found .1 day after death. Years of storage did not affect genotyping success.Observed heterozygosity was 0.60, with a mean of 5.2 alleles/marker. We used factorialcorrespondence analysis (Program GENETIX) and Bayesian clustering (Program STRUCTURE)to compare 424 GYE genotypes with 601 existing genotypes from grizzly bears sampledin the Northern Continental Divide Ecosystem (NCDE) (FST 5 0.096 between GYE andNCDE). These methods correctly classified all sampled individuals to their population of origin,providing no evidence of natural movement between the GYE and NCDE. Analysis of 500simulated first-generation crosses suggested that over 95% of such bears would also bedetectable using our 16-locus data set. Our approach provides a practical method for detectingimmigration in the GYE grizzly population. We discuss estimates for the proportion of the GYE population sampled and prospects for natural immigration into the GYE.
- Type
- Journal Article
- Authors
- Haroldson, Mark; Schwartz, Charles; Kendall, Katherine; Gunther, Kerry; Moody, David; Frey, Kevin; Paetkau, David
- Units
- GLAC , GRYN
- Keywords
- Bayesian clustering, DNA, factorial correspondence, Grizzly Bear, immigration, Northern Continental Divide, Ursus arctos, Yellowstone