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A tale of two markers: Population genetics of colorado rocky mountain bighorn sheep estimated from microsatellite and mitochondrial data
Author(s) -
Driscoll Catherine C.,
Driscoll James G.,
Hazekamp Corey,
Mitton Jeffry B.,
Wehausen John D.
Publication year - 2015
Publication title -
the journal of wildlife management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.94
H-Index - 111
eISSN - 1937-2817
pISSN - 0022-541X
DOI - 10.1002/jwmg.895
Subject(s) - biology , ovis canadensis , microsatellite , population , gene flow , genetic monitoring , population bottleneck , genetic variation , genetic structure , population genetics , herd , zoology , genetics , ecology , allele , demography , gene , sociology
ABSTRACT Five native herds of Rocky Mountain bighorn sheep ( Ovis canadensis ) occupy Rocky Mountain National Park and the immediate surrounding area. One of these herds, the Mummy herd, suffered a significant die‐off following a suspected pneumonia outbreak in the mid‐1990s with subsequent low population size and low yearling recruitment, as compared to the other 4 herds. To test the hypothesis that the Mummy herd's failure to thrive is due to decreased genetic variation as a result of a genetic bottleneck, we analyzed both microsatellite and mitochondrial data to estimate genetic differentiation, gene flow, and the extent of metapopulation substructure among all 5 herds. Our microsatellite analyses showed no evidence of a recent genetic bottleneck or inbreeding. Our comparisons of overall and pairwise population differentiation (F st ) and effective migration (Nm) from both microsatellite genotypes and mitochondrial haplotypes indicated that low population substructure was being maintained by moderate levels of gene flow among all 5 herds. Effective migration rates were both higher and more uniform among herds for microsatellite genotypes than for mitochondrial haplotypes, which exhibited an asymmetrical pattern among herds. A significant isolation‐by‐distance relationship for mitochondrial (but not microsatellite) data suggests that gene flow is primarily due to ram migration. Past translocations of sheep into, out of, and among these 5 herds are an important consideration when interpreting these results; however, our data clearly show that all 5 Rocky Mountain bighorn sheep herds have reasonable and equivalent levels of genetic variation. Thus, herd management and restoration efforts should be focused on other factors that might be detrimental to herd health, such as stress, nutritional deficiencies, habitat fragmentation, climactic factors, or disease. © 2015 The Wildlife Society.