Evidence for recent population bottlenecks in northern spotted owls (Strix occidentalis caurina)

• Published in: Conservation genetics Vol. 11; no. 3; pp. 1013 - 1021
• Main Authors: Funk, W. Chris, Forsman, Eric D, Johnson, Matthew, Mullins, Thomas D, Haig, Susan M
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.06.2010; Springer Netherlands; Springer Nature B.V
• Subjects: Animal Genetics and Genomics; Animal populations; Biodiversity; Biomedical and Life Sciences; Bottleneck; Conservation biology; Conservation Biology/Ecology; Conservation genetics; Ecology; Effective population size; Endangered & extinct species; Endangered species; Evolutionary Biology; Genetic diversity; Inbreeding; Life Sciences; microsatellite repeats; Mountains; Owls; Plant Genetics and Genomics; Population genetics; Population number; Protected species; Research Paper; Species extinction; Strix occidentalis caurina; US Endangered Species Act; US Pacific Northwest; Bottleneck; US Pacific Northwest; Microsatellites; Effective population size; US Endangered Species Act; Conservation genetics
• ISSN: 1566-0621; 1572-9737
• DOI: 10.1007/s10592-009-9946-5

The northern spotted owl (Strix occidentalis caurina) is one of the most controversial threatened subspecies ever listed under the US Endangered Species Act. Despite protection of its remaining forest habitat, recent field studies show continued declines of northern spotted owls. One potential threat to northern spotted owls which has not yet been shown is loss of genetic variation from population bottlenecks. Bottlenecks can increase the probability of mating among related individuals, potentially causing inbreeding depression, and can decrease adaptive potential. Here we report evidence for recent bottlenecks in northern spotted owls using a large genetic dataset (352 individuals and 10 microsatellite loci). The signature of bottlenecks was strongest in the Washington Cascade Mountains, in agreement with field data. Our results provide independent evidence that northern spotted owls have recently declined, and suggest that loss of genetic variation is an emerging threat to the subspecies' persistence. Reduced effective population size (N e) shown here in addition to field evidence for demographic decline highlights the increasing vulnerability of this bird to extinction.