Variation in inbreeding rates across the range of Northern Spotted Owls (Strix occidentalis caurina): Insights from over 30 years of monitoring data

Auk

Tracy L. Fleming^6¹  Robert G. Anthony^3²  Scott Gremel^7³  Katie M. Dugger^3⁴  Damon B. Lesmeister^2,8⁵  Susan M. Haig^1⁶  Lowell Diller^4⁷  Alan B. Franklin^5⁸  Mark P. Miller^1⁹  Eric D. Forsman^2^1,10 

[1] Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, USA^8;Green Diamond Resource Company, Korbel, California, USA^4;Hoopa Valley Tribal Forestry, Hoopa, California, USA^9;National Council for Air and Stream Improvement, Battle Ground, Washington, USA^6;Raedeke Associates, Seattle, Washington, USA^10;U.S. Department of Agriculture Forest Service, Pacific Northwest Research Station, Corvallis, Oregon, USA^2;U.S. Department of Agriculture, APHIS National Wildlife Research Center, Fort Collins, Colorado, USA^5;U.S. Department of Interior National Park Service, Olympic National Park, Port Angeles, Washington, USA^7;U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, Oregon, USA^1;U.S. Geological Survey, Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, USA^3

关键词: estimation;    inbreeding;    incomplete pedigree;    missing data;    Northern Spotted Owl;    pedigree;   

DOI  :  10.1642/AUK-18-1.1

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

Inbreeding has been difficult to quantify in wild populations because of incomplete parentage information. We applied and extended a recently developed framework for addressing this problem to infer inbreeding rates in Northern Spotted Owls ( Strix occidentalis caurina ) across the Pacific Northwest, USA. Using pedigrees from 14,187 Northern Spotted Owls, we inferred inbreeding rates for 14 types of matings among relatives that produce pedigree inbreeding coefficients of F = 0.25 or F = 0.125. Inbreeding was most common in the Washington Cascades, where an estimated 15% of individuals are inbred. Inbreeding was lowest in western Oregon (3.5%) and northern California (2.7%), and intermediate for the Olympic Peninsula of Washington (6.1%). Estimates from the Olympic Peninsula were likely underestimates because of small sample sizes and the presence of few pedigrees capable of resolving inbreeding events. Most inbreeding resulted from matings between full siblings or half siblings, although a high rate of inbreeding from mother–son pairs was identified in the Olympic Peninsula. Geographic variation in inbreeding rates may reflect population declines and bottlenecks that have been detected in prior investigations. We show that there is strong selection against inbred birds. Only 3 of 44 inbred birds were later identified as parents (6.8%), whereas 2,823 of 10,380 birds that represented a comparable cross section of the data were later seen as reproducing parents (27.2%). Habitat loss and competition with Barred Owls ( S. varia ) remain primary threats to Northern Spotted Owls. However, given the negative consequences of inbreeding, Spotted Owl populations in Washington with suitable habitat and manageable numbers of Barred Owls may benefit from translocations of individuals from Oregon and California to introduce new genetic variation and reduce future inbreeding events.

【 授权许可】

CC BY