title: Inbreeding depression in a critically endangered carnivore.
abstract: Harmful effects arising from matings between relatives (inbreeding) is a long-standing observation that is well founded in theory. Empirical evidence for inbreeding depression in natural populations is however rare because of the challenges of assembling pedigrees supplemented with fitness traits. We examined the occurrence of inbreeding and subsequent inbreeding depression using a unique data set containing a genetically verified pedigree with individual fitness traits for a critically endangered arctic fox (Vulpes lagopus) population. The study covered nine years and was comprised of 33 litters with a total of 205 individuals. We recorded that the present population was founded by only five individuals. Over the study period, the population exhibited a tenfold increase in average inbreeding coefficient with a final level corresponding to half-sib matings. Inbreeding mainly occurred between cousins, but we also observed two cases of full-sib matings. The pedigree data demonstrated clear evidence of inbreeding depression on traditional fitness traits where inbred individuals displayed reduced survival and reproduction. Fitness traits were however differently affected by the fluctuating resource abundande. Inbred individuals born at low-quality years displayed reduced first-year survival, while inbred individuals born at high-quality years were less likely to reproduce. The documentation of inbreeding depression in fundamental fitness traits suggests that inbreeding depression can limit population recovery. Introducing new genetic material to promote a genetic rescue effect may thus be necessary for population long-term persistence.
authors.affiliation: Department of Zoology, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Norén
authors.affiliation: Department of Zoology, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Erika
authors.initials: E
authors.lastname: Godoy
authors.affiliation: Department of Zoology, Stockholm University, SE-10691 Stockholm, Sweden.|Department of Bioinformatics and Genetics, Swedish Museum of Natural History, SE-10405 Stockholm, Sweden.
authors.forename: Love
authors.initials: L
authors.lastname: Dalén
authors.affiliation: Department of Zoology, Stockholm University, SE-10691 Stockholm, Sweden.|Department of Pathology and Wildlife Diseases, National Veterinary Institute, SE-751 89 Uppsala, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Meijer
authors.affiliation: Department of Zoology, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Angerbjörn
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources; D056727:Endangered Species; D005260:Female; D005589:Foxes / Q000235:genetics*; D056084:Genetic Fitness; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D006579:Heterozygote; D007178:Inbreeding; D000071422:Inbreeding Depression; D008297:Male; D010375:Pedigree; D012098:Reproduction; D013548:Sweden
keywords: conservation; extinction vortex; inbreeding coefficient; life history; microsatellites