title: Rescue of a severely bottlenecked wolf (Canis lupus) population by a single immigrant.
abstract: The fragmentation of populations is an increasingly important problem in the conservation of endangered species. Under these conditions, rare migration events may have important effects for the rescue of small and inbred populations. However, the relevance of such migration events to genetically depauperate natural populations is not supported by empirical data. We show here that the genetic diversity of the severely bottlenecked and geographically isolated Scandinavian population of grey wolves (Canis lupus), founded by only two individuals, was recovered by the arrival of a single immigrant. Before the arrival of this immigrant, for several generations the population comprised only a single breeding pack, necessarily involving matings between close relatives and resulting in a subsequent decline in individual heterozygosity. With the arrival of just a single immigrant, there is evidence of increased heterozygosity, significant outbreeding (inbreeding avoidance), a rapid spread of new alleles and exponential population growth. Our results imply that even rare interpopulation migration can lead to the rescue and recovery of isolated and endangered natural populations.
authors.affiliation: Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden.
authors.forename: Carles
authors.initials: C
authors.lastname: Vilà
authors.forename: Anna-Karin
authors.initials: AK
authors.lastname: Sundqvist
authors.forename: Øystein
authors.initials: Ø
authors.lastname: Flagstad
authors.forename: Jennifer
authors.initials: J
authors.lastname: Seddon
authors.forename: Susanne
authors.initials: S
authors.lastname: Björnerfeldt
authors.forename: Ilpo
authors.initials: I
authors.lastname: Kojola
authors.forename: Adriano
authors.initials: A
authors.lastname: Casulli
authors.forename: Håkan
authors.initials: H
authors.lastname: Sand
authors.forename: Petter
authors.initials: P
authors.lastname: Wabakken
authors.forename: Hans
authors.initials: H
authors.lastname: Ellegren
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources; D004641:Emigration and Immigration; D005260:Female; D014644:Genetic Variation; D006579:Heterozygote; D007178:Inbreeding; D008297:Male; D011158:Population Growth; D012537:Scandinavian and Nordic Countries; D019596:Wolves / Q000235:genetics* / Q000502:physiology*