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Research article - Peer-reviewed, 2003

Rescue of a severely bottlenecked wolf (Canis lupus) population by a single immigrant

Vilà, Carles; Sundqvist, Anna-Karin; Flagstad, Øystein; Seddon, Jennifer; Björnerfeldt, Susanne; Kojola, Ilpo; Casulli, Adriano; Sand, Håkan; Wabakken, Petter; Ellegren, Hans


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.


wolf; genetic rescue; bottleneck; founding effect; migration; Scandinavia

Published in

Proceedings of the Royal Society B: Biological Sciences
2003, volume: 270, number: 1510, pages: 91-97
Publisher: ROYAL SOC

Authors' information

Vilà, Carles
Uppsala University
Sundqvist, Anna-Karin
Uppsala University
Flagstad, Øystein
Uppsala University
Seddon, Jennifer
Uppsala University
Björnerfeldt, Susanne
Uppsala University
Kojola, Ilpo
Finnish Game and Fisheries Research Institute
Casulli, Adriano
Istituto Superiore di Sanità
Swedish University of Agricultural Sciences, Department of Wildlife Ecology
Wabakken, Petter
Hedmark University College
Ellegren, Hans
Uppsala University

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