Genetic rescue in a severely inbred wolf population

Area of Science:

• Conservation genetics
• Population viability
• Wildlife biology

Background:

• Habitat fragmentation leads to inbreeding depression and reduced genetic diversity in natural populations.
• Small, inbred populations are vulnerable to extinction due to decreased vital rates and increased sensitivity to stochastic events.
• The long-term success of immigrants and inbred individuals in natural settings is rarely quantified.

Purpose of the Study:

• To quantify and compare the reproductive success of first-generation offspring from immigrants versus native, inbred individuals in the Scandinavian wolf population.
• To investigate the impact of inbreeding depression on vital rates and breeding success in a large carnivore population.
• To document a case of genetic rescue in a severely inbred, isolated population.

Main Methods:

• Studied the isolated, inbred Scandinavian wolf (Canis lupus) population following a natural immigration event.
• Compared pairing and breeding success rates between offspring of immigrants and offspring of native, inbred pairs.
• Analyzed reproductive success data to infer the effects of inbreeding and immigration.

Main Results:

• Offspring from immigrant wolves exhibited significantly higher pairing and breeding success than offspring from native, inbred pairs.
• Inbreeding depression is identified as the likely mechanism driving the disparities in breeding success.
• Highly inbred wolves may face reduced survival during dispersal and a competitive disadvantage in mate finding.

Conclusions:

• Single immigrants can have a profound, positive impact on the viability of small, inbred populations.
• This study provides one of the first quantifications of reproductive success for immigrant offspring versus inbred individuals in a natural population.
• The findings document a rare case of successful genetic rescue in a large carnivore species.