Wolves Recolonizing Islands: Genetic Consequences and Implications for Conservation and Management

Area of Science:

• Ecology and Evolutionary Biology
• Conservation Genetics
• Wildlife Management

Background:

• Grey wolves (Canis lupus) are expanding their range across Europe following historical persecution.
• Understanding the genetic structure of recolonizing populations is crucial for effective conservation.
• Estonia's islands, Saaremaa and Hiiumaa, are recent targets of wolf recolonization, presenting unique ecological challenges.

Purpose of the Study:

• To analyze the population structure and genetic processes of wolves in Estonia.
• To specifically investigate the island recolonization dynamics of wolves.
• To identify and manage potential wolf-dog hybridization impacting genetic integrity.

Main Methods:

• Genotyping of 185 wolf individuals across Estonia using 15 microsatellite loci.
• Identification and removal of 17 putative wolf-dog hybrids to ensure accurate population analysis.
• Application of STRUCTURE and spatially explicit DResD analyses to determine genetic groups and spatial genetic structure.

Main Results:

• Four distinct genetic groups were identified within the Estonian wolf population.
• Two areas of genetic similarity were detected, one on Saaremaa island and another in southwestern Estonia.
• Three blending areas and two transition zones with significant local differentiation were found in central Estonia.
• Hybrid removal was confirmed as a valuable methodological step for population studies.

Conclusions:

• Island wolf populations in Estonia are genetically distinct and require specific conservation strategies.
• Human-wildlife conflict, particularly livestock depredation and negative public perception on Saaremaa, threatens island wolf viability.
• Effective management, including careful hunting quotas, inbreeding avoidance, and community engagement, is essential for long-term wolf population persistence on Estonian islands.