Unveiling wolf dietary specialization on free ranging horses using forensic genetics and field monitoring.

Objective Overview

• This study investigated how wolves in northwest Portugal specialize in preying on free-ranging horses by combining field monitoring with forensic genetic techniques.
• The research revealed significant wolf predation impact on horse populations, providing insights to aid conservation and conflict management.

Introduction and Background

• Wolves sometimes specialize in hunting free-roaming horses when these horses are abundant and other prey is limited.
• This specialization can reduce horse population productivity, cause conflicts with horse owners, and affect conservation efforts for both species.
• Despite its importance, the ecological and demographic effects of wolves preying on free-ranging horses had not been thoroughly studied before.

Research Goals and Location

• The study aimed to explore wolf-horse interactions in northwest Portugal.
• The research combined multiple methods: field monitoring of wolves, diet analysis of wolf scats, spatial analysis of where wolves and horses are active, and genetic analysis to identify individual horses affected by predation.

Methods

• Wolf Monitoring: GPS tracking of wolves to identify feeding sites.
• Diet Analysis: Examining wolf scat samples to determine prey types consumed.
• Spatial Overlap: Analyzing wolf and horse movement and activity areas to assess interaction zones.
• Genetic Analysis: Using forensic genetics on samples from wolf scats, horse remains at feeding sites, and horse fecal samples to reconstruct horse pedigrees and identify specific individuals killed or scavenged.

Key Findings

• Horses made up a large proportion of wolf-consumed biomass: 85% in 2017 and 93% in 2018, indicating strong preference or specialization.
• Wolf GPS data located 19 feeding sites, all containing horse remains. About 26% of these sites were within wolves’ core areas.
• Eight predation events were officially confirmed, impacting horses of different age groups:
  • Foals (12%)
  • Juveniles older than one year (38%)
  • Adults (50%)
• Genetic identification revealed 39 distinct horses found in feeding sites and scat samples.
• Of these, 17 horses were assigned to 10 different families, out of 14 horse families identified through molecular data.
• This shows predation affected a broad range of individuals within the population, including both young and adult horses.

Implications and Conclusion

• The research provides rare, empirical evidence demonstrating wolf predation effects on free-ranging horses.
• Strong dietary specialization by wolves on horses suggests significant ecological pressure on wild horse populations in this region.
• Utilizing an integrated approach combining genetics, field tracking, and demographic analysis allows better understanding of predator-prey dynamics.
• These findings support the development of informed conservation strategies and conflict mitigation between humans (horse owners) and wolves.
• The study underscores the importance of multidisciplinary methods to understand complex wildlife interactions in natural habitats.