Wolf predation on cattle in Portugal: Assessing the effects of husbandry systems

- Wolf attacks on cattle greatly increased in Portugal in 1999-2013.
- There were far more wolf attacks on free-ranging than on semi-confined herds.
- Protecting free-ranging herds at night in winter would greatly decrease wolf predation risk.
- Keeping calves < 3 months old indoor would decrease wolf predation in semi-confined herds.
- Under adequate management both free-ranging and semi-confined herds may be compatible with wolf presence.

Mitigating conflicts associated with predation on livestock is essential for conserving large carnivores in human dominated landscapes. This is generally addressed by targeting at individual management practices affecting predation risk, often disregarding that different livestock husbandry systems (i.e., groups of farms sharing similar resource bases, production patterns and management practices) with different vulnerabilities to predation may coexist within predator ranges, each of which requiring tailored prescriptions to reduce predation. Here we evaluated the importance of considering both husbandry systems and individual management practices to mitigate conflicts due to cattle predation by wolves in Portugal, where attacks on cattle increased > 3 times in 1999-2013. Government records from 2012 to 2013 indicated that only < 2% of cattle farms suffered wolf attacks, of which < 4% had > 10 attacks per year. We found that attacks were concentrated in the free-ranging husbandry system, which was characterized by multi-owner herds, largely grazing communal land far from shelter, and seldom confined. Protecting these herds at night in winter was the most important factor reducing wolf attacks, which could be achieved by changing practices of ≈ 25% of farmers in this system. Attacks were much lower in the semi-confined system, probably because herds grazed pastures closer to shelter, and they were often confined with fences or in barns. Farms bringing calves < 3 months old to pastures were associated with about 90% of attacks, but changing this practice would involve ≈ 50% of farmers in this system. Our results underline the importance of identifying livestock husbandry systems and to adjust mitigation strategies to each system.