Implications of free-grazing cattle on wolf (Canis lupus) conservation in Portugal

Francisco Álvares, Francisco Petrucci-Fonseca, Grupo Lobo/Centro de Biologia Ambiental, FCUL, 1700 Lisboa, Portugal

Coexistence of wolves and wild or free-grazing cows (Bos taurus) and horses (Equus caballus) is rare through the wolf range, although it occurs in almost all North Iberian Peninsula. This study presents data collected to assess the ecological relation between wolves and free-grazing cattle in Peneda-Gerês National Park (Northwest Portugal), to evaluate the causes and consequences of the high conflict between wolves and shepherds and to propose guidelines to minimize the wolf's predatory impact.

Twelve packs inhabit the study area, with a mean density of 3.7 wolves/100 km2, in autumn. However, in some mountains, with high numbers of free-grazing cattle, wolf density can reach 6.0 wolves/100 km2, one of the highest wolf densities in Iberian Peninsula, and even in Europe. The wolf diet is based on livestock, with almost 50% frequency of cows and horses. Wolves exhibit a strong selection for horses (Chesson Index, 0.87), but not for cows (Chesson Index, 0.10), showing a preference for cows and horses less than one year old (90% and 70%, respectively). An ancient predator-prey relantionship between free-grazing cattle and wolves is stressed by distinct predatory behaviour towards horses and cows, as well as by the anti-predatory cattle behaviours.

In Portugal, all livestock damages caused by wolves are compensated, and the study area is the region where more livestock damages occur and more indemnities are paid to cattle breeders. These damages maintain the old man and wolf conflict. One of the main threats to the wolf´s survival in this area is the illegal persecution by man (mainly through shooting), motivated by these economic and social issues. However, in areas where free-grazing livestock is reared, poison is used to control wolf numbers, leading to the extermination of a high number of wolves, in a short period of time.

In order to minimize wolf predatory impact in free-grazing livestock, several measures must be implemented, such as the proposal of a fairer compensation programme and the use of autocthonous breeds and the maintenance of the traditional ways of grazing and herding. Ecological studies on the relation between wolves and free-grazing livestock and on wild prey must be carried on.