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Beyond 2000:
Realities of Global Wolf Restoration

23-26 February 2000
Duluth, Minnesota USA

  Wolf recolonization of agricultural areas in Spain

Juan Carlos Blanco, Yolanda Cortés, Projecto Lobo, C/ Manuela Malasaña 24, 4º C-I, 28004 Madrid

Spain's wolves have been recovering since the seventies, and over the last twenty years have colonised flat, densely populated agricultural areas with hardly any wild ungulates, which used to be considered unsuitable for them. Over the last ten years, the building of many fenced motorways has increased concern about the future of the wolf in these areas.

Between 1997 and 1999, we radiocollared 11 wolves in farming areas in the central and western provinces of Valladolid and Zamora. These wolves live in packs, some comprising as many as ten. They usually breed in island patches of woodland of between 15-35 km2, about 30 km apart and surrounded by arable land; some packs, however, breed among extensive cereal fields with no tree cover whatsoever. Territories adjoin or overlap, making it possible to rule out the idea that the populations are fragmented. Wolves use overhead asphalted bridges built for traffic, the only available structures, to cross the fenced four-lane motorways. Three resident wolves crossed a motorway on 4.4%-8.7% of tracking days, while the figure for two floaters was 22.2%-23.6%.

Domestic animals (mainly sheep scavenged in carrion pits) made up the greater part of the wolves' diet (77% of biomass), while rabbits were the most common wild prey (11% of biomass). Damage to livestock is rare because the flocks of sheep are tended by shepherds throughout the day and kept indoors overnight. Despite being a game species, the annual mortality rate was only 13%, density (2.5-3 wolves/100 km2 in 1999) has risen considerably over the last ten years and the distribution area has increased. The study shows that, given a moderate level of persecution by people, wolves can thrive in very humanised farming areas that are almost devoid of wild prey.