The Iberian wolf (Canis lupus signatus) is a subspecies of the grey wolf, and is endemic to the Iberian Peninsula in southwest Europe. This subspecies is slightly smaller than northern wolves, and has distinctive markings and differences in skull shape. Additionally, mitochondrial DNA analyses show great differentiation between Iberian wolves and wolves found elsewhere in Eurasia. In contrast to wolf populations in the rest of Europe, the distribution of the Iberian wolf has declined dramatically during the 20th century. The most recent estimates suggest that there are no more than 2000 Iberian wolves, most of which form a large and continuous population in the northwest region of the peninsula; and two isolated populations, one facing extinction in Andalusia, southern Spain, and the other occurring south of the Douro River in central Portugal.
In Portugal, the Iberian wolf has been protected by law in Portugal since 1988, especially during breeding season, and the species is recognized as endangered by the Portuguese Red Data Book. The government also provides compensation for livestock owners when wolves kill their livestock.
The Iberian wolf used to be widely distributed in Portugal, but populations began to steadily decline around 1930. The first national Iberlian wolf census took place between 1994 and 1996, and suggested approximately 300 wolves, representing 55 to 60 packs, in Portugal. The second national census (from 2002 to 2003) showed both the conservation status and distribution had not undergone significant changes since the first census. Both censuses indicated two isolated subpopulations, and subsequent genetic studies revealed genetically-distinct subpopulations.
The subpopulation north of the Douro River shows connectivity with the wolf population in northern Spain, and is composed of three nuclei, or source populations (Peneda/Gerês, Alvão/Padrela, and Bragança) which are important sources of dispersing indivuals to more unstable packs. The small subpopulation south of the Douro River consists of two very unstable nuclei (the Arada/Trancoso population and the Sabugal/Figueira de Castelo Rodrigo population). These two nuclei are isolated from the rest of the Iberian wolf populations, and this has resulted in reproductive instability and a lack of gene flow to and from other populations, creating a risk of extinction. This isolation is due to the high amount of human activity associated with the major river valleys (Douro and Tâmega) separating these wolf populations, the high levels of human activity and high density of infrastructure deterring wolf colonization.
Populations of the Iberian wolf are particularly threatened by multiple factors. For one, the scarcity of wild prey, and the consequential livestock predation that results in retaliatory illegal hunting of wolves. Also, genetic isolation, as well as loss-, degradation-, and fragmentation of habitat, critically threaten this subspecies. An addtional threat to the Iberian wolf in Portugal is the presence of high numbers of feral dogs. These dogs are often the cause of losses in livestock, which farmers wrongly attribute to wolves, resulting in increasing hostility towards wolves. Feral and stray dogs threaten the Iberian wolf, due to the potential for hybridization, as well as because free-ranging dogs represent potential reservoirs of infectious diseases for wolves. Indeed, canine distemper virus, most likely transmitted from free-ranging dogs rather than other wildlife species, was recently found in two Iberian wolves in Portugal.
Much of the wolf mortality in Portugal is caused by humans (e.g. traffic, shooting, poisoning, trapping). The high level of livestock predation reflects low densities and diversity of wild prey available in Portugal, but also poor livestock farming practices. Livestock are often unguarded or have only one shepherd, and livestock generally wander in unfenced areas. This, and the fact that these domestic animals are easy to kill, lacking most tactics to evade predation, make these domestic animals vulnerable to wolf predation. Additionally, wolves prey on livestock at night, reducing the risk of encountering humans. With the aim of reducing livestock predation and the resulting conflicts, in 1997, the Portuguese non-government organization "Wolf Group" delivered and monitored over 80 pups of Portuguese livestock-guarding dogbreeds to shepherds in north and central Portugal. So far, the results of this program are very optimistic.
Unfortunately, poisoning wolves is still a common practice among horse breeders and livestock owners in the northwest Iberian Peninsula. In the Bragança nucleus, where wolf's diet is primarily based on wild ungulates, no wolves have been found dead due to poison. However, in the Peneda/Gerês and the Alvão/Padrela nuclei, where wolves prey on domestic ungulates, poison has been the main cause of mortality.
Efforts to protect the Iberian wolf must take into account that wolves in these areas depend on the restoration of wild prey populations, and that wolf conservation is not merely a passive protection endeavor. Re-introducing wild prey is especially crucial south of the Douro River. In 2011, a project to re-introduce roe deer south of the Douro River began. Additionally, part of Iberian wolf conservation should involve higher investment in livestock-guarding dogs.
LINK to Torres and Fonseca's 2016 article in Biodiversity and Conservation.
