Landscape structure and asymmetrical inter-patch connectivity in a metapopulation of the endangered Iberian lynx

Among the factors threatening the Iberian lynx, (Lynx pardinus) (the most endangered species of all the Felidae), loss and fragmentation of its habitats are probably the most important. Connectivity between the remaining populations in the predominantly fragmented landscapes is a key factor in the dynamics and persistence of metapopulations. Based on the data collected during a long-term study on the ecology of this species in a small and fragmented population in SW Spain, I analyse the factors affecting connectivity between the two main sources and the rest of local populations. Connectivity was estimated as the proportion of dispersers from a source that reached a given subpopulation. Among the explanatory variables considered, only distance (both straight and effective distance, which takes into account habitat quality between local populations) and location of the source were clearly related to connectivity. Some other variables describing landscape features separating sources and target subpopulations (proportion of unsuitable habitats, patch cohesion, size of targets, overall size of subpopulations closer than the target) were not related to connectivity. Differences in the landscape surrounding sources help to explain the different connectivity from the two sources. An asymmetrical connectivity between the two sources and populations surrounding them (north and south) is likely explained by the configuration of habitats encountered by dispersers, which force those from one source to behave as crossers of unsuitable habitats. These results have consequences for the conservation of Iberian lynx populations and for ecologically similar species. Distance, the factor most affecting connectivity, is difficult to manage, although at least size and configuration of usable patches can be modified. Connectivity could also be improved through recovery of habitats with cover, suitable for dispersing. Reduction of mortality risks would also enhance connectivity indirectly, by allowing longer times and larger areas covered during dispersal. In the case of the study population, it is urgent to promote connectivity with other Iberian lynx populations due to genetic consequences of small population size and effective isolation. (C) 2001 Elsevier Science Ltd. All rights reserved.