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 e ndangered species of all the Felidae), loss and fragmentation of its habita ts are probably the most important. Connectivity between the remaining popu lations in the predominantly fragmented landscapes is a key factor in the d ynamics and persistence of metapopulations. Based on the data collected dur ing a long-term study on the ecology of this species in a small and fragmen ted population in SW Spain, I analyse the factors affecting connectivity be tween 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 dista nce (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 feature s separating sources and target subpopulations (proportion of unsuitable ha bitats, patch cohesion, size of targets, overall size of subpopulations clo ser than the target) were not related to connectivity. Differences in the l andscape surrounding sources help to explain the different connectivity fro m 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 hav e consequences for the conservation of Iberian lynx populations and for eco logically similar species. Distance, the factor most affecting connectivity , is difficult to manage, although at least size and configuration of usabl e patches can be modified. Connectivity could also be improved through reco very of habitats with cover, suitable for dispersing. Reduction of mortalit y risks would also enhance connectivity indirectly, by allowing longer time s and larger areas covered during dispersal. In the case of the study popul ation, it is urgent to promote connectivity with other Iberian lynx populat ions due to genetic consequences of small population size and effective iso lation. (C) 2001 Elsevier Science Ltd. All rights reserved.