The large-scale environment and the rabbit's genetic diversity as factors to bear in mind in Iberian lynx Conservation

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Arnold Clarke
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PDF The large-scale environment and the rabbit's genetic diversity as factors to bear in mind in Iberian lynx Conservation A small-scale study using computer models stresses the need to, when it

1 PDF The large-scale environment and the rabbit's genetic diversity as factors to bear in mind in Iberian lynx Conservation A small-scale study using computer models stresses the need to, when it comes do planning rabbit reintroductions, consider the genetic structure of the populations given their diffences in terms of vulnerability to viral epizootics. A. Márcia Barbosa, Cátedra Rui Nabeiro Biodiversidade, CIBIO, Universidade de Évora 1 / 6

2 At the local level, the presence of the Iberian lynx is mainly determined by the availability of adequate habitat and of its fundamental prey, the rabbit. However, the distribution of the species is also affected by factors that act at a level that is only detected in large-scale studies. The lynx, in particular, can only survive in the Iberian Peninsula as a meta-population, that is, with various populations linked with each other by zones that, although not favorable to the establishment of reproductive nuclei, at least permit the movement (dispersal) of individuals among them. Understanding the possible form and structure of that meta-population is important for adequate planning of conservation of the lynx and can only be achieved by analysing the Iberian Peninsula as a whole. Naturally, the distribution of rabbits must also be analysed and related with that of the lynx at the same scale. With this premise, a study was done at the Iberian scale (with Portuguese and Spanish cooperation) of the effects of myxomatosis and viral hemorrhagic disease on Iberian populations of wild rabbits. This investigation revealed two preoccupying facts. At this scale, the distributions of lynx and rabbit were diverging, with the lynx relegated to the southwest quadrant of the peninsula and rabbits doing better in the northeastern region. The spatial genetic structure of the rabbit populations seemed to be involved (with two well-differenciated varieties in the Iberian Peninsula, one in the northeast half and the other in the southwest half). The rabbits of the southwest variety available for the lynx in its actual area of distribution were resisting worse to diseases than those of the northeastern half of the peninsula, where there are no longer lynx. This indicates the importance of a factor that is not being taken into account in the plans for conservation of the lynx: the genetic diversity of its prey. If it is already risky for a threatened predator to depend so strongly on just one species of prey, it is even more dangerous to be limited to just one genetic variety of the species. The varieties may resist differently to threats like diseases or environmental disturbance; as such, it is important that the lynx be able to count on (as in the past) all the available genetic diversity of wild rabbits. Plans for reintroduction of the lynx should therefore contemplate regions with 2 / 6

healthy natural populations of wild rabbits of both genetic varieties that is, the lynx should also be reintroduced in the northeast half of the peninsula, so long as it be in zones connected with

3 healthy natural populations of wild rabbits of both genetic varieties that is, the lynx should also be reintroduced in the northeast half of the peninsula, so long as it be in zones connected with the lynx populations to the southwest. The introduction of rabbits from the northeast into the southwest region is not a good idea because it would alter the natural genetic structure of their populations (while the lynx does not have a marked genetic structure). Besides that, the two varieties do not mix well and this could even lead to a reduction of the rabbits reproduction rate. A more recent study, also done at the level of the Iberian peninsula, indicates the existence of environmental zones that are simultaneously favourable for lynx and rabbits, both in Spain and in Portugal, on both sides of the theoretical line that separates the distribution of the two lineages of rabbits. Although based on relatively rough data of distribution, the model shows various important aspects. For example, it foresees that the environmental favourability for the lynx is, in general, much lower in Doñana than in Serra Morena, which goes along with what is observed in the field: the population of Serra Morena is clearly more healthy. It also projects that the natural connection between the populations of Doñana and Serra Morena passes through the province of Huelva and the Portuguese border. The lynx called Caribú, that tried more than once to disperse from Doñana, followed precisely this route and was captured in the border zone between Spain and the Portuguese region of Moura-Barrancos. 3 / 6

4 According to the previsions from these models of distribution, the areas in Portugal that are simultaneously favourable for lynx and rabbits are, above all, in the centre and south of the country, including the zone of Moura-Barrancos and the mountains of Malcata (south), São Mamede, Monchique and Caldeirão. In Spain, besides the areas that are already being considered in plans for reintroducing the lynx, others that are highly favourable are the northeast point of Andalucía and the adjacent regions of the provinces of Albacete and Múrcia, where the rabbits are already predominantly of the northeastern variety and where there is a link with the lynx populations of Serra Morena. These zones should thus be taken into consideration in the plans of reintroduction of the Iberian lynx that are being reproduced in captivity. Bibliography 4 / 6

5 Barbosa A.M. & Real R. (2010) Favourable areas for expansion and reintroduction of Iberian lynx accounting for distribution trends and genetic diversity of the European rabbit. Wildlife Biology in Practice, online early: Branco, M., Ferrand, N., & Monnerot, M. (2000) Phylogeography of the European rabbit (Oryc tolagus cuniculus ) in the Iberian Peninsula inferred from RFLP analysis of the cytochrome b gene. Heredity, 85: Delibes-Mateos, M., Ramírez, E., Ferreras, P., & Villafuerte, R. (2008) Translocations as a risk for the conservation of European wild rabbit Oryctolagus cuniculus lineages. Oryx, 42: Palomares, F., Delibes, M., Revilla, E., Calzada, J. & Fedriani, J.M. (2001) Spatial ecology of Iberian lynx and abundance of European rabbits in southwestern Spain. Wildlife Monographs, 148: / 6

6 Palomo, L.J. & Gisbert, J., eds. (2002) Atlas de los mamíferos terrestres de España. Dirección General de Conservación de la Naturaleza-SECEM-SECEMU, Madrid. Real, R., Barbosa A.M., Rodríguez A., García F.J., Vargas J.M., Palomo L.J. & Delibes M. ( 2009) Conservation biogeography of ecologically-interacting species: the case of the Iberian lynx and the European rabbit. Diversity and Distributions 15: / 6

Info Lynx ~ NEWS ISSUE 0 JULY 2012

Info Lynx ~ NEWS ISSUE 0 JULY 2012 ISSUE 0 JULY 2012 Info Lynx ~ Welcome! WWF launches Info Lynx, a quarterly newsletter, published both in Spanish and English, that will cast the spotlight on one of the world's most fascinating and endangered