Possible effect of climate change on demography of a long distance migratory species

GRANDE, J.M.

Algeciras, España

Conferencia; Bird Migration and Global Change Conference; 2007

Fundación Migres

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES; mso-fareast-language:ES;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Climate is probably one of the most important abiotic factors shaping species distribution. Therefore Climate Change is thought to be one of the main threats to biodiversity. It has been shown to affect species distribution and abundance, phenology, and some demographic traits such as breeding success. The impact of Climate Change over migratory species or populations is thought to be even stronger as individuals of those populations may be affected by climate changes in both, their breeding and wintering grounds. In this study we have analysed the relative importance of ecological constrains in both, the breeding and the wintering grounds over survival prospects in a long-distance migrant, the Egyptian vulture. Then we have model the effect of climate change in the wintering grounds over the population trend of the species. The Egyptian vulture is a migratory vulture that breeds in the Iberian Peninsula and winters at the south of the Sahara desert in the Sahel area of Mauritania and its borders with Mali and Senegal. The species has suffered a steep decline in the last decades mainly owed to illegal poison use in predator control and habitat alterations in its breeding grounds. However, until recently no attention has been paid to the possible limitations that the species may face in its wintering grounds. Our results suggest that survival in this species is strongly affected by weather conditions in the wintering grounds so that Egyptian vultures survive better in years in with higher precipitation in the Sahel and worst in dry years. According to a population viability analysis, the reductions in rainfall in the Shelia area proposed by some models of climate change would double the extinction probability of an Spanish Egyptian vulture population. Our results highlight the possible effects of climate change on several trans Saharan migrant species demography. Therefore, it is necessary to increase our knowledge on wintering ecology of trans Saharan migratory species in order to detect the factors that may be limiting their populations in wintering grounds. If we fail to do so, it is possible that conservation measures applied in the breeding grounds will not be enough to secure the persistence in time of these species.