Conserving migration in a changing climate, a case study: The Eurasian spoonbill, Platalea leucorodia leucorodia

Abstract

Migratory species are fundamental for the long-term maintenance of biodiversity, as well as for the ecological functions they provide. Their current protection, however, lacks a clear understanding of how conservation areas are able to maintain the connectivity of populations in different periods of the migration cycle. Such a problem is even more significant in light of the consequences of climate change on the availability of suitable habitats, especially for those species for which the effects can be amplified by the long distances covered during migration. Here, a graph-theoretic approach was implemented to test for the relationship between current and projected climate conditions on the connectivity of conservation areas for migratory birds. The framework was tested by considering the migration system of the northwestern populations of Eurasian spoonbill (Platalea leucorodia leucorodia), characterized by mid-long-range movements between the breeding sites in the Netherlands and wintering sites in Spain, Senegal and Mauritania. Climate effects suggest an ever-increasing range of distances to cover by the spoonbills, increasing the separation between important stopover and wintering areas. The current spatial configuration of areas will hardly support the long-range spoonbill migration, increasing the risk of fragmentation and contraction of populations, unlikely to support the spoonbill migration system. The methodology described can be applied to other migration systems, incorporating useful information in the implementation of conservation policies able to identify important areas for the long-term persistence of biodiversity.