Blowin' in the wind: Dispersal of Glossy Ibis Plegadis falcinellus in the West Mediterranean basin

Abstract

AbstractThe movement of organisms is a central process in ecology and evolution, and understanding the selective forces shaping the spatial structure of populations is essential to conservation. Known as a trans‐Saharan migrant capable of long‐distance flights, the Glossy Ibis Plegadis falcinellus' dispersal remains poorly known. We started a ringing scheme in 2008, the first of its kind in North Africa, and ringed 1121 fledglings over 10 years, of which 265 (23.6%) were resighted. Circular statistics and finite mixture models of natal dispersal indicated: (1) a strong West/Northwest‐East/Southeast flight orientation; (2) Glossy Ibis colonies from North Africa and Southern Europe (particularly on the Iberian Peninsula) are closely linked through partial exchanges of juvenile and immature birds; (3) unlike birds from Eastern Europe, North African Glossy Ibis disperse to but do not seem to undergo regular round‐trip migration to the Sahel; (4) young adults (>2‐years‐old) have a higher probability of dispersing further than individuals in their first calendar year (<1‐year‐old); and (5) dispersal distance is not influenced by sex or morphometric traits. Together, these results enhance our knowledge of the dispersal and metapopulation dynamics of Glossy Ibis, revealing large‐scale connectivity between the Iberian Peninsula and Algeria, likely driven by the spatial heterogeneity of the landscape in these two regions and the prevailing winds in the Western Mediterranean.