Affiliation: | 1. CIBIO/InBio, Núcleo da Mitra, Universidade de Évora, Apartado 94, 7002-554 Évora, Portugal;2. DBIO & CESAM-Centre for Environmental and Marine Studies, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal Institute of Biological and Health Sciences, Federal University of Alagoas, Av. Lourival Melo Mota, s/n, Tabuleiro do Martins, Maceió, AL 57072-900 Brazil;3. REN Biodiversity Chair, CIBIO/InBIO Associate Laboratory, Universidade do Porto, Campus Agrário de Vairão, 4485-661 Vairão, Portugal;4. Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal;5. REN Biodiversity Chair, CIBIO/InBIO Associate Laboratory, Universidade do Porto, Campus Agrário de Vairão, 4485-661 Vairão, Portugal Centro de Ecologia Aplicada “Prof. Baeta Neves”/InBIO Associate Laboratory, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisbon, Portugal;6. REN Biodiversity Chair, CIBIO/InBIO Associate Laboratory, Universidade do Porto, Campus Agrário de Vairão, 4485-661 Vairão, Portugal Centro de Ecologia Aplicada “Prof. Baeta Neves”/InBIO Associate Laboratory, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisbon, Portugal Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal |
Abstract: | Migratory decisions, such as the selection of stopover sites, are critical for the success of post-breeding migratory movements and subsequent survival. Recent advances in bio-logging have revealed the stopover strategies of many long-distance migrants, but far less attention has been given to short-distance migrants. We investigated the stopover ecology of an endangered grassland bird, the Little Bustard Tetrax tetrax, a short-distance migrant in Iberia. Using high-resolution spatial GPS/GSM data, 27 male Little Bustards breeding in southern Portugal were tracked between 2009 and 2011. We studied post-breeding movements using Dynamic Brownian Bridge models to identify the main stopover sites, and generalized linear mixed models to examine habitat selection in stopovers. During their post-breeding movements, males were essentially nocturnal migrants, making frequent stopovers while maintaining a relatively fast pace to reach more productive agricultural post-breeding areas. Stopovers occurred in most post-breeding movements (83%) regardless of the total distance covered (average 64.3 km), and most stopovers (84%) lasted less than 24 h. Birds used mostly agricultural non-irrigated and irrigated croplands as stopover sites and avoided other land uses and rugged terrain. There was a negative relationship between stopovers and the proximity to roads, but not to power lines. The high frequency of stopovers during post-breeding movements, despite the short distances travelled, together with the nocturnal migratory behaviour of bustards, may impose additional risks to a bird mainly threatened by collision with power lines in non-breeding areas. We also conclude that even for short-distance migrants, habitat connectivity between breeding and post-breeding areas is likely to be a key conservation concern. |