Ramos R., Granadeiro J.P., Nevoux M., Mougin J.-L., Dias M.P., Catry P.
Eco-Ethology Research Unit, Instituto Superior de Psicologia Aplicada, Lisboa, Portugal; Centre for Environmental and Marine Studies, Museu Nacional de História Natural e da Ciência, Universidade de Lisboa, Lisboa, Portugal; Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield, South Africa; Laboratoire de Zoologie, Muséum National d'Histoire Naturelle, Paris, France
Ramos, R., Eco-Ethology Research Unit, Instituto Superior de Psicologia Aplicada, Lisboa, Portugal; Granadeiro, J.P., Centre for Environmental and Marine Studies, Museu Nacional de História Natural e da Ciência, Universidade de Lisboa, Lisboa, Portugal; Nevoux, M., Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Hatfield, South Africa; Mougin, J.-L., Laboratoire de Zoologie, Muséum National d'Histoire Naturelle, Paris, France; Dias, M.P., Eco-Ethology Research Unit, Instituto Superior de Psicologia Aplicada, Lisboa, Portugal; Catry, P., Eco-Ethology Research Unit, Instituto Superior de Psicologia Aplicada, Lisboa, Portugal
Predicting the impact of human activities and their derivable consequences, such as global warming or direct wildlife mortality, is increasingly relevant in our changing world. Due to their particular life history traits, long-lived migrants are amongst the most endangered and sensitive group of animals to these harming effects. Our ability to identify and quantify such anthropogenic threats in both breeding and wintering grounds is, therefore, of key importance in the field of conservation biology. Using long-term capture-recapture data (34 years, 4557 individuals) and year-round tracking data (4 years, 100 individuals) of a trans-equatorial migrant, the Cory's shearwater (Calonectris diomedea), we investigated the impact of longline fisheries and climatic variables in both breeding and wintering areas on the most important demographic trait of this seabird, i.e. adult survival. Annual adult survival probability was estimated at 0.914±0.022 on average, declining throughout 1978-1999 but recovering during the last decade (2005-2011). Our results suggest that both the incidental bycatch associated with longline fisheries and high sea surface temperatures (indirectly linked to food availability; SST) increased mortality rates during the long breeding season (March-October). Shearwater survival was also negatively affected during the short non-breeding season (December-February) by positive episodes of the Southern Oscillation Index (SOI). Indirect negative effects of climate at both breeding (SST) and wintering grounds (SOI) had a greater impact on survival than longliner activity, and indeed these climatic factors are those which are expected to present more unfavourable trends in the future. Our work underlines the importance of considering both breeding and wintering habitats as well as precise schedules/phenology when assessing the global role of the local impacts on the dynamics of migratory species. © 2012 Ramos et al.
adult animal; article; breeding; Calonectris diomedea; climate; El Nino; environmental impact assessment; fishery; food availability; habitat quality; human impact (environment); migrant bird; mortality; nonhuman; sea surface temperature; seabird; survival rate; winter; Animal Migration; Animals; Breeding; Charadriiformes; Climate; Demography; Ecosystem; Fisheries; Geography; Humans; Models, Biological; Portugal; Survival Analysis; Time Factors; Animalia; Calonectris diomedea