Winterin distribution of Balearic shearwater (Puffinus yelkouan mauretanicus, Lowe 1921) off the north-east coast of Spain

The distribution and numbers of the Balearic Shearwater during the Novembgr-February period are discussed. Until the 1980’s this subspecies seemed to be concentrated along the coast south of Valencia. Since 1991-1992 this pattern has changed, and up to 10465 birds have been recorded northwards, alon...

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Detalles Bibliográficos
Autores: Gutiérrez, Ricard, Figuerola, Jordi
Tipo de recurso: artículo
Fecha de publicación:1995
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/44590
Acceso en línea:http://hdl.handle.net/10261/44590
Access Level:acceso abierto
Palabra clave:Balearic shearwater
Mediterranean
NE Spain
Puffinus yelkouan mauretanicus
winter distribution
winter population
Descripción
Sumario:The distribution and numbers of the Balearic Shearwater during the Novembgr-February period are discussed. Until the 1980’s this subspecies seemed to be concentrated along the coast south of Valencia. Since 1991-1992 this pattern has changed, and up to 10465 birds have been recorded northwards, along the Catalan coast. The subspecies is distributed along the Valencian and Catalan coasts in 9 main areas and numbers vary, reaching a total of ca. 8000-11000 birds. The accuracy of these figures and subspecies identification is discussed. An increase in the wintering population of Balearic shearwaters in Catalan waters has been noted. No parallel increase in breeding populations has been reported. Therefore, a northwards displacement of its main wintering area is a possible explanation. A trophic hypothesis is suggested to explain this winter distribution, given that some important changes in clupeid stocks of the extreme western Mediterranean have been noted. Observed numbers match the known breeding population and post-breeding counts, and thus almost the whole population of the subspecies may occur during the winter in the study area.