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PATRONES GENERALES DE COLONIZACIÓN Y EXTINCIÓN DE RAPACES EN ISLA


Los archipiélagos de la Macaronesia y Mediterráneo han registrado a lo largo de tiempos históricos, y especialmente en el último siglo numerosas extinciones locales de aves rapaces mientras que otras muchas poblaciones se encuentran al borde de la desaparición (véase Muntaner y Mayol 1996). Este es también el caso de las islas Canarias, que fueron originalmente colonizadas por hasta 7 especies de aves de presa diurnas. La mayor parte de estas especies han pasado o pasan actualmente por situaciones críticas desde el punto de vista de conservación, bien a nivel de alguna de las islas o en el conjunto del archipiélago (Palacios 2001).
La recuperación de las poblaciones pasa esencialmente por un balance demográfico positivo fruto de la dinámica local y de la relación entre las tasas de inmigración y emigración. En el caso de los sistemas insulares como el de Canarias, las posibilidades de inmigración que incrementarían la tasa de crecimiento poblacional, viene “a priori” muy condicionada por el fenómeno de la insularidad. Ya desde hace décadas la bien conocida teoría de la biogeografía de islas determinó que la riqueza en organismos de un sistema insular (oceánico o ecológico) viene determinado por las tasas de colonización y extinción.(...)


José A. Donázar, J.A., Gangoso, L. y Forero, M. G. (2003) Majorensis vol.2. 

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