Evolución de las ardeidas coloniales en la cuenca extremeña del Guadiana (Suroeste de España)

• Autores: María Deseada Parejo Mora, Emilio Costillo Borrego, Cristina Fuentes
• Localización: Butlletí del Grup Català d'Anellament, ISSN 1130-2070, Vol. 14, Nº. 1, 1997, págs. 31-35
• Idioma: español
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• Resumen

  • Since 1975, very little is known about the herons of the middle reaches of the Guadiana River. We studied the status and trends of the breeding population of four species of heron in this area during the period 1994- 1997. All species showed a positive annual rate of increase, although the Cattle Egret showed a rate of increase close to equilibrium (0, 9 1 %). Colonies were unstable: only two of them were occupied for the four years; two colonies disappeared and four appeared during these years. The number of colonies with Cattle Egrets, Little Egrets, and Black-crowned Night-herons increased from seven in 1994 to ten in 1997, while Grey Heron colonies remained the same (two colonies) despite the fact that the number of breeding birds increased.