Variación estacional en la proporción de sexos y edades en los Mirlos (Turdus merula) en una localidad del Centro de España

• Autores: Rafael J. Aparicio
• Localización: Butlletí del Grup Català d'Anellament, ISSN 1130-2070, Vol. 15, Nº. 1, 1998, págs. 25-31
• Idioma: español
• Enlaces
  • Texto completo
• Resumen

  • Jhis paper presents un analysis of the sex and age proportions of Blackbirds throughout the annual cycle in a Mesomediterranean zone of central Spain. Birds were captured with mist-nets. There was an increase in the number of first-year birds during autumn and winter. In this same period, males (72%) were more abundant than females, and first-winter birds (78%) than adults. Based on retraps, it is suggested that the local birds are mainly sedentary and that during winter there is un influx of first-winter males, probably from higher altitudes, that abandon their breeding grounds in that period. Trapping biases do not seem to have affected results.