Invernada diferencial según sexos del Bisbita Ribereño Alpino (Anthus spinoletta) en un carrizal del centro de España

• Autores: Alfonso Villarán
• Localización: Butlletí del Grup Català d'Anellament, ISSN 1130-2070, Vol. 16, Nº. 1, 1999, págs. 17-22
• Idioma: español
• Enlaces
  • Texto completo
• Resumen

  • Capture-recapture data of 62 Water Pipit Anthus spinoletta ringed during four winters were analysed in order to establish details of the sex ratio, phenology and site fidelity. The arrival of Water Pipit ut the study site began in late October, whereas departure took place in March-April. Mean wing-length varied throughout the winter, being greater in October and smaller in December-January. The sex ratio of rnales: females was 1: 2. The percentage of birds retrapped was 7 6% with no significant differences noted between the sexes. The recapture rafe subsequent to the winter of ringing was 5% which suggests a certain degree of site fidelity to the local wintering area.