Residence times and phenology of three warbler species (Sylvia spp.) in a western Pyrenean stopover site.

Full article

Published:

Volume 44(2), December 1997. Pages 163-171.

Language:

Spanish

Original title:

Sedimentación y fenología otoñal de tres especies de currucas (Sylvia spp.) en el extremo occidental del Pirineo

Keywords:

age, autumn phenology, body mass, fat reserves, flight speed, size, stop-over residence times, Sylvia atricapilla, Sylvia borin, Sylvia communis.

Abstract:

This paper analyzes the dates of capture and recapture of three Sylvia species, as well as variations in their size and fat reserves, during a summer-autumn ringing campaign carried out in 1993 in the western extreme of the Pyrenees (northern Spain). The maximum intensity of passage of Garden Warblers (Sylvia borin) and Whitethroats (Sylvia communis) occurred during the second fortnight of September, whereas most Blackcaps (Sylvia atricapilla) passed in October. During these periods of peak passage, migrants showed larger body mass and fat reserves as compared with both earlier and later dates. Only young birds were caught at the end of the migration period. The flight speed of the three species appeared to increase between the northern and southern parts of the Iberian Peninsula. The Garden Warbler is the only species that showed increasing body mass while remaining stationary in the study zone.