Las aves más gordas continúan antes su viaje

Este artículo firmado por personal del Max Planck Institute for Ornithology y un equipo de ornitólogos italianos afirma ser el primero que demuestra empíricamente que los pájaros migradores que alcanzan las zonas de descanso con mayores reserva de grasa continúan antes su viaje:

Body fat influences departure from stopover sites in migratory birds: evidence from whole-island telemetry

Abstract

Migration remains one of the great mysteries of animal life. Small migratory birds rely on refuelling stopovers after crossing ecological barriers such as deserts or seas. Previous studies have suggested that fuel reserves may determine stopover duration but this hypothesis could not be tested because of methodological limitations. Here, we provide evidence that subcutaneous fat stores determine stopover duration by measuring the permanence of migratory garden warblers (Sylvia borin) on a small Mediterranean island during spring migration with telemetry methods. Garden warblers with large amounts of fat stores departed the island significantly sooner than lean birds. All except one fat bird left the island on the same evening after capture, with a mean total stopover estimate of 8.8 hours. In contrast, the mean estimated total stopover duration of lean birds was 41.3 hours. To our knowledge, this is the first study that measures the true minimum stopover duration of a songbird during migration.

Es algo que se suponía, pero que según los autores hasta ahora no había sido demostrado.

Aquí tenéis el artículo completo, en PDF y en la web de Biology letters.