The diet of the Citril Finch (Serinus citrinella) in the Pyrenees and the role ofPinus seeds as a key resource

摘要

The diet of the Citril Finch (Serinus citrinella) in its eastern range is well known, especially in spring; however, no data are available from its western populations. The aim of this paper is to provide extensive data on the diet of the species in the Pyrenees. Samples were obtained by visual inspection of the gullet of 3394 birds from 49 different localities over an area of 4000 km2. Analyses revealed a clear phenological pattern: (1) the Arvensis period, November-January, when the bird relies on farmland seeds, mainlyChenopodium sp. (2) the Arboreal period, February-May, when the birds focus on Pine seeds (Pinus nigra andP. uncinata); (3) the Meadow-Ruderal period, June-October, when the bird feeds on several grasses and herbs, includingTaraxacum officinalis (mainly in June) andCirsium sp. (mainly August-September). Hence the Citril finch normally specialises in a few key species, but during certain periods may opportunistically expand its dietary range. Pine seeds appear crucial, both in determining the breeding distribution of the species and in allowing opportunistic spring breeding.