Förschler M.I. & Kalko E.K.V. (2006) Age-specific reproductive performance in Citril Finches Carduelis [citrinella]. ARDEA 94 (2): 275-279

We studied age-specific reproductive performance of subadult (2nd calendar year) and adult (3rd calendar year or older) Citril Finches Carduelis [citrinella] in several sub-populations of the species (Black Forest, SW Germany; Pyrenees, NE Spain; Corsica, France; Sardinia, Italy). In accordance with the results of many other studies we hypothesised to find an increase in reproductive success with age due to higher experience of older birds. As expected we found significantly higher nesting success in experienced pairs (two adult birds) than in pairs with the participation of at least one subadult birds. Individual breeding performance revealed similar results with considerably higher breeding and nesting success for adult than for subadult males and females. We suggest therefore that adult Citril Finches appear to perform much better than subadult birds, probably due to higher experience in foraging and the acquirement of high quality habitats. Our data let us conclude that the first year in Citril Finch lifetime history seems to be rather unproductive. We suppose that subadult Citril Finches use this first year to gain necessary skills for nest building and optimal food selection to breed successfully in the following years. Their lifetime history may be therefore aligned with longer life span due to a longer learning curve than in comparable species such as Siskins Carduelis spinus, which possess a much faster turnover in their reproduction cycle.