Reproduction and natural history of the Yellow-faced Siskin Spinus yarrellii in northeastern Brazil

The Yellow-faced Siskin Spinus yarrellii is a Vulnerable species with declining populations and little data on its reproduction. Some of its reproductive parameters are presented here, having been obtained in the northeastern region of Brazil, in the state of Alagoas, when four nests were monitored between 1991 and 2009 near the Pedra Talhada Biological Reserve. The nests were located in trees in anthropogenic areas and capoeiras at heights ranging from 2 to 5 m. We measured three of them, resulting in averages of 9.7 cm in external diameter, 4.7 cm in internal diameter, 6 cm in external height and 2.8 cm in internal height. Clutch sizes ranged from three to four eggs. Incubation lasted 11 to 12 days, with both parents participating, and chicks fledged between 10 and 11 days. Our records seem to be one of few that reveal information on the reproduction of this species. Our observations demonstrate undemanding nest site selection, with siskins utilising exotic plant species and disturbed environments for reproduction. Despite this adaptability, Yellow-faced Siskin populations face significant threats from illegal wildlife trade and habitat destruction with the indiscriminate use of pesticides on crops and pastures, which continue to intensify in the species’ habitat. With this study, we hope to provide valuable insights into the reproductive ecology of the Yellow-faced Siskin and contribute to broader conservation strategies for this rare and declining species.