A multiple trait assessment provides insights into the short-time viability of a newly founded population in an endangered island passerine

This study was mainly supported by European Union project LIFE14 NAT/ES/000077 and the Conservation Program for the blue chaffinch implemented by the Cabildo de Gran Canaria. Frank Hailer and two anonymous reviewers made valuable and constructive comments on the manuscript. JCI was funded by a research grant from the Spanish Ministry of Science, Innovation and Universities, and the European Regional Development Fund (PGC2018-097575-B-I00; PID2022-140091NB-I00) and a regional GRUPIN grant from the Regional Government of Asturias (AYUD/2021/51261). The content of the paper is a contribution to the post-LIFE “LifePinzon” (http://lifepinzon.org/). We are very grateful to Felipe Rodríguez, Ángel Cruz Moreno, Dolores Estévez and Ruth de O~nate for the help provided during the field-work in Inagua. Claire Jasinski improved the English of the manuscript. The Canarian Regional Government and the Cabildo of Gran Canaria provided the permits for ringing and taking biological samples from the Gran Canaria blue chaffinch (Ref.: 269/2017, 334/2018, 155/2020, 16/2020, 242/2021) and working within the natural protected areas of Gran Canaria (Ref.: 10588/2017, 16669/2020, 839/2021), some of them lasting two years.