Genetic signature of a severe forest fire on the endangered Gran Canaria blue chaffinch (Fringilla teydea polatzeki)

Abstract

Habitat destruction has been identified as one of the main threats to biodiversity. Among all factors causing habitat disturbance, wildfire is recognized as one of the most important ecological forces that influences not only the physical environment, but also the structure and composition of floral and faunal communities. These processes are often translated in population bottlenecks, which occur frequently in threatened species and result in loss of genetic diversity and evolutionary potential. In this study, we analyzed the genetic consequences of a demographic bottleneck produced by a forest fire that reduced the population of the endangered blue chaffinch (Fringilla teydea polatzeki), which inhabits the island of Gran Canaria, to approximately 122 individuals. Analysis of nine micro-satellite loci revealed that, while a decline in census was observed during the bottleneck, there was no observed excess of heterozygosity or evidence of a decline in allelic richness, two characteristic bottleneck signatures. On the contrary, we observed that the Gran Canaria blue chaffinch has retained significant levels of genetic diversity and shows no evidence of an increased level of inbreeding (F-IS) either before or after the bottleneck. The results from this study have important implications for the conservation of this endangered subspecies and provide insights concerning management strategies to prevent its extinction.