Exploring the expression of genes potentially involved in stress response of the endemic Galapagos Yellow Warbler (Setophaga petechia aureola)

Insights into the molecular response of organisms to environmental change can inform and strengthen conservation strategies, especially in ecosystems undergoing accelerated anthropogenic disturbances. This study explores the expression of stress-related genes in the Galapagos-endemic Yellow Warbler (Setophaga petechia aureola) in natural and anthropogenic habitats on San Cristobal Island (Galapagos, Ecuador). Given the critical conservation status of Galapagos ecosystems, we are beginning to explore whether anthropogenic changes trigger an increase in the expression of stress-related genes. As a first step, we report here on the analysis of blood samples taken from 13 individuals across anthropogenic habitats (urban green areas, silvopasture) and natural habitats (deciduous and evergreen forests). Using RT-qPCR, we quantified expression levels of six stress-response genes and compared the values for each sample to the mean for natural habitats (baseline). The findings from this small sample of individuals did not support the hypothesis of elevated stress-related gene expression in anthropogenic habitats. Instead, we observed substantial variability in gene expression among individuals within habitats, which could indicate that microhabitat conditions or individual plasticity play key roles in shaping molecular responses. The observed variability among individuals underscores the complexity of ecological and genetic responses and suggests the need for more comprehensive genomic approaches to better understand the resilience of Galapagos bird populations to ongoing habitat disturbances.