Geographical and seasonal distribution of the Short-crested Coquette hummingbird: a microendemic and endangered species.

Species movements along elevational or latitudinal gradients occur primarily due to climatic variations and food resource availability. However, the role of seasonal climatic conditions in species with highly restricted distributions has been poorly addressed. In this study, we analyzed the geographic distribution and seasonal climatic niche during the dry and rainy seasons of the Short-crested Coquette hummingbird (SCCH; Lophornis brachylophus), a species with high conservation priority at the global scale. We generated ecological niche and species distribution models for both seasons and used niche similarity tests to represent and compare their climatic differences. We recorded the availability of flowering and fruiting plants that the SCCH feeds on within its distribution area during both seasons and performed a kernel density analysis to evaluate the main peaks in food availability. Our results revealed that the potential distribution of the SCCH is larger (642 pixels) in the dry season than in the rainy season (487 pixels). In the dry season, the distribution of this hummingbird includes sites at lower elevations (reaching 780 m above sea level [masl]). In contrast, in the rainy season, it extends to higher elevations (up to 1,450 masl). This seasonal shift between the two seasons coincides with the availability of flowers and fruits along the elevational gradient. The climatic niche similarity between the dry and rainy seasons shows moderate overlap (Schoener's D = 0.50) and is higher than expected by chance. Our results suggest that the SCCH moderate changes in its climatic niche throughout the year, with plant phenology being a primary driver of changes in its elevational range between seasons.