Abstract
A first instance of parental care by a male-plumaged hummingbird from a sexually dimorphic species contributes important natural history understanding and helps illuminate the possibility of interesting female-limited polymorphisms across hummingbird species. Using photos and 2.5 min of video taken at close proximity, we documented a Veraguan mango (Anthracothorax veraguensis) with male plumage both incubating eggs and later feeding nestlings in the town of Palmar Norte in southern Costa Rica. Based on plumage characteristics and range, we rule out the similar green-breasted mango (A. prevostii) that occurs in close geographic proximity. On-ground exploration and Google Earth imagery revealed the landscape surrounding the nest as a heterogeneous mix of urban, residential, and agricultural land. Given our assumptions about the bird's sex and age, we speculated on potential mechanisms for male-like plumage in adult female Veraguan mango (and related species in the Anthracothorax genus), including age-related plumage ontogeny and the interaction of social and ecological selection pressures. Our observation contributes valuable information to the natural history of the Veraguan mango and opens the possibility of a female-limited polymorphism in the species.