Geographical variation and current knowledge on breeding traits of vultures in the neotropics

Abstract

New World vultures (Cathartidae) have essential roles in ecosystem functioning, but are susceptible to increasing anthropogenic impacts. Knowledge of several breeding, behavioral, and distributional parameters of Neotropical vultures is poorly organized and have not been properly reviewed. Here, we made a comprehensive review of original breeding records from museums, literature, and citizen science (WikiAves) for each of the six species of vultures occurring in the Neotropical region. These data were used to review breeding patterns and geographical distribution, and identify information gaps. The 567 records of breeding from the Neotropics assembled are very biased, mostly for Black Vulture Coragyps atratus (n = 319) and Turkey Vulture Cathartes aura (n = 166), and unevenly distributed among regions and subspecies. The four other species still have a great lack of knowledge about their breeding in the wild (Lesser Yellow-headed Vulture Cathartes burrovianus (n = 20), Greater Yellow-headed Vulture C. melambrotus (n = 2), King Vulture Sarcoramphus papa (n = 21), and Andean Condor Vultur gryphus (n = 30)). We show for the first time that Neotropical Cathartidae have convergent breeding seasons among sympatric taxa, delay start of breeding with increasing latitude, and have an allometric relationship between adult size and egg size. Nevertheless, larger samples of breeding data, especially from some regions and taxa, such as the two “Yellow-headed Vulture” species, are still needed. We also show that breeding traits could be helpful for preventive management and conservation strategies involving both expanding and decreasing populations of vultures in the Neotropics.