A family group of Savanna-Hawk predating snakes in the Pampas of Rio Grande do Sul, Brazil

Small vertebrates are regular items in the diet of a wide range of birds, particularly among Accipitridae. Diurnal reptiles, especially the orders Serpentes and Sauria, while moving or in other specific situations, such as thermoregulation, are conspicuously exposed to predation by birds that share the daytime habit. In the present study, we report two predatory events involving a family group of Savanna-hawks, Heterospizias meridionalis, consisting of an adult pair and their nestling, on snakes’ species Xenodon dorbignyi and Philodryas patagoniensis, in municipality of Rosário do Sul (-30.264533 -54.947345), west region of Rio Grande do Sul, southern Brazil. In the first event (09.04.2016), an adult hawk caught a snake of the species X. dorbignyi, in an area near a small wetland, about 100 meters from the nesting site. Before returning to the nest, with a help of the beak, the hawk removed the serpent’s head, taking the rest of the carcass to the nesting. However, due to difficult visualization, we did not notice the presence of nestling, only another adult individual. In a new event (01.26.2017), in the same place, one of the adult birds captured a snake of the species P. patagoniensis. Once again, the carcass had its head removed by the hawk, which delivered it to a young individual under supervision of another adult specimen. Events like these help to better understand the ecological and behavioral aspects of species, since they elucidate the diet, reproductive biology and parental care of these raptors.