Philodryas olfersii (Serpentes, Dipsadidae) feeding on bats in southern Brazil

Resumen

(Philodryas olfersii (Serpentes, Dipsadidae) feeding on bats in southern Brazil). Snakes are often cited as regular or occasional predators of bats. However, information on predator-prey interactions involving bats and snakes is relatively scarce in Brazil considering the high diversity of both taxa. The present note reports two new records of a snake feeding on bats in two different municipalities located in Rio Grande do Sul, the southernmost state of Brazil. The predation attempts were opportunistically observed, and were made by Philodryas olfersii, a semi-arboreal dipsadid snake. In the first event, the snake was observed eating a Nyctinomops laticaudatus specimen at the entrance of a rocky wall, where there is a colony of this bat species. In the second case, the snake entered a bat roost in a building and bit a Histiotus velatus individual, which escaped and died 30 minutes later. This is the first record of P. olfersii feeding on bats, and the first and second record, respectively, of H. velatus and N. laticaudatus being predated by a snake. The strategy of entering roost sites during the day to attack bats is documented for the first time in P. olfersii, but this predatory behavior is apparently common among large colubrids, which are closely related to dipsadids. Since P. olfersii is diurnal, scansorial, and can be faithful to the hunting site, it is a potential regular predator of gregarious bats inside day roosts.