Attacked from above and below, new observations of cooperative and solitary predators on roosting cave bats

Abstract

Predation of bats in their roosts has previously only been attributed to a limited number of species such as various raptors, owls, and snakes. However, in situations where due to over-crowding and limited roost space, some individuals may be forced to roost in suboptimal conditions, such as around the entrances of caves and may thus be vulnerable to predation by species which would normally be unlikely to predate bats whilst roosting inside caves. Here, we describe the first documented cooperative hunting of the Large-billed Crow, Corvus macrorhynchos Wagler, 1827 (Passeriformes: Corvidae) and opportunistic predation by the Yellow-headed water monitor, Varanus cumingi Martin, 1839 (Squamata: Varanidae) in the worlds largest colony of Geoffroys Rousette, Rousettus amplexicaudatus (E. Geoffroy Saint-Hilaire, 1810) (Chiroptera: Pteropidae) in the Island of Samal, Mindanao, Philippines.