Vampire bats can sing a Halloween duet
The new study presents the first evidence of this singing by adult bats - previously duets have only been recorded in other species between mother bats and their pups.
White-winged vampire bats, the closest living relative of the common vampire bat, appear to keep on singing into adulthood.
"The calls are audible to the human ear, although we can only hear part of the whole sound," lead author Gerald Carter told Discovery News.
"They sound like high-pitched chirping, alternating from different bats," Carter, a University of Western Ontario researcher, added.
He and his colleagues conducted several experiments on 18 white-winged vampire bats, some of which were wild-caught in Trinidad, but are now housed in a temperature and humidity controlled facility in New Mexico.
The researchers used chickens to encourage the bats to sing as they became really vocal when the chickens were around.
Although we don't know what they are singing about, one can only hope around Halloween they are dueting spooky songs.
Individuals do call out to each other in the dark as well. By the end of the study, the researchers could even recognize which bat's 'voice' belonged to which bat.
"White-winged vampires are one of a very few species of obligate blood feeding vertebrates in existence today, likely a reflection of the difficulties associated with securing a stomach's worth of blood from a living, breathing -- and surely unwilling -- large bird or mammal," he said.
"In the wild, successful vampire bats sometimes share blood with their unsuccessful roost-mates," he added. "Such unselfish behavior is rare in animals and the current study intimates that reciprocal altruism among unrelated individuals may be mediated, in part, through vocal identification of individual roost mates."