When one thinks of the blood-feasting vampire bats, friendship and cooperation may not be among the qualities that come to mind But perhaps they should.
Scientists have shown how those bats that have forged “friendships” with others will rendezvous with these buddies while foraging for a meal.
Studying female bats
Researchers attached small devices to 50 vampire bats to track night time foraging in Panama, when these flying mammals drink blood from wounds they inflict upon cattle in pastures. The study involved female bats, known to have stronger social relationships than males.
Among the bats were 23 wild-born individuals that had been kept in captivity for about two years during related research into bat social behaviour. Social bonds already had been observed among some of them. After being released back into the wild, the bats were found to often join a “friend” during foraging,possibly coordinating the hunt.
“Each bat maintains its own network of close cooperative social bonds,” said behavioral ecologist Gerald Carter of the Ohio State University and the Smithsonian Tropical Research Institute, who led the research published in PLoS Biology.
Social bonds among vampire bats as they roost in trees include grooming one another and regurgitating blood meals for hungry pals. The study showed that the social bonds formed in roosts extended into the hunt.
The researchers suspect that the bats, while almost never departing on foraging forays with their “friends,” link up with them during the hunt for mutual benefit. They hypothesise the bats might exchange information about prey location or access to an open wound for feeding.
Live in colonies
Vampire bats, which inhabit warmer regions of Latin America and boast wingspans of about 18 cm, are the only mammals with a blood-only diet. They reside in colonies of thousands.
“Even besides their social lives, vampire bats are quites pecial: specializing in a diet of 100% blood is already quite rare among vertebrates,” said co-author Simon Ripperger, a post-doctoral researcher from Smithsonian Tropical Research Institute. “They are amazing runners, which you wouldn’t expect in a bat. They have heat sensors in their snouts that help them find a spot to make a bite.”