I noticed a behavioural response amongst the Pemba Flying Foxes that intrigued me. The bats natural predators on Pemba are likely to be birds of prey, and humans. I saw the bats exhibit the behaviour twice; once when a bird of prey swooped in close to the colony from above, and once when my field assistant approached the edge of the colony from the ground to take a GPS reading. A large number of the bats simultaneously opened their wings, and the movement travelled across the colony like a Mexican wave. Now it could be that they were just preparing to take off if the threat was considered great enough. But it appeared to me that it may have been a defence mechanism and they were flashing their wings and revealing their russet chests to appear bigger, and startle the predator. I would be interested to know if anyone else has observed this behaviour in Flying Foxes.
Photo kindly provided by Denise Déziel