News Round-Up

For female vampire bats, an equal chance to rule the roost


Female vampire bats establish an egalitarian community within a roost rather than a society based on a clear hierarchy of dominance that is often seen in animal groups, a new study suggests.

Researchers observed more than 1,000 competitions for food among a colony of 33 adult female bats and juveniles living in captivity, assigning a rank to each bat based on a calculation of wins and losses in those contests.

The team found that, unlike in many mammal societies, the higher-ranking animal didn’t necessarily win every bout over food, and there was a randomness to the ranking order – no specific quality they measured gave a bat a better chance at dominance, so any adult female had an equal opportunity to rank very high or very low on a scale of dominance in the roost. MORE

Header image: Rachel Moon.