Boa Constrictors Form Hunting Parties and We’re Totally Fine with That

Scientists have observed Cuban boas lining up, suspending themselves from cave ceilings in a “curtain” of bodies, and waiting for their bat prey to fly through. A report on this never-before-seen behavior was published in the journal Animal Behavior and Cognition [PDF].

At 3 to 6 feet long, the Cuban boa (Chilabothrus angulifer) is a hefty customer, the largest in its genus and one of the biggest in the West Indies. It’s a skilled hunter both on the forest floor and the cave ceiling, dangling like a fanged party streamer and snapping passing fruit bats out of the air.

Cooperative hunting is not uncommon in nature. Wolves do it, as do dolphins, apes, some birds, crocodiles, and even a few species of fish. Snakes … not so much. Scientists have seen snakes hunting in the same place, at the same time, but it was sort of an every-snake-for-itself situation. (In that nightmare-inducing scene in Planet Earth 2, for instance, researchers viewed the snakes as coordinating, not cooperating.) Or so we thought.

Yet when researcher Vladimir Dinets of the University of Knoxville settled in near a sinkhole cave in Cuba's Desembarco del Granma National Park to watch the snakes’ nightly bat-feast, he noticed something unusual: The snakes seemed to be making room for one another.

For eight nights between sunset and dawn, an apparently fearless Dinets watched the cave’s nine snake inhabitants position themselves on the roof of the cave. His first thought was that each snake just had its own favorite or assigned spot on the ceiling.

But over time, he realized that they were rotating, each arriving snake filling in gaps in the curtain space to ensure maximum bat-flightpath coverage.

This wasn’t just a bunch of snakes hunting in the same place at the same time. This was a bunch of snakes hunting together. And it was working. The boas stuffed themselves with little furry bodies.

“It is possible that boas are not unique among snakes, and that coordinated hunting is not particularly rare,” Dinets writes in his paper. “This possibility suggests that at least some snakes are not the ‘solitary animals’ they are commonly considered to be, and that they are capable of high behavioral complexity required for such hunting.”

This is fine.