Killing two birds with one stone? In this case it is two monkeys felled by a single snake. A boa constrictor has captured two marmosets about 4 metres up in a forest near Campos Belos in the state of Goiás, in Brazil.

“This is the first time anyone has recorded a constrictor snake attacking two primates at the same time,” says Danilo Simonini Teixeira of the University of Brasília, Brazil. “We’ve never seen a boa predate on two marmosets simultaneously before.”

He and his team were studying black howler monkeys when he stumbled across the 2-metre long boa constrictor (Boa constrictor amarali). The boa, which is an opportunistic hunter, took Teixeira by surprise as it fell from a tree clinging to two young marmosets (Callithrix penicillata).


“I heard the vocalisation of several individuals of black-tufted marmosets,” he says. At first Teixeira thought the monkeys were fighting or playing but when he investigated, he says: “A snake fell from the tree with two marmosets already wrapped around its body, almost hitting me.”

The snake had wrapped itself around the upper body of one marmoset, while clinging to the other by its legs.

Two adults chased the snake to the ground and repeatedly attacked it trying to save the infants, while the rest of the group called out from above. The boa continued to squeeze the life out of its victims.

“Although we did not see the actual attack, I think the snake captured the first animal while the second was captured by accident in an attempt to save a member of the group,” Teixeira says.

The researchers left the scene after the snake had loosened its grip and left the two carcasses on the ground, so they don’t know if the boa ate the monkeys. They think the episode means boas are more important predators of marmosets than previously thought.

Journal reference: Primates, DOI: 10.1007/s10329-015-0495-x

Top (Image: Danilo Simonini Teixeira) Centre (Image: Edmilson dos Santos)