The World of Antbirds
Flip through a field guide for the South American tropics, and you may be dazzled by the numbers of Antbirds listed. Over 240 species of antbirds live in Central and South America, including the ant-wrens, ant-vireos, and ant-thrushes. These small bird species are dull-colored, in blacks, browns and tans that hide them on the shady rainforest floors. Some species have eyes that are brightly-colored or surrounded with patches of colorful bare skin.
Despite their name, no antbird would actually eat an ant (ants have formic acid in their bodies that makes them unpalatable to most birds and mammals). Antbirds get their name from the 30 species that spend their lives following ants- especially army ants. Army ants march through the rainforest in huge swarms, eating every insect or small animal in their path. Many insects flush up in front of the swarm, trying to flee the hungry ants. The antbirds snap these fleeing insects up.
Antbirds, including the many species that don’t associate with army-ants, often travel in mixed-species flocks. This works well- each species hunts for a slightly different kind of insect. Thus, the flock’s birds don’t compete with each other, and everyone gets enough to eat.
Antbirds are excellent at hopping and gripping onto branches, but they’re not strong fliers. They almost never cross waterways or even roads. This is one reason humans can negatively affect antbirds- more roads and clearings in the rainforest may restrict antbirds’ ability to travel in search of food.