2013
_GLOBAL ENVIRONMENT Entomology

Joining the Swarm
Sean O’Donnell’s research into army ants has opened up a new understanding of a peculiar South American bird species.

_Sean O'Donnell

O’Donnell is a professor in the Department of Biodiversity, Earth and Environmental Science in the College of Arts and Sciences.

Since 2005, Sean O’Donnell, associate department head of the Department of Biodiversity, Earth and Environmental Science (BEES), has been researching army ants and their relationship to antbirds. In fact, he has shared his expertise on documentaries about army ants, the most recent being “Wild Things with Dominic Monaghan.” But his research on ants has helped him better understand another set of species: birds.

“One thing you really can’t help but notice when following army ant colonies around is an amazing array of birds that come down and troop along with the army ants as they sweep through the forest. We started realizing that the set of bird species doing this in the mountain forests was different than the bird species doing it in the lowlands. That got us thinking about how interesting it might be to study bird interactions with army ants in the mountain forests,” O’Donnell explains.

Missing from the mountain forests are a family of birds called antbirds. Antbirds are indigenous across subtropical and tropical areas, including Central and South America.

“Sean o’donnell’s research into army ants has opened up a new understanding of a peculiar south american bird species.”

When army ants are swarming through the forest, they scare off many small animals. The birds swoop in to capture them. Some antbirds get little or none of their food from anywhere else; they rely completely on following army ant colonies. They move through the forests and memorize the ants’ locations, and out-compete other birds.