Cooperation among different species of birds is common. Some birds build their nests near those of larger, more aggressive species to deter predators, and flocks of mixed species forage for food and defend territories together in alliances that can last for years. In most cases, though, these partnerships are not between specific individuals of the other species—any bird from the other species will do.
But in a new study published in the journal Behavioral Ecology, scientists from the University of Chicago and University of Nebraska show how two different species of Australian fairy-wrens not only recognize individual birds from other species, but also form long-term partnerships that help them forage and defend their shared space as a group.
“Finding that these two species associate was not surprising, as mixed species flocks of birds are observed all over the world,” said Allison Johnson, Ph.D., a postdoctoral scholar at the University of Nebraska who conducted the study as part of her dissertation research at UChicago. “But when we realized they were sharing territories with specific individuals and responding aggressively only to unknown individuals, we knew this was really unique. It completely changed our research and we knew we had to investigate it.”
Birds from different species recognize each other and cooperate