'Truce' benefits bird neighbours

Lesser kestrels in Italy have formed a 'truce' with their jackdaw neighbours to save energy, a study has revealed.

Researchers found that birds nesting in a mixed colony patrolled for predators less often than those living in single species sites.

The unlikely co-operation happened despite the birds' conflicting diets as jackdaws can prey on kestrel eggs.

Scientists suggest this could have important implications for the future of the birds of prey.

Up to 20,000 pairs of lesser kestrels are currently thought to exist in Europe and North Africa.

According to BirdLife International, a partnership of conservation organisations, the species suffered rapid declines after the 1950s but they have been recovering in the last three generations.

The sociable raptors roost together in trees and abandoned buildings, preying on small mammals and sometimes other birds.

Mixed roosts
Scientists from the University of Palermo, Italy and the University of Manitoba, Canada noticed the seemingly unusual mixed roosts of kestrels and jackdaws in rural buildings surrounded by cereal crops.

"Jackdaws are opportunist foragers and as such they may be potential predators of kestrel eggs," explained Daniela Campobello whose study, conducted with colleagues Maurizio Sara and James F Hare, was published in the journal Behavioral Ecology.

"The fact that lesser kestrels tolerated them as 'neighbours' triggered us to suspect that it must have been some kind of advantage."

By observing the birds and recording their calling behaviour in response to predator threats, the researchers discovered that both species benefited from the mixed 'neighbourhood'.

By Ella Davies
Reporter, BBC Nature

Read more here ...