Starlings form ‘friendships’ to help each other with breeding, study finds

Superb starlings seen to build reciprocal relations in which they return favours when a helper' has offspring of its own

Birds of a feather flock together, so the saying goes. But scientists studying the behaviour of starlings have found their ability to give and take makes their relationships closer to human friendships than previously thought.

About 10% of bird species and 5% of mammal species breed cooperatively", meaning some individuals refrain from breeding to help others care for their offspring. Some species even help those they are unrelated to.