One good turn: birds swap energy-sapping lead role

Migrating birds 'share the pain' of the arduous task of leading a v-formation, so that they can then take turns saving energy by following in another bird's wake, a new study shows. The research, by an international team led by Oxford University scientists, is the first convincing evidence for 'turn taking' reciprocal cooperative behaviour in birds. It is also only the second good example of reciprocal cooperation in animals, following a study that revealed how vampire bats shared blood to keep other unrelated individuals alive. The team studied 14 juvenile Northern bald ibis ( Geronticus eremita ) migrating from Salzburg in Austria to Orbetello in Italy. The 'human-imprinted' birds followed a powered parachute carrying their handlers. Tiny 23g data loggers worn by each bird enabled the researchers to examine how individuals within a flying v-formation interacted. Although the human-imprinted birds followed a powered parachute the experiment was designed to replicate the behaviour of wild ibis where juveniles from the same location tend to migrate together.