Scientists use pigeons to study human skills

London: Scientists have strapped tiny Global Position Systems (GPS) to pigeons to analyse the way bird flocks change direction and stay together in a study they hope will also give clues to human collective behaviour.

Researchers from Britain and Hungary used GPS "backpacks" to record the flight paths of individual pigeons and then analysed interactions between the birds.

They found that pigeon flocks use a flexible system of leadership where almost every member plays a part, but high-ranking birds have more power.

The findings, published in the journal Nature on Wednesday, could help unravel the collective behaviour and decision-making processes of other groups of animals, including humans.

"We are all aware of the amazing aerobatics performed by flocks of birds, but how such flocks decide where to go and whether decisions are made by a dominant leader or by the group as a whole has always been a mystery," said Dora Biro of the zoology department at Britain's Oxford University, who worked on the study.

The scientists found that while most birds in a flock do have a say in decision-making, a flexible ranking system means some birds are more likely to lead and others to follow.

To conduct their study, the researchers fitted miniature GPS loggers weighing just 16g (less than one ounce) into custom-made backpacks carried by flocks of up to 10 homing pigeons.

The devices allowed scientists to analyse spatial and temporal relationships between birds and the movement decisions they made at the scale of a fraction of a second.

"These hierarchies are flexible in the sense that the leading role of any given bird can vary over time," said Biro.

"This dynamic, flexible segregation of individuals into leaders and followers - where even the lower-ranking members' opinions can make a contribution - may represent a particularly efficient form of decision-making."

The scientists said more studies could help explain how such a sophisticated leadership system is able to give evolutionary advantage to individuals, compared with strategy based on a single leader or one where all members play an equal part.