Peacock’s train is not such a drag

The magnificent plumage of the peacock may not be quite the sacrifice to love that it appears to be, University of Leeds researchers have discovered. Dr Graham Askew, from the University’s School of Biomedical Sciences , filmed five Indian peacocks taking off using two high-speed video cameras to try to work out what price male birds pay for carrying the spectacular iridescent feathers they use in displays to attract females. “These feathers weigh about 300g and can exceed 1.5m, so it’s expected that the male birds would be making a significant sacrifice in their flight performance for being attractive—possibly giving up their lives if the train restricts escape from predators such as tigers and leopards in their natural environment,” Dr Askew said. He filmed the take-offs of birds carrying full plumage in 3D, and then filmed the same birds taking off without their trains. The display feathers, which naturally moult at the end of the breeding season, were clipped to judge the change in take-off performance between the two states. To his surprise, Dr Askew found there was no significant difference. Dr Askew observed the position of each bird’s centre of mass, their wing motions and the movement of the train in take-off and then calculated the amount of power used by the birds to accelerate and gain height over the first two wing beats.