Peacock Tails: Do They Really Affect the Bird’s Flight?
Peacock tail feathers are beautiful and iconic, but scientists have long believed that the birds pay a steep price for impressing peahens with their elaborate plumage. Peacocks are not the greatest of flyers, especially when taking off. Their tails are thought to be both too bulky and heavy for the birds to take flight in a hurry, which could be making them more vulnerable to predator attacks.
So, do peacocks really sacrifice their own safety in order to be more attractive to the opposite sex?
New research from the University of Leeds’ School of Biomedical Sciences suggests not.
Associate Professor of Muscle Function and Movement, Dr Graham Askew, wanted to examine the effects of a peacock’s tail on its flight, and so decided to film five of the birds with and without their tail feathers. He recorded his findings in The Journal of Experimental Biology (JEB).
The professor explained that the tail feathers – also referred to as the “train” – can grow to be longer than 1.5m (5ft) and weigh in the region of 300g (10.5oz). “So it is expected that the male birds would be making a significant sacrifice in their flight performance for being attractive,” he added.
To confirm this widely held theory, Dr Askew filmed five Indian peacocks in high-speed 3D as they took to the air. Analysing the footage, he observed each bird’s centre of mass position, the movement of the tail feathers, and wing motions.
Using this information, Dr Askew was able to calculate the amount of power the peacocks used to accelerate and gain height after the first two beats of their wings. The peacocks’ trains were then clipped and the birds were filmed in the same manner as before.
However, it didn’t matter whether the peacock took flight with or without his tail feathers, the results were essentially the same.
“Intuitively, you expect that the train would detrimentally affect flight performance and so not finding a detectable effect was a bit surprising,” Dr Askew explained. “These birds do not seem to be making quite the sacrifice to look attractive as we thought they were.”
Dr Askew also mounted the detached trains individually in a wind tunnel to investigate how much drag was created. But what he found was that although the drag doubled, overcoming it only used a tiny amount of the power the peacocks use when they take flight. This means birds with and without their trains use more or less the same amount of energy, and the feathers’ impact on the overall ascent performance is insignificant.
The professor did point out, however, that the birds could be compensating for their immense plumage in other areas. For example, around 3% of the birds’ daily energy goes just into producing their elaborate feathers. Their ability to run and their flight stability might also be affected, as well as potentially making them more conspicuous to predators.
So, if you witness a peacock clumsily taking flight, don’t worry that his tail is a hindrance to him – he is just as ungainly without it!