Black Kites Use White Plastic To Warn Other Predators

Researchers studying the birds of prey have found that black kites use ‎white plastic materials to cover their nests as a guard to protect their ‎nests, thus signaling a warning to other fighter birds to keep off their ‎territory and in turn, successfully produce more healthy and able offspring. ‎

The plastic is said to serve as a visible warning sign to other black kites attempting to ‎take over the nest, according to Fabrizio Sergio, Ecologist at Doñana Biological Station ‎located in Spain, after studying around 127 black kites in the Park in southwestern Spain ‎for five years. Other options like the transparent and green plastic were also given to the ‎birds, but the birds preferred white. Both female and male birds, between the ages of 7 ‎and 12, used the plastic to advantage, being at the peak of their reproductive abilities and ‎the most physically fit. Younger and elderly birds did not find much use of this plastic. ‎
All attempts to add extra plastic to the nest, were thwarted by the birds, as the birds ‎apparently did not want to fake their toughness. It is like a social test in which peers are ‎verifying your honesty. ‎

The phenomenon of nest decoration has been recorded since the 1800s, but the study ‎clearly indicated that the plastic was meant as a clear signaling device, and not just ‎another decoration. Earlier, the birds could have used cloth or paper, as cover. ‎It is possible that brightly colored feathers of other birds and wool of sheep or deer was ‎used. The behavior could also have come out after plastic became available.‎