Why do vultures and other birds have plucked necks?

Researchers at the Roslin Institute of the University of Edinburgh, in the United Kingdom, have discovered how the Transylvanian naked-necked chicken , whose head resembles that of a turkey while its body assimilates that of a chicken, developed this hybrid appearance due to a complex genetic mutation.

As reported in the journal PLoS Biology , these animals, believed to have originated in northern Romania, have been around for hundreds of years and were introduced to the UK less than a century ago. Analyzing DNA samples from specimens of the birds from Mexico, France and Hungary, they discovered that a substance derived from vitamin A that is produced around the neck of the bird sensitizes the skin of the neck to the effects of a genetic mutation. This mutation triggers increased production throughout the body of an inhibitory protein called BMP12 , and the combination of these two signals results in the bird having a featherless neck .

The finding has implications for understanding the physiology of some birds, including vultures, and according to those responsible for the study "it could have practical implications to help in poultry production in temperate countries." Chickens without neck feathers are much better prepared to withstand the heat .