This hen has earned the sobriquet 'wonder bird' from locals and zoologists, for the six-year-old hasn't yet shown its 'true colour'!
In a first such documented case, zoologists here are studying the "rare phenomenon" where a bird, which was black originally, has changed its colour four times in last six years without shedding its plume.
The bird turned black-and-white twice in 2009 while it has remained pristine white so far this year, said Selvaraj, a farmer from Mukkola village near here who owns the 'wonder bird'.
"The change of colour of its feathers was noticed after it laid eggs for the first time. The black bird then became white within a year without any ill effect on its health," he said.
According to Dr Oommen V. Oommen, an Emeritus scientist with CSIR who has been observing the hen since 2008, it is a "rare phenomenon" which deserve detailed study.
"It is an uncommon freak case...,"Oommen told PTI.
"Blood and hormone samples of the bird have been collected in 2008, 2009 and 2010 and analysed. Estrogen (female sex hormone) count was found to be very high in the hen, which could be the reason behind the phenomenon," Oommen, former Head of Department of Zoology at the Kerala University, said.
Estrogen could inhibit pigmentation in females. However, this had to be established after further studies including the genetic aspect of the bird, he said.
The chicken of the bird were also being observed as the farmer had reported that one of them appeared to be having the similar tendency.
The matter had also been brought to the notice of experts of the Banaras Hindu University, he added.