Saturday, May 19, 2012
The rat that lacks pigment
Some time ago I photographed a strange looking rat that was so tame that it came to within two or three metres of me and allowed me to take many pictures of it before it walked calmly away.
The rat had white markings on the face showing that it was an albinoid rat.
Albinism is characterised by complete or partial absence of pigment in the skin. It can occur in all vertebrates including humans. The lack of pigment can be partial or complete and can also effect the hair and eyes.
Albinism is not often seen in nature. The lack of pigment results in loss of camouflage and albinistic animals are easily spotted by predators. In areas with no predators albino animals can have a normal life expectancy. A Spanish sparrow (għammiel tal-bejt) with large patches of white on its wings used to breed in a ventilator close to where I live and managed to survive for many years.
Several albino animals have been purposely bred for particular characteristics. The best known are albino rabbits and rats. Albino rabbits are said to have a better taste while albino rats are used extensively in laboratories for biomedical studies and experimentation.
It is said that these rats are the descendants of rats caught around 1800 by English rat-catchers for ratting, a blood sport in which trained dogs were lowered in pits full of rats to kill as many as possible in the shortest time possible. Rats which exhibited any albinism, instead of being thrown in the pits, were kept for breeding and exhibition and these became the stock from which today’s laboratory rats are descended.
Two species of rat are found in the Maltese islands; the brown rat (far tal-kampanja) and the black rat (far iswed). Both species of rat can by found in urban and rural areas.
They are very common animals that can be carriers of disease and can cause a lot of damage to crops and stored food.
This article was published in The Times on 12.10.11