OUTDOOR WORLD BY DON MACLEAN
A friend recently sent me a picture of a white moose he saw while snowmobiling in the Margaree area of Cape Breton a few winters ago. The moose was fully grown and was pure white, indicating it was probably an albino.
White moose are rare, but a few show up now and then. The genetic trait that creates this is called albinism and it can be found in all animals from mammals and fish to birds and reptiles. While I have never seen an albino moose or deer I did see a white crow once and when my daughters raised rabbits for 4-H, we often had albino rabbits.
Albinos do not have the genes for colouration and, as a result, cannot produce the pigments for normal body colours. One of the most common traits people think of regarding albinos is their pink eyes. This results from the fact that the iris of the eye has no pigment and the blood vessels at the back of the eye are visible through the lens.
Albinos are very rare in nature because the condition is usually not an advantage to the animal. Most animals are naturally camouflaged to protect them from predators and being white means you are much more visible. In the same way albino predators also have a difficult time sneaking up on their prey.
Since albinism is a recessive trait it is often accompanied by other problems such as bone abnormalities, organ problems and so on. Typically albinos also have poor eyesight.
While albinos are very rare there are other colour variations which also show up in animal populations. While the chances of finding a true albino whitetail deer are about one in 3,000 there is another colour variation more common in Nova Scotia. These deer are normally coloured but have patches of white hair on their body, much like a pinto horse. This variation is known as piebald and every season hunters harvest a few.
On the other extreme deer may be very darkly coloured, even black. This high level of pigmentation is known as melanistic and finding a true black deer is probably as rare, or rarer, than finding a white one. Other animals may exhibit this trait as well. I have a piece of hair harvested from a melanistic coyote down in the Annapolis Valley which I use for fly tying.
These traits are rare in animals because evolution has favoured animals which are able to survive well in nature and this usually means body colours which help them blend in with the background. While we may be captivated by the various colour variations of whitetail deer, normal deer also undergo some important colour changes throughout the season. While all deer have some white hair around their eyes, mouth and throat as well as their tail, the majority of their body hair is brown. In the fall this hair is dark brown and during the winter it is a shade of gray. This time of year, however, they are in their summer colours and are almost red, like a fox.
Don MacLean is an outdoor writer and biologist who lives in Pictou County.