The Hybrid History of North American Deer

There are five species of deer native to the US and Canada. Two of these, the moose and the caribou, are distinctive animals with no especially close living relatives. The elk, while perhaps not as distinctive in appearance as these two, is even more distant from the others in evolutionary terms. The other two, however, are the white-tailed deer (Odocoileus virginianus) and the mule deer (Odocoileus hemionus) which not only look similar to one another but are, indeed, each other's closest relatives.

When I discussed these two species in detail last year, I mentioned the existence of the "black-tailed deer" a subgroup of mule deer with tails of a more solidly black colour than others of their kind. The black-tailed deer are native to the Pacific Northwest and are generally considered to consist of two subspecies of mule deer that share a common ancestor that split off from other mule deer early on. Since are subspecies, not full species, it should come as no surprise to discover that they hybridise with other mule deer where the two come into contact, although, if anything, this happens more often than we might expect.

All the World's Deer: White-tailed and Mule Deer

White-tailed deer

When I started this series on deer species, I asked some non-experts how many different kinds of deer they were aware of, to see which ones were best known. I got roughly (but not entirely) what I expected, with red deer and fallow deer topping the list. But that's a reflection of where I live; I suspect that, had I been asking Americans, few could have failed to mention the white-tailed deer.

The white-tailed deer (Odocoileus virginianus) is the most widespread and common species of deer in the Americas, and well-known to anyone familiar with the American wilds. They live throughout the whole of the contiguous US, except for the arid south-west, across southern Canada and almost the whole of Mexico. They are also found right across Central America, and into Colombia and Venezuela beyond, reaching the Guyanas and far northern Brazil in the east and as far as Peru in the south.