There are six different species of tree-dwelling squirrels in Canada. You’ve probably seen their energetic antics as they run along electrical wires and fences, jumping from tree to tree looking for places to store food for the winter. Even if you cannot tell the different species apart, you may have noticed their various coat colours, ranging from reddish-brown to grey to black. You may also have noticed some squirrels demonstrating aggressive behaviour. Could there be a connection between the two?
Melanistic squirrels are so-called because they are black in colour. Scientists and laypeople alike have observed that black squirrels tend to exhibit more aggressive behaviour than others. This is important because a more aggressive animal may be more likely to move into human habitation, requiring squirrel removal Hamilton.
Are Black Squirrels a Separate Species From Grey Squirrels?
The origins of melanistic squirrels are not entirely clear, but they do not appear to be a separate species. One theory is that black squirrels are a hybrid produced when eastern grey squirrels and fox squirrels interbreed. It is thought that this inbreeding results in a genetic mutation that causes the melanistic colouring. This would explain why some black squirrels are larger than grey ones. Fox squirrels are the largest squirrel species in North America and one that mates with a grey squirrel could pass on its size to its offspring. On the other hand, fox squirrels are rarely, if ever, found in Ontario because their range does not extend this far north. Therefore, this theory is inadequate to explain why black squirrels are found here.
Another theory is that both fox squirrels and grey squirrels have genetic melanistic variants. It is believed that some members of each species carry recessive genes that produce black fur coloration. If two carriers of this gene meet and mate, at least some of the offspring may have black fur.
Are Black Squirrels More Aggressive?
Melanistic squirrels can behave very aggressively toward other types. It is believed that they have more testosterone, which makes them both more territorial and fiercer in defending their territory. The increased testosterone may also give them more bulk and greater speed than other squirrels. Proponents of the hybrid theory of squirrel melanism argue that the offspring of two different squirrel species inherit desirable traits from each of their parents, making them stronger and more hardy as a result. Increased testosterone may result from this.
When resources are scarce, such as during the winter, it can bring out aggression and territorialism in squirrels. Because their increased testosterone gives them advantages, melanistic squirrels may be not only more likely to display aggression toward others but more likely to win in a fight.
How Can You Tell Black Squirrels Apart From Grey Squirrels?
It should be noted that just because a squirrel appears black, it does not necessarily mean that it has a higher testosterone level and resultant aggression. A grey squirrel’s coat actually consists of hairs of many different colours. As a result, its appearance can change throughout the year. At some times, the grey squirrel’s coat may appear darker, causing it to be confused with a black squirrel.
Does Black Fur Provide Any Advantages?
The mutation may have evolved in the first place because it gives squirrels living in northern areas an advantage. Black fur retains heat better, which can help to keep the squirrel warm when the temperature drops. The increased testosterone could also be seen as an advantage, and the same genetic mutation that causes dark coloration may also produce immunity to disease.
If black fur and related traits give melanistic squirrels an evolutionary advantage, more of them may survive to breed and pass on the traits to their offspring. As a result, you may find more squirrels in your house. Skedaddle provides squirrel removal in Hamilton that is safe and humane. Contact us for help with any wildlife in your home, not just squirrels.
