Tuesday, March 15, 2005

How Are Rabbits And Hares Different?

This month, you'll probably see a lot of Easter decorations around. So, let's have a look at what makes a rabbit a rabbit, and a hare a hare. Baby rabbits are born with their eyes closed and without a fur coat. Rabbits build nests in which to care for these very fragile newborns. In contrast, newborn hares are fully-developed (with open eyes and coats of fur). Hares do not build nests.

Sometimes common names can make the distinction between rabbits and hares a little fuzzy (or furry as the case may be!). For example, black-tailed hares and white-tailed hares are commonly called jack rabbits, even though they are actually hares (not rabbits). The snowshoe hare is commonly known as the snowshoe rabbit. Cottontailed rabbits, however, are actually rabbits.

So, how did the snowshoe hare get its name? The answer is that, in the winter, it grows very long fur over its feet, which makes them look like snowshoes. Just like snowshoes give people a wider base to walk on, the extra fur on the hare's feet gives them a wider base. This helps the hare run more easily through the snow by not getting bogged down as deeply in it. Rather, it glides over the surface of the snow as it runs.

As its name suggests, the snowshoe hare is completely white (except for the tips of its ears) in the winter, but the white-tailed hare can turn completely white too if it lives in a very cold environment. So, sometimes what seems like a snowshoe hare might actually be a white-tailed hare.

In the warmer months, the hares shed their white coats and replace them with grayish brown coats. This makes sense when you think about the forest when it is not covered in snow. If a hare is running through the forest, it is likely to be seen against tree trunks, dead leaves, and rocks. Since these items are brown and gray, the hare can blend in if it too is brown or gray.

Why does environment make a difference in fur color? The answer is that animals survive better if they can hide from their predators (animals that eat them). One common way to not be noticed is to blend into the background by matching it. In nature, this is called camouflage.

Let's think through why different fur colors correspond to different seasons. In very cold regions, the ground is often covered in snow. So, to blend in with its snowy environment, the snowshoe hare and the white-tailed hare grow white coats of fur. In contrast, warmer environments for the hares have darker backgrounds (like mountains and deserts). So, a brown or gray coat of fur is the best camouflage in these warmer areas.

Little Lion Experiment:

Animals don't decide what color to be; rather they have evolved (adapted over time) to have this camouflage. Basically, the animals that blended into their environments were able to hide from predators, so they survived much more often than those that didn't blend in well. As a result, the hares that survived were those who happened to make coats that matched their environments, while the animals that got caught by predators were usually the ones that "stuck out" and were therefore easier for predators to find. Over time, the only families of hares left were those who blended in with their environments.

You don't generally see many wild animals in the winter, but as the seasons change, you will see many more animals (like birds that had flown south for the winter) returning to this area for the warmer months. You will also see animals that stayed here, but did not leave their shelters very often during the winter. As you look around, try to spot other examples of camouflage in the animals that you see. Think about where those animals usually live (as opposed to where they are when you happen to see them) in order to see how their bodies blend into their environments.