Speaking of Nature: the eastern cottontail
The eastern cottontail (Sylvilagus floridanus) is probably one of the most ubiquitous, recognizable animals that can be found in our area. They can easily be seen munching on grasses by the sides of roads, especially by people who are up and off to work at a relatively early hour. They can also be seen out in lawns and gardens, though they are seldom far from cover. Yet, as common as these animals are, there are many things about them that might not be too well understood.
One common misconception is the idea that the cottontail (which is a kind of rabbit) is a rodent. This is a nit-picky detail, but you might as well understand all the details if you’re going to try to understand any of them. A rodent is an animal with a lifestyle that revolves around gnawing. Mice, rats, squirrels, beavers and porcupines are all rodents and they share a very specialized set of teeth to live this sort of life.
Rodents have robust pairs of incisors that grow continuously throughout the life of the individual. They lack any kind of canine teeth at all, which leaves a rather substantial gap between the front teeth and the molars in the back of the jaws. The molars themselves are flattened and specially designed for grinding up vegetable matter. In contrast, the molars in your mouth have more pronounced cusps, which allow for a wider variety of foods to be processed.
Well, rabbits are quite similar to rodents in the sense that they also spend a great deal of their time nipping and chewing plants. As one might imagine, there are tremendous similarities with the teeth of these different groups, but there is also one key difference. Whereas rodents have only two incisors in the upper and lower jaws, rabbits have four incisors in the upper jaws and two in the lower.
The really peculiar thing, however, is the fact that the second pair of upper incisors are actually located behind the first pair. Furthermore, they are not typical teeth, but rather little, peg-like structures that only extend part of the way down the back of the front incisors. You’d actually need a rabbit’s skull in your hand to see this odd arrangement of teeth, but it is there and scientists use it as a key feature in classification. This difference is so distinctive that it puts rabbits in an entirely different order — Lagomorpha.
The lagomorphs (as they are known) are quite different in appearance from the rodents. They tend to have large hind legs, which are clearly designed for running and leaping at high speeds. They also have shortened tails and elongated ears. At least most of them do. As always seems to be the case in nature, there is an exception.
A cousin of the rabbits is an adorable little animal known as a pika. Imagine a cross between a hamster and a rabbit and you’ve just about got it. Pikas are small animals that live in the mountainous regions of North America, Asia and Europe. They are definitely recognizable as being very rabbit-like, but they lack the long ears of their larger cousins. This, as well as a few other little details, makes them different enough to be placed in their own family —– the Ochotonidae.
Rabbits, on the other hand, are grouped with hares in the family Leporidae. Both groups have the more exaggerated hind legs and elongated ears, but there are still a couple minor details that require further taxonomic differentiation. Hares are the largest members of the order Lagomorpha. Their legs are longer, their ears are longer and their body sizes are generally larger than those of rabbits. But the big difference seems to present itself with how the animals reproduce.
Hares are like deer, horses and cattle in the sense that their offspring are precocial. They still have multiple offspring per pregnancy, but they are born fully furred with their eyes open. In just a short time they are up, moving around and able to follow their mothers wherever they need to go. Perhaps it is the result of being larger, or the fact that they live in more open habitats, but the ability to move around is a big deal for hares. Here in North America, we have a few species of hares, including the jackrabbit, which is poorly and confusingly named.
Then you get to the rabbits, which tend to be smaller all around. Their legs are not quite as long, nor are their ears. Rabbits also have altricial offspring, which means they are born naked, blind and helpless. As a result, the rabbits have to build nests where they can safely stash their babies out of the way and it just so happens that I found such a nest last summer.
The nest was a depression about the size of a cereal bowl that had been scraped into the ground and then lined with the softest hair you could imagine. The mother rabbit plucks this hair from her own belly and creates the closest thing a mammal could get to a duck’s nest. Into this nest she will carefully place anywhere from three to eight babies and then she will make herself scarce.
Because the baby rabbits are so helpless, there is real danger in allowing anyone to know their location. The mother must periodically visit the nest to nurse the young, but once this is done, she will tuck them in, cover them up with fur and dry grass and then leave them alone. It is also imperative that the little rabbits stay put. Wandering away from the nest too early is a death sentence for a young cottontail.
Rabbits are desirable food for just about any carnivore out there, so they have to keep the species alive by producing numbers of offspring that overwhelm their predators. Thus, a female rabbit can have up to eight offspring as many as four times a year. To maintain this sort of productivity, a female rabbit will mate shortly after giving birth to a litter of young. She will care for the first litter until the next litter is born approximately 30 days later.
At that point, the month-old babies are responsible for themselves. I have a lot of rabbits in my yard because I don’t have any dogs or cats. As a result, I have a lot of baby rabbits zooming around the yard and every year I manage to find one that is just out and about on its own for the first time. This generally happens while I’m mowing the yard, so I’m always very vigilant. If I see a truly tiny baby, I’ll jump off the tractor, catch the little thing in my hat and bring it over to a quieter part of the yard that I will refrain from mowing for a while.
As the rabbits get older, they start to interact in the most amusing ways. There is a part of my yard that my wife and I have dubbed, “the flat spot” and in this location it is not at all unusual to see several rabbits gather at dusk and start chasing each other around. I’ve even seen rabbits play a little game in which one individual will suddenly sprint at the other, which leaps into the air as the other zooms underneath it. I am fairly confident that this is in fact a game because the rabbits will repeat the sequence over and over. It does actually look like fun, to tell the truth.
Rabbits are crepuscular animals, which means they are most active during the twilight hours of dawn and dusk. If you ever get the chance to wake up early and sip a cup of coffee in the early light of the morning, or perhaps even sip a glass of wine around sunset, keep your eyes open for cottontails. You may be surprised where you find these adorable creatures and you might also be surprised at some of their antics.
Bill Danielson has worked as a naturalist for 16 years. In that time, he has been a national park ranger, a wildlife biologist and a field researcher. He currently works as a high school chemistry and biology teacher. His Speaking of Nature column runs weekly in The Recorder, except for the first Thursday of each month, which is when his Kids and Critters column for young readers appears. To contact Bill, or to learn more about his writing, visit www.speakingofnature.com