The Hippity-Hoppity History of Rabbits

Who doesn’t love bunnies? They are the epitome of the phrase “cute and cuddly.” With all that fluff it should come as no surprise that rabbits are very popular animals across the globe. From the Easter Bunny to Bug Bunny, rabbits are a stable of pop culture. Despite the fact they are so well known, if you were to ask the average person on the street for some facts on rabbit biology or evolution, the response you’d get would probably be along the lines of “What’s up, Doc?” How much do you know about rabbits?

 

Not Rodents

Most people will tell you that rabbits are a type of rodent. At first glance, this seems to be the case. Rabbits are small, reproduce at prolific rates, and have big buck teeth like rodents. However, looks can be deceiving. Despite their rodent like looks and behavior, rabbits actually belong to a different group of animals. This group is known as the lagomorphs and includes not only rabbits but their closest relatives, the hares and pikas. Lagomorphs can be distinguished from rodents by the structure and number of their teeth. Both groups have enlarged, continuously-growing incisors but rodents have only two in each jaw while lagomorphs have four in the upper. Lagomorph incisors are also coated in enamel on both faces whereas rodents only have enamel on the front of their teeth.

Bunny Skull

Rabbits vs Hares

To most people, the differences between rabbits and hares are purely semantics. After all, what’s one long-eared, cotton-tailed critter to another, right? Wrong! Rabbits and hares actually differ from one in several key aspects. Hares, which include the animals commonly called jackrabbits, are larger with more digitigrade limbs suited for cursorial locomotion. They tend to live in open environments and rely on speed to avoid predators. Rabbits prefer more forested habitats where they can seek refuge amidst the foliage. Baby rabbits, called kits, are born blind and furless in the protection of a burrow, whereas hares have precocial young called leverets that can fend for themselves shortly after birth. In general, rabbits tend to be more social than hares.

Unknown   px Jackrabbit crop

Pikas are more distinctive than their better-known kin. They lack the long ears of their cousins and look a little bit like between a small rabbit and a mouse. Like rabbits and hares, pikas are adapted for hopping locomotion. Rather than living in forests or grasslands, pikas prefer mountainous habitat and some species can be found at altitudes as high as 20,000 feet.

Pika, Medecine Lake, Near Jasper, Alberta

Low Diversity

The order Lagomorpha contains a little under 90 species, split almost evenly between the rabbits, hares, and pikas. That may seem like a lot but if we compare them to their close cousins the rodents, that number is mere pittance. Rodents make up over 40% of all known mammal species and come in a bewildering variety of sizes and shapes. They occupy every sort of ecological niche imaginable. Lagomorphs, on the other hand, do not display such great diversity. All the species of rabbit pretty much looks the same apart form slight variations in size and color, and all species occupy the same ecological niche, that of a small grazer. The same goes for hares and pikas, too. This lack of diversity, both morphological and ecological, is in part due to competing with other mammal groups, although not necessarily the ones you’d expect. Rodents do have a part to play, but they were not the main competition lagomorphs faced, at least not initially. Rabbits may be pretty good at eating grass but no mammals are better at grazing than artiodactyls. That’s right, even-toed hoofed animals ruined the day for rabbits. They diversified into most of the grazing niches before lagomorphs did and since rodents were able to adapt to many different dietary strategies, rabbits and their relatives were evolutionary shoehorned into the niche they occupy now. The prior radiation of the rodents prevented lagomorphs from exploiting other niches.