Lagomorphs

The 60 species of lagomorphs are included in two families. The Leporidae consists of rabbits and hares, familiar animals that have long ears and large hind feet. The Ochotonidae or pikas have relatively short ears and small hind feet.

Rabbits and hares are well-known animals to most people. The natural distribution of this group of animals is extensive, occurring worldwide except for Madagascar, Australia, New Zealand, and various Pacific islands. However, humans have deliberately introduced rabbits to these other places, in particular the European rabbit (Oryctolagus cuniculus) and the European hare (Lepus europaeus). Both of these species typically become pests in their introduced habitats, where their abundance is not well controlled by predators.

Rabbits and hares have long ears, and large, strong, hind legs with big feet, structures that are well adapted to leaping, or to more leisurely hopping. Most species are either crepuscular, meaning they are most active around A pika. JLM Visuals. Reproduced by permission. dawn and dusk, or they are nocturnal, being active at night. The young of rabbits are born naked and blind in an underground burrow, while baby hares are born fully furred, with their eyes open in a surface nest. Young rabbits are initially quite helpless, while baby hares are relatively independent and can run soon after birth.

Rabbits and hares produce two types of fecal pellets. One type is soft and green, consists of partially digested food, and is produced at night. These soft pellets are refected, or re-ingested by the animal, and are swallowed without chewing. Eating its own droppings (coprophagy) allows for a twice-through process of digestion and assimilation of nutrients from the cecum, which is sited after the stomach and small intestine. This is similar in some respects to the habit of ruminant animals of regurgitating their cud, which is chewed again, and then reswallowed. The other type of fecal pellet of rabbits and hares is brown and drier, is not eaten again, and is produced during the day.

Pikas or conies are small animals in the genus Ochotona that live in two disjunct parts of the world-in central Asia and Japan, and in western North America. This is an unusual distribution, and it suggests that the pikas probably migrated to North America from Asia via the Bering land bridge, exposed when sea levels were lowered during the Pleistocene glaciation, which ended about fifteen thousand years ago. The two populations of pikas became separated when sea levels rose again, and eventually evolved in isolation into distinct species.

Pikas have short ears and small feet, and they lack an external tail, although close examination of their skeletons reveals a vestigial tail structure. The color of the pelage of pikas varies from blackish to cinnamon-brown. Pikas are diurnal, or active during the day. Their habitat is alpine tundra, where these animals typically live in rocky piles, or bouldery talus at the base of cliffs.