Rabbits, hares, and pikas
Rabbits, hares, and pikas are small to medium-sized mammals belonging to the order Lagomorpha, which is divided into two families: Leporidae (rabbits and hares) and Ochotonidae (pikas). They exhibit a diverse range of physical characteristics, with pikas measuring around six inches and weighing approximately 3.5 ounces, while hares can reach lengths of nearly twenty-eight inches and weights of up to 10 pounds. These animals typically have brownish or reddish-brown coats with color variations influenced by species, habitat, and seasonal changes.
Lagomorphs are primarily herbivorous, possessing specialized teeth that continuously grow and are adapted for gnawing on plant material. They exhibit unique digestive processes, including the ability to produce two types of fecal matter for nutrient absorption. Reproductively, they can have multiple litters per breeding season, with young rabbits being altricial (born helpless) and hares being precocial (able to move shortly after birth).
While lagomorphs play an essential role in the ecosystem as prey for various carnivorous animals, they can also become pests in agricultural settings, feeding on crops and ornamental plants. Their diverse behaviors and adaptations illustrate their significance in both natural habitats and human environments.
Rabbits, hares, and pikas
Rabbit, Hare, and Pika Facts
Classification:
- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Vertebrata
- Class: Mammalia
- Order: Lagomorpha
- Family: Leporidae (hares and rabbits), Ochotonidae (pikas)
- Genera:Brachylagus (pygmy rabbit),Bunolagus (bushman or riverine rabbits),Caprolagus (hispid hares),Lepus (hares, thirty-two species),Oryctolagus (European rabbits),Nesolagus (Sumatran hares),Pentalagus (amami rabbits),Poelagus (Bunyoro rabbits),Pronolagus (red rock hares, three species),Romerolagus (volcano rabbits),Sylvilagus (cottontails, seventeen species);Ochotona (pikas, three subgenera, thirty species)
- Geographical location: All continents except Australia and Antarctica; absent from southern South America and most islands; especially diverse in North America and Eurasia, the only continents where pikas are found
- Habitat: Range from tropical forest to arctic tundra
- Gestational period: Rabbits, approximately twenty-eight days; hares, up to forty-seven days; pikas, approximately thirty days
- Life span: In the wild, rarely more than nine months; up to fifteen years in captivity
- Special anatomy: Flaps of skin able to close the nostrils; peculiarly fenestrated skull; long incisors that grow throughout life; generally long hind feet, with the hind legs strong and positioned for leaping; usually long ears; testes located in front of the penis rather than behind; lagomorphs produce two types of fecal material, one that is wet and eaten again for further nutrient absorption and one that is dry and discarded
Lagomorphs have two families: Leporidae (rabbits and hares) and Ochotonidae (pikas). Lagomorphs range in size from pikas, which are six inches in length and 3.5 ounces in weight, to hares which are almost twenty-eight inches in length and 10 pounds in weight. Most lagomorphs have coats that are brownish or reddish brown above and lighter brown to white below. There are color differences according to species, location, and season. Lagomorphs are well adapted to a herbivorous diet. Rabbits and hares are not known to store food, while pikas not only store food but also dry or cure vegetation for winter. Rabbits and pikas burrow or inhabit abandoned burrows, and hares shelter in natural depressions.
Physical Characteristics of Rabbits, Hares, and Pikas
Lagomorph incisor teeth are long and grow throughout life. They are extremely effective for severing plant stems and for gnawing on bark. Behind the long incisors is a tiny peglike incisor. There are no canine teeth. Cheek teeth, located further back in the jaw, also grow throughout the animal’s life, wearing away as they grind abrasive vegetation. The upper tooth rows are more widely separated than the lower rows, and chewing is done with a transverse movement. Vegetation passes through the small intestine, which has a spiral valve, providing greater surface area for digestion. A large cecum is located at the point of attachment of the large intestine, which contains bacteria that aid in digestion. Lagomorphs have the ability to produce two types of fecal material, one that is wet and eaten again for further nutrient absorption, and one that is dry and discarded.
The bones of the hind limb are fused where they move against the calcaneuni, resulting in increased leverage in locomotion. Lagomorphs are digitigrade, with five digits on the forefoot and five on the hind foot.
Rabbits and hares have a rudimentary tail, while pikas have none at all. Folds of skin on the lips can meet behind the incisors so that gnawing can take place with the mouth cavity closed. Other flaps of skin are able to close the nostrils. The skull is peculiarly fenestrated. The ears are usually long. The testes are located in front of the penis rather than behind.
Rabbits and hares usually vocalize only when frightened or injured. Pikas express themselves with a whistle or bark and a chattering call.
Lagomorphs can yield two or more litters during each breeding season, with two or three litters common among hares and pikas and three to six among rabbits. Litter size ranges between two and eight. Young rabbits are altricial and are cared for in a nest. Hares are born in the open and are precocial, able to run soon after birth.
Destructive and Beneficial Lagomorphs
Lagomorphs can be vectors for disease, as well as pests to human agriculturists. Rabbits eat flowers and vegetables in spring and summer, causing problems in flowerbeds, gardens, and fields. In the fall and winter, they may damage and kill valuable woody plants. Lagomorphs are the dietary staple of many carnivorous mammals and birds, among them wolves, foxes, bobcats, weasels, predatory hawks, and owls. They are therefore an important link in the food chain.
Principal Terms
altricial: born naked, with eyes and ears closed for several days (rabbits)
digitigrade: walking on toes
fenestration: a latticework of openings on the sides of the skull
precocial: born fully haired, with functional eyes and ears (hares)
rudimentary: short or small
Bibliography
Adamo, Gianni, and Albert Costanza, eds. Rabbits: Biology, Diet, and Eating Habits and Disorders. Hauppauge: Nova Science, 2013. Print.
Carnell, Simon. Hare. London: Reaktion, 2010. Print.
Chapman, J. A., and J. E. C. Flux. Rabbits, Hares and Pikas: Status Survey and Conservation Action Plan. Gland: IUCN/SSC Lagomorph Specialist Group, 1990. Print.
Dickenson, Victoria. Rabbit. London: Reaktion, 2014. Print.
Feldhamer, G. A., L. C. Drickamer, S. H. Vessey, and J. F. Merritt. Mammalogy: Adaptation, Diversity, and Ecology. Boston: WCB/McGraw-Hill, 1999. Print.
Hoffmann, R. S. “Order Lagomorpha.” Mammal Species of the World: A Taxonomic and Geographic Reference. Ed. D. E. Wilson and D. M. Reeder. Washington, DC: Smithsonian Inst., 1993. Print.
Vaughan, T. A. Mammalogy. 3rd ed. Fort Worth: Saunders College, 1996. Print.
Wilson, D. E., and D. M. Reeder. Mammal Species of the World: A Taxonomic and Geographic Reference. 2nd ed. Washington, DC: Smithsonian Inst., 1993. Print.