LAGOMORPH

Pika (Ochotona princeps) a member of the mammalian order Lagomorpha, which includes the rabbits and hares and the rarer pikas (see photograph), or mouse hares. Long ears, a short tail, and powerful hind limbs that give them an ability to bound from place to place characterize hares and rabbits, while pikas have shorter ears, no exterior tail, and less-developed hind limbs. Living lagomorphs belong to two families: Leporidae (rabbits and hares) and Ochotonidae (pikas). Ranging in size from the smallest pikas at 15 cm (about 6 inches) in length and 100 g (3 1/2 ounces) in weight to the largest hares at 70 cm (27 1/2 inches) and 4.5 kg (10 pounds), lagomorphs are found nearly worldwide. Wild lagomorphs have long been sought by hunters for sport as well as for food and fur. Domestic rabbits, descended from the Old World, or European, rabbit (Oryctolagus cuniculus), are raised for meat and skins and are used in biological and medical research. Wild rabbits and hares can become pests, especially in areas where man has eliminated their natural predators and they are free to deplete vegetation and damage young trees and orchards. Pikas, usually inhabiting regions far from human activity, are of little importance economically to man. Most rabbits and hares have a coat that is brownish or reddish brown above and lighter to white below, but there are wide differences according to species, location, and season. Their habitats include grassland, desert, forest, marsh, brushland, and tundra. Rabbits burrow or inhabit the abandoned burrows of other animals. Hares shelter in natural depressions. Pikas are found in northern steppes, semideserts, some forests and scrub thickets of Asia, and rocky terrain. They may burrow or find natural shelter, depending on habitat. Rabbits and hares usually vocalize only when frightened or injured; pikas have a whistle or bark and a chattering call used in giving alarm signals and in maintaining territorial boundaries. Unlike rabbits and hares, whose major activity takes place from dusk to after dawn, pikas are active during the day. All lagomorphs are herbivorous. Their well-developed incisors are suited to severing plant stems and gnawing on bark, and they continue to grow throughout life, offsetting the abrasive effects of a herbivorous diet. Rabbits and hares are not known to store food, but pikas not only store but dry or cure vegetation for winter. Some lagomorphs are capable of reingesting moist and nutritionally rich fecal pellets, a practice considered comparable to cud-chewing in ruminants. Lagomorphs themselves are the dietary staple of many carnivorous mammals and birds, among them wolves, foxes, bobcats, weasels, predatory hawks, and owls. The long-eared hares rely on keen hearing and strong hind limbs to escape danger by bounding through their open-country habitat as fast as 80 km (50 miles) per hour. The shorter-eared rabbits, with their weaker hind limbs, lack the endurance of hares and seldom venture far from cover. The pikas' still-shorter ears and weaker hind limbs keep them in areas where secure cover can be reached in a quick scamper. The proverbial fecundity of rabbits and hares yields several litters during each breeding season, with two or three litters common among hares and three to six among rabbits. Rabbits gestate for approximately 28 days and hares for 47; litter size is usually between two and eight. Young rabbits, naked and blind at birth, are cared for in a nest; hares, born in the open, have open eyes, are furred, and can run soon after birth. The pikas, whose reproduction cycle is less well-known, gestate for about 30 days and produce a litter of two to six, with two or three litters born each year. In some pikas the young are born lightly furred and with closed eyes and ears, but they gain the ability to move about after approximately eight days. Northern Asia was apparently the place of origin of the order Lagomorpha, most likely by the end of the Paleocene Epoch (about 55,000,000 years ago). The family of rabbits and hares was in North America by the end of the Eocene, and by the Pliocene (about 7,000,000 years ago) it was present in Europe and had become reestablished in Asia. Leporids now are to be found throughout those ranges and down to South Africa and as far south as northern Argentina. The pika family spread from Asia to Europe and eastern North America in the Pleistocene (about 1,000,000 years ago). Pika (Ochotona princeps) any member of the mammalian order Lagomorpha, a terrestrial group that includes the relatively well-known rabbits and hares and also the less frequently encountered pikas (see photograph), or mouse-hares. Rabbits and hares characteristically have long ears, a short tail, and strong hindlimbs that provide a bounding locomotion. In contrast, pikas have shorter, rounded ears, no external tail, and less well-developed hindlimbs associated with scampering locomotion. Additional reading J.N. Layne, Lagomorphs, in Recent Mammals of the World, ed. by S. Anderson and J.K. Jones (1967), general review of characters, distribution, and habits of living lagomorphs; E.P. Walker et al., Mammals of the World, 2nd ed. (1968), photographically illustrated articles on living genera of lagomorphs; R.M. Lockley, The Private Life of the Rabbit: An Account of the Life History and Social Behaviour of the Wild Rabbit (1964, reissued 1985), semipopular work dealing with the rabbit in Britain and the disease myxomatosis; H.E. Broadbooks, Ecology and Distribution of the Pikas of Washington and Alaska, Am. Midl. Nat., 73:299335 (1965), discussion of habits and habitats of North American pikas; M.R. Dawson, Lagomorph History and the Stratigraphic Record, in Essays in Paleontology and Stratigraphy, ed. by C. Teichert and E.L. Yochelson (1967), review of fossil lagomorphs and their usefulness for stratigraphic studies; A.A. Gureev, Lagomorpha, in Mammals, vol. 3, no. 10, Fauna S.S.S.R., Zoologicheskii Institut Akademii Nauk S.S.S.R., New series no. 87 (1964), comprehensive treatment of the morphology and relationships of fossil and living lagomorphs (in Russian); E.R. Hall, A Synopsis of the North American Lagomorpha, Univ. Kans. Publs. Mus. Nat. Hist., 5:121202 (1951), on the taxonomy and distribution of North American forms; A.S. Loukashkin, On the Pikas of North Manchuria, J. Mammal., 21:402405 (1940), on the behaviour and habitats of Asian pikas. Mary R. Dawson