Rabbits and hares Types, distribution and abundance

Public Health Significance of Urban Pests 431 well as on occasional invertebrates. Their name comes from the distinctive nests they build, which consist of large piles of sticks that are often placed at the base of a tree or other sizeable plant, although the nests of Mexican wood rats Neotoma mexicana are constructed in large cracks in cliff faces, along the walls of caves or under large rocks. Many species in the western United States and Mexico cover their stick nests with pieces of spine-bearing cactus to provide additional protection against predators. If left undis- turbed, wood rats will continue to add items to their nests until they become quite large. Bonaccorso Brown 1972 reported that a single desert wood rat Neotoma lepida could build a complete nest 40 cm high and 100 cm wide over a period of 7–10 days. Wood rats are highly territorial, and the valuable nest sites are defended vigorously, rarely remaining unoccupied for long periods. In some instances, nests can exist for many decades and per- haps even longer, being enlarged by each new resident. Several species of Neotoma are known to build their nests in the walls or crawl spaces of homes, garages or other buil- dings. The gnawing activities of these rats, as well as the extensive piles of excreta asso- ciated with their nests, can result in damage to homes or other property and cause an unsightly mess. Female wood rats in the northern part of the continent typically produce a litter a year, while those living in more southerly areas sometimes have two litters a year. The average litter size is 2–6 pups. Wood rats do not become sexually mature for 7–8 months after birth, and they live longer-than deer mice; one wood rat in captivity lived for nearly 8 years, although lifespans of 3–5 years are probably more typical in the wild. Cotton rats, of the genus Sigmodon, are common in grassy and weedy fields in many areas of southern North America. The most important species in the temperate regions of the continent is the hispid cotton rat Sigmodon hispidus, which is often extremely abundant in thick grassy habitats in the south-eastern and south-central United States Cameron Spencer, 1981. In many ways, the behaviour and ecology of cotton rats resemble those of voles, which are more common in the northern parts of the continent. These similarities include not only types of habitats selected, but also include the construction of grass nests and runways, extremely high reproduction rates and populations that often fluctuate dra- matically from year to year. In the warmer portions of its range, the hispid cotton rat can breed year-round. Females produce several litters a year, with up to 15 young in each lit- ter. Most cotton rats that survive to breed live less than 2 years. Their activity typically peaks around dawn and dusk, during which time they forage on various types of green vegetation, as well as on the occasional insect or bird egg. Cotton rats can be quite des- tructive to some crops, including sugar cane and sweet potatoes.

13.2.11. Rabbits and hares

Rabbits and hares are not rodents, but rather belong to the family Leporidae within the mammalian order Lagomorpha, which also includes pikas. The most notable difference between lagomorphs and rodents is the possession of an extra pair of incisors in the for- mer group. Rabbits and hares are extremely widespread, occupying habitats from the tropics to the Arctic, including forests, deserts, grasslands, wetlands and mountainous areas. All species are long-eared, grazing animals with elongated limbs for running quic- kly over open ground. Their large eyes, placed on the side of the head, improve their chances of detecting approaching predators, even in dim light. These animals also have Non-commensal rodents and lagomorphs 430 species also occur on the continent, the ones most likely to be encountered by people are the fat or edible dormouse Myoxus glis, formerly Glis glis, the common or hazel dor- mouse Muscardinus avellanarius, the garden dormouse Eliomys quercinus, and the forest dormouse Dryomys nitedula. Dormice typically live in wooded areas, hedgerows and rocky places, but will enter gardens or other areas near human dwellings. They find shel- ter in hollow trees, rock crevices and abandoned burrows, where they build a nest of plant materials. Given the opportunity, these rodents also will build nests in building attics or barns. Dormice are normally nocturnal, but can be active at dawn or dusk. Their diet consists primarily of nuts, fruits, insects, eggs and small vertebrates. In the northern por- tions of their range, dormice put on considerable fat in the fall and hibernate during the winter, waking only occasionally to feed on stored food items. Females give birth to one or two litters a year, with each litter containing 2–10 young. Dormice are believed to live for 5–6 years in the wild. Although they occasionally can become nuisances and damage wine grapes and fruits, dormouse populations are typically so small that they have little impact on people.

13.2.10. N ew World rats and mice