Sylvilagus nuttallii (Bachman, 1837)

Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Leporidae, Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona: Lynx Edicions, pp. 107-148 : 116

14.

Mountain Cottontail

Sylvilagus nuttallii

French: Lapin de Nuttall / German: Berg-Baumwollschwanzkaninchen / Spanish: Conejo de Nuttall

Other common names: Nuttall's Cottontail

Taxonomy. Lepus nuttallii Bachman, 1837 ,

“...west of the Rocky Mountains....streams which flow into the Shoshonee and Columbia rivers.” Restricted by E. W. Nelson in 1909 to “eastern Oregon, near mouth of Malheur River.”

Genetic analysis shows that S. nuttallii and S. audubonii are sister taxa. As taxonomists are still trying to clarify the species differentiation in Sylvilagus , the subspecific taxonomy is not elaborated yet. The original descriptions of the subspecies are often not very helpful as they are mostly based on few exterior characteristics and small numbers of individuals. It has been shown that the variability is clinal in more careful investigations. Hence, the distinction in subspecies might be arbitrary and unreasonable. Sylvilagus nuttallii is closely allopatric with S. floridanus where their distributions meet across the northern and central Great Plains and in south-western USA. Sylvilagus nuttallii lives sympatrically over most of its distribution and in syntopy in the subalpine zone with Lepus americanus . Three subspecies recognized.

Subspecies and Distribution.

S.n.nuttalliiBachman,1837—NWpartoftherangeinextremeSBritishColumbia(SWCanada),Washington,WCIdaho,Oregon,NECalifornia,andNWNevada(NWUSA).

S.n.grangeriJ.A.Allen,1895—Cpartoftherange,fromSAlbertaandSSaskatchewan(SCanada)SWtoCECaliforniaandSEtoNArizonaandNWColorado(CUSA).

S. n. pinetisJ. A. Allen, 1894 — SE part of the range in SC Wyoming, SE Utah, C & SW Colorado, NW New Mexico, and NE & C Arizona (SC USA).

Descriptive notes. Head-body 340-390 mm, tail 30-54 mm, ear 55-60 mm, hindfoot 87-110 mm; weight 629-871 g. The Mountain Cottontail is a large species of Sylvilagus . Hindlegs are long, and all four feet are densely covered with long hair. Ears are rounded at tips and short, with inner surfaces haired. Dorsal fur is grayish, and ventral fur is white. Tail is large, grizzled dark above and white below. Female Mountain Cottontails are slightly less than 4% larger than males. Thereis a single molt per year.

Habitat. Sagebrush ( Artemisia spp. , Asteraceae ) areas in the northern part of the distribution and forested areas in the southern part. Mountain Cottontails have been recorded in riparian growth, cultivated fields, desert scrub, grasslands, woodlands, and montane and subalpine coniferous forests. They prefer rocky, brushy, and wooded areas. In California, they occur at elevations of 1372 m to at least 3542 m. Mountain Cottontails use burrows and forms but do not dig their own burrows. They mostly live aboveground in dense habitat, but frequently use crevices in rocks or burrows as shelter in less dense vegetation.

Food and Feeding. In California, the diet of the Mountain Cottontail consists mainly of sagebrush, but they prefer to feed on grasses when available in spring and summer. Western juniper ( Juniperus occidentalis, Cupressaceae ) also is eaten. They usually feed underbrush cover or in clearings near shelter.

Breeding. Start and duration of the reproductive season of the Mountain Cottontail vary across its distribution. It begins in April and lasts into July in north-eastern California and late February until early July in central Oregon. Gestation lasts 28-30 days. Female Mountain Cottontails in California normally have two litters per year, but in Oregon, they have 4-5 litters/year. Litter sizes average 4-6 young (range 1-8). A female might produce 22 young/year in Oregon.Juvenile breeding occurs butis rare. Nest is a cuplike cavity lined with fur and dried grass in a burrow. Top of the nest is covered with fur, grass, and small sticks. Adult sex ratio has been reported to be 1:1-2 (males/females).

Activity patterns. The Mountain Cottontails actively feeds in early morning and evening. In California, activity started at dawn until 09:30 h and again from 14:30 h until dark, but in Nevada individuals were active from 17:45 h until dark. Activity of Mountain Cottontails peaks 1-2 hours after sunrise and 0-1 hour before sunset in Oregon. Adult males become extremely secretive after the reproductive season, but activity of females is relatively constant throughout the years.

Movements, Home range and Social organization. The Mountain Cottontail is more solitary than other species of Sylvilagus , which might be due to its uniform habitat. It might concentrate, as do other species of Sylvilagus , in areas where patches of green grass or other desirable habitat occurs. Social behavior among adult Mountain Cottontails is only observed during the reproductive season.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Mountain Cottontail is common throughout most ofits distribution, and populations do not seem to be declining. The Eastern Cottontail (S. floridanus ) has displaced the Mountain Cottontail in south-western North Dakota, which might represent an ongoing but localized threat. The Mountain Cottontail is a common game species and managed by state and provincial wildlife agencies that determine hunting seasons and bag limits.

Bibliography. Angermann (2016), Bailey (1936), Borell & Ellis (1934), Chapman (1975b, 1999a), Chapman & Ceballos (1990), Chapman et al. (1982), Dalquest (1941), Dice (1926), Frey & Malaney (2006), Frey &Yates (1996), Genoways & Jones (1972), Halanych & Robinson (1997), Hall (1946, 1951, 1981), Hall & Kelson (1959), Hoffmann & Smith (2005), Hoffmeister & Lee (1963), Lissovsky (2016), Malaney & Frey (2006), Nelson (1909), Nowak (1999a), Orr (1940), Powers & Verts (1971), Smith & Boyer (2008b), Turner (1974), Verts & Gehman (1991).

Figures

33. Indian Hare (Lepus nigricollis), 34. Burmese Hare (Lepus peguensis), 36. Scrub Hare (Lepus saxatilis), 37. African Savanna Hare (Lepus victoriae), 38. Yarkand Hare (Lepus yarkandensis), 39. Ethiopian Highland Hare (Lepus starcki), 40. Cape Hare (Lepus capensis), 41. Abyssinian Hare (Lepus habessinicus), 42. Tolai Hare (Lepus tolai), 43. Desert Hare (Lepus tibetanus), 44. Yunnan Hare (Lepus comus), 45. Woolly Hare (Lepus oiostolus), 46. Snowshoe Hare (Lepus americanus), 47. Black-tailed Jackrabbit (Lepus californicus), 48. Black Jackrabbit (Lepus insularis)

Subspecies and Distribution. S.n.nuttalliiBachman,1837—NWpartoftherangeinextremeSBritishColumbia(SWCanada),Washington,WCIdaho,Oregon,NECalifornia,andNWNevada(NWUSA). S.n.grangeriJ.A.Allen,1895—Cpartoftherange,fromSAlbertaandSSaskatchewan(SCanada)SWtoCECaliforniaandSEtoNArizonaandNWColorado(CUSA). S. n. pinetisJ. A. Allen, 1894 — SE part of the range in SC Wyoming, SE Utah, C & SW Colorado, NW New Mexico, and NE & C Arizona (SC USA).