337.

Black-footed Tree Rat

Mesembriomys gould

French: Rat de Gould / German: SchwarzfuR-Baumratte / Spanish: Rata arboricola de pies negros

Other common names: Black-footed Mesembriomys

Taxonomy. Hapalotis gould Gray, 1843, Port Essington, Northern Territory, Australia.

Taxon gouldwas recognized within Coni-lurus by J. D. Ogilby in 1892, but H.A. Longman in 1916 and subsequent authors have placed it within genus Mesembriomys . Three subspecies recognized.

Subspecies and Distribution.

M.g.gouldiiGray,1843—mainlandNAustralia,includingtheKimberleyregionandhigherrainfallareasoftheNorthernTerritory.

M.g.melvillensisHayman,1936—MelvilleI,NAustralia.

M. g. rattoides Thomas, 1924 — N Queensland, NE Australia.

Descriptive notes. Head-body 250-300 mm, tail 320-410 mm, ear 41-48 mm, hindfoot 65-72 mm; weight 580-880 g. The Black-footed Tree Rat is a large, variable, and distinctive, somewhat squirrel-like native rat with aslender build, long face, and long, shaggy fur. Dorsal pelage varies from medium gray to black, with individuals of the subspecies melvillensis being generally darker overall. Ventral pelage varies widely between populations, being white ( gouldii), medium gray (melvillensis), or pale gray ( rattoides); venter and dorsum are not usually sharply demarcated, although individuals with darker dorsum and lighter venter can seem more demarcated. Feet are also variable, with the short and broad forefeet generally being completely black and the elongated and broad hindfeet varying from all black (melvillensis) to mostly black ( rattoides) or with black and white mottling ( gouldii). There is always a dark black ring around the eyes. Ears are very long, rounded, and dark black; vibrissae long and dark. Tail is longer (c.133%) than head-body length, completely furred, and black with a distinctive white terminal tuft. Skull is large and long with an inflated rostrum. Females have two pairs of inguinal mammae. Chromosomal complement is 2n = 48 ( gouldii) or 47 ( rattoides); FN = 52 in gouldii and female rattoides or 51 in male rattoides .

Habitat. Occurs mostly in tropical eucalypt woodlands and open forests, particularly those dominated by Eucalyptus miniata and E. tetrodonta ( Myrtaceae), and especially where there is an understory or midstory of woody shrubs producing fleshy fruits. It is reported also from orchards of fruitand nut-producing exotic tree species, and sometimes roosts in dwellings and other infrastructure. In native woodlands and open forests, it tends to be more abundant in areas with larger (older) trees with more tree hollows.

Food and Feeding. Diet mostly consists of seeds and fruits, including the large tough fruits of Pandanus (Pandanaceae) . Less commonly, the Black-footed Tree Rat also eats flowers, grass, and invertebrates.

Breeding. Breeding has been reported throughout the year, but births peak in middle of dry season (August-September). Gestation lasts 43-44 days, unusually long for Australian rodent species. Litter size 1-3. Females attain sexual maturity at ¢.80-90 days.

Activity patterns. The Black-footed Tree Rat is nocturnal; it dens during the day in tree hollows, in fallen hollow logs, or sometimes in dense foliage of understory plants (particularly Pandanus). The species forages in trees and on the ground.

Movements, Home range and Social organization. Home ranges are 10-100 ha, and males probably have larger home ranges than females. Black-footed Tree Rats are generally solitary. They use multiple den sites.

Status and Conservation. Classified as Vulnerable on The IUCN Red List because of continuing population decline. Also listed as vulnerable under Australian legislation. The Black-footed Tree Rat is now seldom recorded in Queensland or the Kimberley, and monitoring has demonstrated an ongoing severe decline in the Northern Territory. Decline is probably due mainly to the current regime of frequent and extensive fires, and predation by feral cats, but in parts of its range prime habitat has also been cleared and fragmented.

Bibliography. Crichton (1969), Firth, Woinarski, Brennan & Hempel (2006), Friend (1987), Friend & Taylor (1985), Griffiths et al. (2002), Jackson & Groves (2015), Longman (1916), Ogilby (1892), Rankmore (2006), Van Dyck & Strahan (2008), Watts & Aslin (1981), Woinarski, Armstrong et al. (2010), Woinarski, Burbidge et al. (2014), Woinarski, Milne & Wanganeen (2001), Ziembicki et al. (2013).