Bush rat

While there are not many characteristics that readily distinguish the bush rat from other Rattus species, it is characterised by having small tympanic bullae and a straight incisive foramen. Adult bush rats are smaller than the Australian swamp rat (Rattus lutreolus) and in addition, the bush rat's foot pads are a pink colour, whereas the swamp rat's foot pads are dark brown. The hair at the foot is short and pale in colour, subspecies Rattus fuscipes coracius is notably darker. The feet are pentadactyl and all digits are clawed. The tail is a pink shade of brown, almost free of hair, with scales that overlap and give an obvious ringed appearance. The bush rat exhibits sexual dimorphism: the males are larger than the females in the species. Their prominent eyes are large, and this distinguishes them from the narrower snouted Cape York species Rattus leucopus where their range overlaps. The species is varies greatly in coloration and size. The length of the head and body combined is from 100 to 205 millimetres (3.9 to 8.1 in), the tail is 100 to 195 mm (3.9 to 7.7 in); these measurements are approximately the same in the individuals. The ventral side of the pelage is a light grey or cream colour, which grades with the rufous flank and darker brown of the upper-side; the overall colour is a greyish or reddish brown. The length of the hind foot is 30 to 40 mm (1.2 to 1.6 in) and the ear 18 to 25 mm (0.71 to 0.98 in). The average weight, for a range of 50 to 225 grams (1.8 to 7.9 oz), is 125 g (4.4 oz). The number of teats is variable in the regional populations, the females bears one pair of pectoral teats and four at the inguinal region, except in the north of Queensland where the pectoral teats are absent.