Grey Squirrels operate to a different time schedule. They are most active at first light and at the end of the day. Most of their day is spent either in the nest or roosting, often basking in full sun. Activity may continue throughout overcast days or even on bright moonlit nights (Madson 1964). Play activities—running, jumping, chasing—were all reported in Australian colonies by Seebeck (1984).
Neither species has economic significance in Australia, except by causing minor damage to garden plants and as a tourist attraction (Palm Squirrels in Perth Zoo, formerly at Taronga Zoo, Grey Squirrels formerly at Ballarat Gardens). The Palm Squirrel is considered a potential pest species in Western Australia and has been a Declared Animal (Vermin) in that State since 1973 (Agriculture Protection Board of Western Australia 1985). A few of these animals, inadvertently translocated, have been found (and destroyed) in remote areas as far as 140 km from Perth. It is a common commensal in northern India, but does not seem to be a major problem. In the United States, the Grey Squirrel is the third most important game animal, with millions being taken annually for meat and pelts. In the United Kingdom, it is declared vermin because of its damage to forests (particularly hardwood plantations) and its presumed replacement of the indigenous Red Squirrel (Madson 1964; Barkalow & Shorten 1973).
There is a potential pet trade in Palm Squirrels and because of the zoo population in Melbourne, there is a possibility a feral population might be established there.
BIOGEOGRAPHY AND PHYLOGENY
Distribution of both species in Australia is described above. Grey Squirrels are native to the eastern United States and south-eastern Canada and have been introduced to western United States and to other provinces in south-eastern Canada. They have also been introduced into England, Scotland, Wales, Ireland and South Africa. The Palm Squirrel occurs naturally in northern India and in Pakistan.
Ellerman (1940) included both species in the Group Sciuri (the non-volant forms) within the Family Sciuridae. He considered the genera Funambulus and Sciurus to be related closely and had difficulty in defining them as separate genera, although ultimately he retains Funambulus as a ‘natural group’.
COLLECTION AND PRESERVATION
In Australia, both species have been collected by live-trapping in baited cage traps, although the Palm Squirrel seems to be easier to capture than the Grey (Seebeck 1984). Wright (1972) used a multiple-capture drum trap with a funnel entrance, baited with bread and apples to trap Palm Squirrels, and in three short (3–4 days) trapping sessions with 30 such traps, caught more than 270 animals. Other specimens were shot. The feral population at Taronga Zoo was reduced to extinction largely by rat poison. Existing museum specimens are retained as puppet skins and skulls, but future specimens should be maintained in the Western Australian Museum as wet specimens.