Sugar Glider
The Sugar Glider (Petaurus breviceps) is a small gliding
possum native to eastern and northern mainland Australia, New
Guinea, and the Bismarck Archipelago, and introduced to
Tasmania.
It is around 16 to 20 cm (6.3 to 7.5 in) in length, with a slightly
longer tail, and weighs between 90 and 150 grams (3 to 5.3 oz). The
fur is generally pearl grey, with black and cream patches at the
base of the pink ears. The tail tapers only moderately and the last
quarter of it is black, often with a white tip. The muzzle is short
and rounded. Northern forms tend to be brown coloured rather than
grey and, as predicted by Bergmann's Rule, smaller.
Sugar Glider,
Petaurus breviceps
The most noticeable features of its anatomy, however, are the twin
skin membranes called "patagium"s which extend from the fifth
finger of the forelimb back to the first toe of the hind foot.
These are inconspicuous when the Sugar Glider is at rest it
merely looks a little flabby, as though it had lost a lot of weight
recently but immediately obvious when it takes flight. The
membranes are used to glide between trees: when fully extended they
form an aerodynamic surface the size of a large handkerchief.
Sugar Gliders can occupy any area where there are tree hollows for
shelter and sufficient food. Their diet varies considerably with
both geography and the changing seasons, but the main items are the
sap of acacias and certain eucalupts, nectar, pollen, and
arthropods. They are difficult to see in the wild, being small,
wary, and nocturnal, but a sure sign of their presence is the
stripping of bark and tooth marks left in the soft, green shoots of
acacia trees.
The gliding membranes are primarily used as an efficient way to get
to food resources. They may also, as a secondary function, help the
Sugar Glider escape predators like goannas, introduced foxes and
cats, and the marsupial carnivores that foxes, cats, and Dingos
largely supplanted. The ability to glide from tree to tree is
clearly of little value with regard to the Sugar Glider's avian
predators, however, in particular owls and kookaburras.
Although their aerial adaptation looks rather clumsy and primitive
by comparison with the highly specialised limbs of birds and bats,
Sugar Gliders can glide for a surprisingly long distance flights
have been measured at over 50 meters (55 yd) and steer
effectively by curving one or other of the gliding membranes
(patagium). They use their hind legs to thrust powerfully away from
a tree, and when about 3 meters (3 yd) from the destination tree
trunk, bring their hind legs up close to the body and swoop upwards
to make contact with all four limbs together.
In suitable habitats, they are common, often reaching densities of
1 per 1,000 square meters provided that there are tree hollows
available for shelter. They live in groups of up to 7 adults, plus
the current season's young, all sharing a nest and defending their
territory. Adult males mark the territory with saliva and with
scent glands, and also mark members of the group with the scent
produced by separate glands on the forehead and chest. Visitors
which lack the appropriate scent marking are expelled violently.
The dominant male mates more frequently with the female of the
group than the other males, and does most of the scent marking.
When an adult member of the group dies, it is normally replaced: by
one of the group's own offspring if female, but by an outsider if
male.
In the more temperate south, breeding starts in mid-winter (June or
July). In the north, there seems to be no particular breeding
season. Two young per female is typical; they remain in the pouch
for about 70 days, and after leaving it stay inside the nest for
another 40 or 50 days, then begin to forage outside, usually under
the care of the mother. The young are normally ejected from the
group territory at 7 to 10 months of age. Sometimes they form new
groups if an area is vacant, but competition for territory is
fierce and not many survive the first months of independent life.
In captivity, they may live up to fifteen years.
Unlike many native animals, particularly smaller ones, Sugar
Gliders are not endangered. Despite the massive loss of natural
habitat in Australia over the last 200 years, they are adaptable
and capable of living in surprisingly small patches of remnant
bush, particularly if they do not have to cross large expanses of
clear-felled land to reach them. Several close relatives, however,
are endangered,
particularly Leadbeater's Possum and the Mahogany Glider (which, to
the non-expert, looks almost exactly like a Sugar Glider).
Like all native creatures they are protected by law in Australia
where it is illegal to keep them as pets, or to capture or sell
them without a licence (which is usually only issued for
bona-fide research).
However, they are not difficult to breed in captivity under the
right conditions, and small numbers have been legally exported to
America where they have formed a breeding population for sale as
pets. The Sugar Glider is a popular pet because of its sweet,
lively, inquisitive nature, but is illegal in certain
jurisdictions, such as California, Georgia, Hawaii, Maine, and
Alaska. Many other states in the United States require a
permit.
A sugar glider featured on the reverse of the Australian 1 cent
coin, until it was withdrawn from circulation in 1991.
Conservation status: Lower risk
Issue #214
