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Dusky hopping mouse
Dusky hopping-mice are distributed from Ooldea in S Australia to
past Lake Eyre to SW Queensland. They also currently inhabit the
regions of SE Western Australia, S Northern Territory, Southern
Australia, N New South Wales, and NE South Australia (southern
Strzeleki Desert and the Cobblers Desert).
Dusky hopping-mice inhabit sand dunes, grasslands, tree and shrub
heaths, and lightly wooded areas. The temperature of their habitat
is usually very high with desert-like conditions. N. fuscus also
live in sand ridge habitats, which alternate with gibber flats and
clay pans, in the Pelican Waterhole area.
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Dusky hopping mouse
N. fuscus is characterized by its strong incisor teeth, long tail,
large ears, dark eyes, and extremely lengthened and narrow hind
feet, which have only four sole pads. Head and body length is 91-177
mm, tail length is 125-225 mm, and weight is about 20-50 grams.
Coloration of the upper parts varies from pale sandy brown to
yellowish brown to ashy brown or grayish. The underparts of dusky
hopping-mice are white. The body covering is fine, close and soft;
and long hairs near the tip of the tail give the effect of a brush.
Notomys fuscus has a well-developed sebaceous glandular area on the
underside of its neck or chest. Females have four mammae.
Reproduction
Little is known of the breeding biology of this species in the wild
other than that it is an opportunistic breeder. In captivity, its
breeding pattern is polyestrous, with no evidence of seasonality,
thus it breeds throughout the year. The gestation period is 38-41
days; a postpartum estrus is not common in N. fuscus, but some
females enter estrus 14-22 days after giving birth. The estrous
cycle lasts about 7-8 days. Dusky hopping-mice rear litters of 1-5
young. Their young weigh about 2-4 grams at birth and open their
eyes at 18-28 days. The young cling to the nipples of the mother and
are dragged about wherever she goes, and weaning occurs at about 30
days. Both sexes of N. fuscus reach reproductive maturity at 70
days. It was seen that one female N. fuscus produced 9 litters in
her lifetime of 26 months. Males are capable of breeding up to the
age of 38 months.
Behavior
The sebaceous glandular area is active in all adult males but is
active in females only during pregnancy and lactation. Nowak (1991)
suggests that the glands are used for territorial marking and
marking of group members, including newborn young. Dusky
hopping-mice are saltatorial and normally move awkwardly on all
fours or make short hops. If startled, they bound rapidly using only
their large hind feet. The mice dig their own burrows, some being of
a simple construction but others being complex. The dusky
hopping-mouse digs a burrow on the flat top of a dune with a single
tunnel about 10 cm in diameter, more than a meter below the surface
and up to 5 m long. It is connected to the surface by up to 6
vertical entrance shafts that are dug from below and may end up
anywhere on the surface. A nest, consisting of a pad of finely
chewed vegetation, is placed in the center of a small alcove off the
main shaft, and well-marked pads connect different burrows along the
top of the dune. The width of the entrance shafts is critical
because the animals move in them by hopping; they brace their backs
against the sides with their forefeet between hops. Progress when
coming down a shaft is a headlong dive, with the back braced against
the wall of the shaft and the forelegs used as a brake. If the
entering animal finds that the burrow is blocked with loose sand, it
often squeaks several times. This usually attracts other occupants
and together, from opposite sides, they rapidly clear the blockage.
N. fuscus is commonly found in association with marsupial
counterparts and sometimes shares the same tunnel systems. Living in
groups of about five individuals in one or two adjacent burrows
systems, the Dusky Hopping-mouse spends all its life on the dunes.
Being a nocturnal animal, it rests in its burrow during the day,
insulated from the hot surface. At night, it forages on the top and
sides of a dune, and rarely ventures more than a few meters away.
Even in apparently favorable localities, population density is low,
with individuals inconspicuously congregated in a loose colony in a
small area of a sandhill. Dusky Hopping-mice calls include
twittering during animated chases. However, none of the sounds was
associated with threats or fighting.
Food Habits
Notomys fuscus is like other hopping-mice in that it does not drink,
but obtains all its water and food requirements from a diet of
seeds, berries, leaves, green plants and occasionally insects. In
captivity they should be offered a complete diet of rodent lab blocks, and rat or mouse
mix, with bits of fruit or veggies regularly. Cheerios or wheat
bread are great treats, in small quantities. Do NOT feed chocolate,
fried foods, salted foods, candy or junk food! They may enjoy
crickets and mealworms if they are captive bred, never feed wild
insects as they may carry parasites. Vitamins, like Nutri-Cal are a good addition to their diet, and added calcium
during nursing and growth due to demands on their systems at those
times, but take care not to overdo it. Water bottles should be used
to proved constant, clean water. Ceramic or stoneware food dishes
work well for keeping seeds or fresh foods off the floor, and a wire
mesh hopper that allows them to eat the lab blocks through without
extra waste.
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