TARRKAWARRA
Water and Temperature Balance
Spinifex hopping-mouse
Notomys alexis
Notomys = southern mouse
alexis = named after Alexandria Downs
station, Northern Territory where the
animal was first found
The spinifex hopping-mouse really takes care of
water.
It does not need to drink. The seeds, insects and
roots that it eats provide enough water to live on.
It has no sweat glands.
Its droppings are almost completely dry.
Its kidneys waste very little water (its urine is one
of the most concentrated of any mammal).
Mothers produce very concentrated milk (and
drink the urine of their young).
It is active at night (when it is cooler).
It lives together in burrows (this increases the
humidity in the burrow and reduces water loss).
It even uses water from starch in the seeds it eats.
The hopping-mouse has sharp claws to
dig a home and large eyes to see at night.
How does living in a burrow by day and
moving around by night help the hopping
mouse save water?
Burrows help trap the water the mice breathe out.
The steep entrance helps keep out unwanted
visitors.
The Spinifex Hopping-mouse
does not have to drink because it gets
enough water from its food
 can't sweat because it has no sweat
glands
 has kidneys that make very strong urine
 lives in burrows to help save water.

QUESTION 1
What is the
main food
source for the
Tarrkawarra?
QUESTION 2
 Define humidity
QUESTION 3
When are the
conditions
best for the
Tarrkawarra to
feed? Why?
QUESTION 4
Describe a
typical burrow
for the
Tarrkawarra
QUESTION 5
Why do these animals also store their
food in their burrow?
QUESTION 6

How would supplementing their diet with
green leafy shoots and insects assist in
survival?
QUESTION 7
Carbohydrates, fatty foods
and oxygen are oxidised in
an animal’s body and the
main end products are
carbon dioxide and water.
How do humans dispose of
these products?
Why does the Tarrkawarra
make use of this water?
QUESTION 8
If the Tarrkawarra excretes very little
water, what impact does that have on
the concentration of urea in its urine?
QUESTION 9
List the water
sources available
to the
Tarrkawarra
QUESTION 10
List the methods
of water loss by
the Tarrkawarra.
QUESTION 11
Why must water-in
balance with waterout?
QUESTION 12
The Tarrkawarra has no sweat glands.
How would this advantage its survival?
QUESTION 13
Explain how the
Tarrkawarra’s special
heat exchange system
its nasal passages
works.
QUESTION 14
• How does the female
Tarrkawarra balance and
supplement the water loss of
feeding its young?
QUESTION 15



The Tarrkawarra survives in harsh dry
areas with very little free water.
It does so through structural,
behavioural and physiological
adaptations.
From your reading and observations of a
photograph of this animal, list the
adaptations under the three aspects of
structural, behavioural and physiological.
Structural
Behavioural
Physiological