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 7Carbohydrates, 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 water-out?

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