Life in the pouch

During its early life the tiny wombat grows rapidly. After only one month it is about seven centimetres long and weighs about five grams (Figure 6.1). There are small differences between the three species of wombats, according to their differences in size. (See Growth and Development Table, Appendix 1. The range of weights shown in this table reflects the considerable variation in the growth weight, which is influenced by the condition of the mother and her size, as well as the species of wombat.) At one month the shapes of its ears are recognisable, but they are still fused with the skin of the head; the hind legs are beginning to develop; the outer

Figure 6.1 At one month the hairless young is about seven centimetres in length, measured from the crown of the head to the rump. Photo: p Presidente

edges of the lips are still joined together, and it is still constantly attached to the teat, sucking small amounts of milk at frequent intervals.

In the next two months the small pouch young doubles its length, while its weight increases to about 150 grams (see Plate 15). Facial structures -eyelids, nostrils and so on - are developing and the ears are fully unfolded. Whiskers are beginning to appear beside its mouth and on the cheeks and eyebrows, but it still has no other sign of hair for another two to three weeks, when very fine fur appears on its ears. The skin is still pink and wrinkled in some places (see Figure 6.2 and Plate 16).

By the time the young wombat is four months old it weighs nearly 400 grams, and its eyes are open. A month later it has a fine layer of fur on its limbs and its lower incisors have erupted. Although it still suckles frequently it is no longer permanently attached to the teat, and its lips are now fully separated from one another. Much of the time it lies on its back, swinging comfortably in the pouch. As the young grows and needs more room, the pouch expands. Green and Rainbird found that there is much individual variation in the way the pouch enlarges, but that generally, by

Figure 6.2 At three months of age the crown-to-rump length is about 15 centimetres. The young is still firmly attached to the teat. Photo: pPresidente

the time the fine fur is developing, it has expanded for up to 12 centimetres in any or all directions from the mid-point of the opening. Usually, the pouch expands more anteriorly - towards the mother's chest - than in the other directions.

Very fine fur, only one to two millimetres long, covers much of the young wombat's body by six months of age, and now it is ready to take its first look at the world - or what it can see of it from the opening of the pouch. A pink nose or forepaw, or occasionally a whole back leg, can sometimes be seen poking out of the pouch (Figure 6.3); but to look out the young wombat either lies on its front with its front paws tucked in and its head framed in the opening (see Plate 17), or it sits hunched over, so that its head and all four feet are near the pouch opening (Figure 6.4).

The young wombat's upper and lower first molars are usually present by the time it is six months old, and the lower incisors are about three or four millimetres long. The upper incisors also erupt about this time.

Occasionally, while the mother is feeding, the young in the pouch will bite at a blade of grass or extend a small forepaw, grasp a blade and pull it towards its mouth. It probably does not eat it at this stage, but it makes its first investigation of grass in this way.

Figure 6.3 Occasionally the young wombat's back leg may be seen poking out of the pouch. Note the pale sole of the foot which later darkens. Photo: R Green
Wombat Pouch

Figure 6.4 The young wombat often sits in the pouch with its head and feet visible. illustration: © Peter Schouten

Figure 6.4 The young wombat often sits in the pouch with its head and feet visible. illustration: © Peter Schouten

No actual observations of the mother cleaning the young in the pouch, or attending to it in any way, have been recorded. It is not known how the young wombat copes with its waste products, but it seems likely that the mother licks the cloaca of the young when it is very small, to remove urine and faeces in the same way as a kangaroo mother does, although it is anatomically much more difficult for a wombat to reach its head into the pouch. By the time the young is detached from the teat it is about 15 centimetres long, and it would be almost impossible for her to reach over and into the pouch entrance. Young, fine-furred pouch young have been seen to push the tail section out of the pouch and pass urine and small faecal pellets.

+1 0

Responses

  • Stephanie
    Do wombats have pouches?
    4 months ago

Post a comment