Aggressive encounters

Sometimes, when two bare-nosed wombats meet, more aggressive sounds are made. Like most animal sounds, these are difficult to describe, but one appears to be made by the tongue hitting the palate while the breath is drawn in and a flat 'chikker chikker' is the result; the other is a slightly more guttural sound, not unlike the hoarse, churring sound made by an angry brushtail possum. These vocal signals may also be made by a wombat when it hears, or smells, another a considerable distance away, and they are often answered by similar chikkerings and churrings from the second wombat. A series of calls and answers can continue for some time until the second wombat has either passed the first, still at some distance, and gone on its way, or until it has approached the first more closely, when a chase often results. In several chases I have watched, the wombat that is first on the scene almost always chases the second arrival, but the roles may be reversed if the chased wombat stops and turns, calling again. Both wombats may sit down while another duet of chikkers ensues before the chase resumes - and now either wombat may be the pursuer. In one chase sequence I saw the roles of pursuer and pursued change four times before both wombats settled down to graze about 30 metres apart, still chikkering occasionally.

Robert Taylor, studying wombats in north-east Tasmania, observed three lengthy chases, the chased wombat often making veering movements to avoid being reached by the pursuing wombat; throaty snorts and nasal squeals were heard during the chase. Two of these chases involved a male pursuing another individual near the boundary of its home range.

Both the aggressive chikker and the rasping churr can be the prelude to a fight. They are often interspersed with other hostile gestures. Standing, or sitting with the front feet wide apart and the body humped to make it appear larger, the wombat's head swings from side to side in a feigned biting action, while the teeth grind together and the whole body shivers. Not surprisingly, this display of threat usually causes an approaching wombat to retreat to a safe distance, but occasionally it will stand its ground and make similar aggressive signals. What happens next probably depends on several factors such as the age, sex and, possibly, rank order of the confronting wombats - or it may just depend on their mood at the time. Too few encounters have been seen or reported for any general conclusions to be drawn.

Few of the aggressive encounters that I have watched have resulted in an actual physical contact; the majority ended, after a mutual exchange of unpleasantries, in one of the contestants turning away and leaving the field to the other. Nevertheless, if the scars and wounds carried by almost all adult wombats are any indication, physical clashes do occur quite often. Scars on the forehead and ears and the upper part of the muzzle are very

Figure 5.15 The ears often show signs of past battles.

common; they are probably the results of head-on conflicts, which frequently occur in burrows or at burrow entrances when the wombat in residence resists the entry of another wombat.

The ears, flanks and back often show signs of past battles (Figure 5.15). I saw some of these wounds delivered during a fight between two adults, a large grey male and an even larger black female. These gradually grazed closer and closer together until they were about five metres apart, when they both sat down and chikkered at each other for a few moments. Then the male suddenly stood and charged the female, lunging at her flank, tearing a strip of fur from it. She quickly turned and, thrusting her head upward, caught his right ear in her teeth. Holding on grimly to the ear, she shook her head violently several times, while the male tried to shoulder her away. Blood was oozing from his ear when he did finally wrench himself free. Almost immediately, the female jabbed at his head again, but this time the male whipped his whole body round in a 180 degree turn so that his rump was presented to her charge. She bit his rump savagely several times, but the male had had enough. Giving a few rapid backward kicks with his hind legs, he lowered his head and broke into a lumbering gallop, which he maintained until he disappeared into thick undergrowth 50 metres away. The female pursued him for only a few metres before turning and ambling away in the opposite direction.

A few nights later these two wombats met again. Standing about five metres apart, shivering and chikkering at one another, they both began to score the ground in front of them with their forepaws. The grey male bit savagely and repeatedly at the trunk of a small sapling before he turned and trotted quickly away, apparently disinclined to repeat the previous experience.

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