The animals under study would normally exist widely dispersed among the trees, yet here they were living virtually in one another's pouches. Yet they betrayed few of the familiar neuroses of captivity or crowding, and breeding success of the Sanctuary was proof that they were functioning well. Most of the time they were neither friendly nor hostile to one another, just indifferent. They even slept on top of each other without complaint or discomfort.
There is a certain simplification of their behaviour repertoire. For instance, the way a baby flails around with its arm when faced with a leaf too big to handle properly is similar to the way it moves when trying to get into its mother's pouch or, if too big, her lap. The common feature is a frustrated drive, and the action is not all that different to the way an adult swings it arm over an opponent preparatory to biting it. The posture in which a baby sleeps in its mother's lap is the same as it will later use when in the fork of a tree. And it must be remembered that, in the pouch, its body is also severely flexed.
I was surprised, however, to find that a mother does not clean her pouch like other marsupials. The mother's role in child care is essentially passive, a common feature among marsupials. She displays extreme tolerance to the cub, and allows it to suckle and ride. However, if the baby happens to be off her back when she decides to move, she does not appear to worry, although later she will wander around, apparently looking for it. In the wild, it is unlikely that mother and cub would be separated by any distance for any length of time. And because they are so dispersed, there is no reason for mother and child to recognize each other.
In the wild, koalas do not live in groups, and so they possess no "friendship" behaviour. They have no dominance and submissive behaviour, as all social animals, such as dogs, monkeys, and humans must possess. Thus, a dog will growl at an intruder when protecting its bone. More to the point, the intruder will also growl in an attempt to take the bone without fighting for it. If the first dog realises it is too small to win a fight, it will display submission by, for example, putting its tail between its legs. Thus, both dogs can live together without having to fight over everything. That sort of system is completely missing in koalas. Females vocalise when a stranger approaches to defend their space; they do not vocalise to usurp another individual's space. Males do not even possess threat vocalisations; they simply attack. They do not fight directly over females, and least of all over food, but in the wild an outsider will normally be attacked unless his bellow indicates that he is too big to deal with.
Finally, let me make two additional observations. Some time back I took my new wife to visit Lone Pine and, in order to make it more interesting, I made sure we went during the breeding season. We heard a few bellows, but why weren't they echoing back and forth throughout the Sanctuary? And where was all the frenetic activity described in previous chapters? It turns out that the current management have housed the males and females separately because, if they are together, fighting ensures. If that had been the practice when I was there, this study would not have been possible.
Secondly, when I was at university, ethology was all the rage. I therefore expect, when I read a monograph such as those in the Australian Natural History Series, to find at least a full chapter detailing the species' behaviour. No such luck - not even with species on which I know there has been detailed research. Modern experts just aren't interested. However, I was pleased to discover that Stephen Jackson's 2007 book, Koala, origins of an icon did refer back to my own ground-breaking research, and included specific drawings from my original papers. But the same could not be said for The Koala, natural history, conservation and management (2nd edn, 1999) by Roger Martin and Kathrine Handasyde. They failed to mention me even once. It seems my fifteen minutes of fame has come to an end!
ReferencesMy original research was published in the scholarly journal, Australian Wildlife Research. If you are interested in the technical details, complete with figures and statistics, on which these posts are based, you can read them at:
Smith, M. (1979). Notes on reproduction and growth in the koala, Phascolarctos cinereus (Goldfuss), in captivity. Aust. Wildl. Res. 6, pp 5-12
(1979). Behaviour of the koala, Phascolarctos cinereus Goldfuss, in captivity. I. Non-social behaviour. ibid. pp 117 -129
(1979). .... II. Parental and infantile behaviour. ibid. pp 131 -140
(1980). .... III. Vocalisations. Aust. Wildl. Res. 7, pp 13-34
(1980). .... IV. Scent-marking. ibid. pp 35 -40
(1980). .... V. Sexual behaviour. ibid. pp 41 - 51
(1980). .... VI. Aggression. ibid. pp 177 - 190
Prior to this, I had been asked to provide a popular, non-technical summary of the findings for the benefit of the Lone Pine management. This resulted in the two part article which has been essentially copied for this blog:
Smith, M. (1976). The koalas of Lone Pine. Part I. Wildlife in Australia 13(2),
pp 57- 60 [June]
Koalas. Part II. Wildlife in Australia 13(3), pp 93 -97 [Sept]
I also wrote:
Smith, M. (1987). 'Behaviour and Ecology', chapter 3 of Leonard Cronin (ed), Koala. Australia's endearing marsupial, Reed Books, pp 56- 78.
Some other passages of mine were included in the other chapters unacknowledged.
THE ENDCongratulations! You have now reached the end. If you want to go back and check on anything, go to:
Part 1. Background
Part 2. Basics
Part 3. Bringing Up Baby
Part 4. Communications
Part 5. Sex
Part 6. Fighting
And, as I mentioned before, you may want to look at The Possum Book for adventures with brushtailed possums.