Gang Gang Cockatoos Part 2
by John McGrath ©
NATURAL HABITAT CHANGES
The introduced Hawthorn tree seems to have filled a gap in the Gang-Gang's winter food requirements in this area. They tend to ripen late summer, early autumn when the Gang-Gangs traditionally flock, post breeding season. This traditional 'non-native' food supply will last a number of birds for up to several months. Hedges of these and other exotic flora to the Gang-Gang's taste, sustain them in the cooler months in quite a few of the Southern Tableland's towns. Unfortunately, for the Gang-Gang, these hedges are planted along busy arterial roads. Upon approach to or leaving some hedges, many Gang-Gangs lose their lives in collisions with motor vehicles.
The Gang-Gangs appear regularly every year in the late summer, early autumn months with the season's young. They are particularly common in some of Canberra's suburbs at this time of year.
When I was younger, I was always led to believe that these birds only bred in the mountains. But now, after speaking with a senior colleague, who has been involved with cockatoo's, informs me that they nest a lot closer to home than that and has promised to show me some nesting sights one day. Apparently they will nest anywhere only a couple of metres off ground level, to nearly 30m. Information my friend gave me also was that they did not enter into a limb very far - only about 600 - 900mm from the entrance.
I can remember times when there were more Stringy Barks about, which is a major natural food supply in autumn for these birds. Large Stringy Barks, drooping to the ground laden with nuts and Gang-Gangs clambering about feeding is not a common sight any more. As I mentioned earlier, the birds spend a lot of time stripping these trees of nuts and passing time. Now, unfortunately, most of these trees have been cleared for the pastoral industry in our area. This clearing reduces the nesting sites as well!
But the traditional flocking still coincides with this Stringy Bark 'banquet' and this has been replaced to a certain extent by the introduced Hawthorn.
They arrive with their young, usually fairly good on the wind, but content to wait in a crèche area, (removed from the feeding ground), whilst their parents gather food for them.
I have had the opportunity over the last few years to study an area of Hawthorn trees on the Yass River. The Gang-Gangs arrive at this place in their small flock and the young birds usually wait in this crèche area in tall eucalypts above the Hawthorns. After several days the young follow their parents down to the Hawthorns continually begging for food. This latter action probably occurs with the onset of weaning, although the parents usually succumb to the begging offspring and feed the young. At the same time the young are being introduced to the food of the Hawthorn berry. Thus weaning would be complete.
I would imagine that the clearing of suitable trees would affect the seasonal movement of Gang-Gangs. I still believe that the majority of Gang-Gangs come down to lower altitudes to avoid the harsh winter conditions of the alps. What I am saying is that the birds will eventually have no 'winter home' due to the fact that a once traditional food supply will be non-existent. Therefore more birds are forced to come down to lower altitudes. I can see a high mortality rate for this species.
It can also be argued that land clearance has benefited the Galah (the Gang-Gang's close relative). This bird is suited to the open country and moved into this area in the late 30's, a fact confirmed by my late father. Land clearance, more stock watering points, cereal crops and spilt grain have aided this new cockatoo wave - Galahs now out-number the Gang-Gangs.
Above I mentioned that I think the Galah and the Gang-Gang are closely related and I will give a few reasons for my beliefs: apparently the Gang-Gang and Galah have hybridised in captivity. If you look closely at their basic plumage colour, they are very much like each other and only "smaller black cockatoos". The Gang-Gang's basic dark colouring of grey body and the cock with his red helmet, both sexes having a reddish-orange fringe to their chest and abdomen feathering all make the Gang-Gang a unique cockatoo. The Galah has a pink crest and chest, with a grey back. The lighter grey probably suits their ground feeding habit. The former bird's darker plumage suits their feeding in shadowy branch areas. Therefore both species have adapted to blend in with their surroundings. If you have ever had the opportunity to study these two birds in flight, it is very hard to distinguish between them, especially at dusk when they give their pre-roosting display flights.
The begging notes of the young also is virtually the same. The habit of both species forming a crèche area for the young is another similarity. A type of area where the young sit and wait patiently for their parents to bring food to them is the crèche. (I have observed this myself).
The two species, as well as having extremely similar flight patterns, have the habit of taking off and performing very similar aerobatics. They form rapid flock formations and call in flight - wheeling and spiralling downwards to alight to resume feeding.
My own observations of this species over the last thirty years in my local area give me a guide to this species' future in the wild. A species with "narrow" food sources (ie. one in which the habitat is of a specific type of eucalypts) depends on the existence and protection and the maintenance of large tracts of such stands of forests. As I stated earlier the Gang-Gang is a very desirable aviary bird and it is such a very interesting bird. Even the way this bird clambers about on the mesh of its aviary; its unique calls; the way it flicks its crest out forward when excited and the slow use of its feet in putting food to its beak. I would stress here, that this is not a bird that should be subjected to aviary conditions unless you are prepared to provide a good and healthy environment. By this I mean the food and branch requirements mentioned earlier. Nevertheless we need to encourage this species to propagate itself in captivity.
© Article under Copyright with the Author, Mr John McGrath, and cannot be reprinted without written permission.
© 1997 Parrot Society of Australia Inc