Monday 9 November 2009

Bird-banding at the Weddin Mtns, NSW.



Over the weekend I was at the Weddin Mountains assisting with a long-term study of birds in the area. John Rawsthorne was organising the trip this time and Richard Allen who has been running the study for many years now was also there.

Several of us camped for the weekend and caught birds in mist nets set in the woodland at the base of the hills. Once caught we banded them so that they can be individually identified when caught in later years.

Here a dusky woodswallow is being fitted with a band.


Once banded, the birds were all measured and if possible their sex and age established from such features as their plumage colouring or size. Here the length of a woodswallow's head and bill are being measured very precisely.


One of the more abundant birds at the site were rufous whistlers, especially adult females like the one shown below.


Much of the land is still dry following the recent drought. Although the vegetation had grown well this spring after the rains, many birds were still not breeding. The bird on the left below is an adult brown-headed honey-eater, that on the right is a juvenile. Note the colour differences and the young bird's yellow gape. These birds are co-operative breeders - they live in extended family groups where they all help to rear the chicks. As can be seen, these are small birds, yet some of those which we caught had been banded several years ago. One bird was more than ten years old and another more than 14. Many Australian bird species seem to have adopted a strategy of long life and not necessarily breeding every year - unlike, for example, many northern European species which have short lives and breed every year. The former life-plan has perhaps evolved as an efficient method for maintaining a population through periods of drought.


Often, when a male bird cannot find a mate, he will sing all day long trying to attract one to his territory. This hooded robin was doing this, his whistle sounding to me much like that of a green woodpecker.


One of our party was Bill Mannan, visiting from Arizona where he studies Coopers Hawks. Here he is with a male collared sparrowhawk which we caught.

Sunday 1 November 2009

Tawny Frogmouth study - 8


The frogmouth chicks are quite large now, although they are slow-growing. Most are about four weeks old and ready to leave the nest.

These chicks are typically lying quietly in the nest while the adult male keeps watch from farther along the branch.




The chicks are still partly downy and can only fly short distances. This chick has flown to the next branch from its nest, where its sibling was still with the male. The female meanwhile stands guard over this fledgling.




Two days after leaving the nest this chick was about seventy metres from the nest. Although they can be regarded as fledglings at this stage because they have left the nest. They are still much smaller than the adult birds and weak fliers. They are more aptly described as branchers.

Their tails are still short and wing feathers rather stumpy. The bristle feathers on their forehead have developed well though, and these help to conceal them when they instinctively adopt their head-erect concealment pose.

Sunday 18 October 2009


Tawny frogmouth study - 7

The first tawny frogmouth chicks hatched about two weeks ago and it is only now that they can be seen as they have become too large for the bird to cover completely all the time as they wriggle around in the nest. The male bird broods them all day, drooping his wings over them. This hides their white down from the roving eyes of predators, such as currawongs, and protects them from excessive heat from the sun, or the cool wind and rain - which there has been much of in Canberra since they hatched.




Tawny frogmouth study - 6

Tawny frogmouths occasionally nest in the old nests of other species. Here a pair have used an old clay nest built by white-winged choughs. The nest is set about half way along a branch 12m up in a yellow box tree overhanging a gully.


Saturday 26 September 2009


Tawny Frogmouth study - 5




While the male birds sit on the nests during the day, the females roost on a nearby perch. Whenever a predator or person approaches they stretch into their cryptic pose. This bird is only half in this pose as she was familiar with me and the photograph was taken with a 400m lens from a distance far enough for her to consider me as only a possible threat.
Tawny frogmouths are so well adapted to concealment in the trees. Here, the bird sits on a dead limb, which they almost invariably do, and the dashes on the grey feathers of her belly match the pattern of the dead wood. The feathers on her back, the coverts on her wings and her scapulars all resemble the flecks of peeling bark on the trunk of the tree which she is sitting close up against. Her eyebrows droop like strips of bark and all the time she keeps her eyelids closed, yet still watching from behind them, through tiny gaps in the not quite straight fitting closure.We might not see them but they are always watching us as we pass by unaware of their presence.