Young pigeons

A first year Common Bronzewing Phaps chalcoptera

On the weekend I was out mist-netting birds at Charcoal Tank Nature Reserve, NSW, helping Mark Clayton with a long term cooperative bird banding study. As it is now late summer almost autumn, the birds there have all finished breeding and the birds caught were a mix of adult and birds of the year. I am in the process of putting together an online guide to aging and sexing woodland birds of South-east Australia, based on photographs taken of birds in the hand, prior to release after banding them. And this trip provided a chance to photograph young pigeons as we caught examples of Common Bronzewing and Peaceful Dove.  

The young bronzewing, which would have hatched last spring, differs from the adult in still  having a soft bill, especially the cere above the nostrils. This is a residual feature of squabs, young pigeons,which have large wide and soft bills. An adult bronzewing has a hard bill and the cere is less spongy. This young bird was probably a male as there are some chestnut coloured feathers growing into the sides of the crown - adult females do not have such well coloured heads. The adult male also has a bright pale forehead and there seems to be signs of such growing into the young birds head.

An adult male Common Bronzewing

A first year Peaceful Dove Geopelia placida

The young Peaceful Dove was instantly recognisable by its generally dull plumage compared with that of an adult, which cannot be sexed on plumage. The adult bird has a smart blue-grey forehead, chin and cheeks, and boldly marked black and white bars on its breast. The young bird has a white/buff speckled head, and the barring is of brown, buff-tipped feathers.Also, the young bird has only a faint blue ring of bare skin around its eye, while that of the adult is bright, together with the prominent blue cere and irides. Again, the young bird has a soft bill, especially the cere, and the adult has a a hard, worn and flaky appearance, through wear and tear after years of foraging.  

An adult Peaceful Dove

The Nature Conservancy
Australia

I have added a link to The Nature Conservancy, Australia to the list of associated websites on the right of this column. Please click on  http://www.natureaustralia.org.au/ and have a read though to see just what they are doing and needs to be done to secure a future for wildlife and wildplaces in Australia.

Sulphur-crested Cockatoos

The fruit in the garden has now all passed, the last of the apricots were eaten by the Red Wattlebirds, Crimson and Eastern Rosellas. But all is not over yet. The Suphur-crested Cockatoos have moved in to eat the apricot kernels which the other smaller birds could not open and eat. They only ate the soft flesh like we do. A carpet of split shells now lies below the apricot trees.

Great flying at the cricket 

The Foxcopter hovers over Manuka Oval

As part of their TV coverage of the Prime Minister's XI v West Indies cricket match at the Manuka Oval, Canberra yesterday, Fox Sports were flying their new Foxcopter. This is an eight-rotor helicopter drone which carries an HD camera, and the whole is controlled to line up overhead pictures of the game. What a wonderful machine it is, it was very competently and safely controlled - and it produced great pictures.

When the machine first took off for a tour around the ground airspace during the afternoon session, an Australian Hobby Falco longipennis gave it a fly-past, probably to investigate this strange new flyer in its territory. There was never any danger of conflict or collision however as the bird was never closer than about 70-100m. 

Later, when the sky darkened, the new stadium lights were switched on and moths soon fluttered around them as it became darker. Then just as it became truly dark, a Hobby, probably the same bird, began hawking moths from in front of the lights. It disappeared into the shadows behind to eat its prey, and this was repeated several times, with the vast majority of the crowd unaware of the wildlife flying display above them.

Tawny Frogmouth breeding success

An average brood size of two Tawny Frogmouth chicks

I have been monitoring the breeding success of Tawny Frogmouths Podargus strigoides in Canberra, Australia, for several years and have found that the pattern is fairly constant. About half the breeding pairs rear two young to fledging; a few rear three in any year and about a quarter rear one chick. The proportion of pairs which fail to rear any chicks is about 24% on average over the years, ranging from 17 – 34% (Figure 1). I do not disturb the birds to record clutch size, but it is known to range from 1-3.

Figure 1: The number of young reared per breeding pair of Tawny Frogmouths in 2006 - 2012.

In recent years I had thought that more birds were failing to rear young, but this is just the impression gained as I have added more pairs to the study in the past few years. Although I have been recording more failures, this has been in proportion with larger sample sizes, there is no statistical difference (χ² = 3.8, df = 6, P = 0.43). The main causes of failure, which are usually the loss of whole clutches or broods, are predation by unknown species, but likely Brush-tailed Possum or Brown Goshawk. One male was taken off the nest by a feral cat. A few nests have been blown out of their trees by strong winds.

Figure 2: The number of Tawny Frogmouth pairs which failed to rear any young in any year is proportional  c24%, to the number studied (r = 0.899, P = 0.003).

Further study will aim to determine whether there are any differences between the breeding success of frogmouths in grassy woodland, dry sclerophyll forest or suburban remnant woodland; or if there is any difference between years of drought and high rainfall. Fortunately the study has already covered these criteria.

A male Tawny Frogmouth protects his chick