Monday, 26 November 2012

Tawny Frogmouth fledging dates



There has been some discussion between members of the local Canberra Ornithologists' Group on the apparent synchronisation of the Tawny Frogmouth fledging dates in the Canberra area this year. So I have plotted these and those of the previous years on the graph below and ran some simple statistical tests on the figures. As not all birds have fledged in 2012 yet, the expected dates have been calculated for use now as some people have been asking for these figures. These dates will be corrected when possible and more precise analyses published at a later date.

The mean fledging date has been in mid-November every year, ranging from the 13th in 2009 and 2011, to 22nd November in 2010, although that year the mean date was late due to the influence of several late fledgings from re-lays after first breeding attempts failed. The median dates, from each year in order from 2009-2012 were 12th, 16th, 10th and 15th November. A simple ANOVA test for differences between years, not using any birds fledged from re-lays, showed no difference (P = 0.217, F = 1.51, n = 29,30,25,24).

The earliest fledging was on 14th October 2011 and the latest was 7th February 2010. 



Wednesday, 21 November 2012

Colour-banded Tawny Frogmouth has chicks

Double Pink, she has a pink band on each leg, sits quietly on a branch all day while her mate looks after the chick.
She is a mum - Double Pink, the colour-banded Tawny Frogmouth, which I reported on previously as a bird rescued by the RSPCA and successfully re-established in the wild and paired with a mate, now has chicks. She and her partner lost their first clutch of eggs, probably to a brush-tailed possum, then they quickly found another nest site and she laid another clutch of eggs. Although it looks like she only laid one egg in the second nest, as I can only see one chick in the nest below dad. It is he who sits on the eggs and young all day, while she hides close by in another tree. The chick is about two weeks old now from what can be seen of  it - a small fluffy white ball of down. Hopefully they will succeed in rearing this one. I'll post any more news as it comes in.

A white downy chick sits quietly and snugly under its dad, Double Pink's mate


Thursday, 8 November 2012

White-winged Trillers

Last weekend I was out west helping Mark Clayton and several other bird-banders catch a variety of birds with mist-nets at Charcoal Tank Nature Reserve, West Wyalong, New South Wales. The species we caught most of was the White-winged Triller Lalage sueurii, an interesting species as the male and female have different plumages and when young or not breeding the males resemble the females. Which makes it all very tricky when one has to identify, age and sex each bird. I have pulled several images of various birds in these plumages and give a few pointers for identifying them. Although it is Spring, the birds were in flocks on passage and in all sorts of plumages, pre-breeding.

Adult male in breeding plumage
Pied, with a fully grey rump and all black bill
Same adult male


Adult female in breeding plumage
Light tawny body feathers, with fully grey rump
and a dark bill with a pale base to the lower mandible
tips to the primary coverts are cinnamon coloured

Immature female
Pale brown body feathers with a scalloped grey rump
tips of the primary coverts are whitish

Immature male
The bill resembles those of the females,
but it is beginning to grow dark adult male primaries
scalloped rump
 



Adult male in non-breeding plumage
The body feathers are pale brown, the bill is dull black with no distinct pale base to the lower mandible, the rump is scalloped grey, the feathers having buff tips

Bird faces

White-winged Chough

I have added a few more images of bird faces to my website portfolio. These were all taken quickly with high-speed image capture while others were banding the birds, and they were immediately released afterwards. This gives an opportunity to see birds face-on, which is unusual when they are free, walking, perching or flying. There is such a variety of faces. 

Peaceful Dove


Laughing Kookaburra


Dedication and Commitment


This male frogmouth has now been sitting on his nest for ten weeks. Unfortunately he must be covering infertile eggs as the normal incubation period is about four weeks. I don't know how many eggs he has, but it seems particularly unfortunate as he is in a relationship with two females, as he has been for the past two years when they have raised three and two chicks. I haven't had a camera up at the nest to see which birds are doing what proportion of the night-time incubation, but hopefully they will give up on the eggs soon and they can all get on, and build themselves up back into condition. There was another pair which incubated a dud egg last year (after losing a partly-developed egg over the side of the nest early on) and they didn't give up until the end of November.