Tuesday, 22 September 2015

Dragon fight

Two Common Bearded Dragons Pogona barbata face one another off
The reptiles in Canberra are becoming more active every day as the weather warms. I found a gecko on the front doorstep this morning and a blue-tongued lizard has taken to sunning itself on the edge of the drive. Then while out in the woodlands I came across these two bearded dragons fighting in the middle of the path.

The dominant dragon gains the high ground
I stopped and watched them from a few metres off to follow the outcome, although by the time I found them they appeared to have settled most of the dispute as one seemed to be dominant and the other subordinate. The dominant dragon was circling around the other, always clockwise, spreading out his body and tilting it to show a broad back artificially widened, with spines along the edges. And he blew up his throat to make that look large, again with spines frilling the edge. Meanwhile the subordinate dragon lay low, with its body held slim, his throat non-extended and spines held close, but still showing his teeth and in his bright yellow mouth as if ready to defend. The two, reminded me of red deer stags rutting, facing off to one another, adopting postures that threaten, by exaggerating their size and height.

The inside of their mouths is bright orangy/yellow
 which I am sure when seen from close contact is a formidable threat display
They fought for several minutes, strutting, biting, chasing and tumbling into the grassy verge, knowing I was there, but ignoring me as they were locked in a combat each wanted to win. Then it soon became obvious that one had won the contest. He held his head high and the other lay low. As with stags, they seemed to hold back from inflicting serous injury to one another. Each had a few scales knocked off and even the winner had a bloody smear below one eye. The two seemed evenly matched in size, about 500mm long, and neither looked stronger to me, so how the contest was decided I do not know, strength in endurance perhaps.

The victor posed with head up high and his throat inflated

The loser cowered low with his spines retracted and body held thin
I photographed a more aggressive fight back in 2011, to see those shots follow this link:

In the end, the loser lifted up on his hind legs and ran into the bush, spreading out his belly and neck to look big from behind - a final act of defence in case the other dragon might still attack.

Saturday, 12 September 2015

Warming up

A Gippsland Water Dragon Physignathus lesueurii howitii sun-basks on a rock
The days are lengthening and warming up now in Canberra and the reptiles are beginning to show themselves. There are various species of skinks basking on the rocks in our garden, they are little animals of only several centimetres in length, but while at the Botanic Gardens yesterday, I photographed this metre-long water dragon. By its colouring this one looks like a youngster turning into adulthood - its back is more green than dark brown or grey, and there is some yellow coming through on its throat. Full adults have a pale but true green skin and a fully orange/yellow throat.

The throat was blotchy yellow
I only saw the one dragon and it was very approachable. A sign that it was still early Spring and the group that usually frequent the pool where this one was basking next to had yet to get going for the season.

The dragon was lying flat and tight against the rock it was lying on, making maximum use of the warmth of the rock by contact as well as catching as much direct sunshine/heat as possible. The hind legs are turned out wide and it was orientated along the line of the sun, with its shadow falling off under its chin. A well-adapted piece of animal behaviour.
These dragons are found in and near water around the Canberra area, and throughout south-eastern New South Wales and Victoria. There is a colony of them living in the Gardens, around the ornamental pools. They are much more approachable than those in wild settings, where on approach, they will run and dive straight into the water and remain submerged until any threat of danger has passed. Some of their dives can be rather dramatic as they will also climb trees and will dive into the water from the branches if disturbed.

A true dragon - with a magnificent line of nuchal spines running down the back of its neck.
So I took my chance and grabbed some nice close up shots of the dragon features: the scaly lips, the nuchal spines (elongated and enlarged scales on the neck) and that magnificent dragon's eye.

A dragon's eye

Tuesday, 1 September 2015

First day of Spring

Apricot blossom
Today, the 1st of September, is the first day of Spring here in Canberra and the garden is full of activity. The new growth is bursting from the plants and I saw the first butterfly of the season, a cabbage white. The skinks are sun-basking on the rocks and the crested pigeons are collecting nesting material.

But the best show is the blossom in the orchard. The apricots are always first to open and there is a terrific amount of flower heads, so lots of fruit in late summer if all goes well, and the rosellas don't eat too many buds. The plums are a few days behind, but the apples are still in tight bud.

A honey bee approaches the blossom
As it was the first day of Spring I thought I should capture the flavour, so grabbed a few shots of the blossom, then focused on the honey bees as they busied themselves around the blooms. Or rather, I tried to focus on them. They fly so quickly and being so small, there isn't much insect to focus on. But here are a few shots which I took at 40000 - 64000 ISO, 1/4000-1/8000 sec.

Bees are such wonderful fliers
If it takes such high speeds to freeze their movement (except their wing beats), I wonder what speed their own perception operates at, they must live fast furious lives.

And they make apricots for me..., the family, the neighbours, friends; the trees bare so much fruit every year we need to share.

Pollen sacs filled , maybe one little bit more...

Sunday, 30 August 2015

Prospecting ducks

A pair of Australian Wood Ducks Chenonetta jubata above a potential nest hole high in a tree


It's not only parrots that nest in tree holes in Canberra, although there are so many around it seems like it sometimes. Tree holes are prime real estate for a many animals; brush-tailed possums and sugar gliders, kookaburras and treecreepers, bats and smaller creatures such as spiders. Also, as Canberra has lots of open grassland in parks and road verges, it has a large population of wood ducks, which are grass-eaters. And they all need nest holes too.

The other day I watched a female wood duck cooing and grunting from high in the branches of an old eucalyptus. She was prospecting for a nest hole and seemed to have found a suitable one if only she could work out how to fly into and land on its rim - the hole was on the underside of a thick limb.

The female was the more interested in the hole, the male was simply following her, protecting her


She spent more than ten minutes bending over and peering into the darkness, while the male spent most of that time preening himself. The drake's purpose is to protect his mate from predators and any other suitors. So, this one's investment is in her and the fertilised eggs she was carrying. Her investment is a safe place to nest, hidden away from danger while she incubates the eggs. She will be in her nest hole, whether this one or another, for about a month, only coming off perhaps once a day to feed. Then when the ducklings hatch, she will encourage them to jump down from the nest hole, then lead them away to the nearest water for safety, and surrounding grass for the ducklings to eat.

She seemed to like the hole but wasn't sure how to get into it?


Monday, 17 August 2015

Spring Plumage

Diamond Firetail Stagonopleura guttata in bright adult breeding plumage
Spring is ever nearer in the south-east Australian bush and many of the birds, especially the passerines, are beginning to breed. Which means that they are now in full breeding plumage and looking their best.

Over the past weekend I was part of a team mist-netting birds at The Charcoal Tank Nature Reserve in south-western New South Wales, as part of a long-term study of birds in the area, organised by Mark Clayton. And it was clear by the condition of the birds' plumages that they were fit, healthy and ready to breed.

Diamond Firetail 
There was a flock of Diamond Firetails feeding on grass seeds along the edge of the reserve and they were dazzling as their red rumps flashed through the grasses. The bird shown here is an adult in full breeding plumage, with all the feathers on the head and breast clean and fresh. For these are the feathers which any potential mate or competitor would see when assessing its fitness. However, the flight feathers, the primaries secondaries and their coverts were a bit tatty, with chips and worn edges. For these feathers would have been moulted and re-grown at the end of the previous breeding season, and they will be again at the end of the current season, but for now they are still perfectly functional and there is no need to replace them yet. Birds are almost constantly moulting part of the their plumage at any time of the year, and for the moment it is the bright signalling feathers that need to be in top condition.  

White-plumed Honeyeater Lichenostomus penicillatus
It is not only their feathers which are spruced up for breeding. The white-plumed honeyeaters which we caught, also adopt shiny dark colouring to their bills - they are duller and greyer when not breeding. This adds impact to their dark eye and the slight fringe of dark feathers on their neck, next to their white-plume, which the dark colouring emphasises. By the time the birds are half-way through the breeding season, the best of these colours will have begun to fade.

Chestnut-rumped Thornbill Acanthiza uropygialis
Even the little-brown-jobs, the small dull coloured birds adopt brighter plumage. This chestnut-rumped thornbill had a particularly well marked face pattern, in relative terms, and it's only when we see them up close, in this case in the hand while ringing/banding them, that we can appreciate the detail of these tiny birds' markings. Although to a bird's eye, they see things across a wider spectrum than us, these markings probably also signify the birds health, fitness and hierarchy in the flock, only more demurely.

Chestnut-rumped Thornbill - face
The sexes of all three previous species have similar plumages to one another of their species, they are monochromatic to our vision - but probably not to their own. For birds can see ultra-violet colours and in some species this has been found to be used in their markings to differentiate between the sexes. Do these species sport such colouring?

Golden Whistler Pachycephala pectoralis - male
Some of the brightest birds in the study were the male golden whistlers, and if their plumage is enhanced with ultraviolet colouring they must be amazing to see through a whistler's eyes. This species is dichromatic - there is a colour-difference between the male and female. The female is an almost overall grey colour, which is fit for purpose, as she incubates the eggs and broods the young. That involves a few weeks of her life each year, spent sitting on a nest set amongst grey-barked branches, so the grey colouring acts as camouflage while she is on the nest. The species has evolved for the females to be camouflaged while the males are brightly coloured to show off their fitness and hence value for a female to mate with, or for another less-brightly coloured male to avoid.

Even in her grey plumage, the female can be seen to be healthy and fit to breed as her feathers are clean and fresh. She too is fit to breed.

Golden Whistler - female