Thursday, 30 October 2014

Sun Orchids

Trim Sun Orchid Thalymitra peniculata 

The current warm and sunny Spring seems to be suiting the local orchids as there are thousands of them in flower in the woodlands around Canberra at the moment. The shy Sun Orchids are the species that I have particularly noticed this year on Black Mountain. This is a great place for orchids in number and variety with about sixty orchid species recorded in the woodlands there. I don't go out looking for them especially, I simply notice them while in the woods looking for Tawny Frogmouths, my main study species here in Australia.

Trim Sun Orchid in woodland habitat

Some orchids grow in small colonies, however the Sun Orchids are usually found singly and as they are slow to open their flowers every day, and only if the sun is bright, they can be easily missed. The tallest of these plants was the Trim Sun Orchid which stood erect at about 40cm, which was just about the same as the surrounding grasses so it was well concealed until it opened up and displayed its bright purple-blue petals.

Large-spotted Sun Orchid Thelymitra juncifolia

The most difficult to find species of those shown here was the Large-spotted Sun Orchid as they were growing in partially shadowed woodland, where the dappled light hid them in the partial shadows - always tricky conditions for our eyes to detect anything due to the loss of detail in the contrasting light.

Large-spotted Sun Orchid on forest floor

The one species I found out in the open grassland on the edge of the forest was the Slender Sun Orchid, the smallest of those here with a flower only 15mm wide. They were growing in quite tight flower spikes and reminded me in their form and soft hue of alpine gentian species.

Slender Sun Orchid Thelymitra pauciflora 

I might have found these orchids difficult to find but the local herbivores seemed to find them alright. There are Eastern Grey Kangaroos, Swamp wallabies and  rabbits all in there munching away. When I passed through the area a few days later, the flowers were gone, the plants were gone. So they weren't just not open or gone to form seed and even more tricky to find, they had been eaten. What a beautiful meal.

Slender Sun Orchid plant in grassland

I thank Dennis Wilson for help with identifying these orchids, he is always so patient with me.

Saturday, 25 October 2014

Noisy Miners

Two Noisy Miners - a pest or a successful adaptable species?
As a woodland species that favours clear ground with not much shrubbery, Noisy Miners Manorina melanocephala have adapted well to the human-cleared woodlands around Canberra. They nest in loose colonies with their nests about a hundred metres apart, and as they as very demonstrative against intruders they fit their name. Although we can tolerate their mobbing and chasing, smaller birds can't and many parts of the woods which hold Noisy Miners lack some of the usually more common bird species.

A typical clutch of three Noisy Miner eggs lying on a lining of kangaroo hair
A secondary factor which also helps the miners dominate parts the woodland is the grazing of the understorey and grasses by Eastern Grey Kangaroos Macropus giganteus. These large herbivores have grazed the ground cover down to very short swards and bare ground in some places. And in the absence of a predator, the kangaroos numbers are abnormally high. The local authorities do cull some animals but the population was allowed to build up to such a high level previous to this that it will take many years before the vegetation is restored to a more balanced composition of ground cover and shrubbery, which in turn will support a wider range of animal life including those missing species of birds.

But the Noisy Miners are happy and they further benefit from the kangaroos by using their cast fur as a lining for their nests. So, can these two species be regarded as pest native species, due to their abundance and effect on the woodlands and other bird species, or are they simply successful adaptable species that can thrive in a human-created landscape.

A group of Eastern Grey Kangaroos in Canberra woodland with little understorey

Thursday, 23 October 2014

Natural History Museum Wildlife Photographer of the Year.

Zipped up the back
Here is my humble entry and semi-finalist photograph in this year's Natural History Museum Wildlife Photographer of the Year competition. I never thought it would win, but it is good fun to take part and when we view the winners, there is lots of inspiration on what to shoot, or a good simple, 'I like that'.

Another shot I entered was a close up of a Tawny Frogmouth perched on a branch, showing how the plumage merges so well with the bark.Only the claw gives the game away, which I deliberately captured. I also kept a bit of bird shape to show the similar form of a branch, part of the bird's camouflage.

Bird and bark

I was tempted to crop in even closer, but even if I had I would not have caught such a powerful image as that by Jess Findlay, 'Pauraque study'.  His subject and lighting give a much more striking image - well done Jess. I won't submit any more 'brown' images in future.

Once again, the overall winning shot was of a top favourite animal species, in this case lions. The competition is linked and promoted by the BBC Wildlife Magazine and as any editor knows, competitions are partly run to promote the magazine and increase sales. So they would like popular animal subjects wouldn't they. The winning shot is a nice shot, but would it have won if the subjects were slugs? However, the important points are, the Museum gets publicity, which I agree with, the magazine gets a wider readership which is all good for the wildlife and conservation issues it promotes, and the photographers get media coverage. So we are all winners and what can I say but thank you to the promoters for inspiring we photographers and making us keep improving.

My pick of the shots are the arty ones by Andrew Lee, 'Edge of creation'. and Herfried Marek, 'Golden birch'.

Thursday, 9 October 2014

Lunar eclipse

What I like about a red moon is how, when viewed through binoculars, we can see it in a three dimensional effect with the stars beyond - much better than that through a telescope, or when the moon is too bright.

Last night, October 8th, at about 2150 hrs, I photographed the Lunar Eclipse as the blood red colour began to wash off the lunar surface. A night with a  full moon is usually a good time to watch Tawny Frogmouths, or any other nocturnally active animal as they can be seen without artificial light or night-vision equipment. Not under a red moon though, it was too dark. I don't normally take flash photographs of frogmouths, but I took this one to see if there was a chick beneath the adult bird sitting on the nest. I just couldn't see for sure. However, the camera didn't help. Yet there was one, as I saw a little later when the bird's mate, the female, came in with some prey and passed it to a tiny chick hidden by the nest rim. The adults red eye-shine reminded me of the red moon.

Thursday, 2 October 2014

Grey Butcherbird

A Grey Butcherbird Cracticus torquatus arrives at its nest with food for its young
The bird breeding season around Canberra is a protracted affair, with some birds like the Wedge-tailed Eagles and Superb Lyrebirds laying their eggs in winter, as well as a few small birds such as, for example some Buff-rumped Thornbills. At the moment a White-browed Scrubwren is incubating eggs in a nest in our garden - due to hatch any day now. However, Spring is the main breeding season and for most species; whether building nests, laying eggs, incubating them, feeding nestlings or caring for fledglings, some part of their breeding programme usually occurs then. It simply makes sense, timing their offspring's fledging and dispersal into the population to fit the period of the year when most of their food is abundant. Depending on species, the birds' food can be flower nectar, fruit, insects or other smaller animals such as, well, young birds. And each species times its breeding period to fit their young fledging when their food is most abundant

I often find these birds in the woodlands when I am monitoring the Tawny Frogmouths,
and this pair were nesting in a small tree next to a Frogmouth nest tree
Insects are becoming more abundant every day as the weather warms up, although flying insects can be difficult to catch and often it is their larvae that are bigger and more nutritious than the adult forms, such as moth caterpillars. Butcherbirds catch most of their prey on the ground, like the big fat grub that this one caught.

All butcherbirds have hooked tips to their bills - for catching and holding prey efficiently
There is a reason for all bird behaviour and all bird anatomy. Evolution if driven by efficiency

But birds' bills are sensitive organs and the butcherbird thrust the food
deep into its chick's throat without the slightest bit of harm