Saturday 10 November 2018

Small Ant-blue

Acrodipsas myrmecophila


Small Ant-blue butterflies are indeed small.

Although when they fly in swarms like this one, in which there were of over a hundred individual males, they are spectacular.


This is the tree they were flying around, a small Blakeley's Red Gum sapling, with some dead wood lying around, in an open grassy woodland on the edge of the suburbs. The butterfly is a rare resident in the Canberra area, and is uncommon or very localised throughout its range from Victoria to southern Queensland.

Here a group of four adults (all male) have newly emerged from the ant nest they have developed within and overwintered as larvae. The ants are Coconut Ants Papyrius nitidus, and the butterfly larvae feed on their larvae. The ants build their nests in dead wood lying on the ground and in the base of the saplings.


Once their wings are fully extended they begin flying around the nest trees and perch on the branches and leaves, ever watching or smelling for females.

When fresh, their wings have a delicate fringe of scales.

When a few days old, the fringes are tattered and the wings themselves become chipped and ragged. The metallic blue of the bronze upperwing shows in this photo.

Two males perched on my watch as I was photographing the flock. They seldom sit with their wings open for more than a few seconds.

The females were scarcer and seemed to mate as soon as they could fly. The next time they became obvious was when they were seeking a crevice or shady piece of bark at the lower parts of a sapling to lay their eggs in.

I never saw a female sit with her wings open and this one only shows a glimpse of the bright metallic blue of her upperwing.

Once they have laid their eggs the females die. Or in this case are immediately killed and dismembered by the ants. How did the ants know to let her lay her eggs before attacking her. They were in attendance all the time she was laying. The blue of her wings is more easily seen now.

The males probably live for a week of so, competing to mate with a female, but they too can become prey. This one flew into a spider's web, she can be seen top right. Other males were caught by birds, such as Noisy Miners which had a nest in the ant-tree.




The whole flying season probably only lasts for a one or two weeks. Then once the adults have died, the species continues as several instar stages within the ant nest until the next generation emerges the following year. But what do the ants gain from the partnership? or are they simply conned by some pheromone emitted by the butterflies and larvae?

Wednesday 31 October 2018

First Frogmouths fledging now

An adult male Tawny Frogmouth sits with one of his chicks in the nest, while the sibling sits out along the nest branch.

This one would likely have been flying about between the branches, if not neighbouring trees, over the past few nights, then returning to the nest by dawn. Perhaps, the sooner they can leave the nest at night the safer they are from predators, by separating from the group. The chicks do make a rasping, coughing call when they are being fed, and that could attract owls, for example.

When viewed from the other side, it seems like both chicks are actually out of the nest and on the branch rather than in the nest, which is just the cradle of twigs in the fork. That is all frogmouths need for a nest, enough to hold the eggs, any more twigs and the nest would be bulky and so betray the birds presence. A little is better for these birds, who rely on their camouflage for concealment.

This chick doesn't look much younger, only a day or so in difference. These shots were taken yesterday, so I am sure both chicks will have fledged by tonight, although they might still return to their nest for perhaps one more night. As it's Halloween tonight, watch out for some of these spectres flying between the trees, silently gathering moths. There is nothing frightening in nature, just fascinating.

Two Ochres

A Heath Ochre Trapezites phigalia rests on leaf litter, with its wings closed along the line of the sunshine
- so not casting a shadow to aid me seeing it. 
The butterflies are finally beginning to show here in Canberra after a slow dry spring. In the past week I have seen two species of Ochre, Heath and Yellow, but wow when they close their wings and settle on the ground cover they just disappear from view.


They are only a couple of centimetres long with a wingspan of about 3 cm, so I had to get down to ground level to capture the detail of the wing pattern.

This was the only one of its species I saw that day and it didn't seem to be keen to be out searching for a mate, or food which was sparse as there were so few herbs in flower. It has been so dry, little is growing. The habitat was open grassy woodland, which normally has a good shrub and herb understorey.

This was all I saw of its upperwings, it never held them fully open.

A Yellow Ochre Trapezites luteus flying between flowerheads.
The Yellow Ochres were just over the border in New South Wales on a grassy verge of a rough mountain road. Here some daisies provided several individuals with nectar. These are more localised butterflies in their distribution, uncommon but not rare. the heath Ochres are more common, but still have a localised distribution.


The yellow of the butterfly complements that of the daisies well, and the white spot on the underwing.

The sun was bright and the butterflies were flitting between flowerheads, so I cranked up the camera speed and tried a few flight shots. They look so different when in flight, this one still has its tongue unrolled.

Monday 22 October 2018

Bees on blossom

The garden has been full of honey bees over the past few weeks. First they had the apricot blossom, then the plums, now they are collecting nectar from the apple trees. They really are busy little things and trying to grab some photographs of them is challenging, the fly so quickly. Here are a two shots taken with ISO settings of 4000, and exposure time of 1/4000 of a second. And they still are not frozen in action, well their bodies are but not their wings.

So I tried some slow-motion filming of them. This was more tricky as the camera could not focus closely enough to give larger images and tracking the bees before pressing record was difficult through a viewfinder. Here are the results of my better efforts. Fun trying.


The action shown in each of these clips was over in a few seconds.


And one last final clip



Sunday 30 September 2018

Cunning nest builders

High in my list of favourite nests are those of the Varied Sittella Daphoenositta chrysoptera. I remember wanting to see one since schooldays when I first saw a photograph of a nest, then when I visited Australia I wasn't disappointed. They are extremely craftily built and difficult to see, but last week I heard these birds busy in a tree above me, and there was another.

Sittellas are cooperative breeders, where there is one breeding pair and up to several helpers. The breeding female incubates the eggs, and broods the chicks; the others help by providing food, defending the contents from predators and of course, as seen here, they aid in the building of the nest.

The nest is constructed with spiders web and strips or flecks of paper-thin bark.

Their nests are typically set in the upright fork of a dead bark-less branch.

The birds deftly layer the material to fit within the fork and mold the bark flakes to flow with the contours of the branch.

All that material has to be shaped just right to fit the incubating bird, so I think this is the breeding female turning about on the nest.

Some of the birds came in with rather large beak-fulls of nest material.

Sittellas always land on branches in an upright pose.

Although they seem to prefer to walk down the branch to the nest.

Yet another shuffle to get it all into shape, then repeat.

Monday 24 September 2018

Spring at last 
common and not so common, all welcome

My blog has been quiet for quite a while recently, a reflection of not inactivity but the opposite - high activity. Since migrating back south to Canberra in July I have been doing something in the field most days, and desk-work most evenings. I find that when I am busy I have less time to write up the blog, so readers, please be patient if you do not see anything new for long periods.

In a very brief summary, I arrived back in Canberra to a long cold dry winter which has dragged on into a long slow, cold, dry spring. At last the weather has warmed, it still hasn't really rained, although blossom is out, butterflies and dragonflies are flying and the birds are nesting.


This Bearded Dragon was basking on top of a cut tree limb yesterday, although the sky was overcast and it looked rather slow, as if not very warmed up. I took these shots in late afternoon, when they would usually be active and quick to react to approach. Although these are long-lens shots and I didn't disturb it.

I am always captivated by how Bearded Dragons' scales fit around their faces, each one, from the spines on the neck, to the lips and those amazing eyelids. Beautiful.


Bearded Dragons are common in the Canberra woodlands and they are a sure sign of spring. Much less common, in fact very rare at local, national and international scales is the Canberra Spider Orchid Arachnorchis actensis. This plant is critically endangered as it is only known from the Australian Capital Territory and only from three sites there. The bush is still very dry with very few plants of any sort throwing up fresh shoots, yet a group of these orchids, only several cm tall, were stretching up from the stony forest floor yesterday. rare jewels indeed. But it is not their rarity that appeals to me, it is their form, like that of the dragon, each flower part is beautifully formed.



Welcome back Spring.


Tuesday 10 July 2018

Three alpine/arctic specialist birds

The path into Coire an t-Sneachda
I went for a walk in the Cairngorms last week, to count Ptarmigan Lagopus muta and their brood sizes, as they mostly have well-grown chicks now. Ptarmigan are an alpine/arctic bird so they are restricted to such ground in Scotland and if we want to see them we have to do so on their terms. Two other species which are such specialists are Snow Bunting Plectrophenax nivalis and Dotterel Charadrius morinellus, and I saw them both while looking for the Ptarmigan.
 
The castellated rim around the top of the corrie cliffs
I walked into the hills via Coire an t-Sneachda and took the Goat Track up onto the plateau. A fine spectacular route through a boulder field and under the crags.

The twin pinnacles from above the rim
I passed the common generalist hill birds, Wheatears Oenanthae oenanthe and Meadow Pipits Anthus pratensis in the corrie, and a couple of Ptarmigan, then as I neared the summit I heard a Snow Bunting singing. His song ringing around the rocks on such a clear windless day.

A handsome Snow Bunting singing from the edge of the cliff
When I reached the top, I sat on the cliff edge for a while and soon realised that the Snow Bunting was flitting between a few rocky points which he was using as song-posts, one right by me. And he was confiding, he seemed to accept my presence and came to sing next to me. He would fly from a cliff across a gully then slowly descend in a parachute drop to his post next to me, singing as he came down.

A cock Ptarmigan sits on a rock ledge overlooking the corrie floor 200m below

The Snow Bunting was easy to see as he was making himself conspicuous by his singing display. The Ptarmigan were much more secretive. But just around a rocky corner from the bunting I noticed a male sitting quietly and inconspicuously on a rock more fitting for a bunting song-post than a Ptarmigan perch. He was squatting there watching over his hen who was in the gully below, feeding on the mountain herbs, Heath Bedstraw Galium saxatile and Alpine Lady's Mantle Alchemilla alpina.

If he hadn't moved I would probably not have seen him


That female didn't have any chicks, and it was probably too late for her to re-lay if she had lost her first clutch of eggs. So they would probably have the rest of the season off from raising young, then join into a flock of failed breeders and males who would soon leave their partners to rear their chicks alone.

A hen Ptarmigan, she was alert and watchful as she had chicks
- a different colour from the males, more suiting to the heath and moss habitat


The next Ptarmigan I found was a female with four chicks, who were feeding on the top edge of the next corrie, where the herb-rich cliff vegetation merged into the sparse windswept plateau vegetation.

She had four chicks - two can be seen in this photograph


This was prime Ptarmigan habitat, a loose mix of boulders for cover from predators and weather, and food plants growing close to the base of the rocks. They would never have to wander far from cover to feed, and if it was difficult for me to find them it would be difficult for any predators. Such mountain habitat might seem harsh or inhospitable to some anthropocentric humans, but to Ptarmigan it is perfect. And I like it too.

The Cairngorms plateau spreads out above the cliff edge
Braeriach is the highest hill in the background


The high ground of the Cairngorms, above the cliffs, is mostly sweeping, rolling plateau. There are Ptarmigan throughout this habitat of wind-scoured boulders, gravel and Juncus trifidus heath, but the main specialist bird of this ground is the Dotterel. I have studied these birds for over thirty years, and although I am very familiar with them, it was still good to see some. They fit the landscape so well. Although waders, they spend their non-breeding time in arid north Africa, then fly north to breed on dry mountain/arctic heath. I have only once seen one stand in water. The birds in Scotland are one of a few species that can live on the highest ground, and select to breed only there. They were the third such alpine/arctic specialist bird species I saw that day, the high three.

A male Dotterel skulks in the alpine heath - mostly Juncus trifidus  


I wasn't there to study Dotterel that day, so although I did see a few, I walked on by. The males mostly had chicks - they incubate the eggs and rear the chicks alone, but this one was with a female, so he had perhaps lost his first clutch and she might have been about to lay another for him. 

He showed himself briefly as he ran between the tussocks


The female Dotterel are bigger and brighter coloured, but she never showed herself clearly and I didn't chase her. I have seen hundreds before. I simply appreciated them, took a few long-lens shots as the male popped close, and I walked on by. There are too many human visitors, hillwalkers and bird-watchers to that area, I didn't want to add to their disturbance.

I was happy, I had spent a perfect day in my favourite habitat, one I share with three special birds.