Thursday 25 February 2016

First year plumage

I was out west over last weekend catching birds as part the long-term study at The Charcoal Tank Nature Reserve, which is a cooperative site and the trip was organised by Mark Clayton. The most noticeable trend that I noticed amongst the birds we caught and banded was the high proportion of young birds. It is the end of the breeding season for the passerines and most of the young were free-flying and independent, although some were still being fed by attending parents. The other point I noticed was the different strategies of moult that the various species have adapted to suit their lifestyles. Below are only a few examples.

A first year Sacred Kingfisher Todiramphus sanctus


This young Scared Kingfisher was in perfect condition with a full set of fully-grown flight feathers, all with fine clean edges. This is a single brooded migrant species and the adults had probably flown north already. The buff tips to this bird's crown and covert feathers indicate that it is a bird hatched in the recent breeding season. So, this bird was ready to fly north probably following innate properties to guide it to its winter quarters in the north of Australia or perhaps Papua New guinea.

A first year Yellow-plumed Honeyeater Lichenostomus ornatus
This young Yellow-plumed Honeyeater is clearly very young, as it still has a yellow gape - the flap of skin at the base of its bill. Therefore, this bird was from a late brood, perhaps a second or even a third reared by its parents. Unlike the kingfisher, this is less critical as it will not have to fly far very soon. At most it will probably range locally or nomadically in and around the breeding region. This bird will join a flock of its species, probably a mixed flock of several honeyeater species, unlike the kingfisher which will live singly until it returns to breed.

The same Yellow-plumed Honeyeater - face on


The plumage details which discern this bird as a youngster are: the brown feathers on its back and crown, the incompletely-grown wing coverts, some of which are still in quill, the yellow base to its bill, the pale brown streaks on its throat and breast and the thin yellow line across the side of its neck.

An adult Yellow-plumed Honeyeater - face on


The plumage details which discern this as an adult Yellow-plumed Honeyeater are: the bright yellow crown with no brown feathers, the yellow plume feathers standing out from the sides of its neck, the heavy black streaks on its throat and breast, and the lustrous black bill.

A first-year Restless Flycatcher Myiagra inquieta
The young birds of the two previous species were both similar in plumage pattern to the adults, only less brightly marked. However, this young Restless Flycatcher is different from the adult birds, it has an orange/buff breast, the adults have almost pure white breasts. These flycatchers live singly when not breeding, or at most in pairs if they stay in their local area, but very little is definitely known of their non-breeding movements. They are also multi-brooded, so any young birds from early broods have to share habitat with breeding pairs, and those pairs would not be their parents if they move from their natal area. Therefore, by having a distinctly coloured breast any adult birds can identify them as youngsters and not regard them as a threat to their breeding, So they are less likely to attack the young birds and the immature birds can live unobtrusively with less harassment. This young bird has a fully grown set of fight feathers, but the primaries and their coverts are a dull dark grey, these are shiny black in the adults. Although, shiny black is not a true appraisal of this wonderfully coloured bird's plumage. The dark feathers have a rich metallic blue lustre, and when they raise their crest as in the image below, they present a very vivid frontage. This young bird has not quite grown all the lustrous feathers on its crown, some still have dull tips. But by next year's breeding season, they will be truly magnificent and offset by a bright white breast. A handsome bird indeed.

The same Restless Flycatcher - face on



Thursday 18 February 2016

Too hot sometimes

Meadow Argus Junonia villida
When I came home this morning there was a butterfly sun-basking on the wall next to the front door, which faces east. It had clearly found the wall a perfect place to catch the morning sun for its daily warm-up. However, by the time I returned it was sitting with its wings closed to avoid the ever warmer sunshine.

The shadow cast by the butterfly was so clear
Then, as I walked past the butterfly I noticed how it seemed to be in a rather awkward pose. It was aligned askew with the wall.

A minimal shadow
But as ever, things make sense in nature. The butterfly had aligned itself along the direction of the sunshine, and angle, so that it cast the smallest possible shadow.

It was holding itself perfectly, all in line with the sunshine by leaning and twisting its body
I took a look from its front, and I was impressed by how it held itself stationery, although I expect that it had moved ever so slightly to re-align as the sun rose and arced across the sky.

Very well adapted - the butterfly was even tilting its body to minimise exposure to the sunshine
As for the species, a Meadow Argus, I usually only see them in the nearby forest glades, often feeding on ground cover weeds, and they are usually much to flighty to photograph. I have seen them in the garden over the past few weeks, but this is the first one I've managed to grab a picture of.  This is a freshly emerged example, note its clean complete and un-frayed edges. My butterfly guru, Suzi Bond, tells me there has been a noticeable emergence in recent weeks.


Sunday 7 February 2016

A spider jewel

A female jewel spider Austracantha minax
It's late summer, spider time.



I have been busy at the desk for most of January, hence the shortage of recent posts, but that is all part of my seasonal behaviour. When the sun is out at this time of year in Canberra, it is not much fun walking about in the hot bush, so I use the time to catch up on writing and editing photographs. Meanwhile, as the summer has progressed, the spiders have been more active and I found this little beauty spinning her web this morning, before it was too hot - for me that is not her.



She is a Jewel Spider, otherwise known as a Christmas spider as they are abundant from then on, or another name is spiny spider. I like that last name as it is so apt. They have six spines set around the hind edge of their abdomen. And the jewel name is apt too, as their glossy bodies catch the light, with all those little pin-spots of colour on the abdomen. Most of those are white on the dorsal, top, side and yellowish orange on the ventral, belly side. This spider is hanging upside down as she was walking along her silk threads, and as she has such a heavy abdomen, she was belly up.



They are only about 7-8 mm long and the abdomen is so large in proportion to the rest of her body that the cephalothorax can barely be made out in these photographs. Her legs are also quite long, and in the top image, the two hairy black pedipalps can just be made out at the front, between the legs. This spider was busy spinning a new web, a circular orb-type, suspended between some grasses about a metre tall. It was nice to see a bit of colour, in the dusty sunshine.





Wednesday 20 January 2016

Hot summer

A female Cabbage White Pieris rapae feeds on a dandelion flower


It's January, mid-summer in Canberra, and it's hot. So, I have been a little quiet recently, keeping cool and getting back into working at the desk. I try to take short sorties into the local bush, but most days I'm happy to sit on the veranda and watch the birds come and go in the garden. Then, while sitting there I counted six species of butterfly flitting between the plants, searching for food plants for themselves or to lay eggs on. So, I thought I might grab a few quick shots. No, the sunshine is so hot that the butterflies are all flying almost non-stop and at speed. They are not easy targets.

A female Common Grass Blue Zizina labradus feeds on a clover flower


The male cabbage whites were chasing one another through and over the bushes, then I spotted a female feeding on the dandelions on the lawn. One down. Next the blues, but they are so tiny and they really chase one another, fast and in unpredictable twisty flight. Fortunately this seems to take its toll on the males as they stopped every now and then to sun up and re-charge. No chance of close approach though, a long lens shot only. Similarly for the one female I saw and captured as she supped from the clover.

A male Common Grass Blue takes a short break to bask in the sun


The butterflies are certainly pretty to see, from our perspective, but the most stunning lepidorteran in the garden at the moment is a great big caterpillar, a Batwing Moth caterpillar. This one has grown to over 10 cm and the adult when it emerges has a wingspan well over that. They will emerge from their cocoons at the end of the summer, early autumn.

Batwing or White Stemmed Gum Moth Chelepteryx collesi.. Every spine hurts if it sticks into a predators skin



It is a few years since I saw one of these in the garden, which is good and bad news. Good for me as these insect larvae are protected by a mass of spines which break off into our skin if touched. And they are very irritating when they do, as they are very difficult to see and remove. A bit like pieces of very fine glass. But, then bad for the caterpillars as their main food plant in the garden, the tall red gums have been rather sickly in recent years, due to dry weather and an infestation of lerps (Google that, they are a fascinating life form and a rich source of food for birds).


Six true legs stretch forward, searching for a hold


These caterpillars have such dense spines/hairs around their thorax and head that it is difficult to discern exactly where the head is. It is a tiny section set low, beginning somewhere just in front of the legs. The best clue is their tiny black eyes which catch in the sunshine. But their mouth-parts are so swarmed by hairs, not much else can be made out. Then, of course, like so many caterpillars it is tricky to tell which end is which, as the tail resembles the head, or is it the head that resembles the tail...

A tiny beady eye looks out from beneath all those hairs


This one was not on a gum tree, but wandering across some old cut branches. I reckon that it had fed enough for that stage of its life and it was looking for a place to tuck into while it metamorphoses into an adult moth. Their cocoons are also prickly as they push those spines out thorough the casing. That is a very annoying habit for anyone like me you tends to climb trees. The cocoons are well camouflaged and too easily laid hands upon. Ouch.

So, til autumn....

Now which end was which again?




Thursday 31 December 2015

Last Post for 2015



My last day out in the bush for 2015 has been a trip to Tidbinbilla Nature Reserve, in the Australian Capital Territory. It is only a half-hour drive from the city and is tucked into a valley of the local hill range, the Brindabellas. This was an easy day out in a parkland type setting, and the clouds were flying high over the ridges on a clear mid-summer day.



The reserve is a great place to see the local wildlife without trailing through miles of thick scrub. A casual walk around the laid paths takes you past pools where platypus swim, in full view all day. And they are on calm water, so easy to see as their wakes ripple the flat surface. They can be tricky to spot on rivers, where they can pass unseen in the tumbling water.



As the sun was out, and quite warm, the skinks were out catching the heat. A group of Cunningham's Skinks Egernia cunninghami were conspicuous as they lay on a rock right next to the path. The main group were scurrying about in cracks in the rocks, with only their heads protruding from the shadows. They had obviously warmed up enough as they were busy clambering about. But this younger one was out in the open, basking in the dappled sunshine. It was even lying with its eyes closed, as it was so used to people walking by. When alarmed, they dart into a crevice and curl their spiny tails across the entrance. Those are sharp-edge scales on the tail, and they present a formidable barrier to any predator.



There are also some good views or plants from the path-side, such as this Mountain Spiral Orchid Spiranthes alticola which was growing on close by a pond.


Simple single orchid stems can be difficult to spot in thick cover, so it was good to just stroll along a clear path and see all these animals and plants - not to mention the two red-bellied black snakes which were hunting and sunning themselves close by on the banks of the streams.