Friday, 23 September 2016

Heads or Tails

Not the head, but the tail of a Shingleback

The local reptiles are beginning to show as Spring moves on and the days warm up. There have been rustles in the garden when the little skinks scurried for cover as I passed and I saw my first Shingleback Tiliqua rugosa in the bush a few days ago. These are a species of blue-tongue skink, one of the larger types of lizards in south-east Australia, and as they are slow moving and terrestrial, they need a few tricks for defence from predators.

A Shingleback out in the open, seen from above - a raptor's eye view. Which is the head end?

Their main adaptation for protection from predators is deception by camouflage. They are a simple long brown, grey shape that mimics a stick or small broken branch lying on ground. This probablly hides them from aerial predators such as, in our area, Little and Wedge-tailed Eagles. Then if a predator ventures closer, it might be tricked into attacking the tail rather than the head end of the Shingleback because the tail mimics the form of the head. The skink's next strategy when touched is to turn itself around into a tight U-shape, open its mouth wide open, and thrust out its large blue tongue - a shock or startle defence. Blue is such an unusual colour in animals, that it probably has a particularly high startle effect. However, this startle is mostly bluff as the Shingleback has little else to defend itself. They are mostly vegetarian, with a fondness for soft flowers, so they do not have large or sharp teeth or claws.

When seen from ground level, the eyes make the head more obvious

I would like to see their defence in action against a predator, although at the same time would rather not as I like shinglebacks and would not like to see one hurt. They are such quiet non-aggressive animals. Perhaps the evidence of me seeing them quite frequently when out in the bush is enough to prove their defence's efficiency.

Shinglebacks are quiet and easily overlooked, but their slow lifestyle makes them easy prey for their main predators,
which these days are the introduced fox and domestic cat 

See the previous posts on shinglebacks listed on the right for more information on them, including a shot of that blue tongue.

Wednesday, 21 September 2016

Bathing in the creek

Thigh-deep water is just the perfect depth for birds to bathe in and have a good splash around.

The wet Spring in Canberra continues, and the number of birds visiting the garden pond for a drink or bath has dropped dramatically. Few birds are using it, mostly the local residents such as the Red Wattlebird, Superb Fairy-wrens and the Crested Pigeons. When it is hot and dry, birds from all around seem to drop in, but the ground in the nearby nature reserve, at the top of our street, is saturated with puddles lying all over the place. The dams are full and the water courses are all running and bubbling. So there is no need for the bush birds to go elsewhere to seek water.

The rosellas could immerse their bellies with a gentle dip, their tail lies softly on the surface and they can jump straight into the air and fly off if any predator approaches while they are otherwise potentially vulnerable. Consider this when you set up a bird bath in your garden. Provide gradual edges, not steep edges for birds with different leg-lengths.

I heard these two Crimson Rosellas splashing when I was out walking through the woods the other day. The creek line they were in is usually a dry ditch for most of the year. This Spring it has been full of water every day. It wasn't the perfect picture opportunity, with branches obscuring the view - which was a probable reason why the birds were using that spot. However, as they were happy to bathe a few metres from me I grabbed a few shots.

Overhanging or nearby branches are valuable assets as they provide cover from predators
 and safe perches for the birds before and after entering the water. 
The rosellas were so confiding in me that they flew up onto a perch to dry their feathers while I stood watching. Although they did keep watching me too, just in case I was a predator.

The water ran off the birds backs, like snow-melt running off a well waxed snowboard. 

The waterproofing on the birds' feathers is provided by the preen gland (uropygial gland) which is below the feathers at the base of the tail, just about at the bottom the bird's back in the image above. Birds collect oil from the gland with their bills and spread it over all their feathers when they preen. Not all species of birds have this gland, some rely on powder down for a similar purpose, but more on that in a later post. For now, just look at how well the oil system works as the water runs off the tip of this rosella's tail.

Meanwhile the rain is hammering down again...........

Sunday, 18 September 2016

Black Morels

Australian Black Morel Morchella australiana 

This wet Spring has not only been good for flowers, but also for early fungi and yesterday I found a stand of these morels, a classic Spring mushroom. If I have identified these correctly, they are of a recently identified species and apparently an Australian endemic morel, probably the only one. However, I am not a mycology expert, for more information read this article which describes the naming of what looks like the species I found. The species was only named in 2010.

The distinctive black ridges on the caps above stipes that were turning brown

I did not pick any of these, although I know the taste value of morels, because it was a new species to me, and I always err on the side of caution when eating fungi. Now that I have looked them up, perhaps I should have. Although, as some were already turning past their best freshness, I think I'll just wait for next year's crop.

I like to eat wild mushrooms, and I like to photograph their colours and shapes too 

Black Morels are found in south-east Australia; Victoria, New South wales, and apparently the Australian Capital Territory (ACT). Although I cannot find any records of the species in the ACT, which puts me in a dilemma. Is it a rare species which I should submit a record for, or do I follow the fungiphile code and keep the location of my find secret. No, I'm a scientist first, I'll do the right thing and submit the record. And for the record, the morels were growing in a scattered group over an area the size of a tennis court. The fruits were in clusters of twos and threes, and the habitat was Yellow Box - Red Gum Grassy Woodland, within several kilometres of the Canberra city centre. Because of their proximity to the city, I do wonder if they have are accidentally introduced specimens of the European Black Morel. Any comments welcome from anyone who knows more on these fungi.

Remember - never eat any fungus that you do not know to be absolutely safe to eat.

Thursday, 15 September 2016

Spring Flora

False Sarsaparilla Hardenbergia violacea 

It has been a wet Spring in Canberra this year, following a wet winter, so there is lots of growth sprouting in the bush. All the plants need now is a bit of sunshine and warmth to bring out the flowers. Although the fruit has blossomed well, I fear that there have been too few insects out and about to pollinate them. I'll know in a week or so, and the local wild flowers might be having the same problem.

Alpine Grevillea Grevillea australis

Nature is full of surprises though and when I was out for a walk through the forest on Black Mountain the other day I was amazed at how many flowers were out in bloom. Purple tufts of False Sarsaparilla were creeping over the ground and up through shrubs, the local native grevillea, the Alpine Grevillea, was showing as well as such a shy flower can show, and the moist air was rich with the scent of wattle - several species were in flower. While all around there were tiny single-flowered orchid stems. Their subtle tones hidden, then shown, by shadows and speckles of light dropping through the leafy canopy.

Box-leaf Wattle Acacia boxifolia

The main insects I saw were Painted Lady and Cabbage White butterflies. Although of course to our human eyes, those would have been the obvious ones. I did see some flies dotting about and several caterpillars on leaves. A few were stretching and folding themselves across the paths after a rain shower. I hope there were more.

Dusky Fingers Caladenia fuscata - white form - about 10 cm tall
(Highly sensitive, very rare/threatened)

Yet, once again, despite all the abundant purples, reds and yellows, filling the woodland with a coloured haze, it was the teeny inconspicuous orchids that stole the show. Why are we attracted to orchids so much? Well, for me, it is the way such small, highly specialised plants can grow in such nutrient-poor soils. They were literally shooting straight out from the leaf and bark litter on the forest floor, with nothing but a poor stony soil beneath.

Dusky Fingers Caladenia fuscata - pink form

These finger orchids are so short that we have to get down on our hands and knees, or lower to see the detail of their flower forms. Yet, they are probably holding their flowers at a perfect height to catch the attention of passing flies or whatever insect they rely on for pollination. For, as witnessed, most flies that I did see were hovering and wandering through the forest at just such a height as they passed through the low shrub layer. There was probably another set of insects flying through the canopy, where the next layer of greenery grew.

Blue Fingers Cyanicula caerulea 
(Highly sensitive, very rare/threatened)

It's good to take a ground level look at the world now and then. To see it as others do.

Wednesday, 31 August 2016

First frogmouths now on eggs

A few pairs of Tawny Frogmouths are now incubating their first eggs of the year. The earliest eggs in Canberra were probably laid over last weekend, about the 27th August. This is a little early, the earliest I have seen birds on eggs has been the 12th August several years ago. Most will probably lay in early-mid September which is not much different from the usual dates. Some birds began building their nests over a month ago, possibly in response to the high rainfall in the area during the past few months over winter. However, after a warm spell, there has been some colder weather and this might have halted any early developments. This bird is unusually easy to see as his tail breaks the outline of the branches. Their tails usually lie along the nest branch. (It is the male that incubates during the day, while both sexes take turns at night).

When seen along the nest branch, a predator's view, the bird is less noticeable. Its grey plumage blends well with the colour of the tree's branches.

This nest is quite large and substantially raised up above the branch. This causes the bird's tail to lie high above the branch and hence, reveal the bird's presence.

Meanwhile, the females roost by day, relying on their camouflage for concealment from potential predators. Spots and flecks blend with spots and flecks.