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She who must be obeyed

September 20, 2019

This morning I was watching a Common Blackbird (Turdus merula) skip across the back lawn wondering where the neighbour’s cat was when you really needed it when WHAM, within a split-second the aforementioned Blackbird was skewered to the ground by a Collared Sparrowhawk (Accipiter cirrocephalus), see photo below. Man, it happened quickly.

The scientific name for this species is derived from the Latin words accipere meaning ‘to seize or to capture’,  kirros  meaning ‘orange-tawny’ and kephale meaning ‘head‘. Collared Sparrowhawks normally hunt in flight or by diving on prey from low, concealed perches using speed and surprise as an advantage. Small birds make up most of the diet, which can also include birds up to the size of domestic chooks. Our chooks often act as if the Sparrowhawk is around by all of a sudden scurrying with much squawking under the nearest bush and then spending the rest of the day looking skywards. Sparrowhawks  also feed on insects, lizards and small mammals including bats. The kill is taken and eaten on a nearby perch.

As for the Blackbird, if it wasn’t dead already the stare (pictured right) would be enough to stop it in its tracks. Not as deadly as the stare from ‘She who must be obeyed’ but terrifying enough.

vorare, Gk meaning ‘to devour’

September 13, 2019

Many words in the English language are derived from Ancient Greek. One of those is vorare  meaning to devour. You find it in words such as carnivore (carnis being Greek for flesh) used to describe meat eaters or omnivores (omnis being Greek for all) to describe something that eats everything. This blog post is about sporivores, creatures that eat spores.

The autumn rains have triggered the annual explosion of fungi across the landscape. Mushrooms are the fruiting body of the fungus (the same as a pear is the fruiting body of a pear tree). When the mushroom ripens it opens and releases millions of spores. These spores drop on the ground or get dispersed by the wind so the fungus can propagate. Feeding on these spores are sporivores. Knowing how big spores are (not very), these creatures are none-too-big themselves (see photo below).

Springtails (previously featured, click HERE) are small six-legged non-insects. They feed primarily on spores and hypha, the branch-like filament structure of a fungus. Some are sporivores and others are omnivorous, also feeding on animal remains and plant material. A close look at the underneath of mushrooms at the moment will reveal springtails of different colours.

Other creatures disperse spores by consuming mushrooms (fungivores) and by default consume the spores as well. These include mites, millipedes, some species of beetles and fly larvae. And finally the creatures that predate on creatures that eat spores, for example centipedes, are also known to carry viable spores which they eliminate in their faeces.

What goes in must come out…eventually.

Leaf-eaters

September 7, 2019

Young Yellow Box tree

While inspecting with dismay the considerable damage done by deer (Sambar and Fallow Deer) to revegetation plantings at the back of our place (bark stripped, defoliation and broken branches, even on well-established plants), we came across a young Yellow Box, Eucalyptus melliodora (see photo at left), with extensive damage of a different sort. Most of its leaves were severely skeletonised in patches, and in some cases eaten right through. A quick inspection of the foliage revealed many interesting-looking sacs hanging from branchlets in the tree (photo below). These we assumed were associated wih the leaf damage, and later discovered that they belong to the Ribbed Case Moth, Hyalarcta nigrescens.

Actually most of the sacs seemed to be old and inactive – one we dissected had only a dry pupa case inside, the moth having flown the coop. On closer inspection of the leaves, we noticed there were numerous much smaller cases (less than 1cm long), and these contained tiny dark larvae actively chewing and moving around, which were clearly responsible for much of the leaf damage.

The wingless female Ribbed Case Moths remain in the case for life, and lay their eggs in there. Hatched male larvae (caterpillars) leave the case and feed on the surface of eucalyptus leaves. They construct silken cases which they enlarge as they grow. Eventually they pupate and leave the case as a small hairy moth with transparent wings, as can be seen on the BowerBird website.

Larval case

Ribbed Case Moth caterpillar


The cases are built of tough silk and are incredibly strong. Unlike those of many other members of the Psychidae (case moth) family, they are not reinforced/decorated with leaves or sticks, apart from a few bits and pieces when small.
 
This young Yellow Box will no doubt survive and soon put on a new flush of growth, unlike some of the deer-damaged plants, unfortunately!

Fauna beware

August 28, 2019

Day of the Triffids by John Wyndam was one of the first books I ever borrowed from a library, and it probably had a lot to do with my following science as a career. The story describes a world where humankind, blinded after watching a spectacular meteorite shower, is at the mercy of carnivorous plants (called Triffids) which roam the country-side killing all and sundry. Even to this day, whenever I observe a shooting star I do it with one eye closed … just in case.

Some triffid-like carnivorous plants showing signs of life at the moment are plants of the genus Droseraceae (from the Greek word drosos meaning dewdrops), the Sundew plants. Though not as sexy as the well-known Flytraps, which catch their prey by snapping shut their leaves, the way in which sundews capture their food is equally interesting.

Sugar Ant trapped in Scented Sundew leaves

Each leaf of the sundew sprouts a number of tentacles that exude sweet liquid, which attracts insects (see photo above). When the insects touch this sticky liquid they become trapped and eventually die either of exhaustion in trying to escape, or asphyxiation as the sticky goo covers them. Enzymes are then released to dissolve the insects and the plant absorbs the nutrients. The picture (right) shows a mosquito trapped in the sticky tentacles. The black debris seen on the leaves are the remains of digested insects.

Scented Sundew

The commonest species of sundews in our area are the Scented Sundew (Drosera aberrans) and the Tall Sundew (Drosera peltata). In Scented Sundews, which are flowering now (pictured left), the leaves lie along the ground. In Tall Sundews these leaves are on stems (pictured below), making them look much more sinister and triffid-like. It has pale pink flowers in early summer.

Tall Sundew

These sundews won’t dissolve your leg, should you stand on one, unless you’re a mosquito. The Tall Sundews stand about 50 mm high so kangaroos and possums are safe from entrapment. But knowing evolution, it’s just a matter of time.

A New Holland, almost!

August 21, 2019

The flowering of plants in late winter and early spring marks the beginning of the nectar wars when honeyeaters spend the day frantically defending their food sources. In our district a black and white bird with a yellow wing patch flashing through the foliage (and sometimes that’s all you see) usually means the New Holland Honeyeaters (Phylidonyris novaehollandiae) are back in town (pictured left).

Maree from Junction Hill, who recently provided photos for the blog on the Mantis Parasitic Wasp she observed outside her kitchen window, noticed a ‘yellow-flashed’ honeyeater in her loquat tree recently. It looked like a New Holland Honeyeater…but not quite. After spending hours trying to get a clear photograph of the bird, the pictures (right and below), showed it to be a Crescent Honeyeater (Phylidonyris pyrrhopterus), not seen by Macwake, our resident ‘birdo’, in the King Parrot Valley since 2008.

Crescent Honeyeaters inhabit dense eucalypt forests and woodlands in coastal southeast Australia, breeding in the high country in summer and moving to lower altitudes in autumn and winter. They feed primarily on nectar but also consume fruit and invertebrates such as scale insects.

Pairs of birds form long term socially monogamous relationships. Even though territories are defended by the males the species is sexually promiscuous with females often wandering into other territories to mate.

For Marie this was a ‘lifer’, first ever observation of this species. I’m heading up to Marie’s this weekend. I want a lifer too.

Tina’s Hoax?

August 1, 2019

Tina is the local creative artist, flower arranger extraordinaire and style icon for vintage clothes. She works in the local garden supplies centre and as such frequently comes across weird and wonderful fauna amongst the pots and plants. The latest is this beauty (pictured below). On first appearances it looks like a candy-cane coloured slug. It is in fact a flatworm, a Howitt’s Flatworm (Artioposthia howitti) to be exact.

Flatworms are one of the most primitive lifeforms. They have no body cavity and hence lack organs for breathing and circulation. Oxygen instead enters the body by diffusion. This limits the size that flatworms can attain and creates a body shape with a large surface area i.e. flat. They are also the ultimate regenerator. Cutting a piece off will result in a new flatworm.


Superficially they look a bit like leeches but do not loop up when moving. Like slugs and snails flatworms move on a slime track. They are predators. Some trap small invertebrates in their slime trail. The insides of the victim are then sucked out. As they also have no anus waste products and undigested food are expelled through the mouth (talk about ‘potty mouth’!)

It’s all very interesting but beware. Knowing Tina’s sense of the mischievous and her artistic talent it would not surprise me if a search of the garden centre turned up some very thin brushes, pots of yellow and brown paint and a very annoyed ordinary garden slug (painted).

Dam platypus

July 14, 2019

We’re quite used to seeing platypus in the King Parrot Creek and there have been sightings from there in recent months, even when the creek was reduced to barely connected pools. This included a platypus at Flowerdale which unfortunately had fishing line tightly wound around its body.

But we were a little surprised to get an email from Peter and Terry saying there was a Platypus, Ornithorhynchus anatinus, in their large farm dam (see photo at left), which in fact is more of an ornamental lake in the sizeable garden area surrounding their Strath Creek house.

We were less surprised after reading the following sentence in Mammals of Victoria, edited by Peter Menkhorst: “Wandering individuals, probably mainly dispersing immature animals, are occasionally found crossing dry land up to 2 km from the nearest water body … or in apparently sub-optimal habitats such as irrigation channels and farm dams.” Farm dams for livestock are often less than ideal habitat for platypus because of their depth and bare shallow-sloping hard-packed banks unsuitable for constructing burrows for nesting and shelter. Fenced-off dams with vegetated banks, like the one shown here, encourage the invertebrates that platypus feed on and are generally more suitable habitat.

Whether the platypus came up from the nearby Strath Creek or Wild Dog Creek after they began flowing again following recent rain, or came down from another dam on the property is open to speculation, but it is certainly a long way from any permanently flowing waterway.

One good piece of news regarding platypus is that new rules in Victoria banning the recreational use of opera house traps (and other enclosed yabby trap designs) in all waters came into effect from 1st July this year following a campaign by the Australian Platypus Conservancy. So there should hopefully be no more reports of platypus drowning in these lethal traps.