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Slip, slidin’ away

November 6, 2020
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A neighbour of mine has a regular night-time routine – slug hunting. Rain, hail or shine she is out with a torch hoping to rid her garden of these pests. Slugs and their shelled cousins snails make up a class of animals known as Gastropods, creatures which have the same general characteristics, like:

  • Snails and slugs have two tentacles extending from the front of the head, pictured left. The upper two are the eye stalks. The lower pair contains ‘smell’ organs and is retractable.
  • These animals are hermaphroditic, having both male and female sex organs (I wonder how they decide which one to use!)
  • The snail shell keeps growing during the life of the snail. Calcium carbonate is added to the shell from the base that gets larger with time to accommodate the growing body. The shell spirals in a clockwise direction.
  • Snails and slugs have a single lung-like organ. The breathing hole known as the pneumostome is on the right side of the body and opens and closes as the animal breathes (pictured above). In snails the pneumostome is hard to see as the shell often obscures the view.
  • Snails and slugs have a series of microscopic teeth known as a radula with which they scrape lichen and other vegetative matter off surfaces.

Finally snails (not sure about slugs!) are delicious sautéed with parsley butter and garlic with a squeeze of lemon, and a glass of cold Chablis (I am not sure that applies to our garden snails).

It depends how you look at it

October 23, 2020

One group of the plants flowering at the moment, if you are looking carefully are Australian bush orchids. They come in a vast array of shapes, sizes and colours. Most orchids replicate by producing seed and for this to happen they need to be pollinated. Some species self-pollinate but the majority rely on insects to do this task. Most orchids however do not produce nectar or pollen with which to attract the insects but instead use various deceptions to lure them. These generally take two forms, food deception and sexual deception.

Orchids that use food deception look like plants that provide insects with pollen or nectar. The Common Donkey Orchid (Diuris orientis), pictured above, mimics the bush-pea flowers of the Fabaceae family, for example Common Bossiaea (Bossiaea prostrata), pictured right. The orchid flowers are larger than the pea flowers thus creating a more visible target for nectar-seeking insects.

Orchids that use sexual deception have petals that look like female insects. The flowers emit a pheromone that attracts the male insect who then proceeds to ‘pseudo-copulate’ with the orchid petal. The Orchid Dupe Wasp (Lissopimpla excelsa), pictured below, is so named because it is one of the insects deceived.

This wasp, a native of Australia, ‘mates’ with plants of the genus Cryptostylis, the Tongue Orchids. To the human eye the orchid petals are similar in colour to a female wasp. However to the visual system of a wasp, more in the green, blue and ultraviolet range, the similarity is more striking.

It depends how you look at it.

The perils of being a Crane Fly

October 5, 2020
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A walk through the long grass at the moment should disturb clouds of Crane Flies (pictured left). Unlike dragonflies, damselflies and scorpion flies, Crane Flies are true flies i.e. they are two-winged Dipterans. These slow flying long-legged insects are short-lived, up to a couple of weeks, so short-lived that some species do not even possess mouthparts for eating and drinking and the female fly emerges from the pupa stage already containing eggs for the next generation. Despite their short lifespan, many Crane Flies do not even reached that potential as their lives filled with dangers.

For a start their long legs mean that Crane Flies are often mistaken for mosquitos and being a slow flyer many cranefly/human interactions often do not end well (for the Crane Fly). But nature also throws up a number of other hazards. Crane flies are the prey of fish, birds, mammals and other insects. Spiders are also natural predators, not only those that build webs but also Jumping Spiders (pictured below) that have the ability to leap out and ambush the unwary.

It is not just the local fauna that can end the life of a Crane Fly prematurely. Local flora in the form of Tall Sundews (Drosera peltata) can also lead to a sticky end if you are a Crane Fly. The long dangling legs are prone to get snagged on the tentacles of this carnivorous plant (see below).

I’ve heard of the saying ‘Live fast, die young’. For Crane Flies ‘Live slow, die younger than the short life span you already have’ seems apt.

Things come to those who wait

September 30, 2020

When cycling through the district I keep an eye on any water body I pass in the hope of seeing an elusive rakali or platypus. Ripples on the water surface could indicate the presence of either. And so whilst riding I saw some tell-tale ripples. The trick then is to be still and wait to see what caused them.

Whilst waiting, two Spotted Pardalotes (Pardalotus punctatus) slowly made their way down a nearby tree, branch by branch, chirping loudly as they went. These are exquisitely coloured birds (pictured left) not often seen because they feed on lerp, the honeydew/wax houses that the nymphs of psyllid insects construct to live in. Psyllid nymphs are generally found on young eucalypt leaves i.e. at the top of a tree hence this is where pardalotes hang out.

The two birds I was watching dropped to the ground and scurried to the nearby road bank and started digging into the side of the bank (pictured right). Spotted Pardalotes nest in horizontal oval chambers usually connected to the outside world by a tunnel up to 1.5 metres long. The nests are usually built in riverbanks and embankments but have been found excavated in piles of builders sand on housing sites. The nest is lined with shredded bark. A neighbour of mine built a successful nest box from agricultural poly-pipe leading to a wooden box.

After half an hour of industrious work the pair flew off…and the water ripples were caused by ducks. Watch this space for further developments.

There’s a crayfish in the garden

September 18, 2020
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Last week I was asked whether slaters were harmful to the garden. So I looked back at all the blog posts we had written over the past decade and discovered we had never discussed these ubiquitous critters – apart from one blog post on Slater-eating Spiders.

Slaters are crustaceans just like lobsters and prawns and are an introduced species in Australia. Although terrestrial they still have a need to be in a moist environment, commonly living under rocks, logs and leaf litter and coming out at night when the chances of dehydration are minimised. They have seven pairs of legs and two pairs of antennae. The female slater does not lay her eggs but carries them around in a pouch. The young remain in the pouch for a short time after hatching. They look like small adults and grow through a series of moulting stages. Unlike most arthropods the moult takes place in two stages rather than one. The exoskeleton splits and the back half is shed, followed by the front half a couple of days later.

And as to the garden question, slaters are great in the garden. They are detritus feeders, feeding on decayed plant (and animal) matter and returning nutrients to the soil.

I am glad evolution chose these to come on to land. Can you imagine having crayfish in your garden hiding under your flower pots?

The mask of Zorro

September 13, 2020
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After a while one gets to know all the waterbirds of an area but when the weather conditions provide different conditions new habitats are formed and new birds appear (or maybe they have been there all along but are more widely seen!).

I am familiar with the herons, egrets and spoonbills – those long-legged waders who inhabit our dams and riparian zones where the water level is deep. This winter has been particularly wet, just like the old days the old-timers will tell you. Dams are full and waterways are flooding. When rain continues to fall on water-logged soil small, shallow temporary lakes are formed in depressions where water does not normally sit for long. This provides an opportunity for different waterbirds to come in and forage.

The Black-fronted Dotterel (Elseyornis melanops), pictured, is one such example – the term melanops coming from the Greek melas meaning black and ops meaning face.

The adult features a black breast-bone, mask and forehead. This bird is a wading bird commonly widespread in Australia around fresh water bodies. But as the photos show it has short legs and is therefore restricted to foraging in very shallow water, precisely what all this rain is creating in abundance in the landscape. These photos were taken at the local golf course.

A type of plover, the Black-fronted Dotterel feeds on insects and seeds. The young birds lack the black breastband and forehead but have the black-mask.

Zorro from birth.

L’amour Frogs

September 9, 2020

Frogs are all around us. You may not always see them, but you do hear them. They are an important part of the food chain, they eat lots of insects and many creatures eat them.

However frog populations are declining from habitat loss and degradation, disease and climate change.

In Victoria there are 36 different species of frogs, of these 12 are found in the Goulburn catchment. So it is not that difficult to become familiar with the calls and behaviour of all our local frogs.

Frogs of the Goulburn Catchment:  https://frogs.org.au/frogs/ofVic/Goulburn_and_Murray

Perons Tree Frog

FrogID is a national citizen science project that enables anyone to record and upload frog calls, along with time and location data, using the free app. By downloading the free FrogID app onto your smartphone, you can record and submit any frog calls you hear, which helps us to understand where different frog species are, and how they are doing.

Click here for information and to download the free app: Frog ID app.

Frogs are one of the planet’s most threatened groups of animals and are often an indicator of environmental health. Through the Frog ID app people across Australia have already begun to reveal the impact of drought and bushfires on frogs.

You usually do not have to venture too far to find frogs. Water bodies are of course the easiest places to hear frogs. Wherever there is a creek, stream, dam, pond or flooded area these are the best places to go especially after rain. Many frogs prefer still water in ephemeral areas as these don’t usually have the fish that prey on tadpoles and small frogs.

Pobblebonk Frog spawn

Frog Spawn (eggs)

Frogs tend to be nocturnal so the first few hours after dark is when they are easiest to hear but frogs will also call during the day. The calls you hear are male frogs calling to attract females.

Frogs can also be seen at night around the edges of wet areas. Without disturbing them, look carefully around the edges with a torch and look for their eye shine.

Pobblebonk or Banjo Frog

The Banjo Frog, or Pobblebonk (Limnodynastes dumerilii) is one frog that is often heard calling day and night. The male calls while he is floating in the open water and some will call from inside a yabby burrow to amplify the sound. After mating, the female lays a large white floating raft of over 500 eggs. When the tadpoles hatch, they are dark brown and can sometimes take up to 15 months to metamorphose into frogs, depending on the temperature.

When my son was a boy he loved this short animated video that features Banjo Frogs. He still loves frogs, who doesn’t love frogs?

Chris Cobern.

Cacophany is the word

September 6, 2020

At the moment the hill is being mobbed by Pied Currawongs (Strepera graculina), lots of them. A search of the web revealed no formal collective noun for these birds. Many had suggested the word I had in mind – cacophony, because when they get together currawongs make a racket (listen to audio clip below).

The word currawong is onomatopoeic from indigenous origins. It is not surprising that the scientific name is derived from the Latin words strepo, to make a noise, and graculus meaning jackdaw-like (a jackdaw being a European bird of the crow family).

Pied Currawongs are in the same family as Butcherbirds and the Australian Magpie. They are altitudinal migrants moving down from the forested highlands in winter to lower altitudes. They are also omnivorous. In winter i.e. now the birds forage in large flocks, but in summer currawongs forage in pairs. They eat fruit, berries, insects and small lizards but are also voracious predators of bird’s eggs and small and young birds. Many a blog has lamented the demise of the occupants of avidly watched small bird nests at the beak of a Pied Currawong or Raven.

This doesn’t mean the currawong gets its own way all the time. In parts of Australia (Sydney and north) the Channel-billed Cuckoo parasitises Pied Currawong nests by laying their own eggs in it. The cuckoo chick is then raised by the currawongs.

Down around these parts particularly in winter, mornings can be a noisy affair due to flocks of currawongs. In addition most other bird species actively mob currawongs to move them away from their own nests in the hope of protecting their eggs or chicks.

Cacophany multiplied.

It’s in the name

August 31, 2020
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A lot of fauna derive their common names from either the location where they are found or their appearance, or both, for example the Crimson Rosella, Blue-banded Bee, Eastern Yellow Robin. A few however are named after what they do. This is very useful when trying to look for them in the bush. With Spring almost upon us some of these ‘doing’ named critters are acting true to type.

uraba lugens DSCN9072One of the most delicate artefacts one can find when walking through the bush is a perfect skeleton of a gum leaf with all the veins intact. It should be no surprise given the theme of this blog that one of the architects of this is the caterpillar of the Gum-leaf Skeletoniser Moth (Uraba lugens). The adult moth lays between 100 and 200 eggs, twice a year. The resulting caterpillars (see picture above) eat only the surface layer of a leaf on both sides before moving on to the next leaf, leaving the gum-leaf veins.

z Eucalyptus Tip-wilter Bug (Amorbus sp.) DSCN6408Another critter with a name suggesting its habit is the Eucalyptus Tip-wilter Bug (Amorbus sp.). These insects are Hemipteran i.e. equipped with sucking mouthparts for extracting sap. In Spring gum trees start to develop new shoots. Both the adults and instars of the Tip-wilter Bug attack these shoots extracting the sap and causing the new growth to shrivel and die.

I suggest we start renaming some of our local fauna. How about a ‘Destroying the windscreen rubber of your car’ Cockatoo and ‘Poo all over the patio’ Swallow.

Black cockatoo query

August 28, 2020

Recently the question was asked if the Strath Creek/Flowerdale area had ever been part of the home range of black cockatoos other than the Yellow-tailed Black Cockatoo Calyptorhynchus funereus.

A long term resident of the district recalls seeing what he assumed were the Red-tailed Black Cockatoo Calyptorhynchus magnificus over 50 years ago.

There are two types of black cockatoos in Victoria that have red markings on their tails the Red-tailed Black Cockatoo and the Glossy Black Cockatoo Calyptorhynchus lathami.

GBC

Glossy Black Cockatoo

RTBC

Red-tailed Black Cockatoo

 

 

 

 

 

 

 

 

 

Historically both species were more widespread in Victoria than they are now but these days both birds have a very reduced home range (See map below). However Strath Creek/Flowerdale would have always been outside the normal range of both species.

C. lathami are now usually only found in far East Gippsland and C. magnificus is restricted to the western part of Victoria.

RTBC map current

Occasionally C. lathami will still appear more westerly. This year for instance there have been sightings of them at Mt Macedon and even close to Melbourne in the SE suburbs around Dandenong and Frankston. Their recent movements are probably due to the fires that occured over large areas of East Gippsland. Other observations in recent years have also occurred in the Strathbogie Ranges.

In past decades it may not have been that unusual to occasionally see either of the species in the Strath Creek/Flowerdale district if their main feed plants were present.

A major part of the C. lathami’s and C. magnificus’ diet is the seed of sheoaks (Allocasuarina species) and the loss of these plants in the landscape is almost certainly the cause of the decline of both species in Victoria. Over the last few years UGLN have been including the drooping and black she-oak in many of our landcare plantings in an effort to increase the distribution of the plants and the wildlife that feed on the plants.

There are still a few remnant she-oaks in the district but logging, clearing for agriculture and browsing by stock, rabbits and feral deer have severely affected their ability to regenerate and these plants are now quite rare in much of the upper goulburn region.

drooping-sheoak

Drooping Sheoak Allocasuarina verticillata

If anyone has any old or new observations from the area about either of these two magnificent birds or sheoaks i’d be very interested to hear about them.

Email Chris Cobern: ugln.projects@ugln.net