Core Cormorants
The easiest way to think of the cormorants in Australia is that we have 2 large and 2 small: Large Pied and Little Pied, Large Black and Little Black. Except that those names aren’t used exactly anymore. The Large Black is properly called Great Cormorant (Phalacrocorax carbo) and the larger of the pied cormorants is just called Pied Cormorant (Phalacrocorax varius). The sizes are as indicated – the 2 species called ‘Little’ are smaller than the other two but that’s not helpful when you see just one. However, there are two other rules that make identification easier:
1. Of the pied cormorants – ie, those with a black back and a white front – only the Little Pied Cormorant (Microcarbo melanoleucos) is common in inland waters. This is the cormorant found sitting on logs, dam banks, channels, bridges, trees around lakes.
The Pied Cormorant, on the other hand, mainly sticks to the coast (though to be fair, it is occasionally found on large reservoirs and rivers inland).*
2. Of the 2 black cormorants, one is all-black (the Little Black Cormorant Phalacrocorax sulcirostris), the other (the Great Cormorant) has a yellow face – and in juvenile phases has various patches of white or off-white that can be confusing.
So, a cormorant that is pied is almost certainly a Little Pied; a black cormorant can be quickly distinguished by whether it is all black around the face and bill (Little Black) or has some yellow around the face (Great Cormorant).
Wonderful birds, these. Great fliers, great swimmers, great fishers. When it comes to our district and which ones are regular residents, three out of four ain’t bad.
*There is a fifth species, the Black-faced Shag, found around rocky cliffs and ocean fronts along the Southern Coast, especially in Tasmania.
Don’t take it as read
Ladybird Beetles belong to the family Coccinellidae. There are several proposed origins of this word one of which is that it is derived from the Latin ‘coccinus’ meaning ‘scarlet’. The common view is that the ladybird is predominantly red with black spots. There are about 500 species of ladybird in Australia but not all of them are red and black.
The beetle pictured left is a Mealybug Ladybird (Cryptolaemus montrouzieri). Like most ladybirds this species in both the adult and nymphal forms are highly predatory of soft-bodied sap-sucking insects such as scale insects, aphids, etc. This one has a penchant for mealybugs. The female ladybird lays her eggs amongst the mealybug eggs and the hatched ladybird nymphs attack both the eggs and the emerging nymphs of the mealy bug.
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The black and yellow ladybird pictured right is a Fungus-eating Ladybird Beetle (Illeis galbula). It is a vegetarian feeding on pollen in Spring but on powdery mildew at other times. Powdery mildew is a type of fungus that forms on the surface of leaves. The mouthparts of the Fungus-eating Ladybird are modified to be able to scrape the leaf surface. The FELB are commonly found on the leaves of cucurbits – zucchinis, pumpkins, squashes, etc.
For those whose world view has collapsed at seeing ladybirds that are other than red and black, here’s a picture for you (below).
Aussies of international reknown
The Cottony Cushion Scale (Icerya purchasi), pictured below, is one of Australia’s more infamous exports. It is an Hemiptera i.e. a sap-sucking bug that has a liking for many Australian woody plants (particularly Pittosporum) but loves citrus plants in general. Both the adult and the nymph insects suck on sap of the leaves and woody material of the food plants. The adult, pictured, is reddish-brown in colour and crusted with waxy secretions.
This insect is a true hermaphrodite having both male and female organs within one body. When the female is ready to breed she will attach herself to a piece of vegetation and extrude a white egg case several times the size of her body (pictured above). This case contains hundreds of eggs. The nymphs when hatched disperse and find another site at which to suck sap. After each moult the nymphs move on leaving their ‘cottony cushion’ shell attached to the plant.
The Cottony Cushion Scale has caused a lot of damage to the citrus industry in the United States. A particular species of Australian ladybird imported into the US has been successful in controlling the scale.
Who said we aren’t an exporting nation.
Just passin’ thru
Some butterfly species are known for their long annual migrations. Each year the Monarch Butterfly (Danaus plexippus) makes a 3000km long flight from Canada to Mexico. The Painted Lady butterfly undertakes an even longer 9000km journey from Europe to Africa every year. This trip spans several generations. Australian butterflies such as the Meadow Argus, the Australian Painted Lady and the Caper White are known for their annual treks spanning thousands of kilometres.
The Caper White butterfly (Belenois java) (male is pictured above and below) is a primarily white butterfly that is often mistaken for the Cabbage White (Pieris rapae), pictured right. It is distinguished from the latter by having black wing margins and veining and orange marks that can easily be seen when the butterfly is at rest with its wings closed. The butterfly is named for the Caper bushes (Capparis sp.) that it lays its eggs on.
Caper Whites have several migration routes within Australia. The one that brings these butterflies our way starts each Spring when they leave their breeding grounds in the northern Flinders Ranges and head south. Their trek covers several thousand kilometres but how far they actually travel and in which direction depends on the weather, particularly the prevailing winds. A couple of times a decade very large populations of Caper Whites migrate together.
This year there seems to be a higher than normal number of Caper Whites in the district. Mass migration or tail winds? We’ll have to see.
Not everything is web-based
One of the truisms from my childhood is that spiders build webs with which to catch their food. The webs are circular, two-dimensional, vertical and strung up between pieces of vegetation. This of course is correct however things aren’t nearly as clear cut. Not all spiders catch food using webs.
Jumping Spiders such as the Prowling Jumper (Opisthoncus grassator), pictured above left, capture their prey by leaping on it. They use their excellent eyesight to not only detect prey but also to calculate how far they need to jump. They use hydraulic pressure in the legs to propel themselves forward and just in case they miss Jumping Spiders are attached from their start point by a filament of silk.
Lynx Spiders, picture above right, on the other hand catch their prey by running it down. The front legs are bristly so as to confine any prey that is captured and prevent the thrashing victim from damaging the spider’s eyes.
Another strategy albeit a lazy one is to hide in flowers and simply ambush the prey as it comes in the feed (pictured above left).
I wonder if spider fast food is defined by how quickly you have to move to get it.
Local knowledge
For many years the electricity pole across the street has been home to small birds in Spring where small holes in the concrete pole have provided the entrance to perfect nesting sites. In the past Striated Pardalotes (Pardalotus striatus) were the regular inhabitants but in 2016 the site was taken over by House Sparrows (Passer domesticus) a feral intruder in the area (click HERE to view).
Recently the infrastructure on the pole has received several upgrades as first a high voltage spike and then a severe storm damaged it. Serious maintenance was required to be done. During that maintenance all the holes in the pole were blocked (see photo above) and I despaired at being able to ever see birds using the pole as a nesting site again.
Yesterday the distinctive call of a Striated Pardalote was heard ringing from the very top of the pole. In one of the metal crossbeams, hidden behind a heavy duty earthing wire is a pre-drilled hole in the crossbeam wall and in that opening Striated Pardalotes have started building a nest, pictured right.
The view of the hole from the road is obscured but hopefully later in the season we might get a family photo.
Australia Post
One of the more stunning flowers at this time of year is the red and yellow Running Postman or Scarlet Coral Pea (Kennedia prostrata). Along the rail trail it is generally found in small clumps on the slopes of the railway cuttings but just east of Homewood there is a stretch of about 20 metres of the prostrate shrub twined in amongst the grasses (see left).
Frequenting the plants was a sole Long-tailed Pea-blue butterfly (Lampides boeticus) pictured above. Its name is derived from the tail-like appendages at the bottom of the hindwings (see photo), the fact that it is a member of the family of butterflies known as ‘Blues’ and that its young feed on the leaves of pea plants such as the Running Postman.
The butterfly spent some time taking nectar from the flowers but more time visiting the leaves, on which closer examination showed it was laying eggs. Pea-blues can have up to three generations in a year.
As is the case with some other members of the ‘Blue’ butterfly family, the caterpillars and pupae of the Pea-blue are sometimes associated with attendant ants. When the caterpillars hatch they emit a pheromone to attract ants in the area of the correct species. The ants tend the caterpillars by providing protection from predators and parasites in return for a sweet liquid food that the caterpillars/pupae exude, click HERE for a related blog. It is an amazing symbiotic relationship.
This will now be a regular stop on the rail trail. I want to see if the ants will come. Such anticipation.
Orange is the new green
Annelids are a group of animals that include earthworms and leeches. The term derives from the Latin ‘annellus’ meaning ‘little ring’ and if you look at a garden earthworm closely you’ll see that they look like a tube made up of a line of rings attached together (pictured left). What you probably can’t see is that each ring has a number of outward projecting hairs called setae. These help anchor and propel the worm when I moves. Near the front of the worm is a pale, thick glandular section known as the clitellum (pictured below). It develops when the earthworm is sexually mature.
Earthworms are hermaphroditic. Even though each worm contains both male and female sex organs two worms are needed for reproduction. Mating takes place above ground usually at night when two worms wrap around each other and exchange sperm. This sperm is stored for later use. Sometime later after the worms have gone their separate ways reproduction occurs. The clitellum exudes a ring-shaped sac around the worm. As the worm backs out of this sac it injects its eggs and the stored sperm into it. It is in this donut-shaped sac that fertilisation occurs. The offspring grow as young adults with no intermediate stages.
When an earthworm is ready to reproduce the pale clitellum turns a dark orange. Unlike with traffic-lights in earthworms orange means go.
The case for hairy toes
Hairy feet have generally been frowned upon as a physical attribute, unless you live in Hobbit-town. But for some creatures having them is a real asset.
The warm weather has seen the early emergence of some of the reptiles, in particular geckos. It is only early September but they are already prowling about the windows at night hunting unwary insects. The Marbled Gecko (Christinus marmoratus), pictured left, is Australia’s southern-most dwelling gecko and is the species that has staked its territory around my kitchen window. Like all geckos in the Gekkonidae family it uses its tongue to clean the lenses of the eye, has a pre-weakened cleavage points in its tail so that when attacked it doesn’t necessarily have to lose the entire tail and has the amazing ability to walk on walls, ceilings and even vertical glass.
It turns out the geckos ability to walk up windows is not due to suction cups on its toes as I thought as a kid but is due to millions of tiny hair-like structures called setae under each foot. The setae are made of similar materials as our finger nails and are tiny – much tinier than can be observed on the underside of the gecko’s foot pictured right. On each toe between each of the pads is a tiny retractable claw. Each setae has thousands of flat structures on them that further increase the contact surface area between the gecko and the glass. So effective is the arrangement that a gecko’s feet can support well over 100kgs.
So it appears that a way to ‘rock’ hairy feet is to have the hair under the foot.
Open for inspection
Australian has unique fauna in that many of it’s birds and animal use tree hollows for breeding or shelter sometime in their lifecycles. Seventeen percent of bird species, 42% of mammals and 28% of reptiles use tree hollows (Gibbons and Lindenmayer 1997). They include bats, possums, gliders (pictured below left), owls, parrots, ducks and kingfishers.
There is however an increasing dearth of tree hollows in our landscape. Depending on the tree species it takes over 100 years to develop a ‘decent’ tree hollow for fauna to live in. Old trees are disappearing due to old age, logging of old growth forests, land clearing for agriculture and housing and bushfire.
Recently several of our neighbouring Landcare groups have embarked on projects to increase the number of usable hollows in their area by installing nest boxes. Earlier this year Yea River Catchment Landcare Group purchased 105 nest boxes using a Habitat For Wildlife grant from the GBCMA. Last week Kinglake Landcare Group launched their Boxes for Birds project, a collaboration with Birdlife Australia’s Yarra to Yea bird conservation effort. They acquired 105 nest boxes using a Victorian Government Landcare grant. The boxes will be distributed across 21 private and public sites.
In autumn I installed nest boxes from the Yea River Landcare project and today I observed the first visit (that I know of) of a prospective tenant to one of those boxes (pictured above). Crimson Rosellas (Platycercus elegans) breed between September and January producing 5 – 8 white rounded eggs. They nest in tree hollows and cavities in buildings. The reason the nest box has been placed 7 metres up on the side of my building is to encourage them not the nest in the roof space, again!
Looks like it is working.
Focus On Fauna 