Don’t swat that mozzie!
Through open doors mozzies will zoom in
Attracted by odour of human
Whether O, A or B
She drinks blood like tea
It helps produce eggs, I’m assumin’
I have mixed feelings about mosquitoes. I know they are vectors of some terrible diseases and responsible for about 700,000 deaths a year. I know they are very irritating when they sneak in to bite my ankle in the dark.
But that’s not all mosquitoes – not even a majority. As a group, mosquitoes are primarily sap feeders. Both male (they’re the ones with feathery antenna and no biting mechanism) and female mosquitoes land on grass stems or leaves and suck sap.
In their favour, they provide a bulk snack food for bats – though one moth provides more nourishment than many mozzies. They are believed to help pollinate some plants, though Australian evidence is not definite on this point. They are certainly eaten, both in the larval and adult stages, by many wetlands creatures. Dr Cameron Webb of Sydney Uni says they have been unable to find any plant or animal completely dependent on mosquitoes but they are a sign of a flourishing wetland ecology.
The female only needs one feed of blood in order to be fertile.
The eggs are laid on water (typically, not always) where they hatch into a ‘wriggler’. They go through a few growth phases as they eat algae and microbes in the water. The pupal stage is less active. They are the bigger ones in the photo. They are curled up like a comma and swim down to the bottom if movement is detected above.
Without leaving the water, the adult emerges from the pupa supported on the meniscus of the water. It flies away and mating often happens within a few hours. The males fly together in complex dances in a swarm, and the female bustles into the middle looking for a mate. It’s like a night-club!
She needs the blood for the extra protein to form eggs. It’s unfortunate for us that in obtaining that tiny few drops of blood, they leave a great itch and sometimes leave viruses like the Ross River fever virus or Murray River Encephalitis, or much worse things in tropical areas.
Mosquitoes are consequently very hard to live with but I doubt whether our ecosystems could exist without them.
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I used to scoop the wrigglers out of this backyard pond with a sieve, but for now I’m letting them live. They might attract more frogs, bats, dragonflies, and birds.
I don’t want those bad disease-bearing mosquitoes to give all mosquitoes a bad name. I’m going to give these guys one more chance.
Introducing geoffleslie
Even though this post is published by ‘ronlit‘ it is the first post of a new member of the team ‘geoffleslie‘ (no prizes for guessing what his actual name is!). Geoffleslie is a keen amateur naturalist and leader of the Murrindindi Birdwatchers, a group of twitchers and photographers that (pre-covid at least) did a monthly trek to some part of the district to check on the bird species there. So it is no surprise that the first post is about …. birds. Read on…
When I was out with an old birdwatcher in the Yea district some years ago, a couple of corellas flew over. “Little Corellas”, he said. “How do you know they are not Long-billed Corellas?”, I asked. “The common one around here is the Little. The other one is a feral that’s just moved in.”
That was not my experience. I had only been in the area a short time and I thought the two species were equally common. I have photos of both in the same tree. The Little Corella (Cacatua sanguinea), pictured left, has a crest and no visible red on its front. The Long-billed Corella (C. tenuirostris), pictured below, has a less-noticeable crest, a long upper mandible for a beak and looks like its throat has been cut with a red gash easily visible when it is perched. The calls are different, too. The Little corella always sounds sad, a plaintive one-note call; the Long-billed has a quavering curr-ur-rup. Both can be deafening when flocks go past.
Some birds decline when people move in. Some birds thrive. The Long-billed Corella is one of the latter. They used to be confined to a small part of Western Victoria – now they’ve spread up and down the East Coast with populations in Cairns and Townsville, even Perth. One reason for their success is the spread of Onion grass (Romula rosea), a widespread weed whose bulbs are dug up by that long bill, providing food in Winter. Meanwhile, the Little Corella is doing well also, now common in more parks and farmlands than previously, even in Melbourne where I never saw them as a child.
So my old friend was right that Long-billed Corellas are feral recent arrivals. But that doesn’t mean they’re less common. They’re trying to take over the place!
All about gliders
The Sugar Glider (Petaurus breviceps) is a species of small possum found in our area. It is closely related to the less common Squirrel Glider (Petaurus norfolcensis) that is found on the other side of the Strathbogie Ranges.
Both gliders have membranes of skin extending from the front to the hind legs. This membrane when stretched out enables the animal to glide long distances (up to 50m). They do this to avoid predators and to move between food sources without having to be on the ground. They feed on insects, pollen, nectar and the sap from trees particularly wattles.
The two species are difficult to tell apart. The Squirrel Glider is slightly larger with a longer, pointier face and a tail that is as wide as the body at the base. As they are active, nocturnal creatures these distinctions don’t help very much when trying to identify them in the field but watching them glide is truly a sight to behold.
The gliders have similar markings (see photos) and are ‘countershaded’ for camouflage. When an object is lit from above the upper surface appears lighter and the undersurface (in shadow) appears darker. This makes the object very obvious. Animals such as gliders are countershaded i.e. have distinctly lighter underparts to counteract this and afford a level of camouflage (Thayer’s Law).
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This of course does not apply to Hang Gliders (pictured left) that are diurnal creatures, often seen flying above the hills on the Three Sisters property.
Raising the bar
Red-browed Finches (Neochmia temporalis) are small birds easily recognisable by the red streak above the eye and the bright red rump displayed when flying. The scientific name meaning ‘new bird with temples’ is derived from the Greek words ‘neokhmos’ meaning new and ‘temporalis’ meaning to do with the temples i.e. forehead.
These finches are seed-eaters and are often found on the ground where forests meet open pasture. They forage in flocks of up to 20 birds and often with other groups of social birds such as Superb Fairy-wrens. Red-browed Finches are ‘weaver finches’ constructing in dense shrubs large communal woven domed nests made out of grass that have a side entrance.
The male courts the female finch by holding a piece of grass in its beak and then dancing to and from the female. I recently observed the same behaviour with a male holding a feather in its beak (pictured above/right, unfortunately with only an iPhone). I am not sure if it was trying to impress a female or was just collecting nest-building material.
If it was the former, it had just raised the bar.
Hanging it out to dry
Birds such as Australasian Darters (Anhinga novaehollandiae), pictured left, and Little Pied Cormorants (Microcarbo melanoleucos), pictured below right, can often be seen standing with their wings outstretched drying them in the sun. The assumption many people make is that they lack the ‘preening’ gland at the base of the tail that produces an oil type substance used by waterbirds to waterproof their wings. Darters and cormorants do indeed have the gland. The birds use their heads and beaks to spread the oil through the feathers. There is some debate as to whether the oil actually produces the waterproofing or if the feather structure itself does the job and the oil just keeps the feathers in good condition.
Feathers work by trapping air both to insulate a bird in cold weather and to create buoyancy so that birds such as ducks can sit on the water surface with little effort. Darters and cormorants however dive to catch their food. Having air in their feathers impedes their ability to dive. To reduce their natural buoyancy their wing feathers are wettable so that air bubbles can be shed. This means that they can dive deeper with less effort but the downsize is they need to dry these feathers afterwards.
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So what does it mean when you see a non-diving bird sunning its wings? (pictured left). I don’t know. It’s probably trying to keep its tummy warm.
The perils of being an arborist
I have always thought that arborists particularly those who, wielding chainsaws whilst using ropes to suspend themselves from trees led dangerous lives. Of course if you know what you’re doing it’s probably not as bad as it looks. Unless…
I recently had to call in a group (plantation?) of arborist to fell some dead pines on my property. Everything was going well until a ‘down tools’ was called. An enormous wasp nest was found suspended from one of the branches high up in the tree (pictured left). Buzzing around the nest were what appeared to be, from a distance, some European Wasps (Vespula germanica). Interestingly I could not convince any of the arborists to climb up and get a closer look at the insects for identification purposes!
The nest removal involved me covering myself from head to toe in thick clothing i.e. CFA gear, such that not a bit of skin was exposed and under cover of nightfall and using a red light head torch for lighting knocking the structure down with a large pole. Fortunately the nest was unoccupied.
All social wasps i.e. those which live communally, build nests made of paper. Tree bark and other plant fibres are chewed, mixed with saliva and then molded into shape. At the centre of the nest are the hexagonal chambers where the eggs are laid and the larvae grow. This structure is usually surrounded by a protective paper shell. European wasps, even though they construct nests underground, line the nests with paper using the same technique.
Needless to say that after attacking the nest with a pole none of the brood structure remained intact but the picture above right shows the amazing structure of the external paper shell.
I am not convinced it was the nest of European Wasps. Given it was abandoned, the wasps seen (if in fact they were European ones) may have been scouting around looking for dinner….or a place to doss down for the night.
Different colour, same species #2
The last blog attempted to illustrate the (I thought) interesting fact that sometimes birds that look different can be the same species. Apparently the two colour morphs of the Brown Falcon were not different enough to excite anyone about the fact that this was so.
So let’s try again. Crimson Rosellas (Platycercus elegans), pictured left, are widespread through south eastern Australia commonly found in the more forested areas. They feed on a variety of seeds, nectar, berries and nuts as well as invertebrates and their larvae.
En-route whilst driving to Adelaide recently I spotted a Yellow Rosella (pictured right). The scientific name for this parrot is also Platycercus elegans i.e. the same species but clearly a different colour. Scientifically the birds are divided into races – the Crimson Rosella (race: elegans) and the Yellow Rosella (race: flaveolus). To confuse the situation more whilst cycling north through Burra I came across Adelaide Rosellas, pictured below, again Platycercus elegans but the race subadelaidae. Adelaide Rosellas are thought to be the hybrids of Crimson and Yellow Rosellas that are known to mate where their distributions overlap.
Given the definition of a species is that individuals can mate and produce viable, fertile offspring (and clearly this is happening), the three birds are the same species but of different races. The definition of race is very ambiguous.
In the case of the two Brown Falcons from the previous blog, the colour differences are called morphs (not races). The definition of a morph is that the different populations co-exist in the same habitat and can randomly mate with each other. I am not sure how this relates/differs from race.
Clearly I need to consult someone with a greater knowledge of taxonomy. My head hurts!
Different colour, same species #1
When considering fauna, particularly birds we are generally pretty good at recognising different genuses. For example we can tell that an Eastern Yellow Robin and a Scarlet Robin are obviously related because of their physical form and their general behaviour. They are of the genus Petroica , rock-dweller, from the Greek words petros for rock and oikos for dwelling place. This reflects the island where the type specimen originates. Furthermore we infer they are different species because of their colour.
But colour is not always a good indicator of species. Brown Falcons (Falco berigora) are found all over Australia and are a common raptor in our district. They come in three colour morphs – pale, intermediate and dark. Pictured above is a pale morph Brown Falcon. Pictured below is also a Brown Falcon but a darker morph. The further you go north the more prevalent is the latter although all colour morphs can exist in all of the range. The head markings are obviously different as are the colourations on the undersides between the two pictures. But are they different species?
The answer is no. A species is described as a group of animals that can mate and produce viable, fertile offspring. The definition has nothing to do with size colour or shape of the animal. That is why dogs, despite the many and varies shapes and shapes are all one species…they can successfully mate with each other.
As can humans…
Challenge accepted
One of the challenges of writing a blog like this is that people bring photos of fauna and expect you to be able to identify them to the species level. Although it is the part of blog writing that turns me on that doesn’t mean it is easy, particularly where insects are concerned. Sometimes the difference between species comes down to genital configuration and I have neither the knowledge nor tools to go there. Moths also present a difficulty simply because of the sheer numbers of species there are in Australia.
Enter Terry Hubbard. Terry sent me with the photo (above) and asked what type of moth it was. Luckily it is the only species of the genus Oenosandra so it’s picture appears in most moth reference websites. It is a Boisduval’s Autumn Moth (Oenosandra boisduvalii) a night flying moth seen in southern Australia and Tasmania in the months of March and April. The larvae feed on various eucalypts.
The female (pictured) and the male look markedly different. The male is a darker grey in colour and is the gender most often seen.
Terry called the photo ‘colliwobbles’ I guess referring to the black stripe on a white wing. What the photo fails to show is that the abdomen is yellow and black striped – a football conundrum that has caused many a family argument.
Mothers Day special
The terms mother and spider do not usually appear together in the same sentence…unless it is something like ‘that Huntsman was the mother of all spiders‘. However Wolf Spiders are one of the few spider species where the mother looks after its young.
A previous blog commented on the discovery of a Wolf Spider carrying around its egg sac, pictured left. Spiders lay their eggs in a woven sac of silk. For many spiders the sac is fixed either within the web or on vegetation, for example under bark. Wolf Spiders do not build webs. They are ambush hunters and can also chase and catch prey. Wolf Spiders and the related Sac Spiders are unique in that they carry their egg sacs with them. A Sac Spiders carries its sac around with its pedipalps, the multi-functional organs at the front of the spider often mistaken for legs. For Wolf Spiders the sac is attached by a line of silk (see photo) to the spinnerets on the abdomen. When walking the spider has to raise its abdomen so that the sac does not drag on the ground.
The Wolf Spider is unique in the spider world in that when the young spiderlings leave the egg sac they climb up the legs of the adult and sit on its back, pictured above. The spiderlings may stay on the mother’s back for several weeks until they are old enough to fend for themselves. Last week Judy B from Limestone, famous for providing photos for this blog of dead things, captured this photograph showing exactly that, a mother spider with spiderlings aboard.
An early Happy Mothers Day to all, including all the Wolf Spider mothers out there.
Focus On Fauna 