Banded Orb-weaving Spider, Argiope trifasciata

A fast moving spider in a football jumper

The Banded Orb-weaving Spider, also known as a Banded Garden Spider, has a bright banded yellow, white and black abdomen, but instead of standing out like a sore thumb, in its habitat it blends in remarkably well. This spider constructs a modest sized vertical web (about knee high) amongst sedge or grass, which provides an environment of green, yellow and black streaks, the perfect background to her camouflage. Here the large female remains motionless, head down day and night, remaining safe and overlooked by most predators.

The Banded Orb-weaving Spider, Argiope trifasciata

The underside is just as colourful

When under threat the female banded spider will suddenly drop to the ground and seek shelter in the tangled vegetation. But should an insect fly into her web, she rockets from her resting-place, and has the intruder silk wrapped within a blink of an eye. It is then bitten on or near the head, after which she will return to the centre of the web until her venom has paralysed the intruder. She will then return and wrap her meal even more securely.

The first paralysing bite into a March Fly

The female Banded Spider is around 2 cm in length (excluding legs), so a reasonably large orb-weaving species. It is a little larger than the closely related St. Andrews Cross Spider, Argiope aetherea. This spider is well known for the bright white cross made from non-capture silk in the centre of the web, called the stabilimenta. The spider rests on this formation also in the shape of a diagonal cross, with its legs outstretched and arranged in pairs.

The Banded Spider also rests in the shape of a diagonal cross, but seldom weaves a stabilimenta, or if so, only a partial one. A study published in the scientific magazine Behavioral Ecology suggests that the bright-white stabilimenta is made to make the web more visible to flying birds and so reduce web damage from accidental collisions. It is a trade-off however, as the web also becomes more visible to flying insects and so the spider's catch is reduced.

In the Esperance region, the Banded Spider seldom weaves a stabilimenta, possibly because they construct their nests close to the ground where local birds seldom fly. Whereas the St. Andrews Cross Spider when mature (an Eastern States species not found in WA), always construct a stabilimenta, but they generally build their webs at a higher elevation and more likely in the flight-path of birds.

A partial white stabilimenta at bottom right of center

Banded Orb-weaving Spider, Argiope trifasciata

In Australia the Banded Spider is only recorded in Queensland and WA, but is found in many other parts of the world with a major exception of Europe. They do vary slightly in size, but coloration and behaviour are similar, so is the low-lying habitat amongst grass and sedges, so the international banded spider is not currently considered evolved sufficiently (due to their wide separation) into different species.

A popular habitat is a low-lying sedge area, surrounded by grasstrees

The male banded spider is a fraction the size of the female (usually between a third and a quarter) and sometimes with other males, can be found on the outer edge of the web. It is very hazardous however being a suitor to the large female, as many males end up being her lunch; those that do escape often have to shed a leg or two to distract her in the process.

A fully intact male Banded Spider

A male Banded Spider who has lost the back legs escaping the female

For reasons possibly related to nursery duties, the female will leave her web unattended. On one such occasion a very bold male took her place in the centre of the web, but alas his triumph was short lived, as next day he looked like a silk-wrapped snack.

The female Banded Spider snacking on the unfortunate male

Despite having very effective venom for paralysing invertebrates, banded spiders are harmless to humans preferring to flee and play dead rather than bite. And unless you are looking in the right place, you will probably never see one, but should you be so lucky, it is worth checking this spiders activities daily, for besides being very colorful, they are also interesting to know.

The underside of the female Banded Spider, note the broad spinneret region for fast wrapping

Western Banjo Frog, Limnodynastes dorsalis

The best known burrowing frog. Once heard, never forgotten.

It doesn't matter if you are tone deaf or even hard of hearing as the 'bonk' - 'bonk' banjo like call is difficult to confuse with anything else. And if in their territory you have reasonable pools of water, you will hear it just about every night. I even had one hopeful banjo frog who had found a sunken plastic container full of water for the birds, he bonked loudly for over three weeks trying to attract a lady to his little paradise. But it was to no avail, being over 100 metres from an actual swamp, the banjo ladies were not taken in by calls of love from a dry sandy area. Eventually the frog gave up and presumably joined the competition at the swamp.

So you hear the call and say to yourself, I know that - it’s a western banjo frog, so you go looking for it. Now your troubles really start as tracking the actual frog from their calls is no easy thing to do, and most times given up in frustration, even when you know it is within a metre or two. Most frogs are very well camouflaged and their calls deceptive, particularly relating to distance from you. This is often made even more difficult when several frogs are calling from the same area. Fortunately they are quite distinctive when seen, so I just go looking and usually find them when they are moving around.

Western Banjo Frog, Limnodynastes dorsalis

I often think of the banjo frog as a bandit, just take note the distinctive mask-like eye patch that is underlined by a glandular white stripe, next note the bulge (oval gland) on each thigh. Despite other marking variations, these features are common to all of these frogs. Also with most of these banjo frogs there is a strongly marked pale stripe running down their back and the groin is usually crimson. The above distinctive features make it difficult to confuse it with other species, particularly when it is also the only Limnodynastes species in southern WA.

A bandit-looking western banjo frog - also note the raised thigh glands

Frogs from the genus Limnodynastes occur in areas where water can collect in deepish pools and therefore tend to be more common in the higher rainfall regions of eastern and northern Australia. These frogs differ from other frogs by constructing floating rafts of foam, into which the eggs are laid and fertilised. Once the tadpoles hatch they fall through to the water below. In my district there is little permanent water, but due to the dominant winter rainfall, many ephemeral swamps usually fill with water to provide suitable breeding habitat. Although frogs will move from one swamp to another, they are seldom found far from these areas. During long hot dry periods they will dig a burrow and await the winter rains.

"I don't think he saw me"

The range of coloration and markings amongst frogs of the same species is often remarkable, even within a small area. I have written about this before in relation to the Slender Tree Frog, Litoria adelaidensis 07. Frog colouration where there was a distinct correlation between the frog markings/coloration and habitat. Interestingly, the same thing seems to occur with the Western Banjo Frog. In the all these photographs, please note not only the coloration of the frog, but the habitat background, they are remarkably similar.

Probably the most extreme color variation of the banjo frog, but look at the sandy background

At the other extreme, these banjo frogs do not get much darker

The range of the Western Banjo Frog is just a little larger than the WA Wheatbelt zone, extending from the Murchison River (500 km north of Perth) to around 200 km east of Esperance. However there are other Banjo Frogs in Australia, so their call is known far and wide. The Eastern Banjo Frog, Limnodynastes dumerillii occurs from Adelaide to around Brisbane including most of Victoria and Tasmania. Then there is the Giant Banjo Frog, Limnodynastes interioris that inhabits central NSW and northern Victoria. And lastly the Northern Banjo Frog, Limnodynastes terraereginae that occurs from central NSW to the top of Cape York Peninsula. So if you like the sound of the banjo, there is plenty to keep you amused. Another name for this frog is Pobblebonk.

Western Banjo Frog, Limnodynastes dorsalis

Frogs are very reliant on suitable habitat and if that habitat is destroyed or altered, the frogs are often the first to suffer. Even if you have many frogs, if they are of the same species then you should be looking at providing greater diversity of habitat so other species can find a place too. Attracting frogs to your garden is much like attracting birds; it can be an absorbing hobby to see how many species you can accommodate. But it is important not to collect frogs from one area and introduce them to another, as a serious frog fungal disease can also be introduced by this means that can devastate frog populations and even kill entire species. So if you provide the habitat, they will move in of their own accord, where hopefully they can then build their numbers to spread to other suitable areas. This is a terrific way of being eco-friendly.

"Us frogs are really very friendly, plus we eat all the things you don't like"