Monday, May 28, 2007

Wildlife

Australia has many species of venomous critters, both on land and in the sea.
These include 38 land snakes and 23 sea snakes, 22 spiders, 4 ants, the honey bee, 3 wasps, 2 beetles, 6 scorpions, 2 caterpillars, centipedes, millipedes, mosquitoes, sandflies, thrips and other insects.
The platypus and echidna also have a venomous defence system.
Coastal waters are frequented by 2 blue-ringed octopuses, 7 jellyfish, cone shells, 2 stonefish, 21 other fishes including the flathead, the Port Jackson shark, 11 rays, starfish including the crown of thorns, corals, anemones, urchins, stinging sponges, marine worms, leeches, frogs and toads.
Australia is home to the ten most lethal snakes in the world. Of the world's top 25 venomous snakes, Australia has 21. After considering venom toxicity, average yield, and aggressiveness, the North American diamond-backed rattlesnake is ranked number 25 in the world, with the Indian cobra and African black mamba 12th and 13th respectively!
And we haven’t even mentioned the animals and fish that want to eat you eg. crocodiles and sharks
Much is made of this on nature programs seen overseas and I have often been asked how we manage to live in such a dangerous environment.
I don’t think Australia is any more dangerous than a lot of other places around the globe. It is all a matter of what you are used too. At least we don’t have any land animals that want to do you harm like bears. And rabies is a disease that has been kept out of the country by very strict quarantine laws.
We have a range of ‘nasties’ that live around the farm that we can come across on a regular basis depending on the season.
The red bellied black snake is the most predominant snake in this area. The upper surface of this snake is glossy black while the belly is light pink to brilliant red.

We see them from late August to March. They eat mainly frogs so you mostly see them around the dams, creeks and wetlands. They will also eat lizards, mammals, birds and occasionally fish.
During mating season they are on the move and that’s when you can see them around the house. These reptiles are a protected species so we generally leave them alone. They are quite timid unless cornered and make every attempt to get away when disturbed. However any found around the house are ‘dispatched’. A sharpened hoe is kept in a strategic place for this purpose. Most snakebites occur when people are trying to kill one so you need to be careful.
It grows to 1.5 to 2m and its bite is very dangerous and requires immediate medical attention.
Funnel-web spiders are some of the world’s most deadly spiders and are found in coastal and mountain regions of eastern and southern Australia. They are large black spiders with a shiny head/thorax. The body may range from 1.5 cm to more than 5 cm long depending on the species. Funnel-web spiders live in burrows in sheltered positions in the ground, in stumps, tree trunks or ferns above the ground. Their burrows are lined with a sock of opaque white silk and several strong strands of silk radiating from the entrance. Funnel-web spider venom is highly toxic, and all species are considered potentially dangerous.


Female funnel-web spiders are long-lived, possibly up to 20 years, but are rarely seen except during tree felling, excavation or landscaping work. They spend their entire lives inside the burrow, only venturing out momentarily to snatch passing prey, which consists of insects and small vertebrates such as lizards and frogs.
Males wander at night, especially during or after rain, and may enter houses. In the northern suburbs of Sydney it was always advisable to check in the bed before climbing in.
Bites by males of two large species, the Sydney funnel-web and northern tree funnel-web, have resulted in death. I have seen a few over the years working in the vineyard and maybe an occasional one in the vege garden. We should wear gloves but we don’t. But we always shake out our boots, if we have left them outside overnight, before putting them on.
The Redback Spider is very common in the area. The females are black with an obvious orange to red longitudinal stripe on the upper abdomen and an "hourglass" shaped red/orange spot on the underside of the abdomen. They have a body about the size of a large pea and slender legs.
The male is only about 3-4 mm long and its red markings are often less distinct. The body is light brown with white markings on the upper side of the abdomen, and a pale hourglass marking on the underside.
The notorious Black Widow Spider of the United States is a close relative of the Redback Spider, and only differs in appearance by the absence of a red dorsal stripe.

Webs consist of a tangled, funnel-like upper retreat area from which vertical, sticky catching threads run to ground attachments. The spider favours proximity to human habitation, with webs being built in dry, sheltered sites, such as among rocks, in logs, shrubs, junk-piles, sheds, or toilets. Redback bites occur frequently, particularly over the summer months but are less common in winter.
Only the female bite is dangerous. They can cause serious illness and have caused deaths. However, since Redback Spiders rarely leave their webs, humans are not likely to be bitten unless a body part such as a hand is put directly into the web, and because of their small jaws many bites are ineffective.
The main rule is never to stick your hand into or under anything outside unless you have checked first.
We have two types of ticks, the bush tick and the paralysis tick. Both are a nuisance if they attached themselves to you leaving a large itchy red lump and have the potential to pass on Lyme disease. The Australian paralysis tick is widely distributed in south eastern coastal temperate regions and secretes a neurotoxin in its saliva that causes a progressive, and occasionally fatal, paralysis.


Sometimes a severe hypersensitivity reaction can occur.
This tick is particularly severe on dogs and cats causing hundreds of deaths every year and this keeps the vets in our area particularly busy administering antivenom and supplying preventative collars, tablets and pour ons. My neighbour nearly lost a very expensive foal from a paralysis tick last year.
There are many theories on how to remove a tick safely without it injecting more toxin into you. Personally I just pull them out but prevention is better than cure and a spray on insecticide is the best protectant.
Leeches are found in damp cool areas. They live in the grass and on the leaves of bushes and shrubs and are always waiting for a host to come along to attach to. Finding a thick blood engorged slug on your person (and they get in the most awkward places!) is always not pleasant. Removal is easy by just pulling them off. This is considered dangerous because they disgorge bacteria laden liquids from their stomachs which can cause infection.


Other methods include sprinkling them with salt, applying tea tree oil or menthol or a lighted match. The latter always seems more dangerous to me. The wound can bleed for quite a long time due to the anticoagulants they have injected and the lump left can be itchy for weeks and become infected.
We usually apply a spray on insecticide before working in the bush to combat them.

1 comment:

Anonymous said...

cool