Chilopoda are top predators

In the world of invertebrates, top predators are not only tough, but also well equipped.

Chilopoda is a class of animals commonly called Centipedes. In Australia these are divided into five orders, of which Scolopendramorpha (to be illustrated here) contain the largest species, both in Australia and throughout the world.

The largest centipede Scolopendra gigantca, is from the tropical regions of Central America and can exceed 12 inches, 300 mm in length, whilst our largest species is little more than half that size, but it is still a large invertebrate and a top predator.

Below is an Esperance species from the same family as the largest centipede Scolopendridae, but from the genus Cormocephalus, which is very similar except for the overlapping plate behind the head. The Esperance species is one of seventeen Cormocephalus species, Australia wide.

These larger centipedes are highly solitary and will often cannibalise others during the mating process, which has probably happened in the photo above. They generally prey upon spiders, insects, slugs and worms. The larger ones will also tackle small vertebrates like snakes, lizards, frogs and small rodents. A major part of their weaponry is a pair of legs just below the head; these have evolved to form a large pair of sharp pincers that will grasp an animal and inject paralysing venom from poison glands. The other legs have sharp claws that can also hold the victim (as shown in the above photo). So with 21 pairs of legs, these guys could be described as super huggers, but as far as people are concerned, their bite although painful is not fatal (unless there is an allergic reaction to the venom).

Although centipedes are regarded as ground dwelling animals, they do climb some trees in search of prey like the centipede below, who is checking out a Banksia flower. Note the sharp claw on the ends of the legs. Those two long ones at the rear are used in display with other centipedes or for grasping prey. So as far as weaponry is concerned, these animals are very well equipped.

Although centipedes occur in desert regions, they are more common in warm tropical areas where they obtain their greatest diversity and size. Their breathing system is less efficient in dry conditions and so they mainly hunt at night and rest up during the day in rotting logs, under rocks, in burrows, under leaf-litter or tree bark where more humid conditions exist.

Centipedes have a very long history, having originated in the sea, they are related to lobsters, crabs, shrimps, etc, but they began taking to the land and semi-aquatic environments around 400 million years ago and have prospered ever since. From fossil records, they have been recorded from the coal making Carboniferous period (over 300 million years ago), growing to 1½ metres in length.

Centipede from the genus Cormocephalus

This group of centipedes can live for around 6 years and have developed an unusual nursing habit, whereby they wrap their body around their eggs and later, the defenceless young, where they will remain until their first moult. It is thought that the mother may provide them with their first meal by allowing them to feed from her body. After this period the mother usually dies and the young disperse. The main predation of centipedes is during their first few moults, when they are likely to be taken by spiders and carnivorous insects, but after that stage their main predators are other centipedes.

Despite their fierce reputation, there are always those who cannot resist a photo opportunity with them. Such is the case with this preying mantis.

Now for a little centipede horror story. A number of years ago during winter, I was on a camping trip to Central Australia. Although the days are pleasantly warm, the nights can be bitterly cold, so like most people we built a nice fire to sit around and socialise. Someone had placed a large log on the fire and the lady next to me was relaxing, with her legs resting upon it. All of a sudden clutching her leg, she jumped up screaming and began frantically pulling off her clothing. It turned out that a very big centipede (over 6" in length) had vacated its home in the burning log and took off up her trouser leg.

The sharp claws on its legs had perforated the shin and when she grabbed it from outside her trousers, it had bitten her savagely, injecting much venom. After a few hours she had recovered her composure, plus with some first aid had patched up her wounds, but for the rest of the trip, she never once rested her legs on wood (regardless of size) and always tucked her trouser legs into her socks. So be warned, although the Australian species are not life threatening, it is an experience well worth avoiding.

Despite the horror stories, these animals do not go out of their way to attack people, so if you accidentally come across one, let it go about its business as like all main predators they perform a major function in the ecosystem.

My thanks to the Australian Museum (Sydney) for the identification and sundry information.

White-tailed Spiders, Lampona species.

A spider with a bad reputation?!

This spider has been accused of biting people and causing flesh-eating ulcers that refuse to heal. However, recent research of 130 bite victims (by two of the most common species from this genus), found no incident of skin damage other than from a painful bite (greater than a bee sting) lasting up to 24 hours. The conclusion given was these spiders are innocent of their reputation.

Nevertheless, something has caused these flesh-eating ulcers, which the people affected claim were from a spider bite. Another possible explanation is the bacteria living around the mouthparts of most spiders, probably as a result of their meals. If this was the cause, it could involve a range of possible spiders as few people have more than an elementary knowledge of spider identification.

Yet another factor, assuming the people were actually bitten by a Lampona species, is there are around 60 recognised species in this genus (occurring Australia wide), but only two of these were tested. Although not all of these spiders have a white spot on their tail, they are however of similar shape and the white dot in most instances is not particularly obvious.

This is one of the White-tailed Spiders. Note the white spot on the tail.

White-tailed Spider a Lampona species

These spiders are wandering night-time hunters that do not build a web, although they sometimes construct a tubular silken retreat, or to lay eggs. Their main diet is other spiders, especially the black house spider, so for those who dislike the look of the house spider and its untidy web, they might prefer the smarter white-tailed spider.

Being hunting spiders their eyesight is good. They have eight eyes (all forward facing) in two rows of four.

During the day, the white-tailed spider rests under bark, logs, rocks or leaf-litter.

This young spider is checking out what the Pie-dish Beetle is eating, but fortunately for the beetle, it is not on the menu.

Most of these spiders are between 1 and 1½ cm in length (excluding legs), but some (like the one below) are closer to 2 cm. I discovered this individual in the open on one of my nightly rambles and like most invertebrates in this situation, they tend to either freeze or move slowly. This one decided to move slowly. It was obviously not happy being caught in the open and initially hugged the ground.

However, it started to become annoyed when I continued to follow it.

In this shot it was very upset and began arching its back, presumably an aggressive posture.

When it reached the weeping foliage of a sedge, it turned and stood on tip-toe like a defensive/aggressive cat, side-on with arched back to make it look more dangerous. It certainly worked on me, as I had no intention of placing a part of my anatomy anywhere near it.

So my advice with spiders, is to treat them all with respect. Don't tease or mess with them because like most wild animals, they will regard you as a threat and are then more likely to bite. If you want to relocate any, simply place a glass over them, then slide a piece of paper or thin board under to trap it. Then release it outside! Alternatively if difficult to reach, a gentle nudge with a broom will usually make the spider crawl aboard so it too can be carried outside, but do it slowly/gently in order not to panic the spider.

Many people are paranoid about spiders, but this is usually due to ignorance and fear. The more you get to know them, the less fearful you become. So get to know your local species and discover how diverse they are in appearance and habit. Most spiders are not aggressive and none are interested in going out of their way to attack you, so inspect them from a respectful distance and learn to appreciate the importance of these creatures in your environment.

Two Esperance Geckos, one agile, one not!

What is the first thing you notice about a gecko?

For me it was their large unblinking unaggressive eyes, making them very cute looking. There are more than 100 Australian species, but in Esperance only three are recorded and I have never seen one of them. Of the two I do know, one is noticeably common possibly because it will also take up residence in your home, or take advantage of outside lights that attract insects. This human friendly species is the Marbled Gecko, Christinus marmoratus, which has learnt to take advantage of our energy guzzling activities.

However the Marbled Gecko and other species usually live under loose bark or under stones, some even live in spiders burrows. So maybe you can see why our houses look appealing to some.

They dine on a wide range of fare like insects, spiders and scorpions, but they also will partake of fruit, nectar and sap. Some large species will even eat smaller geckos. However, not all geckos have it all their own way. I have found geckos entrapped in the tangled webs of Redback Spiders, which I understand will also eat them.

You can see by the photos below how dexterous the Marbled Gecko is, being able to firmly grasp objects, or stick like glue to smooth vertical surfaces, it will even use its tail for additional traction.

Marbled Gecko, Christinus marmoratus

The Marbled Gecko have an interesting color variation, namely (with some animals) red patches on the tail. However most geckos in my area are without these markings, but it has been noted by Herpetologists that they are particularly common on juveniles. I have seen many juveniles and adults without any noticeable tail markings, so personally I am not convinced that they had them as juveniles or lose them at maturity, but more likely a color variation that for some reason, is only applicable to a minority of animals.

Just because geckos appear cute and cuddly, it does not mean that they cannot get very upset over territory and femme fatale issues with other geckos. Here one had latched onto the neck of the other and like a pit-bull had no intention of letting go.

The other gecko!

The second Esperance species is a very different animal; it is much shyer, prefers not to climb and has brightly speckled eyes, which often betray an inner sense of its own fatality. This is the Soft Spiny-tailed Gecko, Strophurus spinigerus subspecies inornatus.

As you can see, climbing smooth vertical surfaces is not regarded very highly by this species.

Have a look at the speckled eyes and the inner realisation that this might be the last photo it may ever have to endure.

Soft Spiny-tailed Gecko, Strophurus spinigerus subspecies inornatus

But despite the cute face and worried look, when it turns away you can see the remnants of a much bigger and more terrifying ancestor.

So next time you see a cute little gecko with big eyes and a worried expression on its face, remember if you were only a couple of centimetres high, it would probably eat you. However, except for science fiction, this is not likely to happen, instead they will do you the favour by eating all your nasty creepy crawlies.