10 January, 2009

Weekend Wildlife

Being modern spiders, jumping spiders have only three pairs of eyes. Four eyes look forwards and the other two cover the sides and back. Most are small and beyond the capabilities of me and my camera. This one had a total length of about 2cm. Note that the fangs can work in opposition from each side in contrast to the older, eight eyed spiders which need to rear up on their legs to strike downwards with their fangs together. This is because the 'big hairy' spiders have backward facing fangs.
On wet windy nights these huge Spiny Katydids, Phricta spinosa, come to the forest understorey to avoid the vagaries of the weather. Females also come to the forest floor to lay their eggs. Nymphs are much more commonly seen than the adults. This animal was over ten centimetres long. The red and black of the inner thighs is diagnostic.
I would have driven past this Frilled-neck Lizard, Chlamydosaurus kingii, if it had not been for a sharp-eyed passenger. These wonderful dragons hunt invertebrates and take the occasional lizard.

Their threat display is wonderful to see. They erect their frill, hiss and will even jump towards the threat before turning tail, running on their back legs to the nearest tree and climbing it on the side opposite the observer.
Unlike snakes, they lose their skin in a rather patchy manner.
Just down the road from the Frill-neck were these Eastern Greys and two Agile Wallabies. Before they raised their heads to look at us they were well camouflaged in the termite mounds.

Size differences between the sexes is common in macropods, kangaroos. It reaches its maximum in the Antilopine Wallaroo and minimum in the tree-kangaroos and rock wallabies.
I have mentioned the short faces of tree kangaroos before but did you know that in most macropods the molars erupt in series, migrate to the front and fall out. A young kangaroo might have only its two first in position and use behind the premolar. An older animal may have numbers 1 to 3 in use with number 1 where the premolar was and an old animal only molars 3 and 4 in use. The Nabarlek, a small rock wallaby, has molar teeth erupting and moving forward throughout its life.
This serial use of molars is shared with elephants and allows much more grinding area to be used during the animal's life than could be accommodated in the jaw at one time.

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