Tuesday, 30 December 2008

A Few More Lizards

The Shade Skink, Saproscincus basiliscus, looks like any of a number of small skinks you see amongst the leaf litter. It measures about 4.5 cm snout to vent length. What is different about it is that it always sleeps on leaf surfaces about 50 cm from the ground. There must be some protective value in this strategy, but what it is I have not determined. Perhaps, there are ground marauders that it avoids with this technique. What id does do is to keep it out of the realm of the Cane Toad, Bufo marinus, which patrols the ground each night in search of anything it can subdue. Small lizards are often eaten along with frogs and a wide variety of insects.

A word about the big boys. The Lace Monitor,Varanus varius, is a common resident in rainforests. It is a member of the group of lizards known in Australia as "goannas". This is a perversion of the word "iguana" so-called by the earliest Australian settlers. This lizard is at home on the ground as well as in the trees where it feeds on anything it can subdue. Birds, lizards and small mammals are taken. It lies in wait and unsuspecting Musky Rat Kangaroos bumble into the jaws of these monsters. A full grown Lace Monitor can be over 2.1 m long and have jaws measuring 12 cm. There are lots of stories about Lace Monitors. They often hang around campgrounds where they learn that there is food. They have an excellent sense of smell and if they get a whiff of something they want, almost nothing can deter them. I have seen them enter tents and tear the place up looking for food. I have heard stories of them taking sandwiches from the hands of startled picnickers. They have relatively poor eyesight and have been known to "run up a person" when danger threatened probably mistaking the person for a small tree. Our big Monitors have blunt tails. I was fortunate to see why one day when my camera was not at hand. The Brush Turkeys hate these lizards because they will dig up their mounds looking for eggs. Once they start, they are usually not deterred. When the turkeys find a wandering Monitor, they bite the tip of the tail always staying out of the range of the mouth and claws that would surely spell their end. When the tails are long and slender, pieces are bitten off. The scenario ends when the lizard runs up a tree. The turkeys can fly but I guess they feel less threatened when the lizards are treed.

(Gary Wilson photo)
(Gary Wilson photo)
(Gary Wilson photo)

The Northern Leaf-tailed Gecko, Saltuarius cornutus, is probably found on our property but I have not seen it--or heard it. These large lizards (14 cm snout to vent length!) live in trees and emerge at night to sit and await unsuspecting prey. They seem to prefer geckos of other species. They have been found around homes where they prey on the Asian House Gecko. I have seen and heard similar species in Borneo where they do much the same thing. They are said to be quite aggressive if encountered in nature.

A most unusual gecko!
Imagine our surprise to find this structure at the Mareeba Wetlands, a marsh-lake habitat just to the north of Mareeba. A plaque states this stainless steel gecko was donated by a Japanese sculptor who places one of his creations wherever he finds native wild rice growing. Unusual to say the least.

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