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Adaptable Nocturnal Predator, Sydney Speciality… Broad-tailed Geckos

By Keith Hutton on February 18, 2014 in Other

Picture: Flickr user Andy Burton Oz

Picture: Flickr user Andy Burton Oz

I was out at Malabar Headland over Christmas, enjoying the mild conditions, cool breeze and a clear sunny day. On the more exposed eastern and southern parts of the headland conditions were perfect for lizards to bask in the sun in warm protected patches along narrow pathways in the scrub, and on exposed rocks.

Eastern Water Skinks preferred damp areas close to pools, and brightly coloured Copper-tailed Skinks were obvious along narrow sandy tracks in the taller heath, sometimes with scarce and beautifully marked White’s Skinks, and once with an Eastern Bluetongue. In more open areas with invasive kikuyu grass, Jacky Lizards perched prominently in isolated low shrubs.

All the lizards that have ever been recorded at Malabar still live there, but I’ve always wondered why one spectacular species has never been mentioned. Broad-tailed Geckos are easily identified and resident in the Sydney region but have not yet been recorded on Malabar Headland. Maybe this is because they are nocturnal and hide in rock crevices during the day, and nobody has searched for them at night.

Broad-tailed Geckos have also been known as Southern Leaf-tailed Geckos and adults are moderately large lizards with a body length up to 10cm and a tail adding an extra 7cm.

They have prominent heads and broad leaf-shaped or heart-shaped tails constricted at the base. Limbs are long and spindly, slender and bird-like, with clawed digits, and they have flat bodies and tails that are moderately short, broad, flat and flared, with long narrow tips. Their skin is granular and spiny, particularly on the tail and flanks. They are superbly camouflaged, pale brown to dark grey in colour with darker mottling, flecks and spots that blend into the rocks. There are no other lizards like them in Sydney.

Broad-tailed Geckos are largely restricted to the Sydney Basin area of NSW, from Nowra in the south to the southern edge of the Hunter Valley in the north. They are found almost exclusively in sandstone outcrops, ridges and escarpments, where they hide in both vertical and horizontal crevices, or under rock slabs and in caves. They are well adapted to human settlement, finding shelter on buildings and in sheds, woodpiles, garages and dwellings adjacent to rocky outcrops. Large numbers may share a suitable shelter site; up to 16 individuals in one crevice. In such sites spider webs are often festooned with sloughed skins. However, they are more often found alone.

Broad-tailed Geckos eat spiders, moths, beetles, cockroaches, flies, centipedes, millipedes and soft-bodied worms; they also eat smaller geckos. They emerge at night to feed, then rest motionless, usually head down and almost invisible, waiting to ambush passing prey.

They are protected species, not often seen, but apparently widespread and successful in preferred habitats in the Sydney region, and in artificial habitat adjacent to natural sandstone areas. They may be killed by cats but are not regarded as threatened.