About Gehyra variegata (Duméril & Bibron, 1836)
This species is commonly known as the tree dtella. For adults, the snout-vent length of the body reaches 55 mm, and tail length reaches 70 mm. The tree dtella has highly variable dorsal coloration; this variation is likely because the current classification actually includes multiple distinct species. Color ranges from grey to brown across different populations. Eastern populations have chequered dark and pale blotches and marbling, while western populations have white to pale brown spots paired with dark bars. All these patterns form an irregular reticulate pattern across the entire dorsal surface.
The tree dtella inhabits arid to sub-humid areas, including woodland, shrubland, and dry rocky environments. It is both arboreal and saxicolous: it can be found under loose bark and in tree hollows, as well as in rock crevices and under exfoliating rock. When on trees, it prefers sheltered sites that are more than 1 metre above the ground, and it may also be found under ground debris.
Its distribution is limited to inland Australia, excluding the north-west and south-east regions. Field studies confirm that tree dtella populations have a metapopulation structure across their geographic range. The species can survive in small patches of disturbed land, because it can adjust its habitat use in response to environmental change. For example, populations in nature reserves occupy shrubs, while populations in small fragmented remnant vegetation shelter in logs and eucalyptus trees.
The tree dtella is an ectotherm, and falls into the thigmotherm subgroup, meaning it relies on heat exchange with a substrate to maintain its body temperature. Arboreal tree dtellas perform this by shifting their position under tree bark as the sun warms different parts of the tree throughout the day. This behavioural thermoregulation is thought to be linked to the high thermal requirements the species has for digestion.
The tree dtella has a lifespan of at least 5 years, and reaches sexual maturity at 3 years of age. It is oviparous. Each clutch holds one hard-shelled egg, which is laid beneath cover, usually in bark, logs, or holes under rocks. Females lay two clutches per breeding season, around one month apart. The first clutch is laid in late November. Eggs measure 10 by 11 mm. The gestation period lasts 61 to 79 days, which is slightly longer than two months. Newly hatched tree dtellas are 45 mm in total length. Nests are often communal, and a single nest has been found containing 35 eggs.
