Ctenophorus nuchalis (De Vis, 1884)

Taxonomy and Basic Classification

The central netted dragon (scientific name Ctenophorus nuchalis (De Vis, 1884)) is a medium-sized terrestrial lizard.

Body Coloration and Pattern

Its body ranges in color from pale reddish-brown to bright orange-brown, and it gets its common name from a dark chocolate-brown net-like (reticulated) pattern covering its head and body. This camouflage pattern helps the lizard blend into its habitat to avoid predators.

Limb Structure

It has short, strong limbs with long toes and strong claws, which let it run at high speeds and dig burrows.

Head Shape

Compared to other iguanids and agamids, its head is short and blunt, a trait thought to be linked to its herbivorous diet and burrowing behavior.

Head Scale and Spine Features

Its ears are exposed, a row of enlarged scales curves under each eye, and small spines surround the head.

Neck and Body Scale Features

It has a low crest along the top of its neck, a narrow vertebral stripe running the full length of its body, and small, smooth body scales.

Adult Male Size Measurements

Adult males measure 25–28 cm from snout to tail, with a 10 cm snout-to-vent length and the tail making up the remaining length.

Sexual Dimorphism

This species shows sexual dimorphism: males are slightly larger overall, and have proportionally larger heads than females.

Wild Lifespan

In the wild, this dragon is relatively short-lived, with a typical lifespan of 2 to 4 years.

Geographic Distribution

Central netted dragons are distributed across the desert plains of Western Australia, the Northern Territory, western Queensland, and New South Wales.

Habitat Preferences and Abundance Drivers

They are abundant in open, sandy areas with sparse vegetation, and surveys show the species becomes more abundant in grazed areas, and may also increase in number in cleared or burnt areas.

Activity Pattern

Central netted dragons are burrowing, diurnal (day-active), ground-dwelling lizards.

Basking Behaviors

They spend their days basking on logs, stones, and termite mounds. Like most reptiles, they are ectotherms, relying on their environment to regulate their body temperature, which averages 36.1 °C.

Thermoregulation Rationale

A dragon starts its day by basking in the sun to raise its body temperature and gain energy, because adequate body heat is required for these lizards to digest their food.

Midday Thermoregulation Strategies

When desert temperatures peak at midday, they either retreat to their burrows to cool down, or climb plants to escape extreme heat.

Burrow Location

They typically have six to eight separate burrows, often built at the base of living spinifex (Triodia) grass stumps, or within hillocks formed by dead grass hummocks.

Burrow Characteristics and Uses

These are relatively shallow, dead-end burrows located in different parts of the lizard's home range, and are primarily used as nocturnal retreats and escape routes from predators.

Burrow Entrance Modification

They often back-fill the entrance of their burrow to block predator access and keep external heat out.

Perch Preferences

They prefer perches with high vantage points, such as termite mounds (which also act as a food source for this insectivorous species), dirt hills, logs, and fence posts.

Vegetation Cover Association

Vegetation cover is an important part of this species' ecology: it dominates areas with low vegetation, for example after drought when spinifex has died back and ground cover is sparse (less than 10%).

Conspecific Communication Methods

Like many dragon species, central netted dragons communicate with conspecifics by bobbing their heads and waving their legs.

Male Territoriality

Males are quite territorial, and use these displays to intimidate rival males to fend off attempts to take over their territory.

Reproductive Mode

Central netted dragons are oviparous, meaning they lay eggs rather than giving birth to live young.

Female Clutch Characteristics

Females lay two or three clutches of 2 to 6 eggs each, usually during spring and summer, with timing varying by location and conditions.

Breeding Season Male Behavior

During the breeding season, males actively defend territories and often fight with other males to establish dominance.

Annual Lifecycle Demographics

The species has an annual lifecycle, with adults making up the majority of the population during the breeding season, and juveniles predominating during other seasons.

Sexual Maturity Timing

Juveniles usually reach sexual maturity at 5 to 6 months of age, after winter.

Rainfall-Driven Reproductive Timing

Reproductive timing is primarily determined by rainfall: breeding occurs predictably after winter rains in the southern part of the species' range, and in late summer after cyclonic rains in the Pilbara region further north.

Pilbara Regional Breeding Variation

Breeding may also occur in spring in the Pilbara, but only if winter rainfall was substantial.

Rainfall Fitness Benefits

Rainfall appears linked to improved survival, improved growth, and possibly larger clutch sizes and higher hatching success.