frilled lizard

Frill-necked lizard
Conservation status
Least Concern
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Sauropsida
Order:	Squamata
Suborder:	Iguania
Family:	Agamidae
Subfamily:	Agaminae
Genus:	Chlamydosaurus
Binomial name
Chlamydosaurus kingii Gray, 1827

The Frill-necked lizard (Chlamydosaurus kingii), also known as the Frilled lizard or Frilled dragon, is so called because of the large ruff of skin which usually lies folded back against its head and neck. The neck frill is supported by long spines of cartilage which are connected to the jaw bones. When the lizard is frightened, it gapes its mouth showing a bright pink or yellow lining, and the frill flares out, displaying bright orange and red scales. This display is usually used to discourage predators or in courtship. The lizard is a member of the agamid family which means it a relatively large lizard, growing up to 91.4 cm.^[1] The lizard is also capable of bipedal locomotion.

The frill-necked lizard does not have a standard colour; however, it is characterised by a body that is darker than its frill. There is only one recorded species of the frill-necked lizard; however, the immense variations of colour among the species has lead some scientists to hypothesise more than one species.

Habitat

Frill-necked lizard in natural environment, showing camouflage

The frill-necked lizard is found mainly in the northern regions of Australia and southern New Guinea. Within these regions, the lizard inhabits humid climates such as those in the tropical savannah woodlands.^[2] The frill-necked lizard is an arboreal lizard, meaning it spends a majority of its time in the trees.^[2] The lizard ventures to the floor only in search of food, or to engage in territorial conflicts. The arboreal habitat may be a product of the lizard's diet, which consists mainly of small arthropods and vertebrates (usually smaller lizards). However, the trees are most importantly used for camouflage. One of the most intriguing facts noted by scientists who study this lizard is that there is not one standard colour: rather, colouration varies according to the lizard's environment. For example, a lizard found in a dryer, clay filled environment will most likely have a collage of oranges, reds, and browns; whereas a lizard found in a damper, more tropical region will tend to show darker browns and greys. This suggests that the lizards use their habitats for protection in the form of camouflage.

Diet

Like many lizards, frill-necked lizards are insectivorous. They are known to feed on cicadas, beetles, ants, and termites.^[3] They especially seem to favour butterflies and moths, their larvae even more so.^[4] Though insects are their primary source of food, they are also known to eat spiders, other lizards, and small mammals.^[5] Like most members of the agamids (dragons) frill-necked lizards employ an ambush method of hunting, lying in wait for their prey.^[6] When the lizards eat, they eat in abundance; these binge periods usually occur during the wet season, when the lizards will ingest hundreds to thousands of alates (ants or termites).^[6] The lizards will rarely venture to the forest floor in order to obtain food,^[6] and they rarely need to drink, as they can get all required moisture from the food they eat.^{[7][unreliable source?]}

Thermoregulation

Being a reptile, the frill-necked lizard is ectothermic and maintains its homeostatic body temperature by basking for up to 40 minutes. This achieves an average of 2–3 degrees Celsius above the surrounding temperature. Weather conditions, including sunlight, are the main factors working on the lizards’ temperature.This basking period usually occurs in the morning to early afternoon. During the basking period the lizard will be found near the bottom of a tree and out from under the forest canopy. This is because the session is occurring during early hours and the lizard's position insures maximum exposure to sunlight. However, the lizard's final internal temperature depends mainly on the ambiance of the surrounding environment. I is thought that the lizard's frill aids in thermoregulation.^[8]

Reproduction and sexual dimorphism

Chlamydosaurus kingii from Narrative of a Survey Volume 2, by Phillip Parker King, 1827.

The frill-necked lizard is sexually dimorphic, as with most lizards. This means that the male and female frill-neck differ phenotypically. In the case of the this lizard this dimorphism is apparent in the length of the lizard: male lizards are generally larger than female lizards.^[6] There is little to no dimorphism in the color of the lizard. Frill-necked lizards breed in the early wet season from September to October. Adult males fight for mates, displaying their frills and biting each other. One to two clutches of 8–23 eggs are laid from early to mid-wet season from November to February. The eggs are laid in a nest 5–20 cm below ground, and usually in sunny areas. Incubation takes two to three months. Sex is partly temperature determined, with extreme temperatures producing exclusively females, and intermediate temperatures (29 to 35°C) producing equal numbers of males and females. Their eggs are soft-shelled.^{[citation needed]}

In culture

A frill-necked lizard seen on a small tree branch

A frill-necked lizard was featured on the reverse of the Australian 2-cent coin until 1991. This coin was withdrawn from circulation in 1992, after which the 2- and 1-cent coins were melted down to make bronze medals for the 2000 Summer Olympics in Sydney. The same frill-necked lizard, "Lizzie," was the mascot for the 2000 Paralympic Games.^[8]

The emblem of the Australian Army's Regional Force Surveillance Unit, Norforce (North West Mobile Force) is the frill-necked lizard. The lizard was selected as the unit's emblem because of its speed, aggression, and ability to blend in with its surroundings.^{[citation needed]}

Because of their unique appearance and behaviour, the frill-necked lizard is commonly depicted in children's cartoons. A frill-necked lizard named Frank appears in the Disney film The Rescuers Down Under and one named Osgood appears in the anime Noozles. In Adventures of the Little Koala, the character "Macky Macky" is a frill-necked lizard whose neck frill raises up when he gets excited. It is also the fauna symbol used for the Australian wildlife television program, Totally Wild.^{[citation needed]}

In the film Jurassic Park, the dinosaur Dilophosaurus was portrayed with a fictional neck frill, which was raised during attack, similar to that of a frill-necked lizard. According to Investigative reporter, Bryan Christy, the appearance of this type of dinosaur lead to an increase in demand for the frill-necked lizard as a pet.^[9]

References

1. Bedford, G. S. 1995. Anti-predator tactics from the Frilled Neck Lizard Chlamydosaurus kingii. Journal of the Victorian Herpetelogical Society 6(3): 120-130.
2. Harlow, P. S. and R. Shine. 1998. Temperature dependent sex-determination in the frillneck lizard Chlamydosaurus kingii (Agamidae). Herpetologica 55(2): 205-212.
3. Shine, R. and R. Lambeck. 1989. Ecology of frillneck lizards, Chlamydosaurus kingii (Agamidae) in tropical Australia. Australian Wildlife Research 16: 491-500.
4. From The Centre: Kakadu. Australian Broadcasting Corporation 2002.

Footnotes

External links

Wikimedia Commons has media related to: Frill-necked lizard

Wikispecies has information related to: Chlamydosaurus kingii

• Frilled Dragon & Other Lizards Photo Gallery
• Frilled Dragon care sheet
• Frilled lizards in captivity
• Frilled Neck Lizard Information
• Frill Necked Lizard (Chlamydosaurus kingii)
• Videos and Pictures