Excitable delma (Delma tincta)

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Excitable delma fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
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Excitable delma description

The excitable delma (Delma tincta) belongs to an unusual family of lizards with long, snake-like bodies that lack obvious limbs. Although the excitable delma lacks any front limbs, it does have tiny vestigial hind limbs in the form of scaly flaps ^{(2) (4) (5) (6)}, which completely enclose the much-reduced bones of the legs and toes ^{(4) (5)}. These flaps give this and other members of the Pygopodidae family the name ‘flap-footed lizards’ ^{(2) (5)}.

The tail of the excitable delma is more than three times the length of its head and body ⁽⁷⁾. As in other Delma species, the tail is easily broken, but may be regenerated ⁽²⁾. Like the geckos to which they are most closely related, Delma species have lidless eyes that are covered in a transparent scale and must be cleaned by licking them with the broad tongue ^{(2) (5)}.

The excitable delma is brown to greyish-brown above and white beneath, with three to four black bands on the head and neck ^{(2) (8)}. These bands are separated by cream or yellow ^{(2) (7)} and are most conspicuous in juveniles and young adults, usually fading somewhat in older individuals ^{(2) (3)}. The male and female excitable delma are similar in size and appearance ⁽⁴⁾. Like other Delma species, the excitable delma has smooth, shiny scales ^{(2) (4) (6)}.

If disturbed, the excitable delma may make a squeaking or buzzing sound ^{(4) (6)}.

Also known as

black-necked snake-lizard.

Synonyms

Delma reticulata.

Size

Snout-vent length: 9.2 cm ^{(2) (3)}

Total length: 35.6 cm ⁽⁴⁾

Excitable delma biology

The excitable delma gets its common name from the frantic, acrobatic way in which it jumps and thrashes about when disturbed ^{(4) (9)}. This unusual behaviour may serve to startle or disorientate predators ⁽⁹⁾. Like other Delma species, the excitable delma is also able to shed its tail as a defence mechanism if attacked ^{(2) (4) (8) (9)}, and the tail can quickly grow back ⁽⁸⁾.

This species has also been known to bury itself in sand or loose gravel, with only the banded head showing. The pattern of bands then help to conceal the excitable delma’s head by camouflaging it against the ground ⁽⁴⁾.

The diet of the excitable delma consists mainly of insects and other invertebrates ^{(2) (5) (6) (8)}. This lizard is reported to be active during the day and in the evening ⁽⁸⁾, and like other Delma species it is likely to lay a clutch of two elongated eggs that have parchment-like shells ^{(2) (4) (5) (6) (8)}.

Excitable delma range

The excitable delma is found only in Australia, where it is widespread across the north of the continent ^{(4) (8)}. This species has been recorded in northern parts of Western Australia, as well as the Northern Territory, Queensland, northern New South Wales and South Australia ^{(1) (2) (4)}.

Excitable delma habitat

Like other Delma species, the excitable delma is likely to have evolved its snake-like body form as an adaptation for moving rapidly through low, dense vegetation ⁽⁵⁾. Relatively little information is available on the habitat preferences of this species, but it is reported to occur in dry areas ⁽²⁾, and has been collected under stones, rocks, logs, vegetation and even human rubbish ^{(4) (8)}.

Excitable delma status

The excitable delma has yet to be classified by the IUCN.

Excitable delma threats

There are not known to be any major threats to the excitable delma at present.

Excitable delma conservation

There are no specific conservation measures currently known to be in place for the excitable delma, and this unusual lizard is not listed on Australia’s Environmental Protection and Biodiversity Conservation Act. However, all reptiles are protected on Barrow Island, off the coast of Australia, where the excitable delma is known to occur ⁽⁸⁾.

Find out more

Find out more about the excitable delma and its conservation:

• Moro, D. and MacAulay, I. (2010) A Guide to the Reptiles and Amphibians of Barrow Island. Chevron Australia, Perth. Available at:
  http://www.chevronaustralia.com/environment/protectingenvironment/nature-books.aspx

More information on conservation in Australia:

• Australian Wildlife Conservancy:
  http://www.australianwildlife.org/
• Australian Conservation Foundation:
  http://www.acfonline.org.au/

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Glossary

Invertebrates

Animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.

Vestigial

Describing a structure or organ that has diminished in size, through evolution, to the point where it no longer functions. Only traces may remain.

References

1. The Reptile Database (November, 2012)
   http://reptile-database.reptarium.cz/search.php
2. Wilson, S. (2005) A Field Guide to Reptiles of Queensland. Reed New Holland, Sydney.
3. Maryan, B., Aplin, K.P. and Adams, M. (2007) Two new species of the Delma tincta group (Squamata: Pygopodidae) from northwestern Australia. Records of the Western Australian Museum, 23: 273-305.
4. Kluge, A.G. (1974) A taxonomic revision of the lizard family Pygopodidae. Miscellaneous Publications, Museum of Zoology, University of Michigan, 147: 1-221.
5. Wilson, S.K. (2012) Australian Lizards: A Natural History. CSIRO Publishing, Collingwood, Australia.
6. Kluge, A.G. (1976) Phylogenetic relationships in the lizard family Pygopodidae: an evaluations of theory, methods and data. Miscellaneous Publications, Museum of Zoology, University of Michigan, 152: 1-72.
7. De Vis, C.W. (1888) A contribution to the herpetology of Queensland. Proceedings of the Linnean Society of New South Wales, 2(2): 811-826.
8. Moro, D. and MacAulay, I. (2010) A Guide to the Reptiles and Amphibians of Barrow Island. Chevron Australia, Perth. Available at:
   http://www.chevronaustralia.com/environment/protectingenvironment/nature-books.aspx
9. Bauer, A.M. (1986) Saltation in the pygopodid lizard, Delma tincta. Journal of Herpetology, 20(3): 462-463.