Baja California legless lizard (Anniella geronimensis)

Description

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Baja California legless lizard fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Baja California legless lizard description

The Baja California legless lizard (Anniella geronimensis) is a secretive reptile that looks very much like a snake in appearance.  However, both snakes and legless lizards have evolved the legless trait independently from each other. The Baja California legless lizard can be distinguished from snake species by its moveable eyelids, and can even be seen blinking in good light. Unlike snakes, it is unable to flex its jaws to swallow something larger than its own head ⁽²⁾.

The Baja California legless lizard has smooth, glossy scales which vary in colour from silvery-grey to black, with multiple black stripes and a belly which is lighter in colour. The Baja California legless lizard has a shovel-shaped snout and a blunt tail, which are adapted to suit its burrowing lifestyle ^{(2) (3)}.

Size

Length: 10 - 16.5 cm ⁽²⁾

Baja California legless lizard biology

The Baja California legless lizard gives birth to one to two live young, which develop as embryos inside the female’s body before being born. Breeding takes place during late spring and early summer, with the young born in September, October and even November ^{(2) (3)}.

There is little information on the daily habits of the Baja California legless lizard. However, other species in the genus Aniella are known to be tolerant of relatively low temperatures allowing them to remain active in moist, cool, coastal habitats ^{(4) (6)}.

Species of the genus Aniella primarily feed on insects, spiders and insect larvae ⁽²⁾.

Baja California legless lizard range

The Baja California legless lizard is endemic to the Pacific peninsula of Mexico, occurring only on the western side of the state of Baja California. It occupies a narrow strip just 87 kilometres long, ranging from a few miles north of Colonia Guerrero, south to the vicinity of Punta Baja. It has also been found to inhabit the small Pacific island of Isla San Gerónimo ^{(1) (3)}.

Baja California legless lizard habitat

The Baja Californian legless lizard is restricted to the sand dunes of coastal regions, where it burrows into fine-grained sand to avoid detection by predators. It has adapted to a life underground, preferring warm and moist conditions ⁽⁴⁾. The Baja Californian legless lizard is commonly found at the base of plants present on the coastal dunes such as brittlebush (Encelia sp.), bursag (Ambrosia sp.) and locoweed (Astragulus sp.) ⁽¹⁾.

Baja California legless lizard status

The Baja California legless lizard is classified as Endangered (EN) on the IUCN Red List ⁽¹⁾.

Baja California legless lizard threats

Coastal tourist development, road building, intensification of agriculture (in particular the use of pesticides), use of off-road vehicles and general urbanisation all threaten the sand dune ecosystem which the Baja California legless lizard inhabits ⁽¹⁾.

Baja California legless lizard conservation

There are no specific conservation measures currently in place for the Baja California legless lizard. However, changes in the abundance and distribution of this species need to be recorded through the monitoring of its populations, and protected areas are urgently needed for its survival ⁽¹⁾.

Like closely-related species, the Baja California legless lizard may potentially benefit from habitat restoration through the replacement of exotic plants with native communities ⁽⁵⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

Learn more about reptile conservation:

• International Reptile Conservation Foundation:
  http://www.ircf.org/

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

This species information was authored as part of the ARKive and Universities Scheme.

Glossary

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Genus

A category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.

Larva

Stage in an animal’s lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.

Perennial

A plant that normally lives for more than two seasons. After an initial period, the plant produces flowers once a year.

References

1. IUCN Red List (August, 2011)
   http://www.iucnredlist.org/
2. Stebbins (2003) A Field Guide to Western Reptiles and Amphibians. (Third Edition). Houghton Mifflin Company, New York.
3. Shaw, C.E. (1953) Anniella pulchra and Anniella geronimensis, sympatric species. Herpetologica, 8: 167-170.
4. Brucebury, R. and Balgooyen, G. (1976) Temperature selectivity in the legless lizard, Anniella pulchra. Copeia, 1: 152-155.
5. Kuhnz, L.A., Burton, R.K., Slattery, P.N. and Oakden, J.M. (2005) Microhabitats and population densities of California legless lizards, with comments on effectiveness of various techniques for estimating numbers of fossorial reptiles. Journal of Herpetology, 39: 395-402.
6. Fusari, M.H. (1984) Temperature responses of standard, aerobic metabolism by the California legless lizard, Anniella pulchra. Comparative Biochemistry and Physiology, 77: 97-101.