Guatemalan spiny-tailed iguana (Ctenosaura palearis)

Also known as: paleate spiny-tailed iguana
Spanish: Garrobo del Motagua, Iguana de Órgano, Iguana de Tuno
GenusCtenosaura (1)
SizeMale total length: up to 61 cm (2)
Female total length: up to 51 cm (2)

The Guatemalan spiny-tailed iguana is classified as Endangered (EN) on the IUCN Red List (1).

This species belongs to the group of spiny-tailed iguanas of Mexico and Central America, (genus Ctenosaura), which are united by the possession of a spiky tail that can be used to defend itself (2). The Guatemalan spiny-tailed iguana has a relatively slender body that is greyish-brown with some blackish banding. It also exhibits a large dewlap, (a flap of skin that lies under the chin), that is more conspicuous in adult males than females, and a row of flattened spines runs along the centre of the back. Until 1997, the Guatemalan spiny-tailed iguana was considered the same species as Ctenosaura melanosterna, the Rio Aguan Valley iguana, but they were separated based on a number of differences in appearance (3).

Occurs in the valley of the Río Motagua in south-eastern Guatemala, at elevations between 150 and 250 metres (3) (4).

The Guatemalan spiny-tailed iguana is known to inhabit tropical dry forest in arid river valleys (1) (5), where it prefers rocky terrain (1).

The Guatemala spiny-tailed iguana is a semi-arboreal species that rests in hollow branches or rock crevices (1). Like all iguanas, this species is active during the day (6), and will only venture out from its shelter in the morning once temperatures have reached comfortable levels (2). As a cold-blooded animal, the Guatemalan spiny-tailed iguana will find a nearby sunny area where it will bask in the sun’s warmth until the optimum body temperature is reached (2); it can them begin the task of feeding.

The Guatemala spiny-tailed iguana is primarily a herbivore that feeds on plant material, but it may also occasionally capture small animal prey. Should it become threatened by the presence of a predator, the spiny-tailed iguana will rapidly flee to take refuge in a branch or rock crevice again (2).

During the breeding season, male spiny-tailed iguanas pursue females. When a female is caught, the male pins the female down with its front legs and holds her neck in its mouth and proceeds to copulate. Eight to ten weeks after mating, the female lays eggs into a nest she has dug into the ground (2). Like other iguanas, spiny-tailed iguanas exhibit no parental care, and the female will leave the nest once she has laid her eggs (6). Around 90 days later, the eggs hatch and the newly hatched iguanas must dig their way out of the underground nest (2).

In the past, the Guatemalan spiny-tailed iguana has been heavily hunted for both food and the international pet trade (2). Collection for the pet trade continues today, but is not believed to pose such as serious threat as habitat loss (1). The conversion of forest habitat into agricultural land is the greatest threat to the survival of the Guatemalan spiny-tailed iguana (1) (7); the impacts of which are exacerbated by this species’ restricted distribution. (1).

The Guatemalan spiny-tailed iguana does not currently receive any legal protection and is not known to occur within any protected areas, and thus action to prevent its extinction in the wild is clearly urgently needed (1). In 2007, the International Iguana Foundation initiated a campaign to raise funds for an Iguana Specialist Group workshop, aimed at the spiny-tailed iguanas, and to implement recommended conservation actions that arise from that workshop (7). Captive populations of the Guatemalan spiny-tailed iguana exist in several zoos around the world (1), which may act as an insurance against this species’ entire extinction, yet this does not lessen how devastating it would be to lose this armoured reptile from the wild.

For further information on spiny-tailed iguanas and their conservation see:

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:

  1. IUCN Red List (June, 2011)
  2. West Coast Iguana Research (March, 2008)
  3. Buckley, L.J. and Axtell, R.W. (1997) Evidence for the specific status of the Honduran lizards formerly referred to Ctenosaura palearis (Reptilia: Squamata: Iguanidae). Copeia, 1997(1): 138 - 150.
  4. Burghardt, G.M. and Rand, A.S. (1982) Iguanas of the World: Their Behavior, Ecology, and Conservation. Noyes Publications, Park Ridge, New Jersey.
  5. Bosch, H. and Werning, H. (1991) Green Iguanas and other Iguanids. TFH Publications, New Jersey.
  6. Halliday, T. and Adler, K. (2002) The New Encyclopedia of Reptiles and Amphibians. Oxford University Press, Oxford.
  7. International Iguana Foundation (March, 2008)