Utila spiny-tailed iguana  (Ctenosaura bakeri)

The Utila spiny-tailed iguana is classified as Critically Endangered (CR) on the IUCN Red List (1).

Once considered one of the rarest iguanas in existence, the Utila spiny-tailed iguana (Ctenosaura bakeri) is named after the single island it inhabits and the whorls of enlarged spiny scales that encircle the tail (2). The colour of adult Utila spiny-tailed iguanas varies from light grey to dark grey-brown, often with an attractive turquoise tinge (3). All juveniles, however, are a uniform grey-brown (3).

Male Utila spiny-tailed iguanas are not only larger than females, but also have larger spines running down the back and a small fold of loose skin hanging below the throat (the dewlap) (3).

The Utila spiny-tailed iguana is endemic to the island of Utila in the Bay Islands, Honduras. On this island, the Utila spiny-tailed iguana occurs in just one small area of mangrove forest, covering only eight square kilometres (1).

The Utila spiny-tailed iguana inhabits mangroves and nests on the beaches of Utila, where females select areas largely free of vegetation to nest (1) (3). Adults are often found in mangrove trees, while juveniles inhabit the mangrove forest floor and smaller mangrove trees and shrubs (1).

The Utila spiny-tailed iguana feeds on plant matter and small invertebrates that inhabit the mangroves. While mangrove habitat is perfect habitat for feeding and resting, it is not ideal for nesting, and so when the time comes, female Utila spiny-tailed iguanas migrate to the island’s beaches, where they lay their eggs in the sand (3).

The tiny distribution of the Utila spiny-tailed iguana makes it incredibly vulnerable to any threats. Currently, those threats come in the form of habitat degradation and hunting. As tourism on the island of Utila increases, the mangrove forest habitat of the spiny-tailed iguana is being cleared for the construction of houses and marinas, and used as a garbage dump site (1). Beaches are also being affected, with some beaches being sold for the development of houses, hotels and road construction, and other beach areas becoming covered with introduced invasive plants, creating a habitat unsuitable for egg-laying (1). In addition, despite being protected by Honduran law, this rare reptile is still hunted locally for its meat (1).

Tremendous conservation efforts have been initiated for the Utila spiny-tailed iguana in an attempt to prevent its extinction. In 1994, the Frankfurt Zoological Society and the Senckenberg Nature Research Society together initiated work to preserve the Utila spiny-tailed iguana. As well as conserving the iguana and its mangrove habitat, the project aimed to promote the sustainable development of the island and create environmental awareness among the local inhabitants (3).

In 1998, the Iguana Station was constructed, providing a centre for environmental education efforts, ecological research and captive breeding (3). Pregnant females are brought to the Iguana Station to lay their eggs, which are then artificially incubated. Incubation in this protected, controlled environment ensures the greatest possible number of eggs hatch. The young are raised in captivity for two years before being released back into the swamps (4).

The captive breeding programme has been extended to other zoos around the world, for example, in 2007, nine Utila spiny-tailed iguanas hatched at ZSL London Zoo (5). This helps ensure the long-term survival of the species, should something devastating occur in the wild. These incredible efforts need to continue if the future of this species is to be secured.

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

For further information on the conservation of the Utila spiny-tailed iguana see:

• Conservation Project Utila Iguana:
  http://www.utila-iguana.de/