Lizards 7: Utila Iguana

Currently the second largest species of lizard in the Bristol Zoo collection, the Utila iguana Ctenosaura bakeri is also one of the most threatened, as it is currently classed by the IUCN as Critically Endangered. Part of the reason for this is its microscopically small range – it is confined to around 8 sq.km of mangrove swamp on Utila island, off the north coast of Honduras. There are currently 15 recognised species of Ctenosaura, with a natural distribution ranging from Baja California and Mexico south to Colombia, although 2 species have been introduced to Texas and Florida.

 Ctenosaura spp. ranging in size from 12.5cm up to over 1m in C.pectinata and C.similis. With a maximum length of 76cm in males Utila iguanas are among the larger of the group. As with other iguanas, they are almost entirely herbivorous, feeding on leaves, flowers, and fruit, but they will also take some animal prey in the form of insects and smaller lizards. They are quite secretive, resting in holes in mangrove trees for much of the time. 

Utila iguanas have a problem when it comes to reproduction. They cannot lay their eggs in the mangrove swamps, so females leave the forest to lay them instead in sand in drier areas nearby, before returning to their mangrove homes. Incubation takes around 70 days, and once they dig their way to the surface they travel to the mangroves where they spend the first year of their lives on the ground, taking to the trees as they grow older.

Conservation efforts for Utila iguanas on the island are headed up by the Iguana Research and Breeding Station, which is supported financially by Honduran and international agencies. Utila is popular with divers, which creates pressure from tourist development. For more on conservation on the island, see the IRBS website here: http://www.utila-iguana.de/index.php

At Bristol, there is a pair on show. They have successfully bred this species in the past, so it is hoped that they will do so again in the future. The zoo populations provide a safety net for the wild populations, but at present the animals on show at Bristol and other zoos mainly provide publicity for the species and the conservation work on the island itself.

(images are mine)