Motagua Spiny-tailed Iguana
Ctenosaura palearis
IUCN Status: Endangered
Range: Southeastern Guatemala
Population: Unknown, estimated less than 2,500
Size: Average length 8.1 inches in males and slightly smaller for females from snout to vent, 16–17 inches total, average weight ~6.5 ounces
Threats: Over-harvesting for bushmeat; habitat loss by conversion of forest to crops; illegal trade
Conservation Measures

The Motagua Spiny-tailed Iguana (Ctenosaura palearis) is endemic to Guatemala and is listed as Endangered by the IUCN Red List of Threatened Species and is protected under CITES Appendix II. This iguana is restricted to the last remnants of seasonally dry tropical forest in the Motagua Valley in eastern Guatemala, and is thought to occupy an area less than 0.4 square miles. The total population size is not known, but based on population density data from one well-studied location (Heloderma Natural Reserve) and assuming uniform distribution across its area of occupation, the total population is estimated to be ~2,500 adult individuals. This iguana is particularly associated with the Pitayo Organ Pipe Cactus (Stenocereus pruinosus) and plays a key role in its dispersal, as seeds eaten by the iguana show a significant increase in germination success.

At this time, the main threat for Motagua Spiny-tailed Iguanas is over-harvesting by local villagers for bushmeat. Habitat loss is a also a problem for the iguana, primarily due to the increased production of melon crops and the construction of new residential zones within the Motagua Valley. Interviews with local people describe a dramatic decrease in the wild iguana population over the last 20 years. It is also known that illegal trade of the Motagua Spiny-tailed Iguana has occurred.
In situ conservation strategies are taking place in the Motagua Valley. Part of the population is protected within the Heloderma Natural Reserve (HNR), managed by the Guatemalan non-profit organization Zootropic. With IIF funding support, scientific research by Zootropic is assessing the movement patterns, home range, and population genetics of the species in the valley, in collaboration with the Universidad del Valle de Guatemala and Universidad de San Carlos de Guatemala. An education program with children and teachers in elementary schools from eight rural communities surrounding the HNR has been carried out by Zootropic with the support of IIF since 2016, and has reached more than 1,500 children.
Reports from the Field
IIF Grants Received