Cyclura nubila caymanensis

Sister Islands
Rock Iguana


IUCN Status: Critically Endangered
Range: Little Cayman and Cayman Brac, Cayman Islands
Population: ~2,000–4,000
Size: Males: snout to vent length up to 2 feet, 24.3 pounds. Females: snout to vent up to 1.6 feet, 10.5 pounds
Threats: Habitat destruction from road construction and development; feral and free roaming cats and dogs; road mortality.

Species Information

  • This Critically Endangered subspecies of Cyclura nubilais found only on Little Cayman and Cayman Brac – two small islands situated about midway between Grand Cayman and Cuba.
  • Due to its relatively undisturbed quality, Little Cayman supports the more robust population of Sister Islands Rock Iguana, while the comparatively developed Cayman Brac hosts an extremely reduced population (<200 mature adults).
  • Both populations are suspected to be in decline, with expanding island development exacerbating pressures of habitat degradation, predation by feral mammals, road traffic, and interaction with non-native species.
  • In August 2016, a hybridization event between a male Rock Iguana and a non-native female Common Green Iguana raised new concerns about biosecurity on Little Cayman. A local program of the Little Cayman National Trust, Green Iguana B’Gonna, has been working diligently since 2012 to raise public awareness and eradicate this invasive species on Little Cayman.
  • In 2012, the Little Cayman National Trust purchased a major communal nesting site on the west end of Little Cayman and began distributing “Iguana Crossing” signs at high traffic areas around the island in cooperation with the Cayman Islands Department of Environment (DoE).
  • Ongoing efforts headed by the Cayman Brac National Trust, the DoE, and collaborators are aimed at raising public awareness, identifying remnant nesting sites, and evaluating population genetic health.

IIF Grants Received

2016 Grant $7,835

Population Trends and Age-dependent Survivorship in Cyclura nubila caymanensis on Little Cayman: an Ongoing Study in Conservation Biology

Jeanette Moss


2015 Grant $9,150

Mark-recapture Study and the Use of Radio Telemetry to Investigate Nest-site Selection of Cyclura nubila caymanensis on Little Cayman

Jeanette Moss


2014 Grant $4,350

Nesting Ecology of Cyclura nubila caymanensis on the Sister Islands, Little Cayman, and Cayman Brac

Jeanette Moss


Reports from the Field