Escaping the cats' clutches gives the Anegada iguana a good "headstart"


IUCN - The World Conservation Union, Gland, Switzerland, 7 October 2005 - A grant from the Sir Peter Scott Fund for Conservation Action of IUCN’s Species Survival Commission (SSC) is helping to continue the early conservation successes in the fight to save the Anegada iguana, listed as “Critically Endangered” on the IUCN Red List of Threatened Species.

This impressive one metre long vegetarian has suffered an 80% population crash since the late 1960s because of extensive habitat degradation from free-ranging cattle and goats, coupled with feral cat predation. Now fewer than 300 lizards remain.

Formerly distributed throughout the Puerto Rican island chain, the last remaining population is only found on the tiny island of Anegada in the British Virgin Islands, and the iguana may have disappeared completely if positive action, instigated by the SSC’s Iguana Specialist Group, had not been taken.

Researchers discovered very few young iguanas were reaching adulthood because most were being eaten by feral cats, leaving an ageing population restricted to a fraction of its former range.

To overcome the lack of juvenile recruitment, an innovative headstarting programme was developed in 1997, as a short-term solution and stop-gap measure. This involves collecting and rearing hatchling iguanas in captivity and then releasing them into the wild when they are too large to be killed by feral cats.

Young iguanas being fed in the headstarting facility -photo courtesy of the SSC Iguana Specialist GroupThe headstarting facility has been a lifeline for the Anegada iguana and a portion of the grant will go to maintaining and monitoring the success of the release programme.

So far a total of 48 iguanas have been released and another 24 should be released this October. Survival rates are very encouraging (84%) and with each release smaller animals are freed to determine the smallest size that can survive in the presence of feral cats. This will help optimize the headstarting facility by reducing the time the hatchlings need to spend in captivity.

For the latest planned release, iguanas in the 450 g size class, the smallest yet, will be tested. Internal radio transmitters were implanted in the third week of September by a veterinary team from Fort Worth Zoo and the Wildlife Conservation Society. In early October a field team from Dallas and San Diego Zoo will coordinate the releases with staff from the BVI National Parks Trust.

Local Anegadan islander helping with the release of young iguanas from the headstarting facility - photo courtesy of the SSC Iguana Specialist GroupRaising local awareness and building support for these conservation efforts is another cornerstone of the Anegada iguana conservation strategy. To this end a newsletter has been circulated around the island and a follow-up survey showed that it is having a positive impact. With the help of the grant, other promotional materials are planned.

An equally high priority is the involvement of local schools and a portion of the grant will be used to initiate a series of presentations by scientists to teachers and students and to encourage students to engage in the science of iguana recovery.

Tackling the fundamental reasons for the iguana's decline is the only way to guarantee its long-term survival. To achieve this, a Species Recovery Plan for the next five years has been drafted between the parties concerned, and will soon be ready to move into the implementation phase. Sir Peter Scott funding will help with the production costs.

In addition to further development of the headstarting facility, key elements of the Recovery Plan will include removal of feral cats, as well as the removal and control of introduced livestock that have dramatically altered the natural vegetation on which the iguanas feed.

For further information contact:

Anna Knee or Andrew McMullin, IUCN Species Programme Communications Officers
Tel: +41 (0)22 999 0153
Email: or

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