Summary of Recommendations

Priorities for recommended conservation action on behalf of West Indian iguanas are summarized in Table 5. In the subsections that follow, specific guidelines for implementation are outlined. For the majority of taxa, further survey work is required in order to design effective management and recovery plans. For some taxa, existing data are outdated, while for others only a limited part of the range has been adequately documented. In other cases, populations are known to be declining, but quantitative data on rates of population change and their demographic effects are lacking. For all taxa, population monitoring in the form of standardized annual or biannual surveys is critical to updating conservation priorities and to detecting population declines before they have significant demographic impacts and while management intervention is still a viable option.

Many West Indian iguanas remain without adequate protection, either because no habitat has officially been set aside for them or because existing legislation is only sporadically enforced. To insure the survival of all taxa, at least enough suitable habitat to support a minimum viable population should be protected by national law in each country of origin. Because the biology of these iguanas varies considerably across taxa, particularly in terms of social structure and reproductive ecology, as does the carrying capacity of the islands they inhabit, the amount of habitat required for adequate protection will need to be determined on a taxon-by-taxon basis.

Control of introduced mammalian predators and livestock removal are two activities which are crucial to the survival of many West Indian iguanas. For almost all taxa inhabiting larger islands, dogs and cats are having devastating consequences, particularly for juveniles. The recent introduction of black rats to several iguana-inhabited cays in the Bahamas is also cause for great concern. Because these iguanas have evolved in the absence of mammalian predators, they have no natural defenses against them and population declines can occur with alarming rapidity. On at least some islands, browsing by feral livestock has radically affected the vegetation structure and altered the diversity and palatability of food plants available to iguanas. In addition, trampling of nest and burrow sites by livestock is a serious problem.

Basic research is critical to many if not all of the proposed conservation initiatives for West Indian iguanas. In order to conserve and potentially augment wild populations, it is necessary to have enough life history data from wild populations to predict the long-term effects of management strategies before they are implemented. Such data are critical to assessing the carrying capacity of proposed reserve sites, and to determining if and when reintroduction or translocation is warranted and feasible. Population modeling, particularly to estimate minimum viable population sizes and to explore the effects of headstarting, is crucial to designing practical conservation strategies that will have a high probability of success. Behavioral studies are needed to understand the conservation implications of variation across populations and to assess the influence of human impacts. Finally, a complete study of phylogenetic relationships among West Indian iguanas, including both molecular genetic and morphological data, is a necessary beginning in order to adequately rank priority projects and conservation initiatives. The availability of such data will contribute toward a better understanding of adaptive trends within the group and permit informed extrapolations from one taxon to another to be made.

For virtually all taxa of West Indian iguanas, public education is essential. Without effective education at the local, national, and international levels, other conservation initiatives are likely to prove futile. For West Indian iguanas, educational needs range from discouraging people from feeding, hunting, and transporting iguanas between islands, to inspiring local and national pride for these impressive lizards and their unique habitats. Raising public awareness regarding the vulnerability of iguanas to dogs, cats, pigs, and livestock is critical to preventing their intentional introduction to new islands.

Captive breeding programs are recommended for five of the West Indian iguanas ranked as Critically Endangered. Because these taxa have experienced significant population reductions, documented low population size or a severely restricted range, or an extinction probability of at least 20% within five generations, a captive reservoir is imperative as insurance in the event of extinction in the wild. While such programs have already been undertaken for two Critically Endangered taxa (Jamaican and Grand Cayman iguanas) and are in the planning stages for a third (Ricord's iguana), they still need to be implemented for two others. A captive program to gain husbandry expertise has also been recommended for the Lesser Antillean iguana. For those taxa for which reduced juvenile recruitment due to unnatural causes is known to be a severe threat to survival of the wild population (Jamaican, Grand Cayman, and Anegada iguanas), headstarting programs, in conjunction with rigorous predator control, are recommended as an interim measure to allow for population recovery.