social and economic problems, but an understanding of the biological functioning of the system is a prerequisite to amelioration of such problems.

The slash-and-burn farmer is perhaps the principal agent of rain forest destruction, and it is commonplace to hear that he must be stopped. The key question is: “How to stop him?” Simply enacting legislation that would prevent him from further cutting cannot work, for the need for food grows with the blossoming population, and slash-and-burn is the only proven way of exploiting the land. It will continue until suitable alternatives are provided.

In the search for alternatives to destruction, four major projects were selected by STRI researchers, who believe that their knowledge of the species involved combined with the possibilities of finding less destructive crops could be productive. These projects are management of the green iguana, captive breeding of the paca, forest gardening or experimentation with crops that cause minimum perturbation in the existing forest, and management of game mammals. It was, of course, realized that quick fixes can not be expected in the face of so many complex problems, but success in even one or two projects could contribute greatly toward decreasing the seriousness of those problems.

MANAGEMENT OF THE GREEN IGUANA (IGUANA IGUANA)

For over two decades, basic research at STRI has led to great increases in knowledge of the biology of the green iguana (Burghardt and Rand, 1982). Formerly a wide-ranging reptile, and prized as a protein source for more than 7,000 years, this animal is now drastically decreasing in numbers due to habitat destruction from slash-and-burn farming, conversion of forested lands to pasture, increased use of biocides, and uncontrolled hunting. Through much of the natural range of the green iguana, there is a widespread belief that the about-to-be-laid eggs have aphrodisiac properties, and the gravid females, which are easily discovered as they converge on traditional, communal nesting areas, are especially vulnerable.

An early goal in this project was to reduce egg and hatchling mortality. Eggs laid in the wild have about 50% hatching success, and only 5% of the hatchlings survive their first year. Techniques developed at STRI have yielded captive hatching success in excess of 95%. Moreover, survival to the yearling stage is near 100%. Captive-raised hatchlings are fed a low-cost, high-protein diet and gain weight twice as fast as wild iguanas. An artificial nest developed by STRI to facilitate egg collection is preferred by both wild and captive females over nests of their own construction. Techniques developed at STRI ensure production of a predictable number of young iguanas and their regulated multiplication in captivity (Werner, 1986).

Several new directions, including studies of nutrition and disease control, as well as experimental releases of yearlings into the wild, are now being explored. In December 1985, reintroduction experiments using 1,200 7- to 10-month-old, captive-raised iguanas were begun in appropriate habitats in rural communities. Their survival from the age at which they were released appears to be comparable to that of wild-born animals. The repopulation experiment is accompanied by an education project designed to encourage rational resource management and to



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