The importance of the application of non-invasive techniques in the study of wild animal reproduction

RESUMO

Conservation of biodiversity is one of the major goals of the scientists in many countries. Brazil is one of them and is also well known as the world's largest reserve of biodiversity, which leads to a strategic position in this matter. In the last decade a number of scientific works were published with an increasing participation of Brazilian researchers. One of the keys, besides environmental protection, for the successful conservation of endangered species is reproduction; and the first step is to know how the species function. Traditionally the study of reproductive physiology in wild animals depends on some kind of restrainning, either physical or chemical, which implies different levels of stress. Serial blood sampling necessary to obtain some hormonal profiles are also stressful, unless the animal was trained to accept that procedure, which is hard or even impossible to achieve with some wild species. For that reason some non-invasive techniques were developed, i.e. extraction and measurement of fecal and urinary hormonal metabolites, utilizing radio immune assay (RIA) or enzymatic immune assay (EIA). Different methods of extraction were tested in order to achieve lower costs and reliable results; and validation of the immune assays with different antibodies for a number of wild species were performed with the same purpose. These non-invasive methods for the study of reproductive physiology can be used in free-living and captive wild species as a very useful tool for conservation.