Perspectivas e avanços sobre o emprego de técnicas de marcação e recaptura para fauna silvestre

Abstract

The methods of marking and recapturing animals are essential in monitoring and collecting ecological data. Given the different applicability and characteristics of the developed methods, some authors have listed prerequisites to be taken into account when choosing the technique which application values animal welfare and non-interference in the observed results. However, there are questions about the universalization of these prerequisites when applied to general fauna, since there are decisions to be taken at more specific scales, such as species-specific factors, study focus, study location and absence of marking tests that can propagate alternative techniques to different taxa, which can interfere with the different forms of adhesion of the methods by researchers. Therefore, we aimed to carry out a systematic review to unravel the patterns associated with the use of marking and recapture techniques (Chapter I) for vertebrates and invertebrates. To this end, we surveyed articles and analyzed the relationship between aspects associated with the studies and reported marking techniques. We found 312 articles that reported 24 general techniques. There were significant relationships between species-specific aspects analyzed, thematic and biogeographical aspects, advantages and disadvantages of the methods and aspects related to the techniques. We verified that some advantages and difficulties in the use of techniques can behave in a specific way in taxa, and the same happened for disadvantages. We built a guideline with considerations based on the characteristics of the techniques and their performance for each step of defining future studies. In addition to this chapter, we carried out an experimental study to verify the effectiveness of the photoidentification technique, a method for which in the first chapter we verified great potential for applicability, by using the frog species Dendropsophus elegans as a model (Chapter II), in the Parque Estadual de Dois Brothers (PEDI), in Recife (PE, Brazil).We hypothesized that, in the field, the performance of the photoidentification technique would be faster and less invasive compared to elastomers, as well as the identification aided by software would overcome manual comparisons and identification by previous marking with elastomers in recognizing captured individuals. During eight months, at PEDI, we marked and recaptured individuals of D. elegans by photoidentification of natural marks and by elastomers. Then, we compared the recognition of individuals by manual photo identification, aided by software and elastomers. As a result, the accuracy of the techniques was similar, with high rates of correct matches. The time for applying the photoidentification was equivalent to half the time spent for applying the elastomers. The time for software-assisted photo identification was the shortest recorded. The difference in the occurrence of defense behaviors exhibited by individuals marked by the two techniques in the field was not significant, although we report some different behaviors for each technique. These results may indicate that photo identification can be an accessible, fast, efficient and a less invasive alternative for population monitoring of anuran species.