Avaliação do estado de conservação da população urbana de Boa Constrictor (serpentes) em Manaus, Amazônia brasileira

Abstract

Currently almost 1/5 of the species of reptiles are endangered in the world. In this imminent scenario of biological loss, the rapid growth of human population and urban density are considered global threats to reptilian diversity by the destruction, modification and homogenization of the natural environment, far beyond the boundary of the municipality. In the urban landscape in expansion, snakes are among the reptiles impacted primarily due to their ecological and behavioral quirks, which often trigger fear in western human. Manaus, the most populous city of the Amazon biome, since the first decade of the XXI century has accelerated the expansion of the urban area in a disorderly manner on the surrounding continuous forest. Among vertebrates directly affected by this process of degradation of habitat is the jiboia (Boa constrictor). This snake, although it can reach up to 4.2 m in total length, can persist in modified environments and has been one of the vertebrates with the largest number of rescues by power public in Manaus in the last decade. Between 09/2010 and 11/2012 were evaluated 222 specimens of B. constrictor that were rescued in the urban area of the capital of Amazonas. The high frequency of individuals in basically all sizes / ages, of both sexes and distributed throughout the urban area of Manaus indicated that the capital of Amazonas still contains a robust population of B. constrictor. There wasn t relationship between the accumulated rainfall in the last 24 hours and the occurrence of rescues, indicating that the B. constrictor in Manaus aren t simply carried by heavy rain, which would favor its viewing by residents and triggering the rescue. On the contrary, the rescue rate appeared to reflect seasonal movement of the target species, and the monthly precipitation explained 45% of the variance in the number of B. constrictor rescued in the respective months. The sex ratio (male / female) overall was 0.7, indicating general trend skewed towards females, which also remained in the sex ratio (0.8) between the administrative areas of Manaus. Greater number of redemptions (55%) occurred in the city that has greater connectivity with continuous forest. It was also confirmed that the population of B. constrictor in the urban area of Manaus is mainly infested by Amblyomma dissimile and secondarily by Amblyomma aff. rotundatum. The prevalence and mean intensity (n° total of tick / n° total of snakes) high in all administrative areas, and over the months in Manaus, indicated that the infestation is apparently chronic throughout the city, throughout the year. The absence of a clear relationship between the surface area and the number of residents to the number of rescues of B. constrictor by administrative area of Manaus was not expected, and showed how the rescue effort public can be a unique opportunity to obtain robust information on the biology, ecology and conservation status of cryptic species like jiboia - Boa constrictor.