Spatial and population ecology of giant anteaters (Myrmecophaga tridactyla) in a Cerrado Ecological Station, São Paulo, Brazil

Author(s)

Alessandra Bertassoni

• Document type: Doctoral Thesis
• Press: São José do Rio Preto. 2017-08-07.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências Letras e Ciências Exatas. São José do Rio Preto
• Defense date: 2017-06-23
• Advisor: Rita de Cassia Bianchi

Abstract

Giant anteaters (Myrmecophaga tridactyla) are mammals with a wide range and their populations are threatened by several causes, which have led to the inclusion of the species in international, national and regional red lists. This large-sized species feeds exclusively on social insects, contributing to ecosystem dynamics. Despite its importance, the species is poorly known, mainly in what concerns the ecological understanding of populations in areas with anthropogenic influence. The goals of this study were (i) to estimate the home range and core areas of giant anteaters at an Ecological Station with Cerrado habitat influenced by anthropogenic actions, as well as to investigate the spatial organization of the individuals, (ii) to identify the habitats that compose their home ranges and, to evaluate multi-scale habitat selection, (iii) to test a method of individual identification using camera traps, and use it to analyze population trends. Eight giant anteaters were tracked by GPS-Iridium, seven of them concomitantly from May to September 2015 at Santa Bárbara Ecological Station - SBES. Home range and core area were estimated at 3.41 km² and 0.65 km², respectively. Males had a larger home range and were more active than females. The range overlap was low, and the home ranges of males and females overlapped. Males and females were in proximity to each other. Habitat selection was directed to savannas, while exotic forestry areas were avoided. To test a method of individual identification, fur marks were used as diagnostic characters in photos taken by 18 camera traps. The population size was estimated at 16 giant anteaters and its density at 0.4 ind/km². Population trends were simulated under different scenarios resulting in a drastic future to giant anteaters of SBES. The species is, probably, incapable to persist in areas composed only by altered habitats. The low probability of survival of the population calls special attention. Measures to mitigate anthropogenic impacts on the giant anteater should be established. (AU)

• FAPESP's process: 13/04957-8 - Landscape use by giant anteater (Myrmecophaga tridactyla) by satellite monitoring in Estação Ecológica de Santa Bárbara, São Paulo State, Brasil
• Grantee: Alessandra Bertassoni da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate