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At least 30% of the population of this mammal has been lost in the last ten years due to changes in habitat, trampling, hunting, among others.

The giant anteater is a "vulnerable" animal that, in the state of São Paulo, is threatened with extinction: at least 30% of the population of this mammal has been lost in the last ten years, due to the loss and alteration of its habitat, being run over, hunting, burning, conflicts with dogs and the use of pesticides.

This was the conclusion of the doctoral thesis by biologist Alessandra Bertassoni, from the São Paulo State University (Unesp) in São José do Rio Preto, with support from the São Paulo State Research Support Foundation (Fapesp).

“The impacts of human action increase the species' vulnerability and raise the level of threat,” said Bertassoni to the Press and Communication Department at Unesp. The study was carried out at the Santa Bárbara Ecological Station (EESB), near the city of Avaré, in the interior of São Paulo, one of the largest conservation units in the Cerrado region of São Paulo.

According to the researcher, in the worst-case scenario, with the continuation of cases of being run over, hunting and burning in the forest, “the possibility of the population to survive drops to 20 years. If the fire used in the burnings is suppressed, the viability will be 30 years”.

This estimate was possible because the biologist worked with the individual recognition of eight giant anteaters and assessed the number of these animals in the EESB. Until then, there was no estimate of the population size for the species in the State of São Paulo.

To monitor the giant anteaters, Bertassoni used the GPS (Global Positioning System) in eight animals for approximately 91 days. The device enabled free-living control of these mammals, revealing the size of the area used by them; sharing geographic space; the way they interact; and the areas preferentially used or even underutilized by the species.

She says that females monitored by GPS showed a more restricted behavior, with smaller mobility areas than males, using only the habitats within the boundaries of the protected area.

The males had a more exploratory behavior: they crossed roads and spent days outside the station, mainly in the legal reserve area of ​​neighboring properties, amidst the cultivation of sugarcane and pastures. “This behavior can be positive from a genetic point of view, but it increases the probability of being run over, conflict with humans and dogs, in addition to exposing animals to poisoning, given the use of pesticides in neighboring crops”, he explains.

If males are predisposed to explore, only one of the monitored females has ventured out of the protected area. In 10 days of follow-up, it disappeared, indicating an episode of hunting within the Station, which shows the vulnerability of both the protected area and the populations of wild animals residing in the region.

Another point revealed by the research was that the animals selected the savanna areas (habitat typical of the Cerrado) for their wanderings and housing, much more than expected, underutilizing pine and eucalyptus plantations. "Possibly these animals are unable to persist in habitats composed only of environments altered by man, such as timber plantations, pastures and monocultures, given the dependence on native areas (savannas) and the underutilization of plantation areas.”

Another way of working used by Bertassoni to find out if it was possible to identify giant anteaters by coat patterns was through the use of camera traps. Individual recognition of these mammals is regarded as extremely difficult since, at first glance, all animals look identical.

According to the researcher, “the captures are especially useful when it is possible to identify the photographed individuals”. She selected a set of coat pattern characteristics and showed individual variation for the nine anteaters photographed. "Although some scientists referred to the possibility of individual identification, no study had used this pattern to access population information."

To assess the proximity between the anteaters, the researcher used, in addition to GPS, camera traps. Two pairs of male and female were close on several occasions, indicating possible reproductive behavior. None of the females monitored with GPS showed pregnancy, but the trap records showed females with offspring, pointing to reproduction in the region. Data collection was carried out by the researcher in almost two years in the field.

Bertassoni holds a Master's degree from the Federal University of Mato Grosso do Sul. He currently works at the Research and Conservation Institute of Anteaters in Brazil, an NGO known as Projeto Tamanduá. In January 2017, she signed, with other authors, the article Movement patterns and space use of the first giant anteater (Myrmecophaga tridactyla) monitored in São Paulo State, Brazil, published in the scientific journal Studies on Neotropical Fauna and Environment, by the group Taylor & Francis, from England.