Giant Anteaters Travel Farther to Find Cooling Forests

The animals need help regulating their body temperatures.

Giant Anteater
A giant anteater in Brazil. Joe McDonald / Getty Images

Giant anteaters aren’t very good at regulating their body temperature. They rely on covered habitats like forests to help them stay cool. These same sheltered areas help keep them warm from rain and chilly winds.

But when habitats start to dwindle and there are fewer forests, giant anteaters have to roam farther for protection, new research finds.

Giant anteaters (Myrmecophaga tridactyla) are found in the forests and savannas of South America and Central America. They are a vulnerable species, according to the International Union for the Conservation of Nature (IUCN) and their numbers are decreasing.

They have a very low body temperature—around 33 degrees Celsius (91 degrees Fahrenheit)—compared to 37 degrees Celsius (98.6 degrees Fahrenheit) in humans. That’s why they rely so heavily on their environment to help regulate their temperature.

“Giant anteaters are basal endotherms. They present a low production of body heat and, consequently, a low body temperature and a low capacity for physiological thermoregulation,” lead author Aline Giroux, an ecologist at the Federal University of Mato Grosso do Sul in Brazil, tells Treehugger.

“Forests work as thermal shelters, offering warmer temperatures than open areas on cold days and cooler temperatures than open areas on hot days. Therefore, in fragmented landscapes, giant anteaters depend on access to forests to behaviorally thermoregulate.”

Tracking Anteater Movements

Aline Giroux releases giant anteater
Giroux releases the last giant anteater in the study. Aline Giroux

For their research, Giroux and her colleagues caught 19 wild giant anteaters in two savanna areas in Brazil: Santa Barbara Ecological Station, São Paulo state and twice in Baía das Pedras Ranch, Mato Grosso do Sul state.

They measured the animals and put GPS tags on them, then tracked their movement patterns and estimated their home range size, taking into account the effects of sex, body size, and forest cover.

They found that giant anteaters that lived in habitats with a lower proportion of tree cover had larger home ranges, which likely allowed them to find more forest areas as a respite from cold and hot temperatures.

They also discovered that male anteaters tended to move across a larger range area and use the space more than females of a similar size, possibly to increase their chances of finding a mate.

The study findings were published in the journal PLOS One.

Giroux says the researchers were surprised by the results.

“We didn’t expect that males and females would vary their intensity of space use differently across body mass. In general, animals move more with increasing body mass because they need to find more food,” she says. 

“In giant anteaters, while females increased the intensity of space use with increasing body mass (as we expected to both sexes), males showed the opposite behavior. We are very curious about it, and we want to investigate more about the behavioral divergences between male and female giant anteaters.”

Why These Findings Matter

giant anteater wears a tracker
A giant anteater wears a tracker for the study. Arnaud Desbiez

Giroux’s earlier work showed that giant anteaters use forest patches as thermal shelters. Now, this new research shows, like with so many other animals, the space they need changes in response to the resources that are available to them.

As there are fewer forests in their habitats, they need to travel further to find more.

“Giant anteaters are indeed fascinating, and I even cannot explain why. I believe that this kind of fascination that some people feel by nature cannot be really explained. There is a magic feeling when I see animals in nature, feeding, walking, just living their lives. It is like watching another world, another reality. And unlocking the secrets of this other reality is always exciting,” Giroux says.

As much as she is intrigued by the animals, giant anteaters weren’t necessarily the impetus of the research, Giroux says.

“We want to understand how different factors interact to shape the animal movement and how the environment and the intrinsic characteristics of individuals influence the quantity of space that they need to get their resources,” she says. “This kind of information helps us to understand the interaction and the individuals and the changing environment, besides better guide conservation decisions.”

The study findings are important researchers and conservationists can use the information when protecting habitat, researchers say.

“In this current deforestation scenario, our results bring an important implication for giant anteaters’ management: the minimal area needed to preserve a given giant anteaters’ population should increase as the proportion of forests inside it decreases,” Giroux says.

“We strongly suggest that management efforts should focus on maintaining the giant anteaters’ access to forest patches inside their home ranges to provide environmental conditions for behavioral thermoregulation.”

View Article Sources
  1. Giroux, Aline, et al. "Sexual, Allometric and Forest Cover Effects on Giant Anteaters’ Movement Ecology." PLOS ONE, vol. 16, no. 8, 2021, p. e0253345., doi:10.1371/journal.pone.0253345

  2. Miranda, F., et al. "Giant Anteater." The IUCN Red List of Threatened Species, 2014, doi:10.2305/

  3. "148. Giant Anteater." Edge.

  4. lead author Aline Giroux, an ecologist at the Federal University of Mato Grosso do Sul in Brazil

  5. Giroux, Aline, et al. "The Role of Environmental Temperature on Movement Patterns of Giant Anteaters." Integrative Zoology, 2021, doi:10.1111/1749-4877.12539