Sexual, allometric and forest cover effects on giant anteaters' movement ecology

PLoS One. 2021 Aug 18;16(8):e0253345. doi: 10.1371/journal.pone.0253345. eCollection 2021.

Abstract

Knowing the influence of intrinsic and environmental traits on animals' movement is a central interest of ecology and can aid to enhance management decisions. The giant anteater (Myrmecophaga tridactyla) is a vulnerable mammal that presents low capacity for physiological thermoregulation and uses forests as thermal shelters. Here, we aim to provide reliable estimates of giant anteaters' movement patterns and home range size, as well as untangle the role of intrinsic and environmental drivers on their movement. We GPS-tracked 19 giant anteaters in Brazilian savannah. We used a continuous-time movement model to estimate their movement patterns (described by home range crossing time, daily distance moved and directionality), and provide an autocorrelated kernel density estimate of home range size. Then, we used mixed structural equations to integratively model the effects of sex, body mass and proportion of forest cover on movement patterns and home range size, considering the complex net of interactions between these variables. Male giant anteaters presented more intensive space use and larger home range than females with similar body mass, as it is expected in polygynous social mating systems. Males and females increased home range size with increasing body mass, but the allometric scaling of intensity of space use was negative for males and positive for females, indicating different strategies in search for resources. With decreasing proportion of forest cover inside their home ranges, and, consequently, decreasing thermal quality of their habitat, giant anteaters increased home range size, possibly to maximize the chances of accessing thermal shelters. As frequency and intensity of extreme weather events and deforestation are increasing, effective management efforts need to consider the role of forests as an important thermal resource driving spatial requirements of this species. We highlight that both intrinsic and environmental drivers of animal movement should be integrated to better guide management strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Distribution
  • Animals
  • Brazil
  • Ecosystem
  • Eutheria / physiology*
  • Female
  • Forests
  • Homing Behavior*
  • Male
  • Models, Biological
  • Sexual Behavior, Animal

Grants and funding

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brasil (CAPES; https://www.gov.br/capes/pt-br) under finance code 001, PROEX 88887.360861/2019-00 to AG, and PNPD 1694744 to ZO. It was also supported by the Junta de Andalucía under Research Postdoctoral Contract 401 to ZO, and by the São Paulo Research Foundation (FAPESP; https://fapesp.br), under finance codes 2013/18526-9 to AB and 2013/04957-8 to AB. Part of the costs for the field work were covered by the Giant Armadillo Conservation Program, which benefited from multiple grants, mostly from North American and European zoos listed at www.icasconservation.org.br/partners. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.