Cinco Años de Radiomarcaje de Osos Hormigueros (Myrmecophaga tridactyla): Mejoras Implementadas y Lecciones Aprendidas

Several authors have proposed using harnesses to attach radio transmitters to giant anteaters. We assessed harness endurance and applicability on giant anteaters of different ages, tested improvements on its design, and evaluated potential negative impacts on reproduction. We also assessed the performance of an internal transmitter in a female anteater. We radiotagged 29 animals (26 reintroduced and three in-situ-born cubs) with 37 VHF harness-mounted transmitters, accumulating 370 months of radiotracking giant anteaters in Iberá Natural Reserve, Corrientes, Argentina. Each animal was periodically recaptured finding harness-related wounds in four cases for a total of 82 recaptures. All these wounds were properly treated and healed, and there were no cases of deaths related to harnesses. We designed and field-tested modifications on the transmitter canister shape that reduced resistance to vegetation, and also included an expandable section added to the strap around the thorax that prevented animals from removing their harnesses, while avoiding injuries related to changes in the anteater's weight. The internal implant resulted in a significant loss in signal strength. As result of our experience, we recommend the use of harnesses as the best way to attach radio-transmitters to giant anteaters because they offer the best quality of signal while having no apparent effect on reproduction. However, we highly recommend periodical recaptures of radio-harness tagged animals to avoid potentially fatal wounds coming from ill-adjusted harnesses in animals that are experiencing sharp changes in weight.