New non-invasive photo-identification technique for free-ranging giant anteaters (Myrmecophaga tridactyla) facilitates urgently needed field studies

ABSTRACT

Pelage patterns, colouration and other biometric traits are perceived to be uniform in the Neotropical giant anteater (Myrmecophaga tridactyla), a conception precluding the identification of individuals, which is essential for field research on the little known aspects of the species’ ecology and behaviour.

Here we present a new, non-invasive technique of matrix photo-identification to identify individual giant anteaters by their natural markings. In a long-term field study in the Brazilian Pantanal, photographs of 475 giant anteater observations (396 = direct sightings, 79 = camera traps) were captured from 2010 to 2015 and considered for our analysis. Photographs were stored in a catalogue and coded in a computerised identification table, with biometric traits being categorised and described for each observed individual in a matrix. In 71% of all photographed giant anteaters, differences in pelage marking patterns, as well as other characteristics such as ear shape and scars, allowed individual recognition. We ensured consistency of the method by conducting a double-blind verification by an experienced researcher and naïve volunteers.

This simple, non-invasive method can push the level of information about life history and population structure of giant anteaters, as it applies to a large array of study designs. It can thus enhance future studies, be integrated in ongoing research projects or supply additional information out of older data sets. It is applicable to expand data collection and raise awareness in local communities, and potentially for participatory citizen science methods. Altogether these are important cornerstones for conservation actions on the species which is listed as ‘Vulnerable’ on the International Union for Conservation of Nature Red List of Threatened Species.