Communication in the Neotropical Otter

Vocal Communication

The Neotropical Otter has a much smaller range of vocalisations than the sympatric Giant Otter. Being a smaller, more vulnerable animal than the noisy, social Giant, it is altogether quieter. Duplaix (1980) reports a staccato chuckle (like the North American River Otter), a single syllable chirp as a contact call, growls, and, like many other species, Hah! as the alarm call.

Non-Vocal Communication

Much of the research done on this species has been done by spraint mapping and analysis, so quite a lot is known. As a means of communication for a small, solitary animal in a predator-rich habitat, spraint is ideal, as it carries the message without requiring the animal to be present. Quadros & Monteiro-Filho (2002) found that flooding provoked a flurry of re-sprainting activity, as did the application of another otter's faeces at a spraint site.

Preferred spraint sites are conspicuous rocks, especially those sticking up out of water (Josef & Praso, 2004). Where no suitable protrusion exists, otters will scratch up circular mounds of sand or mud and deposit urine plus secretions from their anal glands on top (Duplaix, 1980; Quadros & Monteiro-Filho, 2002). Duplaix also found in Suriname that landing sites were favourite sprainting spots - the animals leave the water, smell and inspect the site, turn round and defaecate and return to the water. Spraint is usually around 2g in weight, 1cm in diameter and 3-5cm long, containing anal gland secretions as well as food debris - this last has been much analysed to give an indication of diet.

The nature of much of the studied habitat meant that spraint distribution across an otter's territory could be misleading - in some areas, spraint is prone to being washed away, or eaten, or rapidly broken down. Pardini & Trajano (1999) found more spraint in areas of higher otter activity, but less round holts, concluding that denning areas were not necessarily centres of activity for the otters in riverine habitats - however, it may be that Neotropical Otters deliberately refrain from creating faecal concentrations outside holts to avoid drawing attention to them. The same authors, however, recorded spraint inside shelters, especially the caves and solution cavities that this species makes use of.