SPRING 2003 No. 16

Page 4

Otter Talk

Spraint hunters are acutely aware that otters communicate with each other (and with Dorset otter spotters) by smell. They also know that they might spend years searching the riverbank without ever once seeing the spraint’s owner. However, despite being unseen lone travellers by night, otters are sometimes active in the daylight hours, particularly mothers and cubs, and could be lying up or hiding just a few feet away from us as we tread by. It would be a considerable privilege to glimpse a Dorset wild otter, but what are the chances of hearing one?

For such an apparently solitary animal, studies and observations have reported otters using a range of vocal signals to each other. A researcher called Dr Rogoschnik has categorised 8 different types of otter vocalisations (see below). Of these there are a few distinct noises that an otter spotter might be on the alert for.

The whistle

If your stretch of the river has breeding otters on it, you may be party to the ‘whistle’, a conspicuous clear single note that can carry over several hundred metres. This is a contact call heard especially between mother and her cubs, who have a squeakier, high-pitched version, along the lines of I’m here! Where are you?’. It is heard frequently when cubs are being taught to swim. Juveniles also use it with ‘chittering’ and other play-challenge sounds. The call solicits an echoed response sometimes resulting in long sequences of whistles; this is the otter vocalisation that a passing human is most likely to hear.

Alarm huff

Another call to be heard when cubs are present is the ‘huff’. This is an explosive exhalation of air which acts as an alarm signal. Similar is the ‘hah’, a quieter sound to warn cubs of danger. Adults also ’hah’ when surprised or to indicate unease or fear. Otter spotters becoming suddenly aware of a gushed breathy huff followed by a quiet plop may have drawn closer than they realised, although, no doubt, seeing absolutely nothing at all. These vocalisations are the two otter calls that, if one is exceptionally lucky, could be encountered on the riverbank. In addition there is a repertoire of other otter sounds and signals that have been witnessed only during detailed observation and study.

Wickering, yickering, twittering and chuckling

Other noises are much rarer. There are the ‘hiss’ and ‘snort’ approaches to an individual, accompanied by a head movement and the small chirruping noises made by very young cubs between suckling, later to become the cubs ‘twitter’ to mother when they are hungry. There is also a noisy rumbustiousness during otter courtship, consisting of chirrups, purrs, ‘yarring’, staccato grunts, squeaks and crooning, all made while chasing about through undergrowth and 90 in and out of the water.

Other elements of the otter’s vocabulary have been described variously as ‘wickering’, ‘yickering’, ‘chitters’ ‘twitters’ and ‘chuckling’, the exact nature of these multifaceted calls seems to depend on the social context. The same sounds as form a greeting at a lower pitch declare, at a higher pitch, annoyance or aggressive intent.