Freshwater systems are of great benefit and necessity to a diversity of animals, and are of utmost importance when it comes to a functioning ecosystem. On the Ezemvelo Nature Reserve these magnificent water bodies accommodate a variety of curious creatures; whether it be crustaceans crawling about in the sands and rocks, fish swimming from stream to stream, birds swooping in for a nice bath or meal, or even an antelope seeking to quench its thirst.
Among these interesting fascinations, the perennial rivers are also home to a more curious mammal – the Cape clawless otter. These otters are primarily aquatic and prefer the shallow waters with thick vegetation that normally provides shelter to several of their favourite prey such as crabs and fish.
On the Ezemvelo Nature Reserve these interesting otters have been found scavenging around the streams of the reserve, and signs of their presence, such as spraints (faeces) and nests, have been detected on the rocks along the stream courses. These shy animals are easily scared off by the presence of humans, and disturbances often force them to relocate their area of occupancy, making them difficult to find. As a result, we placed some camera traps in areas on the reserve where evidence of their movements was found in an attempt to record some valuable sightings of these timid otters.
When on land, these clawless otters take shelter in underground burrows, or under rocks, roots or dense vegetation. Their burrows normally have a nest that is made of grass or other vegetation. They are known to be solitary animals, but occasionally there are groups made up of four otters consisting of two adults and two youngsters, and sometimes larger groups of six are formed to forage. These mammals are active mainly during dusk and early evenings and sometimes at dawn. During the day they sleep in their burrows. When they are awake the otters will spend their time swimming, playing and foraging.
These large otters, weighing up to 23kg and with a body length reaching 160cm, are carnivorous mammals. The majority of their hunting is done in shallow waters of about 1.5 m in depth, whereby the otters submerge their heads in search of a favourable fish, and feel under rocks to grab a sizeable crab. They can dive for up to 30 seconds to catch their preferred target.
The population of these shy otters is reasonably stable and widely distributed. However, the IUCN Red List of Threatened Species has them jotted down as Near Threatened, because of continuous development threatening their habitats.
With these elusive otters in residence at Ezemvelo, with enough luck one can be fortunate enough to spot them running across the rocks through which the streams flow.