These familiar aquatic predators, the African otters, have three distinctive species that occur in sub-Saharan Africa, and their ranges overlap in the western parts of Uganda, where all three have been recorded in areas like Lake Mburo National Park.
Otter-like animals have inhabited the earth for the last 30 million years and over the years have undergone subtle changes to the carnivore bodies to exploit the rich aquatic environment. Otters are members of the Mustelid family which includes badgers, polecats, martens, weasels, stoats and mink.
The Cape clawless otter (Aonyx capensis) and DRC clawless otter (A. congica), regarded to be nonspecific by some authorities, are the largest African otters, growing up to 1.6 meters long, with a rich brown coat and pale chin and belly.
Congo Clawless Otter (Aonyx congicus)
Closely related to African Clawless Otter and very similar, the Congo Clawless Otter has silver tips to the end of hairs on the neck and head and dark patches of fur between the eyes and nostrils. Least adapted of all otters to aquatic way of life and has short fur providing less insulation. The back feet are only partly webbed and the front have no webbing at all.
African Clawless Otter (Aonyx capensis)
The African Clawless Otter is similar in appearance to the Congo Clawless otter. Although it is born with tiny claws it loses these on all toes except the middle three on the hind feet. There is no webbing and it can therefore use its “fingers” more freely than other species. It captures most of its prey in its paws, hunting by sight and also using the long vibrissae (whiskers) which help when hunting in murky waters.
Associated with most wetland habitats, the African clawless otters are most active between dusk and dawn, and are hence less likely to be observed than the smaller and darker spotted-necked otter (Lutra maculicollisi), a diurnal species that is unusually common and visible on Lake Bunyonyi in Kigezi.
These otters are active generally during the late afternoon and early evening, and like many otter species have set sprainting points and grooming areas. They are usually seen alone or in pairs, but occasionally they can be seen in family groups of up to five animals.
Young otters go through rituals of fighting and romping. They often pick up an object, juggle with it, throw it in the water and attempt to retrieve it before it falls to the bottom. These games probably help the youngsters to practice skills they will need to capture prey in later life.
Spotted Necked Otter (Hydrictis maculicollis)
The Spotted Necked Otter is smaller and darker than the African Clawless Otter and has a pale neck with spots. It is a diurnal otter and likes deep water habitats like lakes, where they dive for fish and amphibians.
It is a social animal and forms distinctive male and female groups. Occurs only in Africa in all countries south of the Sahara and is absent only from the desert areas.
The Spotted-necked Otter inhabits freshwater habitats where water is un-silted, unpolluted, and rich in small to medium sized fishes. While comparatively common in the great lakes of Central and East Africa, they are also found in streams, rivers and impoundments up to altitudes of 2,500 m. In riparian and lacustrine habitats adequate vegetation in the form of long grass, reeds, dense bushes, overhanging trees and large boulder piles is essential to provide cover during periods of inactivity and for denning.
Unlike African Clawless Otter, they do not occur in marine or estuarine waters.