Aonyx capensis congica
Congo clawless otter

Congo clawless otters are found in the lower Congo basin, which lies between southeastern Nigeria and western Uganda. (Estes, 1991; Haltenorth and Diller, 1980; Kingdon, 1982; Nowak, 1999)

Congo clawless otters reside exclusively in the small swamps, ponds, and streams of heavy rainforests. Due to their amphibious lifestyle, these otters are both excellent swimmers and skilled explorers of the shores (Kingdon, 1982). Their hair type, reduced vibrissae, and rather generalized dental morphology suggest that they may be more terrestrial than other otter species (Nowak, 1999). (Kingdon, 1982; Nowak, 1999)

Aonyx capensis congica is a large, powerfully built otter, though it is more slender in the neck and back than other populations of Aonyx capensis. Head and body length ranges between 78 and 97 cm, with the tail adding an additional 40 to 59 cm to the total length. Weights range from 15 to 25 kg in adult animals.

These otters have a dark, chestnut-brown coat with some silver frosting on the head and neck, contrasted by a white chest, nose and ears. A distinctive black patch is located between the eyes and nostrils (Kingdon, 1982). Aonyx capensis congica young resemble the adults except for a greater frosting of the coat. Unlike many other otter species, A. capensis congica has no claws, no webbing in the manus, and webbing only halfway down the digits in the pes. All are adaptations to improve dexterity and tactile sensitivity for foraging in the muddy waters of the lower Congo basin. The less specialized dentition of A. capensis congica, when compared to the broader species, A. capensis, serves as a distinguishing characteristic and suggests a broader carnivorous diet than other populations (Haltenorth and Diller, 1980). (Haltenorth and Diller, 1980; Kingdon, 1982)

Lifespan range in A. capensis congica is unknown. Captive specimens of the larger species, A. capensis, and the related species, A. cinerea, have lived as long as 14 and 16 years respectively (Nowak, 1999). (Nowak, 1999)

Congo clawless otters are mostly nocturnal, but have been observed in undisturbed swamp lands during the daytime. Though mostly solitary, family groups have also been observed along the rivers of Cameroon (Kingdon, 1982). The social organization of A. capensis congica is not well understood. In other A. capensis populations, individuals defend territories of around twelve square kilometers that often overlap with three or more other adult males (Nowak, 1999). (Kingdon, 1982; Nowak, 1999)

Home Range

The home range size of A. capensis congica is not known. In other A. capensis populations, home ranges are between four and six square kilometers (Chanin, 1985). (Chanin, 1985)

No form of communication has been specifically documented for A. capensis congica. Clawless otters, in general, communicate vocally with chirps, squeals, and purring noises when expressing affection or play. Often growls, snarls, and a screaming wail are signs of displeasure or apprehension. Clawless otters also use strong olfactory cues to communicate. They musk their coats and produce a sticky feces, capable of clinging to vertical surfaces, to mark the boundaries of their territory. The visual aspects of communication, including body language, are mostly undescribed (Estes, 1991). Tactile communication is undoubtedly of some importance in reproduction, especially between mates and between a mother and her offspring. (Estes, 1991)

Aonyx capensis congica is known to have a broad carnivorous diet, consisting of crabs, mollusks, fish, frogs, and other small vertebrates and invertebrates found in the shallow rivers and muddy shores of the Congo river basin. Its streamlined, powerful body propels it after the aquatic prey of rivers and ponds. Its specially adapted fingers are sensitive and dexterous, well suited for overturning stones, grasping prey, and sifting through the muddy shores of streams and swamps for invertebrates (Kingdon, 1982). Aonyx capensis congica has also been observed hunting in the tangled reeds and shoots of riverside vegetation, actively stalking small terrestrial vertebrates from cover (Haltenorth and Diller, 1980). (Haltenorth and Diller, 1980; Kingdon, 1982)

The dark chestnut coat of A. capensis congica acts as a form of camouflage within the muddy swamps and rivers of the Congo basin. The coloration may protect A. capensis congica from predation by the crocodiles, pythons, eagles, and leopards in this habitat (Kingdon, 1982). Although there is no documentation of predation on Congo clawless otters, other otter species are taken by large snakes, crocodilians, large cats, and birds of prey (Berry, 2000). It is reasonable to assume that similar predators take A. capensis congica.

Although it is not illustrated or described for A. capensis congica, the arched posture, snarled facial expressions, and harsh vocalizations of a defensive otter are commonly observed in the genus Aonyx (Estes, 1991). (Berry, 2000; Estes, 1991; Kingdon, 1982)

Within the rainforest ecosystem, A. capensis congica acts as a predator, preying on crustaceans, fish, frogs, and other small vertebrates and invertebrates. It is also a possible prey animal for pythons, leopards, eagles, and crocodiles (Kingdon, 1982). (Kingdon, 1982)

Aonyx capensis congica has no known negative effects on the economy. However, if provoked, clawless otters have been known to sever fingers from the hands of humans with their bite. They have also attacked and drowned dogs that tread too closely to them (Estes, 1991). (Estes, 1991)

If captured when young, their relatives, Aonyx cinerea have proven intelligent pets and have been trained to catch fish for Malay fishermen. Aonyx capensis congica has been commercially hunted for its beautiful coat as well. Though the fur quality is considered not as high as other otter species. (Nowak, 1999)

The most likely causes for the endangered status of A. capensis congica are habitat loss and pollution due to development in the Congo basin as well as chronic over-harvesting for fur (Nowak, 1999). (Nowak, 1999)

Much of the natural history of A. capensis congica remains a mystery at this point. Most of what is currently help to be true of these animals has been constructed from fragmentary field observations and assumptions based on other populations of A. capensis, which are also poorly understood. Aonyx capensis congica was previously considered a species, A. congicus, but range overlap and similarities with A. capensis resulted in their being considered a population of A. capensis.