Aonyx congicus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Carnivora Mustelidae

Scientific Name: Aonyx congicus Lönnberg, 1910
Common Name(s):
English Congo Clawless Otter, Cameroon Clawless Otter, Small-clawed Otter, Small-toothed Clawless Otter, Zaire Clawless Otter
French Loutre à joues blanches du Cameroun, Loutre à joues blanches du Congo, Paraonyx tacheté
Spanish Nutria Inerme de Camerún
Taxonomic Notes:

Allen (1924) and Davis (1978) treated A. capensis and A. congicus as being conspecific, arguing that they represent clinal variations of the same species. However, mainly based on tooth size and skin differences, Rosevear (1974), Van Zyll de Jong (1987), Wozencraft (1993), and Larivière (2001) considered A. capensis and A. congicus as separate species, but this remains debated, and Wozencraft (2005) did not retain A. congicus as a valid species, contrary to the opinion of the IUCN SSC Otter Specialist Group ( (Jacques et al. 2009). The name Aonyx congica is often found in the literature but A. congicus is the correct spelling as Aonyx, from the Greek onux, is masculine (Van Bree et al. 1999).

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2015
Date Assessed: 2014-01-17
Assessor(s): Jacques, H., Reed-Smith, J., Davenport, C & Somers, M.J.
Reviewer(s): Hussain, S.A. & Duplaix, N.
Contributor(s): Hoffmann, M.
All Africa's otter species are threatened by alteration or degradation of freshwater habitats and riparian vegetation which are the preferred settlements of human population. Congo Clawless Otters have been protected by the remoteness of the Congo forest and the difficulty of catching them. However, firearms are growing in prevalence in the region, providing a possible 10-fold increase in hunters’ success rate over traditional practices (Levi et al. 2009). Road-building opening up the forest for timber exploitation and construction of large hydroelectric projects could also reduce the protection afforded to date.

Habitat loss by direct causes (clearing, inundation) and indirect causes (pollution, invasive species introduction) and competition for fisheries is increasing with the growing human population in concert with declining returns from an unsustainable bushmeat trade (Wilkie et al. 2005). These combined factors predict a severe reduction of otter habitat and populations. Increased global temperature and resultant climate change may also increase periods of drought, with additional losses to otter populations (Davenport et al. 2011). Consequently, all African otter species are likely to be more affected in the next 20 years (generation length 6.5 as proposed by Pacifici et al. 2013). Thus the species isassessed as Near Threatened based on a suspected 25% decline over the next three generations due to the expected decline in habitat quality and other threats to the species. It almost qualifies as threatened under criterion A3cde; this is a precautionary listing.
Previously published Red List assessments:

Geographic Range [top]

Range Description:The Congo Clawless Otter occurs in the rainforests of the Congo basin including Equatorial Guinea, Gabon, Republic of Congo, the Democratic Republic of the Congo, as well as southern Cameroon, southern Central African Republic, northern Angola, and extending eastward to the forests and the wetlands of Rwanda, Burundi and Uganda (Rowe-Rowe 1990, Larivière 2001, Jacques et al. 2009). The limits of the species’ distribution range are still unclear, partly due to the species’ possible confusion with the Cape Clawless Otter; there are, as yet, no confirmed records from Nigeria (Jacques et al. 2009).
Countries occurrence:
Angola; Cameroon; Central African Republic; Congo; Congo, The Democratic Republic of the; Equatorial Guinea; Gabon; Rwanda; Uganda
Additional data:
Continuing decline in extent of occurrence (EOO):YesExtreme fluctuations in extent of occurrence (EOO):Yes
Upper elevation limit (metres):2200
Range Map:Click here to open the map viewer and explore range.

Population [top]


This is a very poorly known species. It may be common in certain undisturbed rainforest locations, but is otherwise thought to be rare to very rare (Jacques et al. 2009). In certain places, locals attest that they see fewer “big otters” (A. congicus versus H. maculicollis) (Jacques 2002b,c; Jacques et al. 2002a; Jacques 2003, 2006; Davenport et al. 2011). A number of documented cases of A. congicus (including mother and cub) being killed by locals in Cameroon, Gabon, Congo and the Democratic Republic of the Congo would suggest that although otters are rarely seen and are difficult to catch, otter populations may suffer from hunting pressure in Congo Basin (Jacques 2002b). This will likely increase in the future as human population grows and preferred bushmeat species become scarce.

Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:

The Congo Clawless Otter occurs in rain forests and lowland swamps of the Congo River basin (Lariviere 2001, Jacques et al. 2009). They are observed in swampy forest clearings (bais), for example, at Langoué Bai in Gabon, and Mbeli Bai in Nouabalé-Ndoki National Park (N.P.) and in Odzala N.P. in the Republic of the Congo (Jacques et al. 2009). They also inhabit some rivers, for example Dji Dji River (Gabon) (Davenport et al. 2011), and Sanaga River (Cameroon) (Jacques 2006). They are recorded up to 2,200 m on the Kahuzi Massif (Rahm and Christiaensen 1963). With one exception (Davenport et al. 2011), all records report the presence of only one young with the mother (Jacques 2002b).

Systems:Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):6.45
Movement patterns:Not a Migrant

Use and Trade [top]

Use and Trade: Otters are occasionally hunted for meat, but have the reputation of being quite difficult to catch. They are seldom recorded in bushmeat reports (S. Lahm and A.Willox pers. comms., Jacques 2002b). The price is quite similar to other bushmeat. While meat is sought after in Congo and Cameroon, this is not the case in Gabon.

Moreover, in Gabon, otters are sometimes considered dangerous, giving an electrical shock when caught with a spear. In Central and West Africa, their meat has the reputation of being an aphrodisiac (as it is with many other species). In some areas, the otter is said to possess magical powers: by wearing a piece of fur one can become invisible to an opponent, or escape an enemy as otters escape fish traps.

In the Democratic Republic of the Congo (DRC), killing has exponentially increased over the recent decade with the proliferation of weapons and munitions, making the shooting of otters from pirogues and the river bank much more common (Thompson pers. comm.). Skins of A. congicus are used in Cameroon to make drums (Alary et al. 2001). According to Carpaneto and Germi (1989), Mbuti pygmies in northeastern DRC use the skins of Congo Clawless Otters to make hats.

Threats [top]

Major Threat(s): Aonyx congicus may not be under threat where the forest is still well preserved  (Gabon and parts of Congo). Nevertheless, road opening for wood exploitation could adversely affect the sustainable use of the forest with hunters using these roads for their illegal activities. Deforestation has dramatically increased in Cameroon and the Democratic Republic of the Congo, and will probably be an even bigger problem in future. As a result of the high human density, lakes and rivers are subjected to pollutants from human activities such as washing, agricultural run-off and soil erosion.

Overfishing has become a critical threat to otter populations as fish community structure has been decimated across the central Congo Basin. Fishes contribute from 23 to 50 per cent of the animal protein trade in Central Africa ( and studies of morphometric measurements have documented the evidence of widespread overfishing for human consumption.

In addition to escalation of hunting for bushmeat and skins, habitat loss and degradation, and overfishing, otter populations in Central Africa are also susceptible to pressure from the development of hydro-electric power projects, under-representation of otter habitat in Protected Areas, fishermen using nylon fishing nets, a growing prevalence of arms and munitions, as well as a dramatic decline in other species (such as the Common Hippopotamus) that contribute to the aquatic-ecosystem functioning and which support otter food supplies. Some of these threats are major, but more important is the dramatic combined effect of threats on the otters.

The Congo Clawless Otter seems to average one pup in a litter and may abandon any area of occupancy with high human activity.  In one study on the Dji Dji River in Gabon (Davenport et al. 2011), reproductive Congo Clawless Otters disappeared from a site previously observed to harbour high densities of the species (alongside Hydrictis maculicollis which did decline to the same degree). Low rainfall in the previous wet season was thought to be the reason, but nothing is known about the adaptability of otters, their seasonal movements or the whereabouts of Congo Clawless Otters in response to drought conditions. As global climate change is predicted to increase the frequency and severity of droughts, these conditions may impact survival and reproduction of the species in the future.

Conservation Actions [top]

Conservation Actions: Congo Clawless Otter is present in several protected areas across their range, including Dzanga-Sangha N.P. in Central African Republic, Ivindo Gabon, and Nouabalé-Ndoki and Odzala National Parks in Congo Republic (Jacques et al. 2009). Thus they are incidentally conserved with other target species..It is listed on CITES Appendix II (as Aonyx capensis). Appendix II lists species that are not necessarily now threatened with extinction but that may become so unless trade is closely controlled. There is a need for a detailed study on the biology, ecology, and distribution of this species.

In addition to threats already cited, Congo Clawless Otters likely to suffer from a general lack of awareness of their presence and conservation needs by the institutions in charge of wildlife conservation in most African countries. The initiative of the Wildlife Conservation Society to include otters in their document ‘Setting conservation and research priorities for larger African carnivores’ (Ray et al. 2005) could aid in greater awareness and promotion of more research on African otters. Otters could be used as symbols of water quality and preservation, and this may contribute to environmental education. The Congo Clawless Otter should be totally protected in Gabon, Congo, DRC and Cameroon until more information is collected about its status.

Classifications [top]

1. Forest -> 1.6. Forest - Subtropical/Tropical Moist Lowland
suitability:Suitable season:resident major importance:Yes
1. Forest -> 1.7. Forest - Subtropical/Tropical Mangrove Vegetation Above High Tide Level
suitability:Suitable season:resident major importance:Yes
1. Forest -> 1.8. Forest - Subtropical/Tropical Swamp
suitability:Suitable season:resident major importance:Yes
5. Wetlands (inland) -> 5.1. Wetlands (inland) - Permanent Rivers/Streams/Creeks (includes waterfalls)
suitability:Suitable season:resident major importance:Yes
5. Wetlands (inland) -> 5.2. Wetlands (inland) - Seasonal/Intermittent/Irregular Rivers/Streams/Creeks
suitability:Suitable  major importance:No
5. Wetlands (inland) -> 5.3. Wetlands (inland) - Shrub Dominated Wetlands
suitability:Suitable  major importance:Yes
5. Wetlands (inland) -> 5.4. Wetlands (inland) - Bogs, Marshes, Swamps, Fens, Peatlands
suitability:Suitable season:resident major importance:Yes
5. Wetlands (inland) -> 5.5. Wetlands (inland) - Permanent Freshwater Lakes (over 8ha)
suitability:Suitable season:resident major importance:Yes
5. Wetlands (inland) -> 5.6. Wetlands (inland) - Seasonal/Intermittent Freshwater Lakes (over 8ha)
suitability:Suitable  major importance:No
5. Wetlands (inland) -> 5.7. Wetlands (inland) - Permanent Freshwater Marshes/Pools (under 8ha)
suitability:Suitable season:resident major importance:Yes
5. Wetlands (inland) -> 5.8. Wetlands (inland) - Seasonal/Intermittent Freshwater Marshes/Pools (under 8ha)
suitability:Suitable  major importance:No
5. Wetlands (inland) -> 5.13. Wetlands (inland) - Permanent Inland Deltas
15. Artificial/Aquatic & Marine -> 15.2. Artificial/Aquatic - Ponds (below 8ha)
15. Artificial/Aquatic & Marine -> 15.9. Artificial/Aquatic - Canals and Drainage Channels, Ditches
1. Land/water protection -> 1.1. Site/area protection
3. Species management -> 3.2. Species recovery
3. Species management -> 3.4. Ex-situ conservation -> 3.4.1. Captive breeding/artificial propagation
4. Education & awareness -> 4.1. Formal education
4. Education & awareness -> 4.3. Awareness & communications

In-Place Research, Monitoring and Planning
  Action Recovery plan:No
  Systematic monitoring scheme:No
In-Place Land/Water Protection and Management
  Occur in at least one PA:Yes
  Area based regional management plan:No
In-Place Species Management
  Harvest management plan:No
  Successfully reintroduced or introduced beningly:No
  Subject to ex-situ conservation:No
In-Place Education
  Subject to recent education and awareness programmes:No
  Included in international legislation:Yes
  Subject to any international management/trade controls:Yes
11. Climate change & severe weather -> 11.2. Droughts
♦ timing:Future ♦ scope:Unknown ♦ severity:Unknown ⇒ Impact score:Unknown 
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

4. Transportation & service corridors -> 4.1. Roads & railroads
♦ timing:Ongoing ♦ scope:Minority (<50%)   
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.1. Hunting & trapping terrestrial animals -> 5.1.1. Intentional use (species is the target)
♦ timing:Ongoing ♦ scope:Minority (<50%) ♦ severity:Slow, Significant Declines ⇒ Impact score:Low Impact: 5 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.3. Logging & wood harvesting -> 5.3.3. Unintentional effects: (subsistence/small scale) [harvest]
♦ timing:Ongoing ♦ scope:Minority (<50%)   
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.3. Logging & wood harvesting -> 5.3.4. Unintentional effects: (large scale) [harvest]
♦ timing:Ongoing ♦ scope:Minority (<50%)   
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.3. Unintentional effects: (subsistence/small scale) [harvest]
♦ timing:Ongoing ♦ scope:Majority (50-90%)   
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality
  • 2. Species Stresses -> 2.3. Indirect species effects -> 2.3.8. Other

9. Pollution -> 9.1. Domestic & urban waste water -> 9.1.2. Run-off
♦ timing:Ongoing ♦ scope:Minority (<50%) ♦ severity:Slow, Significant Declines ⇒ Impact score:Low Impact: 5 
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Research -> 1.1. Taxonomy
1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
1. Research -> 1.5. Threats
3. Monitoring -> 3.1. Population trends

♦  Food - human
 Local : ✓ 

♦  Medicine - human & veterinary
 Local : ✓ 

♦  Wearing apparel, accessories
 Local : ✓ 

♦  Handicrafts, jewellery, etc.
 Local : ✓ 

Bibliography [top]

Alary, F., Moutou, F. and Jacques, H. 2001. Still on the tracks of the Congo clawless otter (Aonyx congicus): first mission in Cameroon. IUCN Bullettin Otter Specialist Group 19(1).

Allen, J.A. 1924. Carnivora collected by the American Congo expedition. Bulletin American Museum Natural History 47: 85-108.

Carpaneto, G.M. and Germi, F.P. 1989. Mustelidae and Viverridae from north-eastern Zaire: ethnozoological research and convservation. Mustelid & Viverrid Conservation 1: 2-4.

Davenport, L.C., Jacques, H. and Terborgh, J. W. 2011. A Whole Otter World. Gabon Magazine.

Davenport, L., Jacques, H. and Yedi, M. 2011. Rapport sur le projet: “Ecologie et conservation de la loutre à joues blanches du Congo (Aonyx congicus). In: Report to CENAREST (ed.). Centre National de la Recherche Scientifique et Technologique, Libreville, Gabon.

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Jacques, H. 2002c. Aonyx congicus, Mission Congo. Grenoble.

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Jacques, H., Parnell, R. and Alary, F. 2013. Aonyx congicus. In: J. Kingdon and M. Hoffmann (eds), The Mammals of Africa. Volume V: Carnivores, Pangolins, Equids and Rhinoceroses, Bloomsbury Publishing, London.

Jacques, H., Veron, G., Alary, F. and Aulagnier, S. 2009. The Congo Clawless Otter (Aonyx congicus) (Mustelidae: Lutrinae): a review of its systematics, distribution and conservation status. African Zoology 44(2): 159-170. doi:

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Citation: Jacques, H., Reed-Smith, J., Davenport, C & Somers, M.J. 2015. Aonyx congicus. The IUCN Red List of Threatened Species 2015: e.T1794A14164772. . Downloaded on 20 September 2018.
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