African slender-snouted crocodile  (Mecistops cataphractus)

Classified as Data Deficient (DD) by the IUCN Red List (3), and listed on Appendix I of CITES (4).

The African slender-snouted crocodile is among the least known of the world’s crocodilians (5). Its defining feature is its extremely slender snout, devoid of any bony ridges (6). The leathery skin of the adult is brownish-yellow with large black spots, and the olive coloured head is spotted with brown. Young crocodiles are greenish-grey to greenish-yellow in colour with black blotches and markings (6). Six or so rows of tough scales run down the crocodile’s back, leading to the species name cataphractus, meaning ‘clad in armour’ in Greek (6).

Occurs in the equatorial rainforest belt of Central and West Africa; from southern Mauritania, east to the Central African Republic and south to Angola and Tanzania (5).

The African slender-snouted crocodile inhabits rivers, marshes, lakes and pools within rainforests (6). While habitat data are not exhaustive, the slender-snouted crocodile is apparently confined to freshwater and typically prefers larger, swift-flowing streams (7).

Like many crocodilians, the African slender-snouted crocodile is apparently a rather shy and timid reptile (6), and despite being a remarkably agile swimmer (6), it is often found resting in the shade of trees (8). It is the only crocodilian species known to climb as high as several meters into the limbs of trees fallen along streams (7). Although it is a fish-eating specialist, the slender-snouted crocodile also feeds on frogs, snakes, shrimps, crabs, and even waterbirds and mammals (6) (8) (9); its slender snout has evolved to move quickly through the water, allowing rows of razor-sharp teeth to snatch fish in open water, or prey from burrows and amongst roots and fallen trees (8).

Depending on the region and its climatological patterns, mating is reported to begin in February; and from March the female constructs a nest by scraping vegetation together with her hindfeet (6). These large mounds, up to 80 centimetres high and two metres wide, are situated in a shady spot a few metres from small rainforest streams (6). The female lays between 12 and 30 large, hard-shelled eggs in two layers in the mound, where a temperature of 27.4 to 34 degrees Celsius is maintained (6). At the beginning of the rainy season, after 90 to 100 days of incubation, young crocodiles start to emerge from the elliptical eggs (6). Their characteristic chirping instigates the mother to break open the nest and assist with the hatching process, causing the hatchlings to scatter over the flooded rainforest floor (10). Slender-snouted crocodiles display some degree of parental care of hatchlings, with females aggressively defending their young when they emit distress calls. It is unknown for how many months this maternal care is given (7).

The sparse information on the African slender-snouted crocodile makes it difficult to determine its conservation status, and thus the World Conservation Union (IUCN) has declared it Data Deficient (3). However, the little survey data that is available suggests that many populations may be depleted, and possibly even extirpated in The Gambia, Senegal and Guinea-Bissau (2). These declines are likely to be the result of hunting, for its hide and for food (2), and the disruption of vital riverside vegetation (2). Slender-snouted crocodiles are extremely vulnerable to being caught and drowned in fishing nets when attempting to eat fish struggling in the nets. Very few significant populations of this species exist in Central or West Africa, and additional data and protection is urgently required (7).

The African slender-snouted crocodile is legally protected in many of its range countries, although this is poorly enforced. The sparse information available indicates that populations of this rare ‘armour-clad’ crocodile are declining, so better enforcement of laws, changes in legal status, and firmer hunting regulations are clearly needed. However, the lack of definitive information on this species’ ecology, population dynamics and status makes such actions hard to develop, and the inaccessibility and political instability throughout much of its range hinders most efforts for further research or action (2) (10).

For further information on the African slender-snouted crocodile see:

• Crocodilian.com:
  http://crocodilian.com/
• Detailed range map for the African slender-snouted crocodile:
  http://www.flmnh.ufl.edu/cnhc/cst_ccat_dh_map.htm
• IUCN SSC Crocodile Specialist Group:
  http://iucncsg.org