Crocodiles in Sri Lanka

Of the 23 species of the family Crocodylidae, Sri Lanka is the home of two species of crocodiles; the Hela Kimbula or the freshwater, marsh, mugger or swamp crocodile (Crocodylus palustris) and the Geta Kimbula or the saltwater or estuarine crocodile [(Crocodylus porosus) Amarasinghe et al., 2015; de Silva, 2016; Santiapillai & de Silva, 2001].

Historical references

The chronicle Culavamsa mentions that during the reign of Gajabahu II (1132-1153 A.D.) men could not pass the deep waters at Yatthikanda and Dumbara due to man-eating crocodiles (Uluwaduge et al, 2018). A granite block of stone with a 15th-century Crocodile Charm and a Talisman has been discovered in the Gin Ganga river at Baddegama in Galle District (Rohanadeera, 2007). From the 17th to 19th century there have been many observations of crocodiles on the island by several western writers such as P. Baldaeus, Robert Knox, and J. E. Tennentin (Uluwaduge et al, 2018). In the early part of the 20th century, crocodiles have been extensively hunted for their skins (Santiapillai & de Silva, 2001; Uluwaduge et al, 2018).

Freshwater crocodile

Freshwater crocodiles are majorly found in rivers, marshes and irrigation reservoirs (de Silva, 2016). The size of a male crocodile at its maturity age is 2.7 m while it is 1.6 m for a female crocodile (Santiapillai & de Silva, 2001). However, a fully grown male crocodile can be 4 m long while a female crocodile can grow up to a length of 3 m (Santiapillai & de Silva, 2001). The skin is olive-green in colour. November is normally the mating period of freshwater crocodiles (Santiapillai & de Silva, 2001).

Presently, freshwater crocodiles are confined to the first peneplain in the low country, below an altitude of 100 m (Santiapillai & de Silva, 2001). The highest elevation from which the freshwater crocodile has been recorded in Sri Lanka in recent times is 230 m a.s.l, in the Randenigala Reservoir built across the Mahaweli Ganga (Santiapillai & de Silva, 2001).

Saltwater crocodile

The saltwater crocodile is the largest of all living crocodiles, and perhaps the largest living reptile (Amarasinghe et al., 2015; Santiapillai & de Silva, 2001). They are more aggressive than freshwater crocodiles. A grown male crocodile is usually 2.7 m long but can be grown up to 6.4 m and weigh over 1 ton (Santiapillai & de Silva, 2001). The average length of a matured female crocodile is 1.7 m but can be grown up to a length of 5.5 m (Santiapillai & de Silva, 2001). April is the mating period of saltwater crocodiles.

Saltwater crocodiles are distributed in a wide variety of saline and freshwater habitats, including rivers and creeks, coastlines, coastal flood plains, lagoons, swamps and canal outfalls (Amarasinghe et al., 2015; de Silva, 2016). Although they are referred to as ‘salties’, a high proportion of the saltwater crocodile population exists in freshwater habitats in the western and southern parts of the country such as in the Nilwala, Bentota, Kelani, Maha Oya rivers (Amarasinghe et al., 2015).

Human-crocodile conflict

Both crocodile species in Sri Lanka are known to attack animals as well as humans, Incidents of crocodiles killing people or domestic animals have been reported in several localities (Amarasinghe et al., 2015). Presently, the conflict between humans and crocodiles has been recognized as one of the major human-animal conflicts in Sri Lanka, second only to the human-elephant conflict (Uluwaduge et al, 2018).

Conservation

Both freshwater and saltwater crocodiles in Sri Lanka are listed as "endangered" and "critically endangered" species respectively and have been protected under the Fauna and Flora Protection Ordinance of 1938 (Santiapillai & de Silva, 2001). Act 1 of the Customs Gazette of 1969 has prohibited the export of crocodile skins.