Crocodylus novaeguineae

The New Guinea crocodile (Crocodylus novaeguineae) is a small species of crocodile found on the island of New Guinea where there are two geographically isolated populations to the north and south of the mountain ridge that runs along the centre of the island. In the past it included the Philippine crocodile, C. n. mindorensis, as a subspecies, but today they are regarded as separate species. The habitat of the New Guinea crocodile is mostly freshwater swamps and lakes. It is most active at night when it feeds on fish and a range of other small animals. A female crocodile lays a clutch of eggs in a nest composed of vegetation and she lies up nearby to guard the nest. There is some degree of parental care for newly hatched juveniles. This crocodile was over-hunted for its valuable skin in the mid 20th century, but conservation measures have since been put in place, it is reared in ranches and the International Union for Conservation of Nature (IUCN) lists it as being of 'Least Concern'. The New Guinea crocodile was first described by the American herpetologist Karl Patterson Schmidt in 1928 as Crocodylus novaeguineae. At one time it was thought that there were two subspecies, C. n. novaeguineae, the New Guinea crocodile native to Papua New Guinea and Western New Guinea, and C. n. mindorensis, the Philippine crocodile, native to several islands including Busuanga, Luzon, Masbate, Mindoro, Negros, Samar and Mindanao. Most authorities now consider that the Philippine crocodile is an entirely separate species. DNA sequencing data reported in 2011 showed that the Philippine crocodile is, in part, paraphyletic with regard to the New Guinea crocodile, and that the latter may constitutes a population within the Philippine crocodile. Among their two samples for the New Guinea crocodile, one was part of the Philippine crocodile clade and the other was separate, estimated to have diverged 2.6–6.8 million years ago. Both samples were taken from captives (could potentially be misidentified or hybrids) and the result should therefore be treated with caution. The genus name Crocodylus comes from the Greek kroko which means a pebble and deilos, a worm or man, referring to the knobbly appearance of the dorsal surface of the reptile. The specific epithet novaeguineae is from the Latin and means 'of New Guinea'. Other common names for this crocodile include New Guinea freshwater crocodile, Singapore large grain, Puk Puk, Buaya air tawar and Wahne huala. The cladogram below follows the topology from a 2011 analysis of mitochondrial DNA sequences by Robert W. Meredith, Evon R. Hekkala, George Amato and John Gatesy. The New Guinea crocodile grows to a length of up to 3.5 m (11 ft) for males and 2.7 m (8.9 ft) for females, although most specimens are smaller. The body ranges from grey to brown in colour, with darker bandings on the tail and body which become less noticeable as the animal grows. Longitudinal ridges in front of the eyes and some granular scales on the back of the neck between four large scales are distinctive features of this species. There are some differences between the northerly and southerly populations in the morphology of the skull and the arrangement of the scales. The snout is pointed and relatively narrow during juvenile stages and becomes wider as the animal matures. The New Guinea crocodile bears a physical similarity to the nearby Philippine crocodile (C. mindorensis) and Siamese crocodile (C. siamensis). The colouring is similar to that of the freshwater crocodile (Crocodylus johnsoni) of northern Australia, but the snout is somewhat shorter and broader. This crocodile is to be found in the freshwater swamps, marshes and lakes of New Guinea, particularly in the interior. It has been known to enter brackish waters such as those of the Fly River estuary but is very rare in coastal areas, and never found in the presence of the competing saltwater crocodile (C. porosus). The animal was first described from the area of the Sepik River in the north of Papua New Guinea. A separate population is found in the southern half of the island, with a range that extends from southeastern Papua New Guinea to the Indonesian provinces of Papua and West Papua. It is separated from the northern population by the New Guinea Highlands, a mountain range that runs along the centre of the island. DNA analysis has revealed these to be genetically separate populations, and there are some differences in their morphology and behavior. There are estimated to be between 50,000 and 100,000 New Guinea crocodiles in the wild. New Guinea crocodiles have a mostly aquatic lifestyle and are largely nocturnal. They spend much of the day underwater, often with their nostrils and eyes above the surface. Powerful side-to-side movements of their tails propel them through the water and they use both tail and legs to steer. When on land, they favour shady, dense areas of undergrowth. They tend to bask in a group during the day, dispersing at night to feed.