New Guinea crocodile

The New Guinea crocodile (Crocodylus novaeguineae) is a small crocodile that lives on the island of New Guinea, north of the mountain ridge that runs down the middle of the island. It is different from the population south of the ridge, which is now called Hall's New Guinea crocodile (C. halli). In the past, the Philippine crocodile (C. n. mindorensis) was also considered part of this species, but today it is treated as its own subspecies.

New Guinea crocodiles mostly live in freshwater swamps and lakes. They are mostly active at night and eat fish and other small animals. When it is time for babies, a female crocodile builds a nest from vegetation and guards it. She also helps the baby crocodiles after they hatch.

In the middle of the 20th century, many of these crocodiles were hunted for their skin. But thanks to conservation efforts, they are now raised on ranches. The International Union for Conservation of Nature says the New Guinea crocodile is of "Least Concern", meaning it is not in immediate danger.

Taxonomy and etymology

The New Guinea crocodile was first described in 1928 by an American scientist named Karl Patterson Schmidt. It was once thought to have two types, one found in Papua New Guinea and Western New Guinea, and another in the Philippines. But now, most scientists believe the Philippine crocodile is a separate species.

The name Crocodylus comes from Greek words meaning “pebble” and “worm,” describing the crocodile’s bumpy back. The name novaeguineae means “of New Guinea” in Latin. Another close relative is Hall’s New Guinea crocodile, which lives south of the New Guinea highlands and was recognized as its own species in 2019. Both crocodiles look very similar but have differences in their genes and skull shapes.

Phylogeny

The genus Crocodylus probably began in Africa and then spread to Southeast Asia and the Americas. Evidence suggests it separated from its closest relative, an extinct crocodile from Madagascar, about 25 million years ago.

Description

The New Guinea crocodile is a smaller crocodile species that can grow up to 3.5 meters (11 feet) for males and 2.7 meters (8.9 feet) for females. Most of them are smaller, though, and can weigh up to 200 kilograms (440 pounds). They have a bite force that can be quite strong.

These crocodiles are usually grey to brown in color, with darker markings on their tails and bodies that become less noticeable as they grow older. They have special ridges in front of their eyes and some small, grainy scales on the back of their necks. Their snouts start out pointed and narrow when they are young but get wider as they mature. They look similar to the Philippine crocodile and the Siamese crocodile, but they have a shorter and broader snout compared to the freshwater crocodile of northern Australia.

Distribution and habitat

The New Guinea crocodile lives in freshwater swamps, marshes, and lakes in the northern part of New Guinea, especially in the interior areas. It sometimes goes into brackish waters but is rarely seen in coastal regions and does not share areas with the larger saltwater crocodile. This crocodile was first found near the Sepik River in northern Papua New Guinea.

A related crocodile, Hall's New Guinea crocodile, lives in the southern half of the island, from southeastern Papua New Guinea to the Indonesian provinces of South Papua. The two types are separated by the New Guinea Highlands, a mountain range running down the center of the island. DNA analysis shows they are distinct species with some differences in their appearance and behavior. There are estimated to be between 50,000 and 100,000 of these crocodiles living in the wild.

Behaviour

New Guinea crocodiles live mostly in water and are active mostly at night. During the day, they stay underwater with just their eyes and noses showing. They use their strong tails to move quickly in the water and can steer with both their tails and legs. On land, they like shady, thick areas and often rest together during the day but spread out at night to find food.

These crocodiles grow up to be about 2 metres long when they are ready to have babies. After mating, they lay their eggs about two weeks later. In the north, they lay eggs between August and October when it is dry. They build a floating nest from plants in shallow water. They lay between 22 and 45 eggs and cover them with more plants. In the south, they lay eggs during the wet season and often build the nest on land with fewer but larger eggs. The mother stays close to the nest for about 80 days until the eggs hatch. When the baby crocodiles hatch, they make loud noises, and their parents help carry them gently to open water.

Baby New Guinea crocodiles eat small animals like insects, spiders, tadpoles, snails, frogs, and small fish. As they grow, they eat bigger animals like fish, shrimp, crabs, snakes, birds, and small mammals. They catch their food by quickly moving their heads to grab it with their sharp teeth and then swallow it whole. These crocodiles are very quick and can jump out of the water to catch bats, birds, and fish. They also search in mud for crabs and mollusks.

Both adult and baby crocodiles make many different sounds. Adult females can make a deep roaring sound when another crocodile comes close. Babies start making sounds while still in the eggs, which may help them all hatch at the same time. When babies are surprised, they make warning sounds that make all the babies dive to the bottom of the water. The adults nearby may respond with growls, threats, or even attacks.

Status and conservation

The New Guinea crocodile was listed as "Vulnerable" in 1986 and 1988, but later changed to "Least Concern" in 1996 because it lives in a large area with plenty of space and seemed common. Its status has not been checked again since then. It is protected under rules to stop people from taking too many away.

In the past, people hunted these crocodiles for their skin, which is valuable. This happened a lot in the 1950s and 1960s, and the crocodiles were in danger of disappearing. Laws were made around 1970 to help protect them. Even with these laws, many crocodiles were still taken for their skin and eggs until the 1990s. Today, rules in Indonesia and Papua New Guinea control how many crocodiles can be taken and how big they must be. Some baby crocodiles are still raised in safe places to help their numbers grow.

2018 killing of New Guinea crocodiles

Main article: Crocodile attack

In July 2018, a man was hurt by a saltwater crocodile at a farm in West Papua, Indonesia. After this, locals removed many crocodiles from the farm.