New Guinea crocodile

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New Guinea crocodile
Temporal range: Late PleistocenePresent, 0.1–0  Ma [1]
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Buaya Irian Crocodylus novaeguineae Bandung Zoo.JPG
New Guinea crocodile at Bandung Zoo in West Java, Indonesia
CITES Appendix II (CITES) [3]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Order: Crocodilia
Family: Crocodylidae
Genus: Crocodylus
Species:
C. novaeguineae
Binomial name
Crocodylus novaeguineae
(Schmidt, 1928)
Crocodylus novaeguineae Distribution.png
Range shown in green (including Hall's New Guinea crocodile)
Synonyms [4]

C. n. novaeguineae

The New Guinea crocodile (Crocodylusnovaeguineae) is a small species of crocodile found on the island of New Guinea north of the mountain ridge that runs along the centre of the island. The population found south of the mountain ridge, formerly considered a genetically distinct population, is now considered a distinct species, Hall's New Guinea crocodile (C. halli). 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".

Contents

Taxonomy and etymology

The New Guinea crocodile was first described by the American herpetologist Karl Patterson Schmidt in 1928 as Crocodylus novaeguineae. [5] 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. [4] 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. [6] 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. [6]

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. [4]

Crocodylus halli , also known as Hall's New Guinea crocodile, is the closest relative of the New Guinea Crocodile. It is also endemic to the island of New Guinea, where it inhabits the lower part of the island, located south of the New Guinea highlands. Crocodylus halli was declared a separate species in 2019, and was named after Philip M. Hall, a researcher at the University of Florida who performed the initial studies to clarify the species' distinctiveness. [7] [8] Both species look very much alike, however they differ both genetically and regarding the bone structure of their skulls. [9]

Phylogeny

The genus Crocodylus likely originated in Africa and radiated outwards towards Southeast Asia and the Americas, [10] although an Australia/Asia origin has also been considered. [6] Phylogenetic evidence supports Crocodylus diverging from its closest recent relative, the extinct Voay of Madagascar, around 25 million years ago, near the Oligocene/Miocene boundary. [10]

Below is a cladogram based on a 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data, [11] as revised by the 2021 Hekkala et al. paleogenomics study using DNA extracted from the extinct Voay . [10]

Note: Crocodylus halli is missing in this diagram, as it was declared a separate species a year after Lee & Yates published their findings.

Crocodylinae

Voay

Crocodylus
Asia+Australia

Crocodylus johnstoni Freshwater crocodile Freshwater crocodile white background.jpg

Crocodylus novaeguineaeNew Guinea crocodile

Crocodylus mindorensis Philippine crocodile

Crocodylus porosus Saltwater crocodile Crocodylus porosus white background.jpg

Crocodylus siamensis Siamese crocodile Siamese Crocodile white background.jpg

Crocodylus palustris Mugger crocodile Mugger crocodile white background.jpg

Africa+New World

Crocodylus suchus West African crocodile

Crocodylus niloticus Nile crocodile Nile crocodile white background.jpg

New World

Crocodylus moreletii Morelet's crocodile

Crocodylus rhombifer Cuban crocodile Cuban crocodile white background.jpg

Crocodylus intermedius Orinoco crocodile

Crocodylus acutus American crocodile American crocodile white background.jpg

Description

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, and can weigh up to 200 kg (440 lb), although most specimens are smaller. [12] In a study, two crocodiles measuring 2.91 to 3.15 m (9 ft 7 in – 10 ft 4 in) and weighing 123–186 kg (271–410 lb) had a bite force in the range of 4,782–5,938  N (1,075–1,335  lbf ). [13] 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. [4] 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. [14] There are some differences between the northerly and southerly populations in the morphology of the skull and the arrangement of the scales. [15] 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. [4] [16]

Distribution and habitat

This crocodile is to be found in the freshwater swamps, marshes and lakes of northern New Guinea, particularly in the interior. [4] It has been known to enter brackish waters but is very rare in coastal areas, and never found in the presence of the competing saltwater crocodile (C. porosus). [4] [12] The animal was first described from the area of the Sepik River in the north of Papua New Guinea. The closely related Hall's New Guinea crocodile is found in the southern half of the island, with a range that extends from southeastern Papua New Guinea to the Indonesian provinces of South Papua. It is separated from the New Guinea crocodile by the New Guinea Highlands, a mountain range that runs along the centre of the island. [15] [16] [17] DNA analysis has revealed these to be genetically distinct species, [18] and there are some differences in their morphology and behavior. [19] There are estimated to be between 50,000 and 100,000 New Guinea and Hall's New Guinea crocodiles in the wild. [4]

Behaviour

At Bandung Zoo, West Java, Indonesia Buaya Irian Crocodylus novaeguineae Bandung Zoo 2.JPG
At Bandung Zoo, West Java, Indonesia

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. [4] They tend to bask in a group during the day, dispersing at night to feed. [16]

Females become sexually mature when about 1.6 to 2 metres (5 ft 3 in to 6 ft 7 in) long and males at about 2.5 metres (8 ft 2 in). Eggs are laid about 14 days after mating. In the northern population, breeding takes place during the dry season between August and October. A floating nest composed of vegetation is made in a shallow water location such as in an overgrown channel, at the edge of a lake, on a scroll swale or beside a stream. A clutch of between 22 and 45 eggs is laid and covered with further vegetation. In the southern population, the wet season is chosen for reproduction. The nest is sometimes built in similar locations to the northern nests, but is more often on land, and a smaller number of rather larger eggs is laid. In both populations, the mother stays near the nest during the incubation period, which lasts about 80 days. When the eggs start to hatch, the emerging young are quite vocal, and both male and female crocodiles have been observed transporting hatching and newly hatched young to open water, carrying them delicately in their mouths. [4] [16]

Newly hatched New Guinea crocodiles feed on aquatic insects, spiders, tadpoles, freshwater snails, frogs, fish and small mammals. As they grow, so does the size of their prey and their consumption of fish rises, but they still will eat anything of a worthwhile size that they can find. An adult's diet is largely fish, caught by sweeping the snout sideways and snapping at the prey, but also includes shrimps, crabs, frogs, snakes, birds and medium-sized mammals. A crocodile catches its prey by stealth with a flick of its head, impaling it with its sharp teeth and gripping and crushing it. The jaws cannot move sideways to chew the food; instead, the crocodile's head is tossed to move the prey to the back of the mouth before the prey is swallowed whole. This crocodile is surprisingly agile and can lunge its body upward into the air to catch bats, flying birds, and leaping fish. [16] It can also probe into the mud at the bottom of a river or swamp with its snout to search for crabs and mollusks. [16]

Adult and young New Guinea crocodiles have a range of vocalisations. An adult female can produce a repeated throaty "roar" when approached by another adult. The young start communicating with each other while still in the egg; this may help synchronise hatching. Newly hatched juveniles use various yelps and grunts. When startled, a warning sound emitted by one will send all the juveniles diving to the bottom of the water. Adults in the vicinity respond with growls, threats, and attacks. [16] The distress noises of a youngster when handled at a ranching facility was observed to cause all the larger animals to become involved in frenzied activity, with some rushing towards the juvenile and others thrashing about in the water and slapping their heads down on the surface. [16]

Status and conservation

At Wuppertal Zoo Neuguinea-krokodil-0272.jpg
At Wuppertal Zoo

The IUCN listed this crocodile as being "Vulnerable" in its Red List of Threatened Species in 1986 and 1988, but changed the assessment to "Least Concern" in 1996. At the time it was stated that the animal has a large area of suitable habitat and seemed to be plentiful. Its status has not been reassessed since then. It is included in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). [2]

The skin of the New Guinea crocodile is valuable and in the 1950s and 1960s the animals in the northern population were heavily hunted to a point where they might have become extinct. Around 1970, legislation was put in place and they received some protection. [4] In the period 1977 to 1980, the harvest of wild skins was over 20,000 per year but in the 1980s this declined to 12,000 to 20,000. As well as this, some 2,500 to 10,000 eggs and hatchlings were collected annually to raise on ranches. However, in 1995, the largest ranch on the island initiated a change of strategy to concentrate on raising the saltwater crocodile, and demand for the eggs and juveniles of the New Guinea crocodile dried up. Since then, cropping of wild animals has been controlled in both Indonesia and Papua New Guinea. In the former it is limited to a belly width of 25 to 51 cm (10 to 20 in) for wet skins and in the latter to salted skins with a belly width of 18 to 51 cm (7 to 20 in). [15] Some eggs and hatchlings are still removed from the nest and raised in enclosures and a similar programme has more recently been initiated for southern populations. [4]

2018 killing of New Guinea crocodiles

In July 2018, a man was reportedly killed by a saltwater crocodile in a breeding farm in West Papua, Indonesia. Locals then killed 292 saltwater and New Guinea crocodiles at the farm in revenge. [20] [21]

See also

Related Research Articles

<span class="mw-page-title-main">Crocodile</span> Family of large reptilian carnivores

Crocodiles or true crocodiles are large semiaquatic reptiles that live throughout the tropics in Africa, Asia, the Americas and Australia. The term crocodile is sometimes used even more loosely to include all extant members of the order Crocodilia, which includes the alligators and caimans, the gharial and false gharial among other extinct taxa.

<span class="mw-page-title-main">Crocodilia</span> Order of mostly large, predatory, semiaquatic reptiles

Crocodilia is an order of egg-laying, mostly semiaquatic, predatory reptiles known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchian, a subset of archosaurs that appeared about 235 million years ago and were the only survivors of the Triassic–Jurassic extinction event. The order includes the true crocodiles, the alligators and caimans, and the gharial and false gharial. Notable extinct groups include the mekosuchines, a diverse lineage of semiaquatic and terrestrial crocodiles from Australasia, and potentially the planocraniids, a hooved lineage adapted for running on land. Although the term "crocodiles" is sometimes used to refer to all of these, it is less ambiguous to use "crocodilians".

<span class="mw-page-title-main">Crocodylinae</span> Subfamily of crocodiles

Crocodylinae is a subfamily of true crocodiles within the family Crocodylidae, and is the sister taxon to Osteolaeminae.

<span class="mw-page-title-main">Saltwater crocodile</span> Reptile of South Asia, Southeast Asia and Oceania

The saltwater crocodile is a crocodilian native to saltwater habitats, brackish wetlands and freshwater rivers from India's east coast across Southeast Asia and the Sundaic region to northern Australia and Micronesia. It has been listed as Least Concern on the IUCN Red List since 1996. It was hunted for its skin throughout its range up to the 1970s, and is threatened by illegal killing and habitat loss. It is regarded as dangerous to humans.

<span class="mw-page-title-main">Mugger crocodile</span> Species of crocodile from Asia

The mugger crocodile is a medium-sized broad-snouted crocodile, also known as mugger and marsh crocodile. It is native to freshwater habitats from southern Iran to the Indian subcontinent, where it inhabits marshes, lakes, rivers and artificial ponds. It rarely reaches a body length of 5 m and is a powerful swimmer, but also walks on land in search of suitable waterbodies during the hot season. Both young and adult mugger crocodiles dig burrows to which they retreat when the ambient temperature drops below 5 °C (41 °F) or exceeds 38 °C (100 °F). Females dig holes in the sand as nesting sites and lay up to 46 eggs during the dry season. The sex of hatchlings depends on temperature during incubation. Both parents protect the young for up to one year. They feed on insects, and adults prey on fish, reptiles, birds and mammals.

<span class="mw-page-title-main">Nile crocodile</span> Reptile of Africa

The Nile crocodile is a large crocodilian native to freshwater habitats in Africa, where it is present in 26 countries. It is widely distributed in sub-Saharan Africa, occurring mostly in the eastern, southern, and central regions of the continent, and lives in different types of aquatic environments such as lakes, rivers, swamps and marshlands. It occasionally inhabits deltas and brackish lakes and rarely also saltwater. Its range once stretched from the Nile Delta throughout the Nile River. Lake Turkana in Kenya has one of the largest undisturbed Nile crocodile populations.

<span class="mw-page-title-main">American crocodile</span> Species of crocodile endemic to the Neotropics

The American crocodile is a species of crocodilian found in the Neotropics. It is the most widespread of the four extant species of crocodiles from the Americas, with populations present from South Florida, the Caribbean islands of Cuba, Jamaica, Hispaniola, and the coasts of Mexico to as far south as Peru, Ecuador, Colombia, and Venezuela.

<span class="mw-page-title-main">Freshwater crocodile</span> Species of reptile

The freshwater crocodile, also known commonly as the Australian freshwater crocodile, Johnstone's crocodile, and the freshie, is a species of crocodile native to the northern regions of Australia. Unlike its much larger Australian relative, the saltwater crocodile, the freshwater crocodile is not known as a man-eater, although it bites in self-defence, and brief, nonfatal attacks have occurred, apparently the result of mistaken identity.

<span class="mw-page-title-main">Siamese crocodile</span> Species of reptile

The Siamese crocodile is a medium-sized freshwater crocodile native to Indonesia, Brunei, East Malaysia, Laos, Cambodia, Myanmar, Thailand and Vietnam. The species is critically endangered and already extirpated from many regions. Its other common names include Siamese freshwater crocodile, Singapore small-grain, and soft-belly.

<i>Crocodylus</i> Genus of reptiles

Crocodylus is a genus of true crocodiles in the family Crocodylidae.

<span class="mw-page-title-main">Orinoco crocodile</span> Species of reptile

The Orinoco crocodile is a critically endangered crocodile. Its population is very small, and they can only be found in the Orinoco river basin in Venezuela and Colombia. Extensively hunted for their skins in the 19th and 20th centuries, it is one of the most endangered species of crocodiles. It is a very large species of crocodilian; males have been reported up to 6.8 m in the past, weighing over 900 kg (2,000 lb), but such sizes do not exist today, 5.2 m being a more widely accepted maximum size. A large male today may attain 4.2 m in length and can weigh up to 450 kg (1,000 lb), while females are substantially smaller with the largest likely to weigh around 225 kg (496 lb). Sexual dimorphism is not as profound as in other crocodilian species. The coloration is light even in adults.

<span class="mw-page-title-main">Philippine crocodile</span> Species of crocodile

The Philippine crocodile, also known as the Mindoro crocodile, the Philippine freshwater crocodile, the bukarot in Ilocano, and more generally as a buwaya in most Filipino lowland cultures, is one of two species of crocodiles found in the Philippines; the other is the larger saltwater crocodile (Crocodylus porosus). The Philippine crocodile, the species endemic only to the country, went from data deficient to critically endangered in 2008 from exploitation and unsustainable fishing methods, such as dynamite fishing. Conservation methods are being taken by the Dutch/Filipino Mabuwaya foundation, the Crocodile Conservation Society and the Zoological Institute of HerpaWorld in Mindoro island. It is strictly prohibited to kill a crocodile in the country, and it is punishable by law.

<span class="mw-page-title-main">Morelet's crocodile</span> Species of reptile

Morelet's crocodile, also known as the Mexican crocodile or Belize crocodile, is a modest-sized crocodilian found only in the Atlantic regions of Mexico, Belize and Guatemala. It usually grows to about 3 metres (10 ft) in length. It is a species at least concern for extinction according to the International Union for Conservation of Nature. The species has a fossil record in Guatemala.

<span class="mw-page-title-main">Papuan eagle</span> Species of bird

The Papuan eagle is a large bird of prey. It is also known by several other names, including Papuan harpy eagle, New Guinea eagle, New Guinea harpy eagle, or kapul eagle, the latter name from the local name for a usually arboreal marsupial that the eagle is known to regularly hunt. This is an endemic species to New Guinea, and it can occasionally be found throughout the island. This is a forest-dwelling species, usually occurring in mature rainforest. The Papuan eagle is a fairly little-known species for a large eagle; however, it is known to prey on a wide range of prey, probably by and large mammals and birds from small to quite large sizes. Unique amongst eagles, the Papuan eagle is a surprisingly fast and agile terrestrial avian predator and is capable of chasing down prey on the forest floor. What little study has been conducted about its breeding habits suggests it nests in a large forest tree, perhaps every other year. The Papuan eagle is probably naturally scarce, but it is under the threat of habitat destruction by deforestation, as well as hunting. Due to its small and declining population, the species has been classified as vulnerable by the IUCN.

<i>Mecistops</i> Genus of reptiles

Mecistops is a genus of crocodiles, the slender-snouted crocodiles, native to sub-Saharan Africa.

<span class="mw-page-title-main">Cuban crocodile</span> Species of crocodile endemic to Cuba

The Cuban crocodile is a small-medium species of crocodile endemic to Cuba. Typical length is 2.1–2.3 m (6.9–7.5 ft) and typical weight 70–80 kg (150–180 lb). Large males can reach as much as 3.5 m (11 ft) in length and weigh more than 215 kg (474 lb). Despite its smaller size, it is a highly aggressive animal, and potentially dangerous to humans.

Crocodylus palaeindicus is an extinct species of crocodile from southern Asia. C. palaeindicus lived from the Miocene to the Pliocene. It may be an ancestor of the living Mugger crocodile.

<span class="mw-page-title-main">West African crocodile</span> Species of reptile

The West African crocodile, desert crocodile, or sacred crocodile is a species of crocodile related to, and often confused with, the larger and more aggressive Nile crocodile.

<span class="mw-page-title-main">Crocodile farming in the Philippines</span>

Crocodile farming in the Philippines refers to agricultural industries involving the raising and harvesting of crocodiles for the commercial production of Crocodile meat and crocodile leather.

Crocodylus halli, also known as Hall's New Guinea crocodile, is a species of crocodile endemic to the island of New Guinea. It is found on the southern half of the island, south of the New Guinea highlands. It is named after Philip M. Hall, a researcher at the University of Florida who performed the initial studies to clarify the species' distinctiveness.

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