Pangolin


Pangolins, sometimes known as scaly anteaters, are mammals of the order Pholidota. The one extant family, Manidae, has three genera: Manis, Phataginus and Smutsia. Manis comprises the four species found in Asia, while Phataginus and Smutsia each include two species living in Sub-Saharan Africa. These species range in size from. A number of extinct pangolin species are also known.
Pangolins have large, protective keratin scales covering their skin; they are the only known mammals with this feature. They live in hollow trees or burrows, depending on the species. Pangolins are nocturnal, and their diet consists of mainly ants and termites, which they capture using their long tongues. They tend to be solitary animals, meeting only to mate and produce a litter of one to three offspring, which they raise for about two years.
Pangolins are threatened by poaching and heavy deforestation of their natural habitats, and are the most trafficked mammals in the world., of the eight species of pangolin, three are listed as critically endangered, three are listed as endangered and two are listed as vulnerable on the Red List of Threatened Species of the International Union for Conservation of Nature.

Etymology

The name pangolin comes from the Malay word pengguling, meaning "one who rolls up". However, the modern name in Standard Malay is tenggiling; whereas in Indonesian it is trenggiling; and in the Philippine languages it is goling, tanggiling, or balintong.
The etymologies of the three generic names Manis, Phataginus, and Smutsia are sometimes misunderstood.
Carl Linnaeus invented the Neo-Latin generic name Manis apparently as a feminine singular form of the Latin masculine plural Manes, the Ancient Roman name for a type of spirit, after the animal's strange appearance.
Constantine Rafinesque formed the Neo-Latin generic name Phataginus from the French term phatagin, adopted by Count Buffon after the reported local name phatagin or phatagen used in the East Indies.
The British naturalist John Edward Gray named Smutsia for the South African naturalist Johannes Smuts, the first South African to write a treatise on mammals in 1832.

Taxonomy

All species of living pangolin had been assigned to the genus Manis until the late 2000s, when research prompted the splitting of extant pangolins into three genera: Manis, Phataginus, and Smutsia.

Among placentals

The order Pholidota was considered to be the sister taxon to Xenarthra, but recent genetic evidence indicates their closest living relatives are the carnivorans, with which they form a clade termed either Ferae or Ostentoria. Fossil groups like the creodonts and palaeanodonts are even closer relatives to pangolins. The split between carnivorans and pangolins is estimated to have occurred 79-87 Ma ago.

Among Manidae

The first dichotomy in the phylogeny of extant Manidae separates Asian pangolins from African pangolins.
Within the former, Manis pentadactyla is the sister group to a clade comprising M. crassicaudata and M. javanica. Within the latter, a split separates the large terrestrial African pangolins of genus Smutsia from the small arboreal African pangolins of genus Phataginus.
Asian and African pangolins are thought to have diverged about 38-47 Ma ago. Moreover, the basal position of Manis within Pholidota suggests the group originated in Eurasia, consistent with their laurasiatherian phylogeny.

Description

The physical appearance of a pangolin is marked by large hardened overlapping plate-like scales, which are soft on newborn pangolins, but harden as the animal matures. They are made of keratin, the same material from which human fingernails and tetrapod claws are made, and are structurally and compositionally very different from the scales of reptiles. The pangolin's scaled body is comparable in appearance to a pine cone. It can curl up into a ball when threatened, with its overlapping scales acting as armor, while it protects its face by tucking it under its tail. The scales are sharp, providing extra defense from predators.
Pangolins can emit a noxious-smelling chemical from glands near the anus, similar to the spray of a skunk. They have short legs, with sharp claws which they use for burrowing into ant and termite mounds and for climbing.
The tongues of pangolins are extremely long and - like those of the giant anteater and the tube-lipped nectar bat - the root of the tongue is not attached to the hyoid bone, but is in the thorax between the sternum and the trachea. Large pangolins can extend their tongues as much as, with a diameter of only.

Behavior

Most pangolins are nocturnal animals which use their well-developed sense of smell to find insects. The long-tailed pangolin is also active by day, while other species of pangolins spend most of the daytime sleeping, curled up into a ball.
Arboreal pangolins live in hollow trees, whereas the ground-dwelling species dig tunnels to a depth of.
Some pangolins walk with their front claws bent under the foot pad, although they use the entire foot pad on their rear limbs. Furthermore, some exhibit a bipedal stance for some behaviour and may walk a few steps bipedally. Pangolins are also good swimmers.

Diet

Pangolins are insectivorous. Most of their diet consists of various species of ants and termites and may be supplemented by other insects, especially larvae. They are somewhat particular and tend to consume only one or two species of insects, even when many species are available to them. A pangolin can consume of insects per day. Pangolins are an important regulator of termite populations in their natural habitats.
Pangolins have very poor vision, so they rely heavily on smell and hearing. Pangolins also lack teeth; therefore they have evolved other physical characteristics to help them eat ants and termites. Their skeletal structure is sturdy and they have strong front legs that are useful for tearing into termite mounds. They use their powerful front claws to dig into trees, ground, and vegetation to find prey, then proceed to use their long tongues to probe inside the insect tunnels and to retrieve their prey.
The structure of their tongue and stomach is key to aiding pangolins in obtaining and digesting insects. Their saliva is sticky, causing ants and termites to stick to their long tongues when they are hunting through insect tunnels. Without teeth, pangolins also lack the ability to chew; however, while foraging, they ingest small stones which accumulate in their stomachs to help to grind up ants. This part of their stomach is called the gizzard, and it is also covered in keratinous spines. These spines further aid in the grinding up and digestion of the pangolin's prey.
Some species, such as the tree pangolin, use their strong, prehensile tails to hang from tree branches and strip away bark from the trunk, exposing insect nests inside.

Reproduction

Pangolins are solitary and meet only to mate. Males are larger than females, weighing up to 40% more. While the mating season is not defined, they typically mate once each year, usually during the summer or autumn. Rather than the males seeking out the females, males mark their location with urine or feces and the females will find them. If there is competition over a female, the males will use their tails as clubs to fight for the opportunity to mate with her.
Gestation periods differ by species, ranging from roughly 70 to 140 days. African pangolin females usually give birth to a single offspring at a time, but the Asiatic species may give birth to from one to three. Weight at birth is and the average length is. At the time of birth, the scales are soft and white. After several days, they harden and darken to resemble those of an adult pangolin. During the vulnerable stage, the mother stays with her offspring in the burrow, nursing it, and wraps her body around it if she senses danger. The young cling to the mother's tail as she moves about, although in burrowing species, they remain in the burrow for the first two to four weeks of life. At one month, they first leave the burrow riding on the mother's back. Weaning takes place around three months of age, at which stage the young begin to eat insects in addition to nursing. At two years of age, the offspring are sexually mature and are abandoned by the mother.

Threats

Pangolins are in high demand for Chinese traditional medicine in southern China and Vietnam because their scales are believed to have medicinal properties. Their meat is also considered a delicacy. 100,000 are estimated to be trafficked a year to China and Vietnam, amounting to over one million over the past decade. This makes it the most trafficked animal in the world. This, coupled with deforestation, has led to a large decrease in the numbers of pangolins. Some species, such as Manis pentadactyla have become commercially extinct in certain ranges as a result of overhunting. In November 2010, pangolins were added to the Zoological Society of London's list of evolutionarily distinct and endangered mammals. All eight species of pangolin are assessed as threatened by the IUCN, while three are classified as critically endangered. All pangolin species are currently listed under Appendix I of CITES which prohibits international trade, except when the product is intended for non-commercial purposes and a permit has been granted.
Pangolins are also hunted and eaten in Ghana and are one of the more popular types of bushmeat, while local healers use the pangolin as a source of traditional medicine.
, set to be destroyed by authorities in Cameroon in 2017
Though pangolins are protected by an international ban on their trade, populations have suffered from illegal trafficking due to beliefs in East Asia that their ground-up scales can stimulate lactation or cure cancer or asthma. In the past decade, numerous seizures of illegally trafficked pangolin and pangolin meat have taken place in Asia. In one such incident in April 2013, of pangolin meat were seized from a Chinese vessel that ran aground in the Philippines. In another case in August 2016, an Indonesian man was arrested after police raided his home and found over 650 pangolins in freezers on his property. The same threat is reported in Nigeria, where the animal is on the verge of extinction due to overexploitation. The overexploitation comes from hunting pangolins for game meat and the reduction of their forest habitats due to deforestation caused by timber harvesting. The pangolin are hunted as game meat for both medicinal purposes and food consumption.

Virology

COVID-19 infection

The nucleic acid sequence of a specific receptor-binding domain of the spike protein belonging to coronaviruses taken from pangolins was found to be a 99% match with SARS coronavirus 2, the virus which causes COVID-19 and is responsible for the COVID-19 pandemic. Researchers in Guangzhou, China, hypothesized that SARS-CoV-2 had originated in bats and, prior to infecting humans, was circulating among pangolins. The illicit Chinese trade of pangolins for use in traditional Chinese medicine was suggested as a vector for human transmission. The discovery of multiple lineages of pangolin coronavirus and their similarity to SARS-CoV-2 indicate that pangolins are hosts for SARS-CoV-2-like coronaviruses. However, whole-genome comparison found that the pangolin and human coronaviruses share only up to 92% of their RNA. Ecologists worried that the early speculation about pangolins being the source may have led to mass slaughters, endangering the animals further, which was similar to what happened to Asian palm civets during the SARS outbreak.

''Pestivirus'' and ''Coltivirus''

In 2020, two novel RNA viruses distantly related to pestiviruses and coltiviruses have been detected in the genomes of Manis javanica and Manis pentadactyla. To refer to both sampling site and hosts, they were named Dongyang pangolin virus and Lishui pangolin virus. The DYPV pestivirus was also identified in Amblyomma javanense nymph ticks from a diseased pangolin.

Claims about medical efficacy

Pangolin scales and flesh are used as ingredients for various traditional Chinese medicine preparations. While clinical tests have not demonstrated the efficacy of those practices and they have no logical mechanism of action, their popularity still drives the black market for animal body parts, despite concerns about toxicity and transmission of diseases from animals to humans. The ongoing demand for parts as ingredients continues to fuel pangolin poaching, hunting and trading.
The official pharmacopoeia of the People's Republic of China included Chinese pangolin scales as an ingredient in TCM formulations. Pangolins were removed from the pharmacopoeia in 2020. Although pangolin scales have been removed from the list of raw ingredients, the scales are still listed as a key ingredient in various medicines.
The medical powers of pangolin meat and scales claimed by traditional Chinese medicine practitioners are based on: they eat ants; they have long tongues, and they have scales that protect them. The Chinese name chuan shan jia emphasizes the idea of penetration or passing all the way through even massive obstructions such as mountains, plus the distinctive scales which embody both penetration and protection and some people think imply similar powers to penetrate blockages within the body and to give protection.
The first record of pangolin scales occurs in Ben Cao Jinji Zhu, which recommends pangolin scales for protection against ant bites; burning the scales as a cure for people crying hysterically during the night.
During the Tang dynasty, a recipe for expelling evil spirits with a formulation of scales, herbs, and minerals appeared in 682, and in 752 CE the idea that pangolin scales could also stimulate milk secretion in lactating women, one of the main uses today, was recommended in the Wai Tai Mi Yao.
In the Song dynasty, the notion of penetrating and clearing blockages was emphasized in the Taiping sheng hui fan , compiled by Wang Huaiyin in 992.
Today, the main uses of pangolin scales result from claims they unblock blood clots, promote blood circulation, and help lactating women secrete milk. The many other claims are that they treat gynecological diseases, and that pills containing powdered pangolin scales will treat blockages of the fallopian tubes to cure infertility.

Conservation

As a result of increasing threats to pangolins, mainly in the form of illegal, international trade in pangolin skin, scales, and meat, these species have received increasing conservation attention in recent years., the IUCN considered all eight species of pangolin on its Red List of Threatened Species as threatened. The IUCN SSC Pangolin Specialist Group launched a global action plan to conserve pangolins, dubbed "Scaling up Pangolin Conservation", in July 2014. This action plan aims to improve all aspects of pangolin conservation with an added emphasis on combating poaching and trafficking of the animal, while educating communities in its importance. Another suggested approach to fighting pangolin trafficking consists in "following the money" rather than "the animal", which aims to disrupt smugglers' profits by interrupting money flows. Financial intelligence gathering could thus become a key tool in protecting these animals, although this opportunity is often overlooked. In 2018, a Chinese NGO launched the Counting Pangolins movement, calling for joint efforts to save the mammals from trafficking. Wildlife conservation group TRAFFIC has identified 159 smuggling routes used by pangolin traffickers and aims to shut these down.
Many attempts have been made to breed pangolins in captivity, but due to their reliance on wide-ranging habitats and very particular diets, these attempts are often unsuccessful. Pangolins have significantly decreased immune responses due to a genetic dysfunction, making them extremely fragile. They are susceptible to diseases such as pneumonia and the development of ulcers in captivity, complications that can lead to an early death. In addition, pangolins rescued from illegal trade often have a higher chance of being infected with parasites such as intestinal worms, further lessening their chance for rehabilitation and reintroduction to the wild. Recently, researchers have been able to improve artificial pangolin habitats to allow for breeding of pangolins, providing some hope for future reintroduction of these species into their natural habitats.
The idea of farming pangolins to reduce the number being illegally trafficked is being explored with little success. The third Saturday in February is promoted as World Pangolin Day by the conservation NPO Annamiticus.
In 2017, Jackie Chan made a public service announcement called WildAid: Jackie Chan & Pangolins .

Taiwan

is one of the few conservation grounds for pangolins in the world after the country enacted the 1989 Wildlife Conservation Act. The introduction of Wildlife Rehabilitation Centers in places like Luanshan in Taitung and Xiulin townships in Hualien became important communities for protecting pangolins and their habitats and has greatly improved the survival of pangolins. These centres work with local aboriginal tribes and forest police in the National Police Agency to prevent poaching, trafficking, and smuggling of pangolins, especially to black markets in China. These centers have also helped to reveal the causes of death and injury among Taiwan's pangolin population. Today, Taiwan has the highest population density of pangolins in the world.