Binturong
Asian mammal also known as a bearcat
From Wikipedia, the free encyclopedia
The binturong (Arctictis binturong) (/bɪnˈtjʊərɒŋ, ˈbɪntjʊrɒŋ/; bin-TURE-ong, BIN-ture-ong), also known as the bearcat, is an arboreal viverrid native to South and Southeast Asia. It is the only species in the genus Arctictis, but is further divided into nine subspecies. It has long, thick hair, primarily dark in appearance, but can also have a whitish speckled pelage. It is unique in morphology with its popcorn-scented musk glands, and its long, bushy, prehensile tail.
| Binturong | |
|---|---|
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| In the Zoo Parc Overloon, the Netherlands | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Family: | Viverridae |
| Subfamily: | Paradoxurinae |
| Genus: | Arctictis Temminck, 1824 |
| Species: | A. binturong[3] |
| Binomial name | |
| Arctictis binturong[3] (Raffles, 1822) | |
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| Binturong range | |
The binturong is an omnivore, feeding on plants, insects, and smaller animals. It is primarily nocturnal, but also exhibits crepuscular behaviour. Females are able to enact delayed implantation, where a fertilized egg is not attached to the uterine walls until external conditions are ideal. The major threats to the binturong include habitat loss and forest degradation, as well as illegal hunting and trading. It has been assessed as Vulnerable on the IUCN Red List.
Etymology
The scientific name Arctictis means 'bear-weasel', from the Greek arkt- "bear" + iktis "weasel".[4] The name "binturong" is derived from the words běnturong and těnturun in the dialect used by those living in Riau, Indonesia.[5] In the Western Malayo-Polynesian languages spoken in Borneo, the name could be attributed to two words, kitan (meaning squirrel) and ma-tuRun (meaning the one who descends).[6]
Viverra binturong was the scientific name proposed by Thomas Stamford Raffles in 1822 for a specimen from Malacca, Malaysia.[7] The generic name Arctictis was proposed by Coenraad Jacob Temminck in 1824.[8]
Taxonomy and evolution
Arctictis is one of four genera found in the subfamily Paradoxurinae, a clade estimated to have diverged 35.5 to 21.9 million years ago (Mya).[9] The first genus to diverge was Arctogalidia, around 21.9 Mya, followed by Arctictis (15.9 Mya), Paguma (10.7 Mya), and Paradoxurus (7.1 Mya).[9]
Paradoxurinae phylogenetic tree:[9]
| Paradoxurinae |
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Although Arctictis is a monotypic taxon, it can be further divided into two clades, with a total of nine distinct subspecies.[10] The northern Indo-Chinese clade is separated from the southern Sundaic clade by the Isthmus of Kra.[11] It was hypothesized that during the Pleistocene, the binturong was able to disperse along a land bridge connecting the two now separated clade regions, and that the gene flow between the two clades was blocked due the rising of sea levels, leading to allopatric speciation.[12][13]
Nine subspecies of the binturong were proposed:[10]
- A. b. binturong (Raffles, 1821) occurs in Malaysia;[7]
- A. b albifrons (Cuvier, 1822) was a specimen from northern Vietnam;[14]
- A. b. whitei (Allen, 1910) was a specimen from Palawan islands;[15]
- A. b. pageli (Schwarz, 1911) was collected in northern Borneo;[16]
- A. b. gairdneri (Thomas, 1916) was a specimen from northern Thailand;[17]
- A. b. niasensis (Lyon, 1916) was collected on Nias island;[18]
- A. b. penicillatus (Pocock, 1933) occurs in Java;[10]
- A. b. kerkhoveni (Sody, 1936) occurs on Bangka Island;[19]
- A. b. menglaensis (Wang & Li, 1937) was a specimen from Yunnan province.[11]
Three of the proposed subspecies are a part of the northern clade (A. b. albifrons, A. b. gairdneri, and A. b. menglaensis) while the other six are a part of the southern clade (A. b. binturong, A. b. whitei, A. b. pageli, A. b. niasensis, A. b. penicillatus, and A. b. kerkhoveni).[13]
Characteristics
The binturong is long and heavy, with short, stout legs. It has a thick coat of coarse black hair. The bushy and prehensile tail is thick at the root, gradually tapering, and curls inwards at the tip. The muzzle is short and pointed, somewhat turned up at the nose, and is covered with bristly hairs, brown at the points, which lengthen as they diverge, and form a peculiar radiated circle round the face. The eyes are large, black and prominent. The ears are short, rounded, edged with white, and terminated by tufts of black hair. There are six short rounded incisors in each jaw, two canines, which are long and sharp, and six molars on each side. The hair on the legs is short and of a yellowish tinge. The feet are five-toed, with large strong claws. The soles are bare, and are plantigrade, applied to the ground throughout the whole of their length―and the hind ones are longer than the fore ones.[7] Its prehensile tail is unique in carnivorans.[20]
In general build, the binturong is essentially like Paradoxurus and Paguma, but more massive in the length of the tail, legs and feet, in the structure of the scent glands, and in the larger size of the rhinarium, which is more convex with a median groove being much narrower above the philtrum. The contour hairs of the coat are much longer and coarser, and the long hairs covering the whole of the back of the ears project beyond the tip as a definite tuft. The anterior bursa flap of the ears is more widely and less deeply emarginate. The tail is more muscular, especially at the base and, in colour, generally like the body, but commonly paler at the base beneath. The body hairs are frequently partly whitish or buff, giving a speckled appearance to the pelage, sometimes so pale that the whole body is mostly straw-coloured or grey. The young are often paler than the adults, but the head is always closely speckled with grey or buff. The long mystacial vibrissae are conspicuously white, and there is a white rim on the summit of the otherwise black ear. The glandular area is whitish.[10]
The tail is nearly as long as the head and body. The body ranges from 71 to 84 cm (28 to 33 in) and the tail is from 66 to 69 cm (26 to 27 in) long.[21] Some captive binturongs measured from 75 to 90 cm (30 to 35 in) in head and body, with a tail of 71 cm (2 ft 4 in).[22] The mean weight of captive adult females is 21.9 kg (48 lb), with a range from 11 to 32 kg (24 to 71 lb). Captive animals often weigh more than their wild counterparts.[23] 12 captive female binturongs were found to weigh a mean of 24.4 kg (54 lb) while 22 males weighed a mean of 19.3 kg (43 lb).[24] In one study, the estimated mean weight of wild females was 10.5 kg (23 lb).[23] However, seven wild male binturongs in Thailand were found to weigh a mean of 13.3 kg (29 lb), while one female was of similar weight at 13.5 kg (30 lb).[25] One estimate of the mean body mass of wild binturongs was 15 kg (33 lb).[26]
Both sexes have scent glands—females on either side of the vulva, and males between the scrotum and penis.[27][28] The musk glands emit an odor reminiscent of popcorn or corn chips, described as "ltpɨt" by the Malaysian Jahai people, likely due to the volatile compound 2-acetyl-1-pyrroline in the urine, which is also produced in the Maillard reaction at high temperatures.[29] Unlike most other carnivorans, the male binturong does not have a baculum.[30]
Distribution and habitat
The binturong can be found across South and Southeast Asia including India, Nepal, Bangladesh, Bhutan, Myanmar, Thailand, Malaysia, Laos, Cambodia, Vietnam, China, Indonesia, and the Philippines.[31][32][33] They are mostly arboreal, but descend to the ground when moving between trees.[34] Binturongs typically occupy elevations between 0 meters and 3000 meters, with primary and secondary lowland forests being more common.[1][35] Keeping the vulnerable species captive in zoos is also common, allowing observation and research access.[11]
In Assam, India, they are commonly found in foothills or hills with good tree cover, but less so in the forested plains.[36] In Laos, they have been observed in extensive evergreen forest.[37] In Malaysia, they have been recorded in secondary forest surrounding a palm estate that was logged in the 1970s.[38] In Palawan, the binturong inhabits primary and secondary lowland forest, including grassland–forest mosaic from sea level to 400 m (1,300 ft).[35]
Ecology and behavior
The binturong is active during the day and at night.[39][37] While binturong have been sighted during the day in Pakke Tiger Reserve, other studies have revealed binturong to be active during nights and early mornings.[40][41] Since binturongs are not very nimble, they likely have to descend to the ground relatively frequently when moving between trees.[34]
Five radio-collared binturongs in the Phu Khieo Wildlife Sanctuary exhibited an arrhythmic activity dominated by crepuscular and nocturnal tendencies with peaks in the early morning and late evening.[26] Reduced activity periods occurred from midday to late afternoon. They moved between 25 m (82 ft) and 2,698 m (8,852 ft) daily in the dry season and increased their daily movement to 4,143 m (13,593 ft) in the wet season. Range size of males varied between 0.9 and 6.1 km2 (0.35 and 2.36 sq mi).[26] The average home range of a radio-collared female in the Khao Yai National Park was estimated at 4 km2 (1.5 sq mi), and the one of a male at 4.5 to 20.5 km2 (1.7 to 7.9 sq mi).[42]
The binturong is essentially arboreal.[10] Pocock observed the behaviour of several captive individuals in the London Zoological Gardens. When resting, they lay curled up with their heads tucked under their tails. They seldom leaped, but climbed skillfully, albeit slowly, progressing with equal ease and confidence along the upper side of branches or, upside down, beneath them. The prehensile tail was always ready as an aid. They descended the vertical bars of the cage head first, gripping them between their paws and using the prehensile tail as a check. They growled fiercely when irritated, and when on the prowl they periodically uttered a series of low grunts or a hissing sound, made by expelling air through partially opened lips.[10]
The binturong uses its tail to communicate.[27] It moves about gently, clinging to a branch, often coming to a stop, and using its tail to keep balance. It shows a pronounced comfort behaviour through shaking its hair, grooming its fur, and scratching its body.[43]
Diet
_camera_trapped_at_a_feeding_platform_on_a_fruiting_Ficus_at_Pakke_tiger_reserve.JPG)
The binturong is omnivorous, feeding on small mammals, rodents, birds, fish, earthworms, insects, and fruits.[21][44] Figs are a major component of its diet.[39][40][45] The binturong is considered to be a keystone species as they are very important dispersers of Ficus seeds, specifically strangler fig, because of their ability to scarify the seed's tough outer covering.[46][47]
Fish and earthworms are likely unimportant items in its diet, as it is neither aquatic nor fossorial, coming across such prey only when opportunities present themselves. Since it does not have the attributes of a predatory mammal, it is likely that most of the binturong's diet is vegetable matter.[10]
Predation and defensive adaptations
Binturongs are not known to be very susceptible to natural predators, but occasionally fall victim to tigers and dholes.[26] Despite this fact, binturongs have a variety of defence mechanisms. When threatened, binturongs use a unique scent gland located under their tail that produces a popcorn-like odor which wards off any potential threats and marks their territory.[29] Binturongs have also been known to defecate or urinate on potential threats. As a last resort, binturongs may defend against predators with their sharp teeth and strong bite force.[48]
Reproduction
As a vulnerable species, many reproductive behaviours in binturong have only been observed in captivity.[23] Copulation typically takes place within the tree canopy, once male and female binturongs reach around 30.4 and 27.7 months old respectively.[23] They reproduce year round, with gestation ranging 84 to 99 days in length, and the estrous cycle ranging 18 to 187 days.[23] They remain fertile for 15 out of their 18 year lifespan.[23] Their characteristic buttered popcorn scent is likely used for reproductive signalling, in addition to defense.[29]
Interactions between male and female binturongs were found to be dependent on the female's ovulation cycle.[23] During anestrus, or reproductive slowdown, females reduce interactions with males, while males act defensive in response.[23] During estrus, or reproductive receptiveness, females increased their mate calling activity and males were no longer defensive.[23] Throughout copulation, female binturongs make a loud and coarse purring sound to signify successful reproductive receptivity between the mating pair.[23]
Female binturongs can enact delayed implantation, which is a reproductive strategy that allows them to keep the fertilized egg from attaching to the walls of their uterus.[49] This helps binturongs maximize the likelihood of a successful reproduction. The pair can mate when the opportunity arises, and complete the cycle when environmental conditions are ideal, ensuring food availability and favourable temperatures.[49] This is a particularly beneficial reproductive strategy, as it helps increase mating events in an otherwise isolated species without the risk of completing gestation under precarious environments.[49] When implantation is successful, gestation occurs. Successful births observed in captivity results in litter sizes that vary from one to six young, with an average of two young per birth.[23] The newborn babies (binlets), weighing between 280 and 340 g, are altricial, requiring maternal care until they are fully developed.[49]
Threats
Habitat Loss
Binturongs face several environmental and anthropogenic threats. As assessed by the International Union for Conservation of Nature (IUCN), one of the major threats of habitat loss is forest degradation through logging and conversion of forests into non-forested land such as plantations.[50] Habitat loss has been especially severe in the lowlands of the Sundaic part of its range, showing no signs of slowing down.[50]
While most sources agree that habitat loss is directly linked to population decline, there have been some contradicting opinions surrounding the topic. In 2016, the IUCN published a report on binturongs, and found no evidence for population recovery after forests were converted to plantations.[50] Since then, a few studies have found that binturongs were able to acclimatize to the plantations, finding no significant differences in population counts between degraded and non-degraded forests.[51] The authors proposed that binturongs were able to remain resilient due to increased nocturnal activity.[51] While the results of this study may provide hope for binturong resilience and successful restoration initiatives, the authors also acknowledged a few limitations that could bias their results. The models used in the study do not fully capture the complexity of binturong behaviour due to limited knowledge of the binturong's life history, and they did not consider a link between degraded forests and increased hunting prevalence.[51]
Hunting, Trade, and Coffee
In Southeast Asia, there is pressure to hunt binturongs for their meat and skins, which are consumed as food and used in traditional medicines.[50] There is also a demand for captive binturongs, especially juveniles, as part of the illegal pet trade and for kopi luwak production.[52] Kopi luwak is a unique coffee product made primarily by Asian palm civets, but can also be made by the binturong and masked palm civets.[53] Due to its rarity and novelty, the beans can cost between 200-400 USD per kg.[54]
Civets are not harmed through the traditional production methods of this coffee, which consists of groups collecting naturally digested beans from the forest floor, defecated by wild populations.[54] However, the global demand is often higher than local groups can supply. To fill the supply gap, commercial production companies collect and produce kopi luwak on much larger scales.[54] These businesses are often connected to malpractice, resulting in the harm or death of the captive civets.[54]
Non-profit organizations, animal welfare, and conservation groups have been shown to work with civet coffee production groups to improve ethical guidelines, and support small-scale traditional producers.[54] However, recent evaluations of "outlets", or civet coffee tourism plantations, found that enforcement of ethical regulations and laws were lacking, and that most plantations did not uphold diet, hygiene, water, or mobility standards.[54]
Conservation
The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is an international coalition that seeks to protect at-risk species.[55] The binturong is listed under CITES Appendix III, which means that it is protected in at least one country, and requires collaboration from CITES countries to uphold regulations for international trade.[56] Nationally, the level of protection for this species varies.[50]
Ex-Situ conservation is a method of conservation that aims to conserve genetic diversity by capturing binturong, breeding them, and releasing them back into the wild.[57] While captive breeding has been successful for other species, a major problem with this method stems from the lack of information on genetic origin or mistakes in pedigree tracking, which can lead to accidental hybridization or inbreeding.[57] In fact, in 2006, a study assessing captive-bred binturong populations found there to be low genetic diversity.[58]
In-Situ conservation methods focus on conserving a species within their natural habitat and ecosystem.[57] ABConservation is the only non-profit collaborative organization focused on binturong conservation. In 2016, they spear-headed an in-situ conservation project called the Bearcat Study Program located on Palawan Island in the Philippines, where they monitored binturong populations, and used their findings to build on binturong research.[57] ABConservation has been steadfast in their commitment to fostering strong relationships with locals and local corporations. This includes collaborating with Sabuya Coffee Trading, a sustainable civet-coffee company, and the Rurungan Sa Tubod Foundation, a local, female-led organization raising funds for the Bearcat Study Program by selling goods made from pineapple fibres.[57]
