Dhole
| Dhole | |
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| Genus: | Cuon Hodgson, 1838
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| Species: | C. alpinus
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| Binomial name | |
| Cuon alpinus | |
The Dhole (Cuon alpinus) is a species of wild dog of the Canidae family. It is also known as the Asiatic Wild Dog; lesser known names include the Indian Wild Dog, the Red Dog, the Asiatic Dog, and the Whistling Hunter (due to the whistling sound it can make).
Within the canid family, the dhole is placed in a genus of its own, which is post-Pleistocene in origin. The dhole has been a distinct species for several million years. Cuon means dog in Greek, and alpinus means alpine (Mountain) in Latin. Thus the dhole’s scientific name means mountain dog. The animal is closely related to the genus Canis, and is by some authors considered part of Canis. Other related genera are Lycaon (African wild dog) and, more distantly, Pseudalopex and other South American Foxes.
The dhole is, generally, most active in the early morning and evening, and sometimes at night.
Three geographical races are believed to exist: peninsular, Himalayan and trans-Himalayan.
The dhole can live to 16 years in captivity, though 10 is common in the wild. The chromosome number is 2n = 78.
Habitat
The dhole exploits a large variety of habitats, reflecting its adaptability. It normally inhabits dry and moist deciduous forests and thick jungles, as well as tropical rain forests, which all provide better cover for hunting. It inhabits areas of primary, secondary, degraded, evergreen, and semi-evergreen forms of vegetation, and dry thorn forests, as well as scrub-forest mosaics. It can also, however, survive in dense alpine forests, meadows and on the open steppes of Kashmir and Manchuria. As the second part of its Latin name, Alpinus, suggests, the dhole is often found in hilly or mountainous regions. Dholes like open spaces and during the day they can often be found on jungle roads and paths, river beds, and in jungle clearings. The dhole inhabits in the widest range of climates in the canid family – from freezing cold to tropical heat, but is not recorded in deserts.
Factors which influence habitat include water, the presence of other large predators (competition), sufficient prey (plentiful medium to large ungulate prey species), local human population, and suitable breeding sites.
Geographical range
The dhole originates from South Asia. Its range is - latitude: 10 deg. South to 55 deg. North; Longitude: 70 deg. East to 170 deg. East. Its historical range extended from India to China, and down to Malaysia and Indonesia, with Java as the Southern limit. In recent decades, there has been huge habitat loss in this region, and restricted surveys indicate serious decline and fragmentation of the former range.
The dhole's current range extends from the borders of Russia and the Altai Mountains in Manchuria (Central and Eastern Asia) to Northern and Western Pakistan to the forest tracts of India, Burma, and the Malayan Archipelago. The best remaining populations are probably to be found in Central (especially in the Highlands), Western and Northern Pakistan and Southern India.
Physical description
Head and body length: 83 – 133cm (35 - 45in), though 100cm is the usual. Northern populations are around 20% longer. Tail length: 28 - 50 centimeters (11-20in) Height at shoulder: 42 – 55cm (16 – 21in) Weight: Females weigh in at 10 - 16 kg, while males average 14 - 20 kg.
The dhole is about the size of a collie, and is similar to the dingo, gray wolf, and golden jackal. Its coat is usually a uniformly rusty red hue, but varies regionally from sandy, creamy yellow through red and brown to dark gray. Sometimes it is grizzled. Generally, the dhole has a black-tipped – though sometimes white or brown or gray - moderately bushy tail, a darker area on its back, and white or pale patches on its chest, paws and belly. Its large ears (about half the length of the face) are rounded with white on the inside, its legs are short, and its eyes are slightly hooded and have amber irises. The dhole has sixteen teats, reflecting its ability to care for many young. This is more teats than most other dogs. It has four toes on each paw, with fur between the toes, which are red, brown, and/or white. The fore-toe pads are hairless, and are joined at the base near the main pad, unlike most domestic dogs. The jaw is thick, blunt, relatively short, slightly convex in profile, and squarish.
Diet
The dhole is an omnivore. Its prey are usually deer (like spotted deer, chital, and sambar, which is over twenty times a dog’s weight), but also wild boar, red muntjac deer, wild goats, wild sheep, nilgai, mountain sheep, water buffalo, hares (like the Black-naped Hare), caribou, reindeer, gaur and sometimes monkeys. On occasion, it will try for large creatures like the banteng, a large bovid. Dholes prefer prey between 31kg and 175kg in weight. Also, the dhole may consume wild berries, insects, rodents, East Asian porcpine, and lizards. In India, the dhole’s favorite prey animal is the medium-sized axis deer. Occasionally they consume grasses and other plants, though this may serve an anti-helminthic function rather than a nutritional one. They are said to feed on the fallen fruit of black wood and bael trees.
Dentition
The dhole has large, sharp teeth, and a shorter jaw and an unusually thicker muzzle than most other dogs. There is one less molar on each side of its lower jaw (meaning that they have forty teeth in total). Its dental formula (Incisors 3/3 : Canines 1/1 : Premolars 4/4 : Molars 2/2) is unique among the dog family. The heel of the lower carnassial M1 is crested with a single cusp, which enhances the sheering capacity of teeth and thus the speed at which prey can be consumed. This may improve their ability to resisit kleptoparasites.
Hunting
Although the dhole is not a fast runner, it has great stamina, and will pursue prey for hours, though not always to exhaustion. Most chases are less than a few hundred metres in length. As it is an excellent swimmer, it will often drive its prey into water, surrounding the animal and swimming out in teams to perform the capture. The dhole is capable of killing prey ten times its own size, and will defend kills very violently. It has been seen killing bears and tigers. The dhole is mainly a crepuscular forager. During hunts, some dholes may lie in ambush, while others drive prey in their direction.
Sometimes several families unite in order to hunt larger animals. The dhole seldom kills by tearing out the throat. Larger mammals are attacked from behind and swiftly disemboweled, and smaller ones are caught by any part of the body and killed by a quick blow to the head. Often, a dhole pack will start on prey before it is even dead, like the African Hunting Dog does. The larger prey (which require a coordinated attack, frequently resulting in a “lead hunt dog” emerging by taking a prominent role in disabling the prey. Other roles taken on include taking the first grab at the prey) more often die from the blood loss as its body parts are feasted upon rather than the attack itself. Two or three dholes can bring down a 50 kg (110 lb) deer in less than two minutes, and individuals can hold 3kg in their stomachs, allowing meat to be transported.
After meals (during which a couple of dholes act as look-outs, wary for leopards and tigers who could kill them or steal their kill, and humans also), they race to a water site, and sometimes, if the water is near their kill, dholes will leave their food for a small drink of water.
Dhole packs compete for food, not by fighting, but by how fast they can consume it. An adult dhole can eat up to 4 kg (8.8 lb) of meat in one hour. When as a pack it can subdue prey over ten times its own body weight and can even attack leopards, the Indian bison, and tigers. Sometimes, however, the dhole prefers to hunt in a pair or singly. The hunting range is about 40sq km (15sq mi). They hunt well in open fields and in thick forest.
Dholes only scavenge in times of food shortage, especially during the dry season. They will return to prey remains three or four days after the animal was brought down. Dholes have been recorded consuming elephant carrion, and may steal the kills of other species.
Reproduction
Sexual dimorphism is not very distinct with no quantitative anatomical differences known. Both males and females become sexually active at one year old, though females usually breed at 2 years in captivity, and in the wild, for the first time at 3 years, possibly due to physiological and behavioural restraints. Females exhibit seasonal polyoestrus, with a cycle of around 4-6 weeks. Pups are born throughout the end of fall, winter, and the first spring months ( November - March ) - dens are earthern burrowns, or are constructed amongst rocks and boulder structures, in rocky caverns, or close to streambeds. In East Java, dholes are thought to mate mainly between January and May. A mating pair engages in marking and lively play, culimnating in a coplatory tie.
After a gestation period of around 60-62 days, females usually give birth to about eight pups (though the range is 5-10, the record is 12, and sizes vary drastically within the same pack through different years), which weigh 200-350g. At 10 days their body weight has doubled, and body length is 340mm. Pups are weaned between 6 and 9 weeks. In captivity, weaning is sometimes recorded later on in the range. By 8 weeks, younglings are less quarrelsome and aggressive, and more vigilant. At three months litters go on hunts, though the pack may not be fully mobile until eight months. Young reach sexual maturity at about a year, and full adult size at 15 months.
After birth, a few other adults will help to feed the young of the dominant pair. The pups, as early as the tender age of three weeks, and the mother are fed regurgitated meat. When lone females breed, rearing the litters only results in limited success.
Behavior
The dhole is a highly sociable and cooperative animal, like the Timber wolf, the Amazonian Bush Dog, and the African Hunting Dog. Generally it lives in organized, extended-family packs of five to twelve individuals (this number rarely exceeds twenty five), with more males, sometimes twice as many more, than females, and usually just one breeding female. Sometimes pack-members interact with other dholes outside of their own group; these interactions may be positive or hostile (home ranges are often quite separate). Group size and composition may vary under different environmental conditions. Large packs of over forty dholes have been sighted, possibly resulting from the temporary fusion of neighboring packs. Older dholes of around 7-8 years sometimes vanish from the group.
Within dhole packs, there is almost never any aggression – there is a strict social hierarchy, so fighting is not needed - or bullying, save for play-fighting among cubs. Each pack contains a dominant monogamous pair, who are usually the sole breeders. However, junior males may display sexual interest in the dominant female, and sometimes father cubs. Pack members play together regularly, allo-grooming, mock-fighting, and rolling around. Social rank is reinforced by shoving and holding, rarely by biting. Dispersal is female-biased.
Within a group, members over-mark each other's waste, creating individual latrines in the home range. These latrines serve intra-group communication, for example passing on information concerning sexual status. Video footage has been taken of a dhole urinating while balancing only on the two front paws.
Dholes are fond of water. They have been spotted sitting in shallow pools of water regardless of the temperature.
Like domestic dogs, dholes wag their tails.
The dhole can leap to at least 2.3 meters (7.5 feet).
Vocalization
The dhole has some extraordinary vocal calls. It can make high-pitched screams, mew, hiss, squeak, yelp, chatter, and cluck like a chicken. Growl-barks and other noises alert pack-mates to danger; the large range of calls like these may have evolved to warn companions of different dangers - human, tiger, etc. Calls also act as threats to scare off enemies. Its best-known sound is its strange whistle, likened by early naturalists to the sound obtained when air is blown over an empty cartridge. These calls are used for contact within the pack. The repetitive whistles are so distinct that individual dholes can be identified by it, and the source is easily located. Whistles travel well at ground level due to their frequency and structure.
Population pressures
It is estimated that 2,500 mature individuals remain in the wild (mainly in wildlife sanctuaries and protected national parks), and the declining population trend is expected to continue.
One major threat to the dhole is habitat destruction (and thus loss of prey, which is aggravated by deer poaching). In India alone, over 40,000 square kilometres of forest has disappeared in the last 20 years. Also, in Vietnam, few natural forested areas over 50 square kilometres remain. The main factors in this were logging, firewood collection, flooding due to dam construction, and agricultural expansion. Habitat deterioration fragments the dhole population, resulting in problems like disease (it is unclear whether this is a significant problem in Indochina and Indonesia, but definitely depletes the population in South Asia) and inbreeding, which have more permanent effects. Dhole habitat is also being transformed, like in Sumatra.
Human persecution also contributes to the dhole’s decline (medicinal uses of the dhole in areas such as China should be looked into). Indiscriminate snaring (“By-catch”) and other non-selective hunting techniques have devastating results. The dhole is regarded as vermin – on rare occasions, dholes attack livestock, at the cost of the owner, e.g. in Arunachal Pradesh - and has therefore been shot, trapped, and poisoned (e.g. from strychnine). British colonial hunters also shot and poisoned dhole-killed prey-carcasses because the canine was seen as a threat to local wild ungulate densities.
However, prejudice towards the dhole still exists. Levels of persecution vary regionally, depending on cultural principles, wildlife law enforcement, and the intensity of livestock predation. Levels of persecution in Laos, Vietnam and Cambodia are especially high. Upset farmers have been known to club pups to death at den sites (breeding and pup-rearing is sometimes inadvertently disrupted, too).
Hunting and trapping for fur is not recorded as a significant contributor to the dhole’s decline, perhaps because they are not numerous. In the 19th Century dhole-fur was valuable in Ussuryisk Krai, and moving into the 20th Century they were pricy in Manchzhuriya. Nowadays the odd dhole-skin is recorded as a curio. Currently there is no known widespread exploitation of the pelts. Dhole mortalities as a result of road-kill are highest in India, where many roads and trails cut through their habitat.
With suitable areas steadily diminishing and cattle being grazed within the forests, livestock occasionally fall prey to the dhole. If protection is not rigidly enforced, stockmen retaliate by excavating the den and clubbing the pups to death. Generally dholes ignore domestic animals, but when their natural prey is diminished, they are starving. In India farmers can be compensated if there is definitive proof that their livestock has been killed by dholes outside core protected areas.
Dholes also sometimes prey on threatened species. For example, the banteng numbers in Alas Purwo National Park (Java) were decreasing drastically due to dhole predation. In the end the dhole population fell when banteng were not numerous enough to support them. In Kanha, India, the dhole preys on a rare, endemic subspecies of swamp deer.
Depletion of the dhole’s prey animal populations is another problem. In much of the dhole’s habitat, even in protected areas, ungulate populations are low. In Laos, Cambodia, and Vietnam, species larger in size than a hare have been reduced significantly because of hunting. Muntjacs and southern serow are some of the few species that haven’t been severely affected. Prey numbers in Indonesia are also low.
Further pressures are applied by local villagers who steal the dhole's kills for their own pot, as dholes do not attack humans, and retreat at the sight of one. In this way, the dhole has become an indirect food source for the people of the jungle. People who have been recorded scavenging dhole-kills include Kuruma tribes of the Niligiris in the south of India, and at least one Mon Khmer-speaking tribe (Laos). In other regions such as Russia, poisons set out for wolves may be responsible for declines in the local dhole population.
The effects of intra-guild competition on dhole densities is unknown, though they have to compete with humans, and perhaps with domestic dogs.
Health
Dholes are in danger of catching infectious diseases when they come in contact with other animals, especially canines – including feral and domestic dogs. They have been known to suffer from mange, canine distemper, and trypanosomiasis. Canine parvovirus was recorded in the Hodenhagen and Chennai zoos. Sporadically, the dhole is a health risk for human beings, since their excreta contain transmittable pathogens (e.g. Toxocora canis). Dhole waste has also been found to contain roundworm, cestodes, and other endoparasites. Like other canines, dholes can catch rabies; in the 1940s, rabid dholes bit and infected villagers in the Billigirirangan Hills, in India. This incident resulted in human death.
Most injuries dholes suffer are from prey animals, but wounds are inflicted by tigers and leopards; sometimes these attacks result in death. Interactions between the dhole and these felines are rare, and are thought to be usually limited to intimidation and stalking, presumably aimed at gaining more hunting ground. However, in the south of India, in Nagarahole National Park, dhole hairs have been found in leopard excreta, suggesting that they occasionally fall prey to the cats.
Conservation
India, bounties were paid for carcasses right up until when the dhole was declared a Protected Species under Schedule 1 of the Wildlife Act of 1972, which prohibits the killing of wildlife except in self-defense or if the dhole is a man-killer – and, even then , permission is required. Hunting in the Soviet Union has been prohibited since 1971; they received the status of ‘protected animal’ in 1974.
In Vietnam, the dhole is protected by certain degrees which limit extraction and utilization, though levels of extraction and utilization are not quoted. In Cambodia, the dhole is protected from hunting. A new forestry law is under preparation, and a proposal to list the dhole as a fully-protected species is being discussed. Also, large protected areas have been declared in Laos. The creation of Project Tiger Reserves has given some protection to the “dukhenesis” subspecies. Project Tiger could potentially maintain dhole prey-animal levels in tiger-dhole inhabited regions.
There are about 110 dholes in captivity (including Dresden, Beijing, Winnipeg, and Howletts), with an even ratio of males to females. There are no current research programmes investigating the dhole. There have been no attempts to re-introduce dholes, as there is no evidence justifying this.
Subspecies
There are about eleven subspecies of the dhole, spanning different sizes and colors. Two subspecies of the dhole are classified as endangered by the World Conservation Union, meaning that they face serious risk of extinction. Another two are on the verge of extinction.
- Cuon alpinus javanicus, found in Java, has a short, bright red coat, though there are regional variations.
- Cuon alpinus sumatrensis, found in Sumatra, has a short, bright red coat and dark whiskers.
- Cuon alpinus infuscus, found in Southern Myanmar, Malaysia, Thailand, and Vietnam has a dark brown coat and distinctive cranial features.
- Cuon alpinus adjustus, found in Northern Myanmar and Indo-China, has a reddish-brown coat.
- Cuon alpinus dukhunensis, found South of the Ganges in India, has a red coat, short hair on the paws, and black whiskers.
- Cuon alpinus primaevus, found in Himalayan regions of Nepal, Sikkim, and Bhutan, has a longer, redder coat than dukhunensis, and has long hair on the paws.
- Cuon alpinus hesperius, found in Eastern Turkestan, Southern Siberia and Western China (Altai and Tienshan), has a long, bright yellow coat with a white underside and pale whiskers.
- Cuon alpinus laniger, found in Kashmir and Southern Tibet, has a full yellow-gray coat.
- Cuon alpinus fumosus, found in Western Szechuan, China, and Mongolia, has a luxuriant yellowish-red coat with a dark back and gray neck.
- Cuon alpinus lepturus, found South of the Yangze in China, has a uniform red coat with thick under-fur.
- Cuon alpinus alpinus, found in Eastern Russia (east of eastern Sayans), including Amur, has a thick tawny-red coat with a grayish neck and an ochre muzzle.
Fictional appearances
Dholes appear in Rudyard Kipling's 1895 children's story "Red Dog" (originally published as "Good Hunting", subsequently included in The Second Jungle Book) as a threat to Mowgli's wolf pack, appearing somewhat more aggressive in the story than in real life.
In an episode called "Alpha" in season six of The X-Files, a cryptid dhole from China is blamed for multiple killings.
References
- Template:IUCN2006 Database entry includes justification for why this species is endangered