Dingo

The Dingo and the New Guinea Singing Dog (Canis lupus dingo. Also known as Warrigal, Maliki, Mirigung, Boololomo or Australian Native Dog for the Austrailian race and NGSD and Singer for the New Guinea race) is a feral dog which mostly lives independently from humans. It is generally thought to originate from a population of domesticated dogs, possibly at a single occasion during the Austronesian expansion into Southeast Asia.^[3] Though commonly described as an Australian wild dog, it is not restricted to Australia, nor did it originate there and is in fact a feral domestic dog rather than a separate species.^[4] Modern dingoes are found throughout Southeast Asia, mostly in small pockets of remaining natural forest, and in mainland Australia, particularly in the north. They have features in common with both wolves and modern dogs, and are regarded as more or less unchanged descendants of an early ancestor of modern dogs. The name dingo comes from the language of the Eora Aboriginal people, who were the original inhabitants of the Sydney area. Singers have remained isolated from other dogs for almost 6000 years,^[5] making them possibly the oldest of the pariah dogs. Once thought to inhabit the entire island of New Guinea. They are exceptionally intelligent, but hard to keep because of wild behavioural traits. However, unlike dingoes, singers can, in some cases, easily become domesticated animals with proper training, their pack-instincts may allow them to live with humans. They are recognized as a breed by the United Kennel Club, which places them in the Sighthound & Pariah Group. However the dingo race is yet to be accepted as a breed.

Description

Appearance

Despite the fact that dingoes and New Guinea Singing Dogs are of the same subspecies, there are a few differences.

Adult dingoes are typically 48–58 cm (19–23 inches) tall at the shoulders, and weigh on average 23–32 kgs (50–70 pounds), though specimens weighing 55 kg (120 pounds) have been recorded.^[6]^[7] Dingoes in southern Australia tend to be smaller than dingoes occurring in northern and north-western Australia. Australian dingoes are invariably larger than specimens occurring in Asia.^[7] Compared to similarly sized domestic dogs, dingoes have longer muzzles, larger carnassials, longer canine teeth, and a flatter skull with larger nuchal lines.^[7] Their dental formula is 3/3-1/1-4/4-2/3=42.^[7] Dingoes lack the same degree of tooth crowding and jaw-shortening that distinguishes other dog breeds from grey wolves.^[6] They are taller in height at the withers than New Guinea Singing Dogs, and their skulls are slightly narrower.^[8]

Fur colour is typically yellow-ginger, though tan, black, white or sandy including occasional brindle can occur. Albino dingoes have been reported.^[6] Any other colours are indicators of hybridization.^[7] Purebred dingoes have white hair on their feet and tail tip and lack dewclaws on their hindlegs.^[6]

The New Guinea Singing Dogs have a fox-like appearance, with a double coat that ranges in color from red to brown, and have a characteristically large carnassial tooth. They stand between 14 and 18 inches (36 to 46 cm) at the shoulders, and weigh 17 to 30 pounds (8 to 14 kg) as adults.

New Guinea Singing Dogs have proportionately short legs and large heads compared to other Canis. They are shorter in height at the withers than dingoes. Their skulls are slightly wider than their Austrailain counterpart's skull. ^[9]

Temperament and behaviour

Dingoes are mostly seen alone, though the majority belong to packs which rendezvous once every few days to socialize or mate.^[7] Scent marking, howling and stand offs against rival packs increase in frequency during these times.^[7] Packs of dingoes can number 3 to 12 in areas with little human disturbance, with distinct male and female dominance hierarchies determined through aggression.^[7] Successful breeding is typically restricted to the dominant pair, though subordinate pack members will assist in rearing the puppies.^[7]

The size of a dingo's territory has little to do with pack size, and more to do with terrain and prey resources.^[7] Dingoes in south-western Australia have the largest home ranges.^[7] Dingoes will sometimes disperse from the natal home ranges, with one specimen having been recorded to travel 250 kilometers (155 miles).^[7]

Dingoes do not bark as much as most domestic dogs, who can be very loud, and they howl more frequently. Three basic howls with over 10 variations have been recorded.^[7] Howling is done to attract distant pack members and it repels intruders.^[7] In chorus howling, the pitch of the howling increases with the number of participating members.^[7] Males scent mark more frequently than females, peaking during the breeding season.^[7] New Guinea Singing Dogs are unique in their ability to howl in a wolf-like manner, but unlike wolves, Singers modulate the pitch, hence the name.

The New Guinea Singing Dog has never been studied in the wild and virtually nothing is known concerning its behavior, social organization or general natural history under free-ranging conditions; and as of 2004, there were less than 50 specimens (all highly inbred) in the documented NGSD captive breeding population.^[10] Most of the NGSD in North America have descended from the original Taronga Zoo pair; in 1976 five were brought from Irian Jaya to the Domestic Animal Institute in Keil, Germany. No others have been captured from the wild.^[11]One singing dog was seen in 1991 in the highlands below Mt Trikora by a British Climbing expedition.

In general, NGSD show all the behaviors described for other Canis species with the exception of the "play bow", typical to most canids but not seen in the NGSD.^[12] However, there have been cases in which NGSDs have attacked other domestic dogs due to misconstruing attempts to play.^[13] Captive populations (the only ones studied) do not form packs, and wild sightings are of single dogs or pairs. They have a distinctive howl, and emit a "trill", described as similar to a sound made by the Dhole (Cuon alpinus.)^[14]

Ecology

Reproduction

Like wolves, but unlike most domestic dogs, dingoes reproduce once annually.^[7] Male dingoes are fertile throughout the year, whereas females are only receptive during their annual estrus cycle.^[7] Females become sexually mature at the age of two years, while males obtain it at 1 to 3 years.^[7] Dominant females within packs will typically enter estrus earlier than subordinates.^[7] Captive dingoes typically have a pro-estrus and estrus period lasting 10–12 days, while for wild specimens it can be as long as 2 months.^[7] The gestation period lasts 61–69 days, with litters usually being composed of 5 puppies.^[7] There is usually a higher ratio of females than males.^[7] Puppies are usually born from May to July, though dingoes living in tropical habitats can reproduce at any time of the year.^[7] Puppies are usually born in caves, dry creekbeds or appropriated rabbit or wombat burrows.^[7] Dingo pups become independent much quicker than wolf cubs.^[15] They usually leave their pack at 3–6 months, though puppies living in packs will sometimes remain with their group until the age of 12 months.^[7] Unlike in wolf packs, in which the dominant animals prevent subordinates from breeding, alpha dingoes suppress subordinate reproduction through infanticide.^[7]

Dietary habits

Over 170 different animal species have been recorded in Australia to be included in the dingo's diet, ranging from insects to water buffalo. Prey specialization varies according to region. In Australia's northern wetlands, the most common prey are magpie geese, dusky rats and agile wallabies, while in arid central Australia, the most frequent prey items are European rabbits, long-haired rats, house mice, lizards and red kangaroos.^[7] In north-western habitats, Eastern Wallaroos and red kangaroos are usually taken, while wallabies, possums and wombats are taken in the east and south eastern highlands.^[7] In Asia, dingoes live in closer proximity to humans, and will readily feed on rice, fruit and human refuse. Dingoes have been observed hunting insects, rats and lizards in rural areas of Thailand and Sulawesi.^[7] Dingoes will usually hunt alone when targeting small prey such as rabbits and will hunt in groups for large prey like kangaroos.^[7] Dingoes in Australia will sometimes prey on livestock in times of seasonal scarcity.^[7] Like domestic dogs, dingoes can survive on fewer calories than wolves.^[15]

Dingoes hunt by assessing their prey's ability to defend itself. Kangaroos killed by dingoes are usually juveniles or females. Male red kangaroos have been observed to act indifferently in the presence of dingoes. Dingoes tend to have greater success in hunting kangaroos in open, arid areas where kangaroos congregate around water sources. Packs are three times more likely to make a successful kangaroo kill than lone dingoes. Dingoes typically hunt large kangaroos by having lead dingoes chase the quarry toward their waiting pack mates, which are skilled at cutting corners in chases. As with wolves, spotted hyenas and African wild dogs, the quarry is chased to exhaustion. Dingoes will kill kangaroos either by hamstringing them and biting their throat, or by running alongside them and biting the thorax and neck regions. In one area of Central Australia, dingoes hunted kangaroos by chasing them toward a wire fence which would hinder their escape. Female swamp wallabies carrying young have been observed to eject their young when chased by dingoes. Kangaroos typically defend themselves by entering water bodies or by backing up against natural barriers, thus protecting their hind quarters from attack.^[16]

Relationship with invasive and native species

In Australia, dingoes compete for the same food supply as introduced feral cats and red foxes, and also prey upon them (as well as on feral pigs). A study at James Cook University has concluded that the reintroduction of dingoes would help control the populations of these pests, lessening the pressure on native biodiversity.^[17] The author of the study, Professor Chris Johnson, notes his first-hand observations of native rufous bettongs being able to thrive when dingoes are present. The rate of decline of ground-living mammals decreases from 50% or more, to just 10% or less, where dingoes are present to control fox and cat populations. Tamed dingoes have also been proposed to be used to track down invasive cane toads.^[18]

However, competition from dingoes has been connected to the extinction of two native carnivores from mainland Australia; the thylacine and the Tasmanian Devil. Dingo predation is also considered a threat to several native Australian species according to the endangered species page of the Queensland Museum internet site, which include the False Water Rat, Greater Bilby and Northern Bettong. Dingoes also prey upon the endangered Bridled Nail-tail Wallaby.^[19]

Adult dingoes have few natural predators, though Saltwater crocodiles have been recorded to occasionally prey on them.^[20] There is at least one record of an adult dingo being killed by a pair of wedge-tailed eagles, though usually only old or crippled dingoes are targeted by eagles.^[21]

Conservation status

Although protection within Federal National Parks, World Heritage areas, Aboriginal reserves, and the Australian Capital Territory is available for dingoes, they are at the same time classified as a pest in other areas. Since a lack of country-wide protection means they may be trapped or poisoned in many areas, in conjunction with the hybridization with domestic dogs the taxon was upgraded from 'Lower Risk/Least Concern' to 'Vulnerable' by the IUCN (International Union for the Conservation of Nature and Natural Resources) in 2004.^[1]

Crossbreeding with other dogs

Crossbreeding with pet and feral domestic dogs is currently thought to be the dingo's greatest threat for survival. Up to 80% of the wild dogs along Australia’s eastern seaboard are thought to be dog-dingo crossbreeds. The current Australian policy is to cull hybrids whilst protecting purebreds. This has proved effective on Fraser Island in Queensland, where dingoes are confined and introgression of domestic dog genes can be controlled. It has however proven to be problematic on mainland Australia, to the point where it is estimated that at the current rate of genetic introgression, pure dingoes should go extinct within 50 years. Conservationists are generally split into two groups; those who view crossbreeding as detrimental to the dingo's uniqueness, and those who believe genetics and appearance are irrelevant, as long as the animals maintain their ecological niche.^[22] Hybrids may enter estrus twice annually, and have a gestation period of 58–65 days, but it is not sure how widespread that phenomenon is or whether they successfully raise two litters per year.^[7] All in all, little is known about the long-term effects of crossbreeding and crossbreeds cannot always be distinguished from pure dingos.

Relationships with humans

Origins and Western recognition

Though originally thought to have descended from Indian or Arabian wolves (who were theorized to be the ancestors of most if not all domestic dogs due to their small size), this was disproven when researchers from the University of New South Wales (UNSW), together with colleagues in Sweden and Great Britain compared samples of mtDNA taken from 211 dingoes to those of 676 dogs throughout the world, 38 Eurasian wolves and 19 samples from Polynesian dog bones dating from pre-European times. The results showed that dingoes were in fact descended from domestic dogs that lived in East Asia. The results suggested that all dingoes descend from a very small number of dogs or even a single female. ^[3] This is supported by morphological comparisons between modern dingoes and fossil Australian dogs dating back 3,900 YBP, which demonstrate that these dogs have changed very little.^[15] Doctor Laurie Corbett hypothesized that a number of ancient dingo-like pariah dogs are in fact domesticated dingoes. Although pariah dogs are being genetically mixed with imported domestic dogs from Europe and Asia, the dingo morphotype predominates in long-term free-ranging, free-breeding modern dog populations, even after many generations. These populations never assume wolf morphology.^[15] The general consensus among biologists is that dingoes were transported from mainland Asia, through South-East Asia to Australia and other parts of the Pacific region by Asian seafarers throughout their voyages over the last 5,000 years. Dingoes arrived in Australia around 3,500–4,000 years ago, quickly spreading to all parts of the Australian mainland and offshore islands, save for Tasmania.^[23] The dogs were originally kept by some Australian native groups as an emergency food source.^[6]

European settlers did not discover dingoes until the 17th century, and originally dismissed them as feral dogs.^[7] Captain William Dampier, who wrote of the wild dog in 1699, was the first European to officially note the dingo.^[6] Dingo populations flourished with the European's introduction of domestic sheep and European rabbit to the Australian mainland.^[6]

Dingoes as pets and working animals

Currently, dingo puppies are only available within Australia and it is illegal to export them, though this may change through the urgings of breed fanciers. Puppies can cost from AU$500–1,000.^[6] Although dingoes are generally healthier than most domestic dogs, and lack the characteristic "doggy odor",^[6] they can become problematic during their annual breeding season, particularly males which will sometimes attempt to escape captivity in order to find a mate.^[24] As puppies, dingoes display typical submissive dog-like behaviour, though they become headstrong as adults. However, unlike captive wolves, they do not seem prone to challenging their captors for pack status.^[25]

There are mixed accounts on how captive dingoes are treated by Indigenous Australians. In 1828, Edmund Lockyer noted that the aboriginals he encountered treated dingo pups with greater affection than their own children, with some women even breastfeeding them. The dogs were allowed to have the best meat and fruit, and could sleep in their master's huts. When misbehaving, the dingoes were merely chastised rather than beaten. This treatment however seems to be an exception rather than a general rule. In his observations of Aboriginals living in the Gibson Desert, Richard Gould wrote that although dingoes were treated with great fondness, they were nonetheless kept in poor health, were rarely fed, and were left to fend for themselves. Gould wrote that tame dingoes could be distinguished from free ranging specimens by their more emaciated appearance. He concluded that the main function of dingoes in Aboriginal culture, rather than hunting, was to provide warmth as sleeping companions during the cold nights.^[26]

Some Aborigines will routinely capture dingo pups from their dens in the winter months and keep them. Physically handicapped puppies are usually killed and eaten, while healthy ones are raised as hunting companions, assuming they do not run away at the onset of puberty.^[26] However, Aboriginal women will prevent a dingo they have become attached to as a companion from escaping by breaking its front legs.^[24] A dingo selected for hunting which misbehaves is either driven off or killed.^[26] Dingoes may be used for hunting purposes by Aboriginals inhabiting heavily forested regions. Tribes living in Northern Australia track free ranging dingoes in order to find prey. Once the dingoes immobilize an animal, the tribesmen appropriate the carcass and leave the scraps to the dingoes. In desert environments however, camp dingoes are treated as competitors, and are driven off before the start of a hunting expedition. As Aboriginal hunters rely on stealth and concealment, dingoes are detrimental to hunting success in desert terrains.^[26] Dingoes make poor guard dogs, having been shown to disregard defending their own offspring if their personal survival is threatened.^[15]

Scott Thomas Post reported that the Kalam people of the Papuan Highlands capture pups and raise them as pets and hunting dogs, but do not breed the NGSDs. Wild dogs (not village dogs) are sometimes eaten.^[27]

The United Kennel Club began registering them as a dog breed in January 1996, in the Sighthounds & Pariah Group. The American Rare Breed Association also registers them as a dog breed, in their Spitz & Primitive Group.

Attacks on humans

Although humans are not natural prey for wild dingoes, there have been a number of instances in which people have been attacked by them. The most famous fatality case is that of 10 week old Azaria Chamberlain, who is thought to have been taken by a dingo on the 17th August, 1980 on Ayers Rock. The body itself was never found, and the child's mother was initially found guilty of murder but later exonerated of all charges and released.^[28] However, since the Chamberlain case, proven cases of attacks on humans by dingoes have brought about a dramatic change in public opinion. It is now widely accepted that, as the first inquest concluded, Azaria probably was killed by a dingo, and that her body could easily have been removed and eaten by a dingo, leaving little or no trace.^[29] The majority of other recorded attacks occurred on Fraser Island. Although Fraser Island dingoes are the genetically purest strain, and were generally considered to be timid, increasingly more violent encounters between dingoes and humans have been reported since the 1980s, largely thought to be the result of both intentional and unintentional feeding of dingoes by tourists. Since 1995, more than 50 people had been cited for illegally feeding dingoes.^[30] Between 1996 and 2001, 224 incidences of dingoes biting people were recorded,^[28] and on the 5th of May, 2001, two children were attacked near the remote Waddy Point campsite. The older of the two, a 9 year old schoolboy was killed, while his younger brother was badly mauled. Authorities on Fraser Island have reportedly culled approximately 40 dingoes over the decade preceding the fatal attack for “showing dangerous habits”.^[30] Three days later, two backpackers were attacked in the same area, leading to the government authorizing a cull, and the establishment of a A$1,500 fine to anyone found feeding dingoes.^[31]

Role in mainland Australian thylacine extinction

The arrival of dingoes is thought by some to have been a major factor in the extinction of the thylacine in mainland Australia. Fossil evidence and Aboriginal paintings show that thylacines once inhabited the entire Australian mainland, only to suddenly disappear about 3,000 years ago. Since dingoes are thought to have arrived around 500 years prior, certain scientists think this was sufficient time for the canids to impact on mainland thylacine populations, either through interspecific competition or through the diffusion of disease. Considering that thylacines managed to survive in the dingo-devoid island of Tasmania until the 1930s, some put this forward as further indirect evidence for dingo responsibility for the thylacine's disappearance.^[23] Some however doubt the impact of the dingo, as the two species would not have been in direct competition with one another. The dingo is a primarily diurnal predator, while it is thought the thylacine hunted mostly at night. In addition, the thylacine had a more powerful build, which would have given it an advantage in one-to-one encounters.^[32] However, recent morphological examinations on dingo and thylacine skulls by Stephen Wroe of the University of NSW biomechanics show that although the dingo had a weaker bite, its skull could resist greater stresses, allowing it to pull down larger prey than the thylacine. The thylacine was also much less versatile in diet, unlike the omnivorous dingo.^[33]