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Dingo - Canis dingo
#1
Dingo - Canis dingo

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Scientific classification 
Kingdom: Animalia 
Phylum: Chordata 
Class: Mammalia 
Order: Carnivora 
Family: Canidae 
Genus: Canis 
Species: Canis dingo 

Closest Relatives - Asian wolves

Current Distribution - Australia wide (except Tasmania) but interestingly the Dingo is not part of Australia's fauna ancestory - rather it was thought to be introduced 3,500 - 4,000 years ago by Asian traders. Some consider it therefore to be a feral species.

[Image: 800px-Dingo-map.png]

Weight - Females weigh about 12 kg and males 15 kg.

Concerns - the dingos genetic uniqueness is being compromised by cross breeding with feral domestic dogs - 
"The distribution of the wild dog in relation to purebred dingoes varies throughout the state. In far western areas, most dingoes sighted appear to be pure, with characteristic white points and broad head. Closer to settled areas a greater number of feral domestic dogs produce a generally hybrid population. It has been estimated that dingoes are 50% pure in south-east Queensland and 90 - 95% pure in south-west and central Queensland."

The 'purest' population of dingoes occurs on Fraser Island.

Territories - "Radio tracking studies show dingoes occupy a
discrete area known as a home range. The dingo visits the edge of this district frequently. The home range can vary in size according to the productivity of the country; from 9 km in rainforest areas to 300 km on the Nullabor plain."

Social organisation - Dingoes in an undisturbed area generally belong to discrete packs (3 -12 members) which occupy long term, non-overlapping territories. The group rarely moves as a pack, rather members meet and separate again throughout the day. Dingoes are most gregarious during the breeding season.
There is overlap of home ranges within a group. In contrast, boundaries between groups are more rigid, actively defended, and infrequently crossed."

Diet - Dietary research entailing stomach content and faecal scat examination has shown dingoes are opportunistic predators.
Medium size animals such as kangaroos, wallabies, rabbits and possums consistently form the major part of their diet.
Studies by the Western Australia Agriculture Protection Board show dingoes in undisturbed refuge areas killed and ate kangaroos strictly according to need.
On grazing country however dingoes harassed, bit or killed sheep in large numbers, often without eating any'. The consumption of these sheep carcasses was the exception rather than the rule.
Even kangaroos in these areas were sometimes killed in "play" type behaviour rather than for food.
Grouping increases foraging efficiency and appears necessary to exploit larger prey. Dingoes co-operating in groups are more successful in hunting kangaroos than lone dingoes. Whilst lone
dingoes can easily kill sheep it is less likely a solitary dingo would successfully attack a calf in the presence of a defending cow."

I'll try to dig up some information on hunting succcess rate for various prey species.

http://www.nrm.qld.gov.au/factsheets/pdf/pest/pa9.pdf#search=%22dingo%20predation%20kangaroos%22
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#2
Dingo's origins tracked by DNA 


Monday, 2 August, 2004,

The dingo may have been introduced on a single occasion to Australia 
A genetic analysis of the Australian dingo suggests the dogs tagged along on an epic expansion of people out of southern China around 6,000 years ago. 

An international team claims dingoes descend from a small group that could have been introduced to Australia in a "single chance event" from Asia. 

Evidence from mitochondrial DNA suggests that the wild dogs arrived on the continent around 5,000 years ago. 

The work appears in Proceedings of the National Academy of Sciences. 

Peter Savolainen of the Royal Institute of Technology in Stockholm, Sweden, and colleagues think the introduction of the dogs may be associated with the spread of seafaring Austronesian-speaking people throughout South-East Asia. 

The Austronesian culture had its origins in south China, expanding from Taiwan via the Philippines to Indonesia. 

Although dingoes are now wild, they descend from domestic dogs that accompanied these Austronesians on their voyages. 

Family tree 

The new data comes from an analysis of dingo, dog and wolf mitochondrial DNA (mtDNA) types. This is the DNA found in the cell's "power houses", and it is passed down from parent to offspring on the maternal side only. 

On a family tree of mtDNA types in different members of the dog family, dingoes sit on a major branch alongside 70% of domestic dog sequences. 

All the dingo mtDNA types either belonged to or showed great similarity to a single type called A29. 


DNA links dingoes to an expansion out of southern China 
Studies of dingo physiques suggest they are very similar to Indian pariah dogs and wolves. This has led some researchers to propose that seafaring peoples from India may have introduced them to Australia. 

But among domestic dogs, A29 is found only in East Asia, suggesting the dogs' origins lie here, rather than on the Indian subcontinent. The researchers analysed mtDNA sequences in 211 dingoes and compared them to a world-wide sample of 676 dogs. 

When Europeans arrived in Australia, the dingo was widespread, living mostly as a wild animal. However, some Aboriginal groups kept them as pets or as hunting dogs. 

The dogs only failed to reach Tasmania because rising sea levels had inundated the Bass Strait some 6,000 years earlier. 

The dingo is not endangered but interbreeding with domestic dogs is a major problem. About 80% of dingoes are now thought to be hybrids. 

Dingoes are most common along the edges of forests and grasslands where prey is usually abundant. They live on small mammals, especially rabbits, but also feed on kangaroos, lizards and carrion. 

The dingo has been implicated in driving the now extinct Tasmanian "tiger" - or thylacine - off mainland Australia, and marginalising it in its final island habitat. 

http://news.bbc.co.uk/2/hi/science/nature/3529010.stm

For a full copy of the study click here -"A detailed picture of the origin of the Australian dingo, obtained from the study of mitochondrial DNA" - Peter Savolainen, Thomas Leitner, Alan N. Wilton, Elizabeth Matisoo-Smith, and Joakim Lundeberg
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#3
ARE DINGOES GENERAI.ISTS OR SPECIALSTS?


"Although a large range of prey is eaten throughout Australia
- at least 177species - almost 80% of the dingo's diet comprises
only 10 species. In order of greatest frequency these
are: red kangaroo, rabbit, swamp wallaby, cattle, dusky rat,
magpie goose, brushtail possum, long-haired rat, agile wallaby
and wombat. Of these, only cattle (mostly as carrion) are
eaten in each of the six regions studied. Given the huge range
of potential prey, the narrow range of species that dingoes
focus on strongly suggests that they are specialists, not the
opportunistic generalists they are often assumed to be.
However, in terms of hunting strategies, the generalist tag
applies because of the broad range of hunting tactics that
solitary and co-operating pack members use.

That dingoes seem to ignore many potential prey species
is surprising and difficultto explain. For example, why are so
few reptiles eaten? At Kapalga, in Kakadu National Park in
northern Australia, 70 species of reptiles have been recorded.
Many species, such as frilled lizards and goannas, are very
common, accessible and don't seem to display formidable
anti-predator behaviours; yet only 8 of these individuals
were recorded in 6,722 faeces over 7 years of study! In central
Australia, lizard diversity and abundance is even greater,
but apart from the regular consumption of one species (the
central netted dragon, 7.8% occurrencd, lizards are largely
ignored even during drought when dingoes may be starving."

Two Dingoes attacking a large Goanna - Fraser Island
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#4
DINGO DIET IN AUSTRAI.IA

In the 20 years between 1966 and 1986, eight major federal and state studies on dingo diet were conducted in six climatic regions of Australia - from the northern wet-dry tropics, to the central hot arid deserts, to the cool south-eastern moun tains. Collectively, these studies by federal and state government bodies provided 12,802 stomach and faecal samples to analyse the variety and relative amounts of prey eaten by dingoes.
For the combined six regions (essentially representing Australia), 177 prey species have been identified, and are listed in Appendix C. Almost 75% of prey eaten are mammals (72.3%, 71 species; see Figure 7.1 a). The remaining quarter comprise birds 08.8%, 53 species), vegetation (3.3%, mainly seeds), reptiles (1.8%,23 species) and an assortment of insects, fish, crabs and frogs (3.8%, 28 species).
The relative proportions of mammals, birds, reptiles and other prey that dingoes eat are remarkably similar throughout Australia (Figure 7.1b). Only in the coastal regions (north and south-east) are more birds eaten, and more reptiles are eaten in central Australia.
Almost 80% of mammals may be categorised as medium- sized or smaller (Figure 7.2a); whereas only 20.30;0 are large (see Box 7.1 for definition of categories). However, the relative proportions of the various sizes of mammal prey varies considerably across the six regions (Figure 7.2b), although medium-sized mammals usually predominate.

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DIETARY OVERLAP AND COMPETITION WITH FOXES AND FERAL CATS

Table 7.2 indicates the broad diets of dingoes, foxes and cats living in different habitats in Australia. To validate comparisons the data were derived from studies that either concurrently sampled all predators in each habitat or sampled each predator in different years in the same locality; thus there were four studies on the eastern highlands and one each on other habitats.
Mammals predominated in the diet of all three predators everywhere, but only dingoes ate large mammals. Instances of large mammals in the diets of cats and foxes were attributed
to scavenging. Both dingoes and foxes tended to focus on medium-sized mammals, and cats focused on small mammals. Consumption data showed no clear distinction between predators' preferences for indigenous or introduced small and medium-sized mammals; rabbits were favoured by all three predators.
Foxes and cats ate more birds and reptiles than dingoes did, except in the coastal tropics where dingoes tended to focus on birds (magpie geese). Except in the eastern highlands, foxes and cats ate more insects and vegetation; they also included a broader range of other items than dingoes did (see Table 7.2).
In summary, there is considerable dietary overlap but dingoes tend to focus on larger mammals whereas foxes and cats focus on smaller mammals, reptiles and birds. In good seasons there is probably minimal competition, but in drought or after severe wildfires, food sources are dispersed and clumped, and competition for them is probably intense. At such times dingoes obviously survive the best, considering the drastic reductions in fox and cat numbers (see Chapter 9) and the inclusion of cats in dingo diet in all regions of Australia (Appendix C).

The diets (% occurrence) of dingoes, foxes and cats compared between different habitats in Australia. (There are no foxes and rabbits in the northern tropics and the Barkly Tableland. Stock comprise cattle, buffaloes, horses, pigs and sheep. Other diet items include crustaceans, molluscs and fish.) 
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#5
Genetic dilution dogs dingoes
Monday 2 July 2007

Most people would describe a dingo as a ginger dog with white paws, white-tipped tail and black muzzle, but the coat colours of dingoes varies widely, Australian National University visiting research fellow Dr David Jenkins says. "They can go from pale yellow right through to a dark biscuit brown, and all shades of ginger in between. You can get brick red dingoes, black dingoes with white tummies and feet, black and tan dingoes and pure white ones they're not albinos, they've got brown noses and brown eyes," he says. Jenkins has spent almost two decades studying dingoes and dingo hybrids (dingoes with domestic dog genes) across south-eastern Australia, chiefly in his role as director of the Australian Hydatid Control program. His long-term studies of the intestinal parasites of dingoes have enabled him to amass a wealth of data on one of Australia's most elusive and least-studied species. He also works closely with molecular biologist Dr Alan Wilton from the University of NSW, collecting tissue samples for studies of dingo mitochondrial DNA, which passes unchanged in females through successive generations and can be used to track the ancestry of species.

Wilton has examined DNA from more than 2000 dingoes and his findings suggest they were introduced to Australia about 5000 years ago from South-East Asia. The mitochondrial DNA of modern dingoes indicates they originated from a small group of dogs possibly just one pregnant female introduced by Asian traders visiting northern Australia. "All dingoes have a similar DNA type and any variation we find in a population is only a single mutation away from the main type," he says. 

Wilton has developed 22 genetic tests to detect dingo hybridisation, and says there is "a large amount of hybridisation in regions close to populated areas". Dingoes can cross-breed with domestic dogs, producing fertile young, and hybridisation is a major threat to the survival of the species. Dingoes breed only once a year, whereas dogs breed twice, but so far there is no evidence to suggest dingo hybrids are breeding twice. "Once domestic dog genes are in the dingo gene pool, they'll be circulated in different combinations in successive dingo generations," Jenkins says. 

"It's estimated the number of pure-bred dingoes living in the bush in south eastern Australia may only be about 25 per cent or less in some areas, with the remainder of animals being predominantly dingo but with some domestic dog genes in their DNA." If that's the case, what can be designated as a dingo? Do the Brindabella brindles the legendary local wild dogs with brindle markings qualify? Or are they a pest that should be culled? Is coat colour an indicator, or does the verdict hinge on the percentage of dog genes detected by DNA tests? "There are more questions than answers on the topic," Jenkins says. 

"But we need to be clear that whether you're looking at a dingo or a dingo hybrid, you're definitely not looking at a feral dog. "That's a specific term for a domestic dog that's gone wild and is breeding true. It's actually very rare, because the pack structure of dingoes makes it unlikely a domestic dog will gain entry. Dingoes are incredibly territorial there'd be huge fights and the intruder would most likely be killed." As for the myths about weekend parties of pig hunters losing dogs in the bush that subsequently go wild, Jenkins, who works with professional dog trappers in the Snowy Mountains, says these dogs are usually picked up by trappers early in the week. 

"Some get reunited with their owners if there's any identification like a phone number but most of these pig dogs get trapped and shot, so they're out of the equation." The presence of dog genes in a dingo may be visually hard to detect. While brindle coat markings or a stumpy tail can hint at hybridisation, they're not a foolproof indication. "A hybrid can look just like everyone's idea of a classic ginger dingo, but there can be subtle physical differences such as tooth length or muzzle width." 

Jenkins says there are two ways of determining if dingoes are hybrids DNA testing or skull measurements. The major advantage of genetic testing is a result can be obtained from a few coat hairs or whiskers, a blood sample or cells from inside the mouth. Skull measurements can only be conducted "on the cleaned skull of a dead dingo". Does it matter if a dingo has a small percentage of dog genes? Should hybrids be culled to keep the dingo population genetically pure? "Some researchers are now using the term 'evolving dingo'. Along south-east Australia there is a high level of dingo hybrids as high as 80 per cent in some populations and there is little that can be done to reverse the situation," Jenkins says. 

"What we've got is what we have and maybe we have to learn to live with it. Ecologically, these hybrid animals seem to be behaving in a similar way to pure-bred dingoes, performing a role as a top order predator that keeps a lid on the numbers of rabbits, kangaroos and wallabies." There are no easy answers to the dilemmas confronting dingo conservation, he says. "What are you going to do, cull any animals that look different to the dingo stereotype? That's not going to work. Even if you have a 95 per cent pure population, that 5 per cent of dog genes will still float around and circulate within populations. At what point do you draw the line on genetic purity? 

"And if you opt for selective culling of dingo hybrids, you can disrupt the pack structure and affect the breeding capacity of animals. If you take out an alpha dog, then you're going to be increasing breeding, because primary breeding is restricted to the alpha male and female." A pack of dingoes can work together in bushland to take down a big eastern grey kangaroo, but if pack structure and territorial ownership are disrupted, animals will disperse over a wider area, with displaced individuals looking for smaller prey. 

"If you've got a sheep property near a national park, ideally you want to create a control barrier to mitigate damage without breaking up the pack structure. The plan should be to control the flow of dogs moving out of the park, but if there's major disruption to the pack, you're creating areas of uncontested territory that act as a natural sink for dispossessed older dogs and young animals looking for somewhere to live." Captive breeding and re-introducing pure-bred dingoes back into the wild isn't an easy option, given the ferocious territorial nature of dingoes, Jenkins says. 

"That's going to be very complicated, and there isn't any research at the moment that's seriously addressing the dynamics of introducing captive-bred dingoes back into the wild especially where there's an existing dingo population." Jenkins says more research is needed to answer basic questions about the impacts of hybridisation. There are claims hybrids are bigger, more aggressive and a risk to public safety but so far, data and personal experience generally don't tend to support these assertions, he says. 

"There are reports of one or two unusually big animals captured each year, but hybrids are usually close to what's considered to be the normal weight range of dingoes." As for public safety, Jenkins has encountered dingoes and hybrids while working out in the bush, but says the animals tend to be curious, rather than aggressive. "I've never felt in any sort of danger. But when these animals look at you, they look really hard. There's something really going on in that hard-wired brain it's not the same feeling as when a labrador looks at you." 

http://canberra.yourguide.com.au/detail.asp?class=news&subclass=environment&story_id=1014864&category=environment
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#6
Effects of Gape and Tooth Position on Bite Force and Skull Stress in the Dingo (Canis lupus dingo) Using a 3-Dimensional Finite Element Approach
Jason Bourke,1* Stephen Wroe,1 Karen Moreno,1 Colin McHenry,1,2,3 and Philip Clausen3

Abstract
Models of the mammalian jaw have predicted that bite force is intimately linked to jaw gape and to tooth position. Despite widespread use, few empirical studies have provided evidence to validate these models in non-human mammals and none have considered the influence of gape angle on the distribution of stress. Here using a multi-property finite element (FE) model of Canis lupus dingo, we examined the influence of gape angle and bite point on both bite force and cranial stress. Bite force data in relation to jaw gape and along the tooth row, are in broad agreement with previously reported results. However stress data showed that the skull of C. l. dingo is mechanically suited to withstand stresses at wide gapes; a result that agreed well with previously held views regarding carnivoran evolution. Stress data, combined with bite force information, suggested that there is an optimal bite angle of between 25° and 35° in C. l. dingo. The function of these rather small bite angles remains unclear.
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http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2376057 

Here's a few more tables from the study:



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Dingo Bite Force
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#7
Reddhole Wrote:Source: Marsack, "Feeding Behaviour and Diet of Dingoes in
the Nullarbor Region, Western Australia" Aust. Wildl. Res., 1990, 17, 349-57


Abstract
Observations were made on the diet and feeding behaviour of the dingo (Canis familiaris dingo) in the Nullarbor region of Western Australia. Mammal species accounted for 96% of food items identified in diet samples. Rabbits (Oryctolagus cuniculus) and red kangaroos (Macropus rufus) were the most frequently occurring prey items. Cattle (Bos taurus) carrion, although available, was a relatively minor part of the diet. Foxes (Vulpes vulpes), cats (Felis catus), birds, reptiles and arthropods were eaten only occasionally. Dingoes usually hunted alone, and solitary dingoes were more successful in hunting rabbits
than were members of groups. Only solitary dingoes were seen to chase and catch kangaroos, but
kangaroo carcasses were often shared. 
We suggest that the widespread solitary foraging characteristic
of dingoes on the Nullarbor may be related to their reliance on rabbits as the dietary staple.

Predation on Kangaroos

During radiotracking and groundwork we found 72 kangaroos (68 red and 4 western greys) killed by dingoes. In 14 instances the time of death was known or could be estimated reliably; 11 kangaroos were killed during the night or the first 3 hours of daylight, and three were killed in the afternoon. Autopsies were carried out on 46 carcasses, including eight initially located during radiotracking of dingoes, with red kangaroos accounting for all but one of those autopsied. Of the 72 kangaroo kills seen, 47 red kangaroos could be reliably sexed either during radiotracking observations (on the basis of coat colour) or at autopsy. Male kangaroos made up 42.6% of this total. 

Radio-collared dingoes were most often seen in open habitats, while kangaroos were seen significantly more often in timbered country (~:=20.9, P<0.001, Table 2). The proportion of kangaroos attacked was similar in each habitat (0.2 of the total seen in the open, 0.18 in timber). This suggests that the smaller number of dingoes in timbered habitats were more likely to be involved in predation on kangaroos than were dingoes in open country.

In spite of being relatively more conspicuous than predation on rabbits, predation on kangaroos was seen less often (Table 1). Dingoes were seen chasing kangaroos on 10 occasions. Six chases were in open habitat and four in timber, including the two chases that ended with the death of the kangaroo. Eight chases were purposeful and sustained, covering a mean distance of 1.5 km (range 350 m to 4.4 km). Two chases were abandoned
within 200 m. None of the chases seen involved more than one dingo.


Three types of predation attempt could be recognised. In the first the kangaroo was unaware of the dingo, which stalked slowly closer to it before making a fast run from short range. In one of these cases a dingo stalked about 400 m towards the stationary kangaroo, approaching downwind to within 20 m before running at it. Both the stalking attempts seen were in open habitat and ended with the escape of the kangaroo.

In a second type of chase, both dingo and kangaroo were alert and aware of each other while still some distance apart (100-300 m). The dingo trotted directly towards the kangaroo,
then ran fast when the kangaroo hopped away. In one instance the kangaroo moved away when the dingo was 200 m off, but twice the dingo approached to within 60 to 70 m. Once the fast chase began, the dingo never came closer than 40 m from the kangaroo. We saw chases of this type, two in the open and one in timber.

In the third type of chase, dingo and kangaroo were apparently unaware of each other until the kangaroo was flushed from cover by the dingo trotting past (only 35 m away in one case, 200 m in another). Both animals then ran fast. In one instance the dingo slowed to a trot and gave up within 100 m; in the other the chase extended over 4.4 km, with the dingo always at least 50 m behind the kangaroo.

In the two successful chases, the start of the chase was not seen nor was the actual capture of the kangaroo. One dingo was seen within a few seconds of a capture, biting at the throat of a kangaroo which was lying on its side.

Twenty-seven kangaroo carcasses were examined for injuries caused by dingoes (Table 4). Some injuries may have been obscured by subsequent feeding. Injury to the head and neck was apparent on 85% of carcasses and damage to the neck was probably a common cause of death. Injury to the main flexor muscles of the hind legs was common and would
presumably have been incapacitating. The attacks resulted in some puncture wounds but most damage was subcutaneous. Bites resulted in severe bruising and tearing of underlying
muscle.


Carcasses tended to have multiple injuries. Bites to both the tail and throat of a kangaroo might indicate a cooperative attack by two or more dingoes, or simply show that it took considerable effort for one dingo to kill the animal. Sometimes blood trails on the fur below bite wounds showed that the kangaroo had stood upright for some time after receiving the injury, before being subdued. 
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#8
Reddhole Wrote:Dingo Skull and Teeth Differences from Similar Sized Domestic Dogs


Dingo skulls are larger than most similar sized domestic dogs and their canines (C1) and carnassials (P4) are much bigger as well.

Source:

Newsome, Corbett and Carpenter, "The Identity of the Dingo I: Morphological Discriminants Between Dingo and Dog Skulls" Australian Journal of Zoology, 28, P 615-625 1980


Most of the dingo skull differences vs. dogs are due to adaptations for predation.

[Image: DingoDogSkullDifferences001.jpg]

Note the longer male dingo skull: 19.37 cm vs. 17.95 cm for a similar sized domestic dog. Also, note the much longer upper canines (Crown Height of C1): 2.22 cm vs. 1.89 cm; and much larger upper carnassials: Crown Width of P4: 7.8 mm vs. 6.9 mm; Crown Length of P4: 12.1 mm vs. 11.7 mm. Both canines and carnassials are used for grabbing and killing prey in canids.

[Image: DingoDogSkullDifferences002.jpg]


This source says that dingos can kill alsations, presumably they were killed in enclosures with dingos in this study.


Source: Macintosh, "The Origin of the Dingo", in Michael W. Fox's "The Wild Canids: Their Systematics, Behavior and Ecology", 1975

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#9
Study shows Aussie dingo may be world's oldest dog

(AFP) – 5 hours ago

SYDNEY — Australia's iconic dingo may be the world's oldest breed of dog, according a major new DNA study that is likely to boost conservation efforts.

The international study has found the dingo and its close relation, the rare New Guinea singing dog, bear the closest genetic similarity to wolves of all breeds tested.

The research, published in science journal Nature, appears to confirm widely held theories about the dingo's history. It involved testing nearly 1,000 dogs of 85 different breeds as well as hundreds of wolves.

"This gives us a huge weight of evidence supporting the theory that the dingo is quite distinct from all modern dog breeds," said joint author Alan Wilton, of Sydney's University of New South Wales.

"It's a bit of information that could be important to the conservation issue. If it's distinct from domestic dogs there may be scientific reasons for conserving the dingo."

Dingoes and the singing dog, named for its distinctive multi-pitched howl, have developed in isolation from other breeds for thousands of years. Dingoes were introduced to Australia from Indonesia about 5,000 years ago.

Dingoes have come under threat from rampant inter-breeding, prompting calls to maintain their genetic purity. Wilton said 80 percent of dingoes on Australia's east coast were thought to be mixed-breed.

http://www.google.com/hostednews/afp/article/ALeqM5h9MAGBks8kQRGnaMbw57FORvNLYA

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The study found that the dingo is most like the dogs domesticated in Asia and the Middle East thousands of years ago. 
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#10
Red Dog Wrote:The red wolf because it has more usable bite force according to Dr. Stephen Wroe's study on thylacine vs. dingo bite mechanics. 

Wroe analyzed the jaw and skull's ability to handle the typical stresses encountered in two types of bites:

1) A single large killing bite (i.e. a skull or nape bite, etc.) - "intrinsic loads"

2) Bite and shake and similar bites where the animal bitten was struggling - "extrinsic loads"

The thylacine and dingo had a comparable useble bite for # 1 above - i.e. the amount of useable force each could apply in a single killing bite. However, the dingo (about half the size of the thylacine) significantly outperformed the thylacine in # 2.

It is generally agreed that # 2 above is the type of bites long snouted, coursing predators (i.e. canids, hyenas, thylacine) use on animals close to or greater than their size. Thus, in a fight a red wolf (northern variants should be similar in size to the thylacine) should be able to control the fight with its more usable bite on a struggling opponent as well as having a more usable killing bite (i.e. smaller dingo has a similar usable killing bite as the larger thylacine).

Below is a key part of Wroe's study:

In summary, if only the results of our intrinsic loading
cases are considered, then we would predict that relative
prey size for the thylacine might have been comparable to
that of the dingo if both taxa are considered as solitary
predators. Given that mean body mass for the thylacine is
approximately twice that of the placental’s, it might also be
reasonable to conclude on theses bases that actual mean
prey size in the thylacine was considerably greater.
However, we consider it probable that for long-snouted
predators, killing behaviours in which intrinsic loads
dominate are more likely confined to relatively small
prey taken in a solitary context. The high extrinsic
loadings, under which the thylacine performs poorly, are
more likely to be encountered in the despatch of prey
approaching or exceeding the predator’s own body mass
and we predict that relative maximal prey size was higher
in the dingo, even if the thylacine did operate as pack
hunter.
We conclude that the thylacine concentrated on
small- to medium-sized prey (i.e. smaller than its own
body size) and that contra Johnson & Wroe (2003), actual
overlap regarding prey size and hence the opportunity for
competition was considerable


Read more: http://carnivora.proboards.com/index.cgi?action=userrecentposts&user=reddhole#ixzz1jCCqADT5

Canidae Wrote:Tool use in Dingoes :

Dingoes use tools to solve novel problems

Dingoes are more intelligent than we think - they have been filmed opening latched gates to get food.


DINGOES ARE MUCH SMARTER than humans give them credit for, according to new research.

While the native canines are known for their smarts in hunting skills, they are also able to figure out ways to snatch morsels of food that includes rudimentary tool use.

Staff at the Dingo Discovery and Research Centre in Melbourne found nametags had been mysteriously and repeatedly removed from the fence wall of a steel mesh dingo enclosure, from a height of 1.7m. Dr Bradley Smith, who was doing PhD research on cognition and behaviour in dingoes at the time, discovered the nametags were in fact being snagged by 18-month-old dingo Sterling.

Intrigued, Bradley set up small plastic envelope containing dry dog food was placed in a similar position to that of the missing name tags, and pointed cameras on the area to catch any unusual behaviour. To his surprise, the footage showed Sterling climbed a table and lent against a fence to get to the food.

"After several unsuccessful attempts at jumping for the envelope, Sterling 'solved' the task by first moving and then jumping up onto a trestle table," Bradley wrote in the paper, published in the journal Behavioural Processes. "Apart from some basic obedience training, Sterling had never been trained or encouraged to exhibit this behaviour."

First canine tool use

Dingoes have been shown to understand human gestures but this is the first known instance of a member of a canine species deliberately using tools and innovative problem solving - something which doesn't work through trial and error.

"Though there are innovative individuals in any group, [tool use and problem solving in dingoes] is definitely quite unique," Bradley says.

In another incident, Sterling moved a plastic kennel, a move Bradley believes "serves as somewhat of a 'look out'."

Professor Gisela Kaplan, from the University of New England, Armidale, says the discovery was "very remarkable," though she isn't surprised, considering what dogs can learn and accomplish.

"Dingoes are highly intelligent," Gisela says, "and sometimes hunt collaboratively and very cleverly."

Dingoes have already been reported to walk around barriers and gates, and like chimps, parrots and cetaceans such as dolphins, join the growing list of animals that more intelligent than we give them credit for. 

Dingoes can open latched gates

Another dingo, Teddy, manipulated a latch on a gate in order to be with his mate, pushing it open with his nose and using his body weight to swing the gate open. When he had his mate in the same enclosure, he didn't attempt to open the gate again, but once she was moved, he tried after just 13 seconds.

So far, this behaviour has only been exhibited in order to achieve a goal, whether it is to get to food,  find a mate, or establish what Bradley believes to be a 'look out' position.

The dingo is now classified by conservationists as vulnerable due to prolific interbreeding with domestic dogs, and Gisela asserts that "we need to make absolutely sure they don't go the way of the thylacine."


http://www.australiangeographic.com.au/j...ol-use.htm

Canidae Wrote:Dingo Weights and Lengths from various regions, from The Dingo in Asia and Australia by Laurie Corbett

Victorian Highlands
Length (mm) Male : 1244.7  Standard Deviation : 76.2  No. Sampled : 12 
Female : 1218.8 Standard Deviation : 64.1 No. Sampled : 16
Weight (kg) Male : 15.5  Standard Deviation : 2.0
Female : 14.7 Standard Deviation : 1.5

Central Australia
Length (mm) Male : 1207.0  Standard Deviation : 32.4  No. Sampled : 25
Female : 1168.5 Standard Deviation : 25.5 No. Sampled : 25
Weight (kg) Male : 14.5  Standard Deviation : 1.5 
Female : 12.4 Standard Deviation : 1.1

Kakadu National Park
Length (mm) Male : 1288.9 Standard Deviation : 84.4  No. Sampled : 12
Female : 1271.1 Standard Deviation : 27.7 No. Sampled : 7
Weight (kg) Male : 17.4  Standard Deviation : 1.9  
Female : 15.2 Standard Deviation : 1.1

Thailand
Length (mm) Male : 1078.0  Standard Deviation : 70.4  No. Sampled: 24
Female : 997.7 Standard Deviation : 39.8 No. Sampled: 19
Weight (kg) Male : 12.4 Standard Deviation : 2.4  
Female : 10.1 Standard Deviation : 1.6

Full Throttle Wrote:Some photos of Dingoes beachcombing:

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#11
Bigger and brainier: did dingoes kill thylacines?

May 3, 2012

[Image: biggerandbra.jpg]
Skulls of two thylacines and a dingo from the Nullarbor in Western Australia. A thylacine, thought to be female (left); a male thylacine (middle); a dingo (right). 

Direct attacks by introduced dingoes may have led to the extinction on the Australian mainland of the iconic marsupial predator, the thylacine, a new study suggests.

A comparison of museum specimens has found that thylacines on mainland Australia were smaller than those that persisted into modern times in Tasmania, and significantly smaller than dingoes. The last known Tasmanian thylacine died in 1936.

Measurements of the head size and thickness of limb bones of the semi-fossilised remains of thylacines and dingoes from caves in Western Australia have revealed that, on average, dingoes were larger than thylacines.

“In particular, dingoes were almost twice as large as female thylacines, which were not much bigger than a fox,” says ecologist Dr Mike Letnic, an ARC Future Fellow in the UNSW School of Biological, Earth and Environmental Sciences, who led the study with colleagues at the University of Sydney. The findings are published in the journal PLoS One.

There has long been debate as to what caused the extinction of the thylacine from mainland Australia, Dr Letnic notes. Because Tasmanian thylacines were much larger than dingoes, direct confrontation between the two species was discarded as a hypothesis for the thylacine decline.

Another hypothesis is that competition between the two species may have been the cause: however, competition is not thought to be a strong driver of extinction. More recently, some authors have suggested that people caused the extinction of the thylacine through direct hunting or suppression of prey.

“We were aware of old reports that mainland thylacines were smaller than Tasmanian ones,” says Letnic. “Modern ecological studies show that larger predators frequently kill smaller predators, so we decided to test the hunch that dingoes were actually larger than thylacines and caused their extinction by killing them in direct confrontations.

“We also measured the brain size of both species and found that dingoes also had much bigger brains than thylacines, so they may have outwitted them, too.”

Dingoes appear to have had a dramatic impact on the ecology of Australia when they first arrived between 3,500-5,000 years ago, probably introduced by human seafarers, and likely also caused the extinction of the Tasmanian devil from mainland Australia (devils are still found in Tasmania, which does not have dingoes).

“However, recent studies suggest that dingoes now play an integral role in maintaining healthy balanced ecosystems by limiting the populations of herbivores and smaller predators, a role that was once filled by the thylacine,” says Dr Letnic.

http://phys.org/news/2012-05-bigger-brainier-dingoes-thylacines.html 
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#12
Tanami dingoes among purest in Australia

ABC Rural Carmen Brown
Updated Tue Jun 4, 2013 11:58am AEST

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PHOTO: A new study has found dingoes living in the Tanami Desert are among the purest in the country.
Read the full story here. (Dr Tom Newsome)


A new study has revealed dingoes living in the Tanami Desert are among some of the purest in the country.

Researchers collected DNA samples from 142 dingoes during the three year project, with 90 per cent testing pure despite the presence of domestic dogs in the area.

Dr Tom Newsome, from the University of Sydney, says the animals were trapped near human habitation, but also in more remote areas.

"Most of the samples we collected from pastoral station, mine and desert areas came back pure," he said.

"Around the Aboriginal community there was little evidence dingoes were inter-breeding with dogs, which was good from a management point of view.

"The results from the mine also show that there was an increase in pack size where there was a high level of human-provided resources, such as waste facilities.

"This potentially also accelerated hybridisation rates around that site."

Dr Newsome says the findings are significant because hybridisation presents one of the greatest threats to the survival of the dingo species.

"A colleague of mine collected dingo DNA samples Australia-wide, and most of the areas where the samples were collected, the results came back as the animals being hybrid.

"So from a conservation perspective, the Northern Territory represents a unique example of an area where we might be able to conserve dingoes as a species."

Although Dr Newsome acknowledges the impact wild dogs have on the livestock industry, he remains confident a balance can be met between conservation and production objectives.

"There is definitely scope for that, particularly if we keep directing research into working out ways that we can maximise both economic and environmental benefits from dingoes," he said.

"It's highly contentious and controversial, and certainly there are areas where there are huge economic losses from dingoes.

"But there is also research coming out to demonstrate where dingoes occur that there might be environmental benefits as well.

"I think there needs to be a clear look at all the different factors involved in each particular area when developing management plans."

http://www.abc.net.au/news/2013-06-04/ntch-tanami-dingo-purity/4729046 
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#13
(07-14-2018, 04:21 PM)Taipan Wrote: Bigger and brainier: did dingoes kill thylacines?

May 3, 2012

[Image: biggerandbra.jpg]
Skulls of two thylacines and a dingo from the Nullarbor in Western Australia. A thylacine, thought to be female (left); a male thylacine (middle); a dingo (right). 

Direct attacks by introduced dingoes may have led to the extinction on the Australian mainland of the iconic marsupial predator, the thylacine, a new study suggests.

A comparison of museum specimens has found that thylacines on mainland Australia were smaller than those that persisted into modern times in Tasmania, and significantly smaller than dingoes. The last known Tasmanian thylacine died in 1936.

Measurements of the head size and thickness of limb bones of the semi-fossilised remains of thylacines and dingoes from caves in Western Australia have revealed that, on average, dingoes were larger than thylacines.

“In particular, dingoes were almost twice as large as female thylacines, which were not much bigger than a fox,” says ecologist Dr Mike Letnic, an ARC Future Fellow in the UNSW School of Biological, Earth and Environmental Sciences, who led the study with colleagues at the University of Sydney. The findings are published in the journal PLoS One.

There has long been debate as to what caused the extinction of the thylacine from mainland Australia, Dr Letnic notes. Because Tasmanian thylacines were much larger than dingoes, direct confrontation between the two species was discarded as a hypothesis for the thylacine decline.

Another hypothesis is that competition between the two species may have been the cause: however, competition is not thought to be a strong driver of extinction. More recently, some authors have suggested that people caused the extinction of the thylacine through direct hunting or suppression of prey.

“We were aware of old reports that mainland thylacines were smaller than Tasmanian ones,” says Letnic. “Modern ecological studies show that larger predators frequently kill smaller predators, so we decided to test the hunch that dingoes were actually larger than thylacines and caused their extinction by killing them in direct confrontations.

“We also measured the brain size of both species and found that dingoes also had much bigger brains than thylacines, so they may have outwitted them, too.”

Dingoes appear to have had a dramatic impact on the ecology of Australia when they first arrived between 3,500-5,000 years ago, probably introduced by human seafarers, and likely also caused the extinction of the Tasmanian devil from mainland Australia (devils are still found in Tasmania, which does not have dingoes).

“However, recent studies suggest that dingoes now play an integral role in maintaining healthy balanced ecosystems by limiting the populations of herbivores and smaller predators, a role that was once filled by the thylacine,” says Dr Letnic.

http://phys.org/news/2012-05-bigger-brainier-dingoes-thylacines.html 

Don’t blame it on the dingo

Our postdoc, Tom Prowse, has just had one of the slickest set of reviews I’ve ever seen, followed by a quick acceptance of what I think is a pretty sexy paper. Earlier this year his paper in Journal of Animal Ecology showed that thylacine (the badly named ‘Tasmanian tiger‘) was most likely not the victim of some unobserved mystery disease, but instead succumbed to what many large predators have/will: human beings. His latest effort now online in Ecology shows that the thylacine and devil extinctions on the Australian mainland were similarly the result of humans and not the scapegoat dingo. But I’ll let him explain:

‘Regime shifts’ can occur in ecosystems when sometimes even a single component is added or changed. Such additions, of say a new predator, or changes such as a rise in temperature, can fundamentally alter core ecosystem functions and processes, causing the ecosystem to switch to some alternative stable state.

Some of the most striking examples of ecological regime shifts are the mass extinctions of large mammals (‘megafauna’) during human prehistory. In Australia, human arrival and subsequent hunting pressure is implicated in the rapid extinction of about 50 mammal species by around 45 thousand years ago. The ensuing alternative stable state was comprised of a reduced diversity of predators, dominated by humans and two native marsupial predators ‑ the thylacine (also known as the marsupial ‘tiger’ or ‘wolf’) and the devil (which is now restricted to Tasmania and threatened by a debilitating, infectious cancer).

Both thylacines and devils lasted on mainland Australia for over 40 thousand years following the arrival of humans. However, a second regime shift resulted in the extinction of both these predators by about 3 thousand years ago, which was coincidentally just after dingoes were introduced to Australia. Dingoes are descended from early domestic dogs and were introduced to northern Australia from Asia by ancient traders approximately 4 thousand years ago. Today, they are Australia’s only top predator remaining, other than invasive European foxes and feral cats. Since the earliest days of European settlement, dingoes have been persecuted because they prey on livestock. During the 1880s, 5614 km of ‘dingo fence’ was constructed to protect south-east Australia’s grazing rangelands from dingo incursions. The fence is maintained to this day, and dingoes are poisoned and shot both inside and outside this barrier, despite mounting evidence that these predators play a key role in maintaining native ecosystems, largely by suppressing invasive predators.

Perhaps because the public perception of dingoes as ‘sheep-killers’ is so firmly entrenched, it has been commonly assumed that dingoes killed off the thylacines and devils on mainland Australia. People who support this view also point out that thylacines and devils persisted on the island of Tasmania, which was never colonised by dingoes (although thylacines went extinct there too in the early 1900s). To date, most discussion of the mainland thylacine and devil extinctions has focused on the possibility that dingoes disrupted the system by ‘exploitation competition’ (eating the same prey), ‘interference competition’ (wasting the native predators’ precious munching time), as well as ‘direct predation’ (dingoes actually eating devils and thylacines).

Unfortunately for the dingo, most people have overlooked that about the same time as dingoes came along, the climate changed rather abruptly, and aboriginal populations were going through a major period of ‘intensification’ (that is, human population growth and technological advances). On mainland Australia after 5 thousand years ago, the climate shifted to a drier, more El Niño-dominated state. At about the same time, the archaeological rock-shelter records demonstrate that the density of humans increased. Humans competed with and hunted the native carnivores, and these pressures would have strengthened as the human population grew. Ecological regime shifts (including loss of species) can be triggered by slowly changing variables once a threshold is exceeded (see figure), and the viability of thylacines and devils on the Australian mainland might have been compromised once human density surpassed such a threshold.

To investigate these competing or interacting (synergistic) proposed causes of the thylacine and devil extinctions, we built a complex mathematical model system to recreate the dynamic interaction between the main drivers (dingoes, climate and humans), the long-term response of herbivore prey, and the viability of thylacine and devil populations. We designed our models to include the key stressors that are implicated in the Holocene extinctions by including predatory interactions, competition between predators, as well as the influence of climate on vegetation and prey population dynamics. We asked whether the dingo invasion is supported as the main and most probable extinction driver after human population growth is taken into account.

Challenging popular belief, our simulations show that although dingoes might have hastened these extinctions, human intensification, possibly made worse by simultaneous climate changes at that time, is the most likely extinction driver. We successfully simulated the thylacine and devil extinctions (with greater than 50 % probability) for scenarios in which human density grew to reach at least 0.55 individuals km-2. This is a realistic estimate of the actual density for a technologically sophisticated hunter-gatherer society. This result assumes human attack rates on the native carnivores that equal one thylacine and devil killed per human every 7 and 0.17 years, respectively. Again, these rates are ecologically reasonable given that Aborigines hunted both thylacines and devils for food and ceremonial purposes.

Our multi-species models support recent claims that the dingo’s role in Australia’s Holocene extinctions has been overstated. In our simulations, dingoes could reduce thylacine and devil populations through different types of competition, as well as direct predation. However, when we included the dingo introduction as the sole extinction driver, dingoes rarely drove thylacines and devils to extinction in the time required. Our results support the notion that thylacines and devils persisted on Tasmania not because the dingo was absent, but because human density remained low there and/or because Tasmania is less affected by El Niño dynamics.

The mechanisms generally involved in the mass extinction of the Australian megafauna (human predation and competition) were also sufficient to exterminate smaller thylacines and devils once the human population had attained a sufficiently high density. Human intensification during the late Holocene parallels in some ways the development of agriculture on other continents, but in a culture that retained a hunter-gatherer economy, and would similarly have impacted negatively on the wildlife exploited for human use. It seems probable that human impacts on the structure and composition of Australian biodiversity were not limited to the late Pleistocene but extended into the late Holocene.

http://conservationbytes.com/2013/08/21/dont-blame-it-on-the-dingo/




Prowse, TAA, CN Johnson, CJA Bradshaw, BW Brook. In press. An ecological regime shift resulting from disrupted predator-prey interactions in Holocene Australia. Ecology doi:10.1890/13-0746.1

Abstract
The mass extinction events of human prehistory are striking examples of ecological regime shifts, the causes of which are still hotly debated. In Australia, human arrival approximately 50 thousand years ago was associated with the continental-scale extinction of numerous marsupial megafauna species and a permanent change in vegetation structure. An alternative stable state persisted until a second regime shift occurred during the late Holocene, when the largest two remaining marsupial carnivores, the thylacine and devil, disappeared from mainland Australia. These extinctions have been widely attributed to the human-assisted invasion of a competing predator, the dingo. In this unusual case, the simultaneous effects of human 'intensification' (population growth and technological advances) and climate change (particularly increased ENSO variability) have been largely overlooked. We developed a dynamic model system capable of simulating the complex interactions between the main predators (humans, thylacines, devils, dingoes) and their marsupial prey (macropods), which we coupled with reconstructions of human population growth and climate change for late-Holocene Australia. Because the strength of important inter-specific interactions cannot be estimated directly, we used detailed scenario testing and sensitivity analysis to identify robust model outcomes and investigate competing explanations for the Holocene regime shift. This approach identified human intensification as the most probable cause, while also demonstrating the potential importance of synergies with the effects of climate change. Our models indicate that the prehistoric impact of humans on Australian mammals was not limited to the late Pleistocene (i.e., the megafaunal extinctions) but extended into the late Holocene.

Read More: http://www.esajournals.org/doi/abs/10.1890/13-0746.1 
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#14
Dingo declared a separate species
The dingo has been given its own species status, recognising that it is not descended from dogs or wolves.


BY JACQUELINE OUTRED |APRIL 15, 2014

[Image: australian_dingo_zpspvajl1qi.jpg]
The dingo has been declared its own species and not a descendent of dogs or wolves. IMAGE CREDIT: Andrew Gregory/Australian Geographic

WHEN THE FIRST Australian governor, Arthur Phillip, landed on Australian shores in 1788 he documented the first written physical description of the dingo.

Formalised by German naturalist Friederich Meyer in 1793, this one-paragraph description of Australia's native canid has remained unchanged ever since, despite the limited level of detail included.

That is, until March 2014, when an international team of scientists, including conservation biologist Dr Mike Letnic from the University of New South Wales in Sydney, established a more detailed physical description of genetically pure dingoes.

The research published in the Journal of Zoology, is based on data collected from 69 forensic specimens predating 1900, before dingoes had come into contact with domestic dogs.

For the first time in its mysterious history, the purebred dingo has a benchmark physical description. And it reveals that many of our perceptions of the physical attributes of pure dingoes are untrue.

Yellow dingoes not the only purebreds

"Common folklore is that pure dingoes are only yellow in colour, like most of the ones on Fraser Island," Mike says. "But this is simply not true. We found that dingoes can be tan, dark, black and tan, white, or can have the sable coloration typical of German Shepherd dogs."

The outdated description of dingoes has meant purebreeds may have been culled under a false premise, contributing to its decline.

Often blamed for the loss of livestock, presumed hybrid dingoes have been culled in Australia under the assumption that any dingoes not yellow in colour are not purebred, and therefore not protected.

But when it comes to determining purity of dingo bloodlines colour is not a reliable characteristic as non-yellow dingoes existed long before Europeans arrived with dogs, Mike says. "We showed that there was all this [colour] variation possible."

Mike says that biodiversity in Australia will be affected by false assumptions about dingoes' purity. "Dingoes play an important role in maintaining the integrity of our ecosystems," Mike says. "It's not just the foxes and cats that change ecosystems; it's the kangaroos too and dingoes help to keep those numbers in check."

Dingo given its own species status

The study has also resurrected the name Canis dingo signifying that dingoes should occupy their own place on the evolutionary tree.

Canis dingo was the scientific name originally proposed by Meyer; however, as scientists struggled to establish exactly how the Dingo came to inhabit Australia, or determine its genetic lineage, other names such as Canis lupus dingo (indicating a connection to the wolf - lupus) and Canis familiaris dingo (implying domestication) were used.

"In the 1980's it became the fashion to treat domestic animals as subspecies of what the wild species were," Mike says. "The Dingo was recognised as a potential ancestor of the domestic dog, but domestic dogs were previously thought to have derived from wolves so the issue became really cumbersome."

Lyn Watson, a cynologist from the Dingo Discovery and Research Centre says confusion over the dingo's scientific name has hindered conservation work. "Domestic dogs were never likely to be considered for protection," she says.

But Lyn hopes that by resurrecting the official scientific name Canis dingo, recognition of the species in Australian legislation will follow. "In 250 years of Australian history, the dingo has never been closer to protection," she says.

http://www.australiangeographic.com.au/topics/wildlife/2014/04/dingo-declared-a-separate-species




An updated description of the Australian dingo (Canis dingo Meyer, 1793)

M. S. Crowther, M. Fillios, N. Colman and M. Letnic
Journal of Zoology, Volume 293, Issue 3, pages 192–203, July 2014

Abstract
A sound understanding of the taxonomy of threatened species is essential for setting conservation priorities and the development of management strategies. Hybridization is a threat to species conservation because it compromises the integrity of unique evolutionary lineages and can impair the ability of conservation managers to identify threatened taxa and achieve conservation targets. Australia's largest land predator, the dingo Canis dingo, is a controversial taxon that is threatened by hybridization. Since their arrival <5000 yBP (years Before Present) dingoes have been subject to isolation, leading to them becoming a unique canid. However, the dingo's taxonomic status is clouded by hybridization with modern domesticated dogs and confusion about how to distinguish ‘pure’ dingoes from dingo-dog hybrids. Confusion exists because there is no description or series of original specimens against which the identities of putative hybrid and ‘pure’ dingoes can be assessed. Current methods to classify dingoes have poor discriminatory abilities because natural variation within dingoes is poorly understood, and it is unknown if hybridization may have altered the genome of post-19th century reference specimens. Here we provide a description of the dingo based on pre-20th century specimens that are unlikely to have been influenced by hybridization. The dingo differs from the domestic dog by relatively larger palatal width, relatively longer rostrum, relatively shorter skull height and relatively wider top ridge of skull. A sample of 19th century dingo skins we examined suggests that there was considerable variability in the colour of dingoes and included various combinations of yellow, white, ginger and darker variations from tan to black. Although it remains difficult to provide consistent and clear diagnostic features, our study places morphological limits on what can be considered a dingo.

http://onlinelibrary.wiley.com/doi/10.1111/jzo.12134/abstract 
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#15
Skulls indicate dingoes 'probably aren't going to disappear' through cross-breeding

ABC Science By Anna Salleh
Updated earlier today at 1:16am

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PHOTO: The researchers made 3D reconstructions of dingo skulls (Karen Black 2012, modified by W.C.H. Parr)

Hybridising with dogs is unlikely to lead to dingoes changing their skull shape or losing their status as the top predator in Australian ecology, researchers say.

Key points
  • It was previously thought the dingo's skull would change due to cross-breeding

  • Latest findings using CT scans find little evidence to support this

  • The dingo's skull shape dominates in hybrids

  • Dingoes are likely to remain Australia's top predator
Their argument is based on new findings from a CT scan-based study that shows the dingo's skull is virtually unchanged when it hybridises with a dog.

Ecologist Associate Professor Mike Letnic of the University of New South Wales said while there are changes to some degree, they "aren't huge".

"We think that what's happening is that the dingo genes are dominant.

"We think that dingoes probably aren't going to disappear or change dramatically."

Canis dingo was introduced to the Australian continent around 3,000 years ago and was largely isolated from other canids such as dogs until Europeans arrived.

A previous study of dingo skulls by CSIRO found evidence that the skull of dingoes changed when they hybridised with dogs.

"They used callipers to compare the skulls of wild-caught dingoes with animals they'd deliberately crossed in captivity with domestic dogs," Dr Letnic said.

Since skull shape can influence what animals are capable of eating, the findings triggered concerns that hybridisation might threaten dingoes' role as top predator in Australia, resulting in knock-on ecological effects.

But Dr Letnic and colleagues have found evidence to the contrary, in a study of specimens including those originally studied by CSIRO, published today in the Evolutionary Biology journal.

"We found that there's a tendency for the hybrid animals to converge towards the wild-type dingo. They look more like a dingo than they do like a dog," Dr Letnic said.

Landmark points help define skulls

[Image: dingo-skull-custom-image-data_zpsiljgzbc5.jpg]
INFOGRAPHIC: A diagram of the dingo skull from below (A) and above (B) with numbered landmark points on it. (W.C.H. Parr)

The new study also included specimens such as cattle dogs that dingoes are likely to breed with, as well as other canids such as wolves and the New Guinea singing dog.

After scanning the skulls, the researchers used a sophisticated method to analyse and compare the 3D shapes they captured

Team member Dr Will Parr of the University of New South Wales said points were used as landmarks to characterise each skull in a 3D space.

"We couldn't find a statistical difference between the skull shapes of the dingoes and the hybrids," said Dr Parr, who studies the morphology of bones.

The landmarks did identify some regions of the skull that changed through evolution and breed development — and these differed between dingoes and other canids like wolves. But these same regions did not change during hybridisation, Dr Parr said.

Dr Parr said the dingo skull shape was "resistant" despite multiple episodes of hybridisation.

"The results show that when you hybridise dogs with dingoes the resulting shape is more dingo like than dog-like, and after subsequent hybridisation back with dingoes, the end result is even more dingo-like," he said.

Ecologist Dr Euan Ritchie of Deakin University said the research was "very important" to understanding the role of dingoes in the ecology.

"The dingo body shape and design is really successful in the Australian landscape," he said.

"There's obviously strong selection pressure for a body shape and a skull shape that's successful in terms of capturing prey."

http://www.abc.net.au/news/2016-03-10/ct-scans-reveal-dominance-of-the-dingo/7233296




William C. H. Parr , Laura A. B. Wilson, Stephen Wroe, Nicholas J. Colman, Mathew S. Crowther, Mike Letnic. Cranial Shape and the Modularity of Hybridization in Dingoes and Dogs; Hybridization Does Not Spell the End for Native Morphology. Evolutionary Biology pp 1-17

Abstract
Australia’s native wild dog, the dingo (Canis dingo), is threatened by hybridization with feral or domestic dogs. In this study we provide the first comprehensive three dimensional geometric morphometric evaluation of cranial shape for dingoes, dogs and their hybrids. We introduce a novel framework to assess whether modularity facilitates, or constrains, cranial shape change in hybridization. Our results show that hybrid and pure dingo morphology overlaps greatly, meaning that hybrids cannot be reliably distinguished from dingoes on the basis of cranial metrics. We find that dingo morphology is resistant, with observed hybrids exhibiting morphology closer to the dingo than to the parent group dog. We also find that that hybridization with dog breeds does not push the dingo cranial morphology towards the wolf phenotype. Disparity and integration analyses on the ten recovered modules provided empirical support for modularity facilitating shape change over short evolutionary time scales. However, our results show that this is may not be the case in hybridization events, which were not influenced by module integration or disparity levels. We conclude that although hybridization events may introduce breed dog DNA to the dingo population, the native cranial morphology, and therefore likely the feeding eco-niche, of the dingo population is resistant to change. Our results have implications for conservation and management of dingoes and, more broadly, for the influence of integration patterns over ecological time scales in relation to selection pressure.

http://link.springer.com/article/10.1007%2Fs11692-016-9371-x 
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