Happy news about animals
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.”