Should the Himalayan Wolf Be Classified As a New Species?

Science
جمعه 12 بهمن 1397 ساعت 18:49
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Smith sonian mag
Geraldine Werhahn had been tracking wolves for two weeks up and down mountains at an average altitude of more than 13,000 feet when she came across a young family. It had been a long day of trekking through the Dolpa district of northern Nepal in 2016, during Werhahn’s third expedition in search of the elusive canines.
During the first expedition, locals told her that the mountain-dwelling cousins of the gray wolf were only found at much higher altitudes in the Himalayas. On the second attempt, she spotted a few animals trotting off in the distance but had to be content to collect scat.
This time, when her crew stopped for camp around dusk, Werhahn set up her camera and spotted a family of wolves far across the valley through a long-range scope. For the next five days she woke early in below-freezing temperatures, when the plants were still crusted with ice, and watched young Himalayan wolf pups playing, feeding and keeping a close watch on the soaring raptors that might prey on them when the adults venture off, one at a time, for a hunt. The video Werhahn shot is the first known footage of an active Himalayan wolf den.
The research that Werhahn and her team gathered during these expeditions has now been compiled, and the genetic findings present strong evidence that these wolves should be recognized as a subspecies of gray wolf, uniquely adapted to living in high altitudes, if not an entirely distinct species.
“[The Himalayan wolf] is more distinct than any of the gray wolf subspecies that are currently acknowledged,” says Werhahn , a doctorate student at Oxford University’s Wildlife Conservation Research Unit and lead author of a study of Himalayan wolves published recently in Global Ecology and Conservation .
Himalayan wolves live in their namesake mountain range as well as the Tibetan plateau, as Werhahn discovered in another expedition in 2017. Apart from Nepal and China, the animals can also be found in the Indian Himalayas, but the wolves of nearby Kyrgyzstan are mostly gray wolves with a few that appear to have hybridized with their Himalayan cousins. To track wolves through such rugged and remote landscapes, Werhahn had to become a type of pack leader herself, guiding a team of researchers and support crew with mules hauling equipment, camping gear and food to last for up to eight weeks .
“You’re roaming like a wolf pack,” Werhahn says, adding that the team ventures as high and remote as they can. Like the wolves, they read the landscape from vantage points, walk for days to get to promising locations, and follow the routes that wolves tend to favor in hopes of spotting the animals.
“It really takes a lot of patience. There are days when we don’t find anything, and there’s days where we’re really close to a den site and I sample 30 scats within five hours,” Werhahn says, joking that she is a professional wolf scat chaser. She has become so good at the skill that she can now tell the difference between wolf and snow leopard droppings by smell alone.
Himalayan wolf pup. With unique adaptations to high-altitude living, these wolves may be classified as a new species or subspecies distinct from the gray wolf. (Geraldine Werhahn / Himalayan Wolves Project)
These samples were crucial, as they provided the mitochondrial DNA, nuclear genome material and other genetic elements that Werhahn and her team later analyzed to find that the Himalayans diverged from other gray wolves between 691,000 and 740,000 years ago.
Werhahn is unsure whether this genetic analysis means the wolves will be recognized as a separate species, but she believes they should be recognized at least as a subspecies by the International Union for Conservation of Nature (IUCN), which needs to make a number of decisions on gray wolf population classifications in general. One of the holdups with the Himalayan wolves is that nobody can agree on a proper Latin name. Various conflicting names such as Canis chanco , Canis laniger and Canis filchneri were given by explorers of centuries past, while Werhahn and other Indian researchers use Canis (lupus) himalayensis. An official decision will likely be made within the next year or so.
Lisette Waits , a conservation biology professor at the University of Idaho who has studied gray wolves in the U.S. and Mongolia but was not involved in Werhahn’s study, says the recent work is a “powerful paper” and a great example of using non-invasive techniques like scat gathering to get DNA samples.
“It would be very hard to go out and trap wolves across this landscape,” Waits says. She would know, having spent time in Nepal tracking snow leopards and tigers through the high mountains.
Waits believes the genetic evidence shows these wolves are unique among the other gray wolf populations the team sampled. “It’s clearly a distinct evolutionary lineage,” she says.
Klaus Koepfli , a research scientist with the Smithsonian Conservation Biology Institute’s Center for Species Survival, agrees that the evidence is strong enough to suggest Himalayan wolves at least represent a subspecies of gray wolf. However, the full genome would need to be mapped before you could say much more. “Whether it’s a unique species or not, still, the jury is out,” he says.
One of the major findings of Werahn’s team is that Himalayan wolves have a genetic adaptation absent in other gray wolves that helps them better cope with the low-oxygen environment of high altitudes, similar to the genetic traits of Tibetans who also live in the area. Part of the Himalayan wolf’s genome allows the animals' hearts to more efficiently process oxygen, a rarified commodity in the mountains.
Other behavioral evidence supports the idea that Himalayan wolves could be unique from their gray relatives. The Himalayan wolf howls to a different tune than other wolves, for example. Werhahn describes the howls as shorter and slightly lower in pitch than the nighttime songs of gray wolves.
While the wolves may have a fitness advantage at high altitudes, their genes don’t necessarily help them with their biggest threat: humans.
In the Himalayas, people hunt wolves with guns, or using poison or snares. Himalayan wolves are often culled by locals who fear the predators will attack their livestock, and Tibetan shepherds count on the health and safety of their herds for their livelihoods. “It is a hard life up there,” Werhahn says.
Himalayan wolves are highly elusive, preferring to avoid human settlements. But even in the national parks of Nepal, clashes between wolves and shepherds tending their herds are inevitable. (Geraldine Werhahn / Himalayan Wolves Project)
During the 2016 expedition, Werhahn felt compelled to hide the fact that her team was observing a wolf family across the valley whenever nomads would pass through their camp. When dens are discovered, she says, people often kill any wolves they encounter, lighting fires near the entrance and putting up stones to block their exit.
“They would basically create smoke so that the pups would suffocate inside the den,” she says, adding that of the five dens she discovered during her 2016 expedition, three showed evidence that the animals had been smoked out.
Part of the larger issue is that these wolves have no space to avoid confrontations with people. While Nepal has national parks, shepherds are permitted to freely bring their herds through these areas. Werhahn says that Himalayan wolves prefer wild prey, but herds of domesticated yaks passing through their territory will often scare away wild animals, leaving the wolves with little choice but to hunt young yaks or goats in the herd.
To exacerbate matters, wolf parts are worth money in the traditional Chinese medicine market, giving locals another reason to kill the animals. Werhahn says that increasing awareness among local Nepalese and Tibetans helped facilitate snow leopard conservation, and she hopes that similar work could help protect the Himalayan wolf.
Currently, there isn’t enough data to determine definitively whether or not these wolf populations are declining. But if the IUCN classifies Himalayan wolves as a unique species or subspecies, researchers can bring the data to the Chinese and Nepalese governments to try to spur conservation efforts.
According to Waits, Werhahn’s work “highlights the importance for conserving the Himalayan wolf” due to the animal’s genetic distinctness.
As far as research goes, Werhahn’s days of roaming with her wolf pack are far from over. She suspects that Bhutan may harbor Himalayan wolf populations as well, and she hopes to venture there next in her never-ending pursuit of wolf scat in the high mountains.
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