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Unsung Species: One of Earth’s rarest land mammals clings to a hopeful future (commentary)

  • South America’s huemul (Hippocamelus bisulcus) is the Western Hemisphere’s most endangered large land mammal, a fleet-footed Patagonian deer. The species once enjoyed broad distribution, but its numbers have been fractured into roughly 100 small disconnected populations, with huemul totals likely less than 1500 individuals.
  • Historically, the huemul was diminished by habitat destruction, poachers, livestock competition and alien predators (especially dogs). More recently climate change may be playing a role, hammering Patagonian coastal fisheries, so possibly causing local villagers to increase hunting pressure on the Andean mountain deer.
  • The huemul also suffers from being an unsung species. Unlike the polar bear or rhino, it lacks a broad constituency. If it is to be saved, the species requires broad recognition and support beyond the scientific community. This story is the first in a series by biologist Joel Berger in an effort to make such animals far better known.
  • This post is a commentary. The views expressed are those of the authors, not necessarily Mongabay.
Curiosity displayed in female huemul. Image by Joel Berger.

A blue whale has a big heart the size of an adult wild yak. Everyone knows the plight of blue whales — as they likewise know about tigers, elephants and pandas. But few know wild yaks and their predicament. And even fewer know Patagonia’s huemul, or Pakistan’s national mammal, the markhor. These too have heart, yet like so many other species, they slip toward extinction in obscurity. This series, as told by scientist Joel Berger, profiles unsung large mammals, giving voice to their secrets and need.

It’s often said, Variety is the spice of life — a phrase stemming from William Cowper’s 1785 poem, “The Task.” While interest in biological diversity escaped most of the world’s attention back then, biodiversity did fascinate the great German naturalist, Alexander von Humboldt, who — some 15 years after Cowper’s poem — explored South America’s tropical forests and heights.

There, he drew notice to the interconnectedness of life zones, writing eloquently of his journey from the Ecuadorian lowlands to ice-enveloped Andes peaks, including Chimborazo at over 20,000 feet, which he tried to climb. Thirty more years would pass until Charles Darwin, in his epic voyage aboard the Beagle, reported on the wild geography at America del Sur’s wind and wave blasted tip. Today, Patagonia remains a mystic realm where land and sea collide, a maze of islands and deep fjords, a place of glacial retreat and Magellanic sub-polar forests.

Water gushes from the sky here; some spots drown in 6,000 millimeters (235 inches) per year. The ocean has penguins and whales. Albatrosses float and condors soar above. On land, hidden in near-impenetrable lenga (beech) forests and ñirre (shrub), lives the huemul (pronounced hway-mool), the Western Hemisphere’s most endangered large land mammal — the epitome of the diversity that Humboldt sought and the variety Cowper celebrated, — an unsung species.

Nineteenth century artist’s rendering of Patagonia’s huemul (Hippocamelus bisulcus), the Andes mountain deer by Jacques Christophe Werner (1798–1856) and Christophe Annedouche (1803-1866). Image in the public domain.

A mysterious mammal living on the edge

Darwin reported this furtive cervid on Argentina’s southern Atlantic coast. Also known as the Andean mountain deer, Hippocamelus bisulcus was hunted by the Tehuelches indigenous group to the east, and by the Kawéskar in rainforests along the misty Pacific. With a face like that of a gray kangaroo, the squat body of a mountain goat, thick reddish tan pelage, and the beguiling elusiveness of a Himalayan takin, this near apparition continues to capture the hearts of Chileans and Argentines. As Chile’s national mammal, the huemul has graced the nation’s Coat of Arms (alongside Andean condors) since 1834.

In 1902, British explorer Hesketh Prichard noted the species’ boldness and curiosity: “These deer, which know little of man, are in general very confiding…  In the unpenetrated districts, the buck is very courageous…. [T]hey showed wonderfully little timidity.”

Today, this ghost of the Antarctic flora zone is so rare that the indisputable face of the climate crisis — the polar bear — is maybe 15 times more abundant. The huemul, which once enjoyed a broad distribution, has seen its dwindling numbers fractured into approximately 100 small disconnected populations, with species totals likely numbering less than 1500 individuals. The IUCN Red List indicates decreasing populations and much uncertainty about its future.

The altitudinal range of H. bisulcus remains extreme — from sea level to around 6,000 feet up into the Andes, with abundance increasing toward the edges of the massive Patagonia Ice Fields where the sub-Antarctic continental ice sheets undergo immense melting annually (similar to those of Alaska’s northern Pacific region). The very heart of its range lies within Patagonia’s peri-glacial zones, particularly in and around the roadless, roughly 35,000 square kilometer (13,500 square miles) Bernardo O’Higgins National Park (BONP). This roadless Chilean park, about four times the size of Yellowstone, is fundamental to huemul persistence. The ice field realm, thanks to its hostile weather, deep fjords and the logistical challenges of settling so remotely, is also the least peopled area of South America. Consequently, little is known of huemul in all but 2 to 3 sites.

We do know that the huemul lives in small family groups, typically with five or fewer individuals. Each has identifying ear patterns, coupled with the darkly-shaded muzzles of males and lighter ones in females — distinguishable marks useful in analyzing individual movements and social associations. Huemul usually freeze in place and stare when danger appears, capitalizing on coloring and lack of motion to blend into their surroundings. So at times, researchers walking the moorlands at the edge of glaciers, are startled by a huemul they’ve nearly stepped on, only to watch it rise to life, leaving scientists with hearts pounding.

Huemul on a de-glaciated spit at the front of receding glacier. Image by Joel Berger.

Complex threats: Changing climate, seas and economies

Among the deeply endangered huemul’s obvious challenges are some of the usual suspects: habitat destruction, poachers, livestock competition and alien predators (especially dogs) as revealed by a 3-year field study.

Other pressures — and the degree to which they are a detriment — are less clear, but they potentially include losses due to disease and to the more rapid melting of glaciers. Speculation: perhaps the scouring effect of ice enriches soil mineral composition, and so the nutritional value of vegetation growing between coastal lowlands and Andes heights, resulting in population variabilities shaped by altitude / nourishment.

But like so much about this animal, we just don’t know for sure. And there aren’t a lot of biologists or a flush of funding flooding into remote Patagonia to find out.

Researchers do know that in the wooded sections of Chile’s new Patagonia Park, in the Chacabuco Valley and adjacent Tamango Reserve — where monitoring has occurred for more than a decade — that pumas account for about 20% of adult huemul mortality, while free-ranging dogs account for an even greater percentage of juvenile mortality. Population data from other sites mostly consists of counts and is far less in-depth.

But deeper insights have come out of BONP research, where scientists have tracked a complicated weave of oceanic and off-shore climatic shifts which, together with human impacts, have had negative onshore consequences for the species. The complex interplay of warming sea temperatures, glacial melting and interactions between marine resources and villagers are adversely affecting human food security — while also affecting huemul. However, the precise threads of this tangled web must be carefully traced to get at root causes, with conclusions still not certain.

Historical distribution of huemul in grey and current distribution in black (points). Blue coloring reflects current distribution of ice caps in Patagonia and past extent shown by lines. Image courtesy of Alejandro Vila.

Begin with the fisheries industry, key to Chile’s national economy. As temperatures warm globally, Patagonia’s marine environment is similarly seeing a rise in temperatures, coupled to an increase in the frequency of harmful algal blooms (HABs). By definition, HABs render important marine resources — including fish and mollusks — unusable due to neurotoxins which accumulate from cyanobacteria, impacting local, national and international economics. So severe are recent HABs that one of the planet’s largest baleen whale death events resulted in 300+ mortalities along the Patagonian Pacific coast in 2015..

HABs especially impact isolated decentralized coastal fishing villages and artisanal fisheries, where local people go out in small boats to harvest king crabs, scallops and other invertebrates for export — vital to food security and for providing ready cash.

Puerto Eden is one such remote coastal village, situated in Bernardo O’Higgins Park below shrouded and often snowcapped peaks. Food staples of the roughly 200 residents are mollusks and fish; a few sheep and livestock also buffer that supply when times get hard.

Now, for the huemul connection: we know from our prior studies in this local area that huemul species density is related in an inverse proportion to the distance from Puerto Eden; the nearer to town, the fewer the huemul. Several close in sites no longer have any huemul. It may be that the loss of marine catches has put increased hunting pressure on the species.

When biologist Alejandro Frid conducted his pioneering huemul studies here 30 years ago he reported: “driven by their strong taste for venison, fishermen have already decimated deer populations near their villages and camps,” and, in a second paper: “Hunters with dogs were present shortly before I began fieldwork… we found recent tracks of humans with at least one dog. Although the Puerto Edén residents I interviewed could not estimate the hunting rate… one hunter claimed that he kills 10–15 huemuls a year. He always uses dogs to corner them.”

In our own conversations with villagers, both before 2010 and in 2017, the practice of using dogs to hunt huemul has not abated. While fishermen clearly supplement their diets with the meat of the hoofed mammal killed in fjords as distant as 100 kilometers (60 miles) from the village, we do not yet know if the intensity of harvest increases as a specific consequence of HABs. More study is needed — if the huemul does us the service of staying in existence until researchers can gather data.

Elsewhere, in the icy vastness of Bernardo O’Higgins National Park another cause can be found for huemul decline. There, cattle were illegally released above Tempanos, a remote fjord. Within fifteen years, the 18 introduced cattle had proliferated to more than two hundred; in 2004 they were removed by government shooters. Regrettably, their legacy lives on. An introduced foot disease infected the huemul, with severe clinical signs and consistent with a parapoxvirus. Population morbidity was 80%, with 40% mortality.

Young huemul exhibiting signs of paropoxis virus. Image courtesy of Alejandro Vila.

Staving off the rush toward oblivion

Doing the science — sussing out the multiple causes-and-effects driving a species’ numbers ever downward — is one thing. Finding and implementing solutions to treat these complex interconnected conundrums in a remote region with a species virtually unrecognized by the general public, raises the problem to a far higher level of challenge.

Meanwhile, illegal harvest, disturbance, and disease continue wearing on the huemul, even as our modern milieu further tips an unlevel conservation playing field awry. Climate change is altering globalized food supply chains, and unless the scientific and conservation community can figure all this out, the huemul could become just a memory — another empty niche and a biodiversity footnote in journals some two centuries after Humboldt.

All places are special, just as all species are unique. Beyond the bio-physical realities that long shaped the harsh southern environment of Patagonia — where sky, water, ice and earth meld, and where huemuls evolved, mastering the art of survival — humans now play prominent roles in the predicament faced by the species.

As small remnant populations struggle on, in remote steeply-sloped watersheds, amid glacial debris and on cliffy outcrops, hope glimmers as huemuls persist. Patrons like Michel Durand, who established a field station in a hidden fjord to observe the animals some two decades ago, became an early huemul defender; others followed.

As the huemul attracts more notice, recognition arrives; and with it comes standing. Chile and Argentina have enacted protection laws and launched public education campaigns. The threats brought by dogs, disease and livestock have been identified and analyzed. A handful of NGOs are committed to huemul protection, and so is a growing portion of citizenry.

The extreme edges of the planet are tattered and exposed to the elements. Life in such places was never easy. Now, with the coming excess of modern ills, the struggle to survive grows even more difficult. If the huemul is to be saved, this species — lacking a voice and veiled among the Patagonian mists — must have more help. The huemul, tracking across icy Andes detritus, must go from being unsung to celebrated.

Banner image caption: Patagonia’s Huemul. Photo credit: Ostrosky Photos on VisualHuntCC BY-NC-ND.

Joel Berger is the Barbara-Cox Anthony Chair of Wildlife Conservation at Colorado State University and Senior Scientist at the Wildlife Conservation Society, USA. His books include Extreme Conservation – Life at the Edges of the World (2018), and The Better to Eat You With – Fear in the Animal World (2008), both by University of Chicago Press. He spends much time hiking canyons and mountains with Darwin, his Australian blue heeler.

Alejandro Vila is the Science Director for the Wildlife Conservation Society’s Southern Cone Program of Latin America. He has studied science and practiced conservation since 1988 and works with rodents, hoofed mammals including huemul, and marine systems, and lives in Bariloche, Argentina.

Cristobal Briceno is a veterinarian who continues to expand his two decades of work on wildlife diseases among native and alien species. He is a professor at the University of Chile in Santiago.

Full disclosure: The three authors on this commentary have received support from the Wildlife Conservation Society to aid with huemul conservation.

Crab boat outside of Puerto Eden, Magallanes Region, Chile. Climate change is altering the ocean, reducing catches, which could be boosting hunting pressures on huemul. Image by Joel Berger.


Corti P., H., Wittmer, U., & M. Festa-Bianchet. (2010). Dynamics of a Small Population of Endangered Huemul Deer (Hippocamelus bisulcus) in Chilean Patagonia,” J. Mammal. 91, 690–97.

Corti, P., Saucedo, C., & Herrera, P. (2013). Evidence of Bovine Viral Diarrhea, but Absence of Infectious Bovine Rhinotracheitis and Bovine Brucellosis in the Endangered Huemul Deer (Hippocamelus bisulcus) in Chilean Patagonia,” J. Wild. Dis. 49 (3), 744–46.

Frid, A. (1994). Observations on Habitat Use and Social Organization of a Huemul Hippocamelus bisulcus coastal population in Chile. Biological Conservation, 67(1), 13-19.

Hulton, N., Purves, R., McCulloch, R., Sugden, D. & Bentley, M. (2002) The Last Glacial Maximum and Deglaciation in southern South America. Quaternary Science Reviews, 21, 233-241.

Saucedo, C. (2016). Patagonia Park: A Decade of Huemul Conservation. Wildlife Bulletin #1. Tompkins Conservation. Conservación Patagónica – Santiago. September. 34 pp

Vila, A. R., Briceño, C, McAloose D, Seimon, T. A., Armién, A. G., Mauldin, E. A., Be, N. A., Thissen,  J. B., Hinojosa, A, Quezada, M., Paredes, J. (2019). Putative parapoxvirus-associated foot disease in the endangered huemul deer (Hippocamelus bisulcus) in Bernardo O’Higgins National Park, Chile. PloS One. 14(4).

Vila, A., R, Saucedo, C, Aldridge, D. E., Ramilo, E. D.,  & Corti, P. (2010). South Andean huemul Hippocamelus bisulcus (Molina 1782). Neotropical cervidology: Biology and medicine of Latin American deer. Pp.89-100.

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