It’s stating the obvious to point out that the grizzly bear is a formidable beast. Even your average wolf pack, more often than not, thinks twice before engaging one of these big, unruly “silvertips.” And, while in most parts of the continent the bulk of the grizzly’s fare is vegetative, it can be an effective predator on an occasional basis, capable even of bringing down moose and the odd bison.

But attacking large mammals is risky – for grizzlies as for any other carnivore. A few months ago a griz in the Canadian Rockies suffered the consequences of predatory ambition (or desperation) in the form of a defensive counterattack by a mountain goat.

Mountain goats have sharp horns which they use with deadly effectiveness when under threat.

Earlier this year, a hiker in British Columbia’s Yoho National Park came upon a grizzly carcass – a female, or sow, weighing only some 70 kilograms (154 pounds). A subsequent necropsy revealed stab wounds at the bear’s armpits and throat which Parks Canada attributed to the dagger-like horns of a mountain goat, a band of which was seen in the general vicinity of the dead griz. The location of those wounds, and the determination that they were received before the bear’s death, suggested a botched predation attempt.

“When grizzly bears attack,” Parks Canada wildlife ecologist David Laskin told Rocky Mountain Outlook Today, “they tend to focus on the head, back of the head, and the shoulders of prey, and it’s usually from above, so in turn the defensive response of the mountain goat would be to protect itself using its sharp horns.”

Indeed, Laskin further noted that this wasn’t the first case of this variety that he’d heard of. “Though rare, other cases of mountain goats defensively killing bears have been reported in the past,” he told the paper. “This is not completely surprising since mountain goats are strong animals that are well equipped to defend themselves.”

Mountain goats wield curved horns capable of inflicting significant damage.

Mountain goats are stocky, snow-white, black-horned ungulates – not true goats, by the way – native to the high country of northwestern North America. Across a goodly portion of that range, they overlap with mountain sheep: Dall, Stone, and bighorn sheep, only distantly related caprine cousins. Whereas mountain-sheep rams square off with dramatic head-on clashes – loud, shuddering, but generally more ritualised than injurious combat – goat billies confront one another broadside, and if intimidation doesn’t work they jab fiercely at their rival’s hindquarters. Though said rear ends are protected by thickened hide, the curved, keen-pointed design of the goat’s horns makes these rut rumbles dicier affairs than the boss-to-boss collision of mountain sheep.

Mountain-goat nannies are notably aggressive toward other goats, quick to deploy a horn slash or two to clarify the social hierarchy. Bighorn sheep on Caw Ridge – a long-standing bighorn and mountain-goat research site along the front of Alberta’s Rocky Mountains – tend to yield to testy goats, surely out of respect for those skull-spikes of theirs.

On occasion, mountain goats may even turn those horns on human beings. A few years back, a man in Utah escaped a tense encounter with a billy unscathed; a 2010 hiker in Washington State’s Olympic National Park was less fortunate.

But wielding dagger horns, useful as they can be for sorting out intra-group dynamics, aren’t a mountain goat’s primary means of eluding predators. It’s their exceptional skills navigating steep cliffs and razor-thin ledges, which gives them a natural advantage over grizzlies and other carnivores in rugged mountainscapes.

Kevin White, a biologist with the Alaska Department of Fish & Game who’s closely studied the species in the burly coastal mountains of that state’s southeast, noted via email that survival rates among mountain-goat kids in “intact, predator-rich ecosystems” tend to be notably higher than those of deer and moose neonates – evidence of the effectiveness of the goat’s anti-predator strategies.

Goats, however, must often forage away from the sheer “escape terrain” that gives them a leg-up, and in at least some goat-roamed landscapes those kinds of gravity-defying refuges are a limited resource. Grazing gentler alpine slopes or browsing subalpine parkland, mountain goats are more vulnerable to carnivores: not only grizzlies, but also wolves (for which goats may be a significant food source in, for example, parts of southeastern Alaska) and cougars, and potentially also black bears and wolverines.

In many cases, goats caught out in such precarious settings will flee to the nearest escape terrain, scrambling up outcrops and rock faces as quickly as they can. But if such terrain is not available, or goats are overtaken before reaching it, they may resort to active defense.

“In most instances,” White told me, “mountain goats respond to threats by running to cliffs/refugia and then climbing into difficult-to-access spots. Yet, when no other options exist, they clearly exhibit defensive behavior, including incredibly quick and dangerous horn-stabbing movements.”

He highlighted the following footage of a goat attacked by a cougar (not taken in Alaska) as illustrative of how effective those horn-thrusts can be:

Sandra Hamel of Quebec’s Université Laval, who’s logged many hours studying goats at Caw Ridge, concurred with White in terms of mountain goats – not least mother goats with especially vulnerable young – favouring flight over fight against predators in most cases. “Defense is more an exception and when it seems feasible to win for the nanny,” she said via email. “I have seen a nanny run to defend her kid from a yearling bear that had taken it, but as soon as the mother bear arrived in sight, the nanny just abandoned immediately the chase and almost ‘flew’ while running away.”

Steeve Côté, another leading mountain-goat authority, and one of Hamel’s colleagues at Université Laval, echoed that point regarding threatened nannies with kids. “They can either escape and not consider their kids,” he emailed, “but they can also defend the kids. I’ve seen them attacking predators, jumping off cliffs to go defend their kid, etc., but this is mainly for wolves, probably less likely with bears, and overall not that common. Overall, the best defense by far is going to a cliff and staying there – that’s what they normally do.”

Whether goats choose to go on the offense or not when faced with predators can make a big difference. In a 1997 paper, Côté and his co-authors described an extended interaction between a band of goats on Caw Ridge and a pair of wolves. One wolf ended up grabbing a three-month-old kid, only to be set upon by its mother, who leapt down from the cliff where the goats had taken refuge and charged the attacker. After a few jabs from the nanny, the wolf released the kid, which escaped; three other adult goats then chased the canid off.

Later that same day, however, after the goats had returned to the slope on which they’d first been attacked, the same wolf reappeared and chased the band. Several goats veered away from the cliff and ran instead (unwisely?) toward a nearby wood, pursued by the wolf. It ended up catching a yearling female, which it soon killed; eventually, it dragged the carcass into the trees. In this case, the mother of the yearling, present in the band, did not attempt to defend her offspring, though this nanny, the study authors observed, “looked for several minutes at the site where the wolf had disappeared and was the last goat to bed.”

Hamel notes that nannies with kids threatened by grizzlies may retreat to ledges and stamp their hooves aggressively, a behavior she and Côté have also documented when goats shield youngsters from swooping golden eagles. A video captured in 2018 shows this foot-stamping behavior in action, as performed by a female goat protecting a kid from a grizzly in the Canadian Rockies:

The Caw Ridge researchers have also seen a nanny run off a wolverine. According to Marco Festa-Bianchet of the Université de Sherbrooke – and co-author, with Côté, of the seminal Mountain Goats: Ecology, Behavior, and Conservation of an Alpine Ungulate – the wolverine “hightailed it out of there.” (Sounds like a smart move.)

“So they are aggressive and showing it to predators,” Hamel noted, “but I feel they will only attack if they stand a good chance at the predator or have no other alternative than to fight for their life, for example if they are ambushed.”

The threat of ambush is a real one for goats that stray from cliffs into parkland or forest. Goats crossing through timber – to reach mineral licks, say, or en route between seasonal ranges – have been seen running along habitual trails, as if to minimise their time in this riskier habitat. In a Caw Ridge study looking at the survival of young goats to breeding age between 1989 and 1993, all except two of the confirmed and suspected predation events took place in forest or krummholz (contorted, weather-beaten timberline stands). In what appeared to be an unsuccessful attempt at snatching a goat from a group amid timber, a grizzly bear observed by the researchers “seemed to detect the goats by scent, then rushed in their direction, possibly attempting an ambush.”

Mountain goats are at greater risk of attack if they stray from the safety of cliff faces and wander into forests. 

In some areas, nannies and young goats seem to assiduously hug cliffs and stay above timberline, while adult males (billies) are more likely to forage lower down in conifer stands. This may potentially put male goats at risk of predatory ambush more frequently; Côté notes the Caw Ridge study has documented numerous instances of successful attacks by grizzlies on billies.

That said, Hamel emphasizes the researchers have also seen plenty of attacks on nannies and kids. “Except for the kidding season, most females and young goats form larger groups than males, so this might help to detect a predator more rapidly to escape (‘many-eyes’ hypothesis,” she wrote by email.) “It might also make them more detectable by predators than smaller groups or individual males.”

In the mountains of coastal Alaska, Kevin White said there’s not strong evidence for sex-based habitat segregation, though adult males and females may use different areas at different times of year. He also pointed out that a large billy – in his study area, he’s weighed male goats as heavy as 175 kilograms (385 pounds) – is “a formidable opponent” even for brown bears.

Among the successful grizzly attacks on mountain goats that Hamel has seen at Caw Ridge was an intriguing predation involving not one but two young bears. The pair had been observed earlier one particular summer “almost searching systematically for cliffs in the kidding season,” managing to take a few kids. Then, in midsummer, the two grizzlies attacked a large group of goats. One of the bears flushed the goats, which ran to the other side of some escape terrain, only to be met by the second bear. That griz ended up killing an adult nanny.

A grizzly at Caw Ridge resting near the carcass of a nanny it killed. Image © Sandra Hamel

The bears went out of view, but shortly thereafter one was seen leaving the vicinity, and the pair wasn’t observed together again for the rest of the summer. Hamel said tracks near the goat kill suggested the two grizzlies may have squabbled over the carcass.

Attaining escape terrain – or, more rarely, counter-attacking – may see a mountain goat out of immediate trouble when it comes to grizzly bears and other potential predators. But it’s important to note that there may be secondary or residual impacts to a local goat population from a carnivore encounter. A Caw Ridge study Côté worked on suggested that even unsuccessful attacks by grizzlies on goat bands may – especially when played out in mountain forests, where visibility is limited – lead to nanny-kid separations by scattering goats this way and that. That could conceivably result in higher mortality among pint-sized goats. “Lone kids are probably at high risk of predation, being small and inexperienced in escaping predators,” the study authors wrote in a Mammalia paper. “Lone kids also appear to have limited knowledge of the location of travel routes and of habitats regularly used in their home range.”

Furthermore, a recent study out of Caw Ridge suggests that the mere presence of predators may have a long-term impact on mountain goats. A bear, wolf or cougar on the scene – even if no attacks result – can elevate stress hormones (glucocorticoids) in goats, in turn lowering the proportion of reproductive nannies in the population.

Mountain goat kids are at greater risk of attack from grizzlies on the prowl.

The superior traction of goats on dicey alpine topography is likely one reason why your average grizzly, wolf, or cougar is likely to treat them as more of an incidental prey source. (Though Hamel—a rock-climber herself – notes that grizzlies can be impressively adept at scaling “areas that are difficult to climb for most humans.”) So is the fact that, within a given landscape, mountain goats often exist in lower numbers and densities than other ungulates.

But the relatively small sizes of typical goat populations could also heighten the impact of predation in certain cases. There is evidence that, at least occasionally, particular carnivores may “specialize” to one degree or another in hunting goats. The Caw Ridge project, Festa-Bianchet told me, identified a “goat-specialist cougar [...] that wrecked the population” for a spell. And the aforementioned Caw Ridge research on kid survival from the late ‘80s and early ‘90s identified at least five grizzlies in the area, but suggested just one bear – perhaps a specialist – carried out all the recorded predation events on goats during the study period.

We’ll close out, just for novelty’s sake, with a goat/bear saga recorded in southeastern Alaska by Kevin White that ultimately is a fair bit odder than a goat-stabbed grizzly. A GPS-collared mountain goat died in the vicinity of the Juneau Icefield’s Meade Glacier during the winter of 2006-2007. Deep snow hampered efforts to retrieve the collar. By the following fall, though, the collar’s signal was, strangely, mobile again. It was eventually revealed that the dead goat’s tracking device was now around the neck of a black bear, which apparently in its enthusiastic scavenging of the ungulate had managed to slip the thing over its head.