'Surprised' grizzly bear that mauled man to death won't be euthanised

A report has concluded that a grizzly bear most likely attacked and killed a US hiker after being 'surprised' last month.

On 9 May, it was revealed that the body of Anthony Pollio had been recovered in Montana's Glacier National Park after being reported missing in the area.

The 33-year-old is understood to have been killed by a grizzly bear, the first fatal bear attack in the region since 1998.

Now a report into the circumstances surrounding Pollio's death has been released, revealing that the Florida native had most likely startled the bear while walking alone along the park's Mt. Brown Lookout trail at around 9:30pm on 3 May.

It's thought that the 'darkness and deadfall on the trail' most likely prevented both the bear and Pollio from seeing each other until they were 'very close'.

The bear then attacked out of surprise, to which Pollio discharged his bear spray.

Anthony Pollio was attacked and killed by a grizzly bear while hiking in Montana (Facebook/Anthony Pollio)

However, it is 'unknown if and where the spray contacted the bear'.

Pollio is understood to have fallen nearly 100 feet down the trail during the bear's 'initial assault'.

At this point, the bear briefly broke off the attack, only to return and fatally attack Pollio after he climbed 18 feet towards the trail he'd fallen from.

Memorialising his son in an interview with The Sun Sentinel, Arthur Pollio described the experienced outdoorsman as 'fearless', saying: "His life experiences in 33 years, some people don’t get to do ’til they’re 90 or their whole life."

In a separate interview with NBC6, Arthur shared his son's last message, revealing that Anthony had said that he loved him.

Responsible bear will not be euthanised or moved

The report concluded that the bear responsible for Pollio's death was an 'adult male grizzly' which appears to be a 'life-long resident of the park'.

It's understood that the bear has no previous history of conflict with humans and would not be euthanised, as the attack on Pollio was considered 'surprise' and not a stalking attack.

"Following a comprehensive review of the incident, no management action has been taken or is planned for the bear involved," Autumn Sifuentes, a spokesperson for Glacier National Park, told SFGate in a comment, adding that the bear had 'reacted defensively during a surprise encounter'.

Sifuentes also noted that the park would continue to monitor bear activity in the area.

Bear attacks in the region are said to be rare, with the last fatality occurring in 1998 (Getty Stock Images)

Hikers reminded of bear safety protocol

There are an estimated 60,000 grizzly bears dotted throughout North America, with the majority of the population found in Canada and Alaska, with the rest living in the states of Alaska, Montana, Wyoming, Idaho, and Washington.

The report concluded by reminding visitors to US national parks of bear safety protocols, which include travelling in a group or making noise, such as 'talking, singing or clapping', in order to avoid startling a bear.

Hikers are also advised not to travel at dusk or dawn, when bears are understood to be at their most active.

Bear attacks in the Glacier National Park region are said to be rare, with Montana Fish, Wildlife & Parks officials saying there have only been 10 attacks since 1967, with the last fatal attack occurring in 1998.