A Maine webcam caught rare footage of an eagle stealing a nearly full-sized osprey chick from a nest this week, providing a glimpse into the oftentimes brutal competition between the birds of prey.

In a display of stealth and power broadcast live over the internet, an adult bald eagle swooped in on three osprey chicks in a midcoast nest Monday evening and hauled off one struggling victim to its likely death. The two other young ospreys survived the attack, one by apparently taking the first flight of its young life.

But the video of nature’s harsh reality generated hundreds of comments – many of them mournful – from the loyal community of followers of the osprey webcam operated by the nonprofit Explore.org.

Steve Kress, vice president for bird conservation at the National Audubon Society, which operates the webcam, said it is one of the best videos of eagle predation he’s ever seen.

“We were all very surprised because I don’t think anybody has ever documented an eagle taking an essentially full-grown osprey chick out of a nest,” said Kress, director of the Hog Island Audubon Camp, a historic ornithological camp on the Maine island where the webcam is located. “That is one of the great things about these cameras because they are giving us insight into what is happening on these nests.”

CHICKS ON THE VERGE OF FLEDGING

Located off the coast of Bremen, the Hog Island osprey camera is the most popular webcam operated by Explore.org, drawing millions of views from around the globe last year. The Aubudon Society has operated a high-definition web camera on the osprey nest for five years, and this particular pair of ospreys are believed to have been using the nest for even longer.

The mating pair successfully reared three chicks this year, all of which were nearing the point of fledging, or taking flight, when the eagle attacked.

In a clip posted by the Audubon Society, the three chicks can be seen perched near the edge of their treetop nest gazing out over the water below. Suddenly, a white-headed bird can be seen racing toward the nest from below with another large bird – apparently one of the osprey parents – in quick pursuit.

Spying the fast-approaching threat, one chick takes a literal leap of faith and makes what Kress and others said was its maiden attempt at flight. A second chick crouches flat against the nest. But the third chick cannot get off the nest fast enough and ends up in one of the talons of the marauding eagle. In a slowed-down version of the video, the chick, affectionately named Spirit by the webcam-watching community, can be seen being carried away from the nest.

Eagles have made a dramatic recovery across the continental United States after nearly being wiped out by exposure to the pesticide DDT, which rendered their eggs too brittle for viability. The resurgence has been particularly dramatic in Maine, where the number of nesting pairs rose from 31 in 1976 to more than 600 during the last count in 2013. Ospreys also suffered declines in Maine, but were never listed as an endangered or threatened species. Today they are abundant throughout the state.

Eagles are opportunistic predators who feed on anything from fish to roadkill. But Kress said some bald eagles along Maine’s coast appear to “have developed a bird-eating habit.” He said the same nest lost its entire brood to eagles last year, although the chicks were much smaller at the time.

“It happened so quickly that if we didn’t have the camera, we might have never known what happened there,” Kress said of the current incident.

LONGTIME RIVALRY BETWEEN RAPTOR SPECIES

Charlie Todd, a Maine Department of Inland Fisheries & Wildlife biologist who oversaw much of Maine’s decades-long campaign to rebuild the state’s eagle population after the bird’s near-elimination, said there is “a long tradition of rivalry” between eagles and ospreys. The species often compete for the same territory and, while they can co-exist, they will frequently seize opportunities to target each other.

Eagles are bigger and stronger, but ospreys are more agile fliers and better at catching fish. This is a risky time of year for many bird species because parents tend to avoid the nest for longer periods of time to encourage their young to take flight and literally “leave the nest,” Todd said.

That might be what happened in this particular incident, Todd said, because an eagle probably wouldn’t attack chicks with the parents in the nest.

“They are watching each other all of the time,” he said of the two species. “If the eagle sees there’s just a fledgling in the osprey nest, they may go after them.”

It wasn’t all bad news for the osprey aficionados who have been watching the three chicks, some since their hatching.

The chick that hunkered down in the nest – nicknamed Eric – and was lucky to avoid the eagle’s attention was still around Tuesday. And an intern working on Hog Island spotted Little B – the chick strong and fast enough to take the leap of faith – perched high in a tree about one-quarter mile from the nest. Its parents were seen nearby.

On Wednesday, the webcam showed both fledglings in the nest, not far from a watchful parent.

“What we see there, in an instant, is a beautiful example of natural selection,” Kress said.