Wolves react to presence of trail cam.

Wolves are keenly aware of their surroundings, even as they venture across the wilderness at night.

They’re also curious, but wary, when something not appear to be natural.

The accompanying trail-cam footage, from Canada’s Yukon Territory, opens with a moose and grizzly bear walking in front of the Yukon Wildlife Cams device during the day.

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The next scene, beginning at 9 seconds, features the wolves. Viewers will note their varied reactions, beginning with the lead wolf pausing briefly before dashing out of frame, and a second wolf passing the camera, then returning as another wolf enters the frame. (Click here if video player does not appear below.)

David Troup, who maintains several cameras, responded to comments about the wolves' reactions by stating: “This is a low glow camera which uses infrared lights at night and the LEDs glow red when the camera is triggered. So the wolves see the lights suddenly illuminate which spooks them.”

Troup added: “I also have no-glow cameras in which the red LEDs are not visible (usually poorer night quality videos) but the wolves don’t visually know those are there at night so they usually don’t react.”

His footage, a compilation from August, ends with several lynx cubs chasing one another and climbing trees.

Reads a top comment: “A true ‘wait for the end moment.’ Playful kittens, they sure can climb!”

This article originally appeared on For The Win: Wolves 'spooked' by trail camera as they pass device at night

Reporting by Pete Thomas, For The Win / For The Win

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