Some combination of a fast OD (COCO has bears so many OTS YOLO models have bears) and striding through frames should make it feasible to somewhat rapidly process the videos.
We should always be weighing this against other options like simply watching the video really fast in VLC or using CV-based motion detection and/or background subtraction that will be able to run even faster through the frames i.e. leveraging how little is happening in these views when bears aren't there.