Ravens are opportunistic feeders enjoying a variety of foods, such as seasonal berries, small mammals, young birds, and amphibians. They are not above enjoying a feast on carrion. For most of the year, ravens are more spread out across the park and primarily function as predators. If a tourist looks to the sky and sees a flock of ravens then there is a strong possibility that there is a predator kill somewhere nearby. It is not unusual to see ravens competing with bald and golden eagles when surrounding carrion. During the summer they have adapted to human activity and will look for any opportunity to steal food off picnic tables. During the winter season, the ravens have adapted to the human activity surrounding the winter visitors, particularly those riding snowmobiles.
snowmobilers will pack their lunches and snacks in backpacks strapped to back of their snowmobiles. Whenever the snowmobilers pull over to take a short hike or go sightseeing the ravens move in to explore for food. As you can see illustrated in this photo, ravens are not easily deterred by packs that are zipped and tied to the back of the snowmobile. They are tenacious creatures. You can chase them away and as soon as you leave the area, they are back at work. At times it seems that they work in teams with a second raven zooming in as the first raven takes his prize off to the surrounding trees.
Unfortunately, visitors seem to ignore the signs and they even laugh when other visitors warn them. On one particularly cold snowy day in January, I chased off ravens and returned items to backpacks. I warned arriving visitors to take their lunch packs with them, with no success. Willing or not, these visitors were enabling ravens to continue their raiding behaviors.