Bald eagles might be regarded as the most fearsome predators of the sky, but like any other wild creature, they\u2019ve got to do whatever it takes to survive the winter.<\/p>\n
Accordingly, they might scavenge more than they hunt during the cold months, biologists told Cowboy State Daily.<\/p>\n
That was evidenced in a raw display of how nature works in Yellowstone National Park. After the Wapiti wolf pack killed a bison and ate their fill, scavengers moved in.<\/p>\n
Among them were a dozen bald eagles and roughly 40 ravens, said John Winnie Jr., who took photos and video of the feast.<\/p>\n
\u201cWhat really impresses me every time I see a carcass is, it\u2019s sort of like a\u00a0conveyor\u00a0belt of scavengers getting in there, grabbing it and taking it away,\u201d he said.<\/p>\n
\u201cWe\u2019re talking about many pounds of meat being taken per hour,\u201d added Winnie, an associate teaching professor in the Department of Ecology at Montana State University.<\/p>\n
Wolves Take Down Weakened Bison<\/p>\n
Some of Yellowstone\u2019s wolves have pivoted from preying mostly on elk to\u00a0hunting bison<\/a>.<\/p>\n It\u2019s not an easy undertaking for wolves, Winnie said. The packs typically target old, sick or weakened bison. And the bigger the bison population, the more chances wolves have of finding softened targets.<\/p>\n But with bison, there\u2019s no such thing as an easy kill.<\/p>\n \u201cNo matter what, they (bison) are kind of badass\u00a0animals\u00a0and hard to hunt,\u201d Winnie said.<\/p>\n He wasn\u2019t there when the Wapiti wolf pack killed the bison that the eagles and ravens scavenged from.<\/p>\n According to what witnesses told him, the bison was suffering from a broken leg, and the wolves killed it either late Friday or early Saturday near a roadside, along the banks of the Madison River.<\/p>\n \u2018Straight-Up Competition\u2019<\/p>\n Once the wolves gorged themselves and backed off, it was time for coyotes and the birds to take their share.<\/p>\n At one point the carcass was completely mobbed by eagles and ravens. And it was a free-for-all.<\/p>\n \u201cI don\u2019t think there was any cooperation at all, it was straight-up competition,\u201d Winnie said.<\/p>\n The ravens knew better than to mess with adult eagles. However, Winnie noticed a raven pestering a juvenile eagle, pecking at the eagle\u2019s tail.<\/p>\n Winter Food Options<\/p>\n During the warmer months, bald eagles in Yellowstone eat mostly fish and ducks, Winnie said.<\/p>\n When lakes, ponds and streams freeze over during winter, the ducks leave to go south. And ice prevents the eagles from getting at fish. So they must scavenge meals.<\/p>\n \u201cBald eagles in particular rely very heavily on carrion as a winter food source,\u201d Winnie said.<\/p>\n That\u2019s the case for eagles across the state, said Bryan Bedrosian, the conservation director for the Teton Raptor Center.<\/p>\n He also noted that there are far fewer ducks and fish available for bald eagles during the winter. And golden eagles can\u2019t find prairie dogs, one of their favorite prey species.<\/p>\n Moreover, the number of eagles in Wyoming soars over the winter.<\/p>\n \u201cThere are just more eagles here in the winter, because so many migrants come into Wyoming,”\u00a0Bedrosian said.<\/p>\n