Common ravens, Corvus corax, preferentially associate with grey wolves, Canis lupus, as a foraging strategy in winter

In Yellowstone National Park, ravens are the most numerous scavengers of wolf-acquired carrion.

“In YNP, ravens are the most numerous scavengers of wolf‐acquired carrion (Stahler et al., 2002).”

In areas away from anthropogenic resources, raven populations often rely on food subsidies provided by large predators, particularly in winter.

“In areas away from anthropogenic resources, raven populations often rely on food subsidies provided by large predators, particularly in winter, and ravens are ubiquitous scavengers at wolf kills throughout North America (Kaczensky, Hayes, & Promberger, 2005; Stahler et al., 2002; Vucetich, Peterson, & Waite, 2004).”

In areas where ravens overlap with wolves, ravens are numerous and ubiquitous scavengers of wolf-acquired carrion.

“In areas where they overlap with wolves, however, ravens are numerous and ubiquitous scavengers of wolf‐acquired carrion.”

Winter-kill, even when available, would not have benefitted ravens in the same way that wolf-acquired carrion does; ravens locate and forage from wolf-acquired carcasses almost immediately, but they can take significantly longer to find and feed from non-wolf-acquired carrion.

“Furthermore, winter‐kill, even when available, would not have benefitted ravens in the same way that wolf‐acquired carrion does; ravens locate and forage from wolf‐acquired carcasses on the Northern Range almost immediately, but they can take significantly longer to find and feed from non‐wolf‐acquired carrion (Stahler et al., 2002).”

The pattern of ravens being highly associated with wolves has held true in Yellowstone since the wolf reintroduction in 1995-1997.

“and this pattern has held true in Yellowstone since the wolf reintroduction in 1995–1997 (Stahler et al., 2002).”

The latter possibility would be most likely in cases where territorial adult ravens are the primary predators.

“The latter possibility would be most likely in cases where territorial adult ravens, which come to closely associate with nearby wolves (Stahler et al., 2002), are the primary predators [e.g., as with desert tortoise (Boarman, 2003) and greater sage grouse (Bui et al., 2010)].”

Territorial ravens across the Northern Range are relatively familiar with the local wolf packs and are able to locate and scavenge from wolf-acquired carcasses almost immediately.

“In contrast to birds in human‐use areas, territorial ravens across the Northern Range are relatively familiar with the local wolf packs and are able to locate and scavenge from wolf‐acquired carcasses almost immediately (Stahler et al., 2002).”

Ravens are more likely to be found in the vicinity of wolves than elsewhere on the landscape, especially when wolves are traveling or chasing prey.

“Ravens are more likely to be found in the vicinity of wolves than elsewhere on the landscape, especially when wolves are traveling or chasing prey”

Ravens can find wolf-acquired carcasses much faster than other carrion on the landscape.

“allowing these scavengers to find wolf‐acquired carcasses much faster than other carrion on the landscape (Stahler et al., 2002).”