Jackals among wolves: balancing between competition and tolerance

Competition plays a key role in shaping predator communities, but carrion abundance can alter these interactions. We investigated interactions between grey wolves (Canis lupus), an apex predator and golden jackals (Canis aureus), an opportunistic mesocarnivore, in carrion-rich regions of Greece, where livestock carcasses are frequently dumped by farmers. Using unmanned aerial vehicles with thermal imaging, handheld thermal cameras and camera traps, we recorded nearly 1100 wolf and over 9000 jackal sightings across landscapes. Our analyses showed that jackals fed and rested more often near abundant food, with larger carcasses leading to prolonged interactions. There was a strong positive relationship between carcass biomass and jackal group size, highly moderated by season, facilitating joint feeding and accelerating carrion consumption. Wolves feeding alongside jackals were mostly solitary, while jackals formed groups of around five, likely benefiting from reduced risk and greater feeding opportunities. Larger carcasses attracted more interactions between species, supporting our hypothesis that ample food supply reduces direct competition and fosters greater tolerance. However, competition persisted, as we recorded multiple cases of jackal food theft and a single fatal wolf-jackal encounter. These findings challenge rigid predator hierarchies, highlighting how resource abundance promotes coexistence and underscoring the need for effective wildlife management in food-abundant environments.