{"fact":"Crows have a complex relationship with gulls.  While sometimes competing for resources, they can also be allies against shared predators.","context":"Interactions were observed between Black-headed Gulls and Carrion Crows (Corvus corone),...","source":"M. Moynihan; H. Kruuk, Predators and anti-predator behaviour of the black-headed gull (Larus ridibundus L.), 10.2307/4511169","index":150}