Two crows and an owl
Crows are never happy to see an owl in their territory. Owls will prey on crow nestlings and great horned owls will attack adult crows when they are sleeping in their roosts at night. Therefore crows have an ingrained desire to drive owls off and use a technique called mobbing to harass an owl until it files off. In the daytime, if you hear and see a group (or murder) of crows gathering in a concentrated area in the trees, look closely to see if there is an owl in there too.
Interesting! Thanks.