When the birds are related a crow will
use a passive strategy and walk up to
or kind of sidle next to the bird with
the food. Often the second bird will
give up the food to the scrounger.
With aggressive scrounging, there
is usually a flying approach by the
thief who nearly lands on the other
bird. This can be followed by vocalization,
physical contact and attempts to take the
food. Usually it also involves chasing
and avoidance by the bird with the food.