Why are Crows afraid on Catbirds ?

Question

Catbirds are always chasing crows, The crow is like 5 times larger.

Answer 1

Crows are not afraid of catbirds. But catbirds (and more typically kingbirds) and other small birds can out maneuver them and harass them. They peck at and pester the crow until they leave. Are you afraid of a swarm of mosquitoes? Probably not but you wouldn't stick around without bug spray where a swarm of mosquitoes is would you?

Crows often mob hawks in large numbers but most small birds I have seen mob one on one. Most often the mobbing bird (the smaler one) is either a kingbird or blackbird, but other birds will mob large birds if they are near their nest. Kingbirds can often be seen mobbing hawks thousands of feet in the air so the kingbird just looks like a black dot.

Answer 2

Crows (and other larger birds) are often "mobbed" by catbirds or other smaller birds. It is a defensive move learned early on. Usually, it is done with larger numbers, but one-on-one is also common. The "pinches" of an attacking bird can still do damage and even pull feathers loose, regardless of the fact that it is a smaller bird. So the larger bird usually will retreat in self-defense.