How deadly is the crow?

I find my crow is very often off to debate with other crows, and I kind of expect that this is also leading up to an attack if crow is not well enough tended to.

How likely is the attack to happen? Will it always cause death? Will there be a warning?

The Teardrop Cottage had me freaked out as I did not know they had a crow "hidden" on the lot. When I found it it was not vey happy, LOL.  Is it ok to check a crow only once per day?