Are there any howling birds? Any birds that howl?

Yes Owls and the Hillary Loon.

I do not like it when she shouts.  That is not as bad as a growl.  The growl comes from the other one.  The animalistic moron in the other corner.

Owls do howl.  Thanks. 

I forgot and was thinking more in terms of the dog howling sound.  But you are right.  DUH ---meaning me. 

Yes, I personally know a few.

Loons  and Orange tufted Banshees howl

I don't know, but when I was living in Belize there were howler monkeys, and boy did they ever howl, and very loud.