I don't want to scare you but a hawk can take a rabbit - why would he think they couldn't take a yorkie ?? Some rabbits get pretty big
A friend had her yorkie snatched by a hawk less than 20 feet from her
:....it really happens and even if the bird doesn't 'fly' off with the dog - the talons alone can hurt or kill them...they're a MAJOR predator and please be very careful