In addition to Snow’s connection with birds, in the pilot Prince Charming mentioned that the animals of the forest were abuzz with news about the dark curse. It seems like talking animals might be more common in the EF than we perhaps realized. Jiminy Cricket could communicate with people. Now, it seems like Billy/Gus the mouse might have been able to communicate with Cinderella in the EF.
Also, in the cartoon version of Sleeping Beauty, Maleficent had a pet crow who was also an evil spy. Crows are typically portrayed as bad omens in folklore and fairytales. Cora using a crow as a messenger is fitting. I also recall hearing or seeing crows in the second episode of S1 when Regina was creating the dark curse.
"That’s how you know you’ve really got a home. When you leave it, there’s this feeling that you can’t shake. You just miss it." Neal Cassidy