Ooh, clever corvids.

With the perspective it's hard to tell their size in comparison with Rosie, but they seem more like smallish ravens (or largeish crows? Although the profiles look somehow more raven-like to me).

Maybe they had a very desperate message to deliver. The heroic band of lurchers who are holding back some hideous threat are overwhelmed, and need reinforcements NOW or all of lurcherkind will be destroyed! But even though it took two of them, and they showed great persistence in the face of blatant uncooperation on the part of the intended recipient, the message went undelivered...

I always get confused with crows and ravens but I love them all. I used to love it when penny chased the birds. X