By definition, if an animal has feathers , it is a bird.
Birds are very highly evolved vertebrates.
They have extreme modifications of the feet and beak for feeding and locomotion. However, there is great uniformity in the basic structure in birds. They are highly evolved flying machines which places restrictions on body shape, for the anatomy of a bird is entirely evolved around the perfection of flight. The isolated islands of the seas often have their own endemic species - Hawaii and Galapagos islands. Most likely yes.