The gluttons are here

Common Starling
Sturnus vulgaris

The local juveniles are growing up fast and are just sprouting their fresh adult plumage. But to fuel this they have to cram it in just as fast as they can and the bird feeder becomes a rowdy battleground of flapping feathers, squawks and pecks. and they can empty it in a day.

Their speckled black plumage shines nicely iridescent in the sun. It Spain they also have spotless starlings ... which have no spots!