In summer their bills are yellow. Winter and juvenile plumage is a muted brown or taupe, and the bill loses its yellow color. Like most other successful species, starlings are generalists in their diet, eating insects, fruit, seeds, suet, agricultural crops, pet food, livestock feed, and city garbage. Happily for gardeners, these birds are a chief predator of clover weevils, cutworms, and Japanese beetles. In the absence of any other food, starlings will even feed on fungus.
Starlings are accomplished mimics.
They have been observed imitating the calls of up to 56 American bird species, as well as barking dogs, meowing cats, human speech, machinery sounds, and even a ringing telephone. In Denver yards, starlings often mimic killdeer and nighthawks. A starling in my backyard once imitated the quacking of a duck. Keeping pet starlings and teaching them to speak is an ancient practice dating back to Roman times. Mozart was reputed to have kept a pet starling.