What kind of white birds are living in a palm tree Arizona making screech sound and dropping pellets filled with bones?

White-tailed Kite:

- Medium-sized raptor (bird of prey)

- Black back and white head and tail

- Found in open areas, including deserts and grasslands, in the southwestern US and Mexico

- Nests in palm trees, typically in colonies

- Known for their distinctive, high-pitched screech call

- Feed primarily on small rodents and other small mammals, catching them in mid-air or snatching them from the ground

- Pellets primarily contain the remains of small rodents and other small mammals

- Pellets typically deposited beneath the nest or in the surrounding area