How do Ring-billed Gulls in the western United States often differ in their primary sustenance compared to inland populations?

Answer

They often forgo fish almost entirely, relying on agricultural fields

Western populations frequently depart from the typical diet, finding the majority of their energy from grain crops and insects found in agricultural fields, sometimes omitting fish.

How do Ring-billed Gulls in the western United States often differ in their primary sustenance compared to inland populations?
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