Every winter the Cedar Waxwings come by our holly trees and in short order remove all the berries. The next year they repeat the process. This year we had no visitors so that in late March we still have trees loaded with berries. What will happen this summer if the berries are still on from last year? Will they “fall” off? Will new berries form? Will the trees croak? Will the frogs eat the berries?
Most berries are pruned away with the yearly pruning.
Frogs don't eat Holly berries.
Here are some articles that will help you.