What physiological adaptation allows robins to consume large quantities of fruit during fall and winter?

Answer

Their esophagus is exceptionally stretchy.

Robins possess an exceptionally stretchy esophagus, which allows them to consume huge quantities of berries quickly before dark, aiding their seasonal dietary shift.

What physiological adaptation allows robins to consume large quantities of fruit during fall and winter?
birdanimalphysical featureRobin