How do crossbills use crossed bills to remove pine seeds?

Crossbills (genus Loxia) are specialized passeriform birds whose unique bill structure is specifically adapted for extracting seeds from conifer cones.

To remove the seeds, the bird inserts the tips of its crossed mandibles between the scales of a cone. Once the tips are positioned, the bird uses its tongue to lift the seed out from beneath the scale. This specialized feeding mechanism allows crossbills to efficiently exploit a food source that is otherwise difficult for many other birds to access.12