The nutcracker is an omnivore, but subsists mainly on pine nuts, burying seeds in the ground in the summer and then retrieving them in the winter by memory.

[2] A skin collected by the expedition was obtained by the ornithologist Alexander Wilson, who used it to produce an engraving for his monumental American Ornithology.

There is also a small isolated population on the peak of Cerro Potosí, elevation 3,700 metres (12,200 ft), in Nuevo León, northeast Mexico.

Outside the breeding season, it may wander extensively to lower altitudes and also further east as far as Illinois (and exceptionally, Pennsylvania), particularly following any cone crop failure in its normal areas.

[6] Depending on the cone crop as well as the tree species, a single Clark's nutcracker can cache as many as 98,000 seeds per season.

), as well as low availability of alternative foods; this surplus seed is left in the cache, and may be able to germinate and grow into new trees, if the conditions are right.

Clark's nutcrackers are known for storing and recovering large numbers of seed caches that are critical for winter survival.

It was demonstrated that the cache recovery ability of Clarks nutcracker is derived from a memory system that has evolved differently for storing spatial information.

[9] The diet also includes a wide range of insect prey, berries and other fruits, small mammals and occasionally flesh from carcasses.

Rotten logs are also hacked into in order to locate large beetle grubs, and animal dung may be flipped over in search of insects.