Clark's nutcrackers can be found in high-elevation forests across much of the western United States and southwestern Canada. At Craters of the Moon, this bird spends most of its life in and around the limber pine (Pinus flexilis), which provides its primary food source.
Behavior
Clark's nutcrackers have excellent spatial memory, which allows them to cache thousands of seeds each summer and fall and retrieve them during winter and spring.
Nutcrackers begin harvesting limber pine seeds in August. They work their sharply-pointed beak between the cone scales to expose the pea-sized pine seeds. Nutcrackers store up to 100 seeds under their tongue in a small sublingual pouch. Seeds remain there until the nutcracker can bury them, 3 to 5 seeds at a time, in dispersed caches, often many miles away from the original tree. A single bird may make up to 20,000 caches a year! Throughout the winter and spring, the nutcracker revisits these caches to eat the seeds and when feeding their young.
Preparing extensive food caches allows nutcrackers to nest earlier than most birds. They begin in February, which in turn means offspring are old enough to participate in the late-summer seed harvest. Nests are built in conifer trees, such as the limber pine, and both parents feed and care for young.
Nutcrackers and Limber Pines: a Special Relationship
Both the limber pine and Clark's nutcracker have mutually beneficial adaptations.
the large seeds are retained in the cones and on the tree so it's possible for the birds to find large numbers of seeds in a small area.
the branches of the tree sweep upward and provide ideal perches for the nutcracker while they collect seeds.
the nutcracker's sharp beak is curved so it can efficiently remove the meat from the shell of the pine nuts.
while many pines rely on the wind to disperse their seeds, limber pine seeds are too heavy to be dispersed this way. Instead, they rely on the nutcracker.
as remarkable as their memory of cache locations is, nutcrackers do not return to every seed cache.
buried pine nuts germinate and take root to produce new pine seedlings.
nutcrackers allow limber pines to colonize areas on younger lava flows, far from other trees.
