Clark's Nutcracker eating seeds from a Whitebark Pine cone. Vogelsang High Sierra Camp, Yosemite, CA. The Clark's Nutcracker's obnoxious yet melodic calls fill the High Sierra air in summer: a comforting sound to anyone who has spent much time in the upper elevations. These corvids, exhibiting ashtonishing intelligence like their cousins (ravens, crows, jays), ultimately provide the foundation for the Whitebark pine subalpine ecosystems. Unlike most pine cones which open to reveal winged seeds that disperse on the wind, the whitebark cones remain sealed until the seeds typically die. Instead, the massive, nutritious seeds remain cemented into massive cones shielded by pitch and tannins. During the month of August, the cones ripen and the nutcrackers blast the cones with powerful long bills and delicately remove each seed for consumption or storage in a sublingual pouch. The nutcrackers fly off, bury the seeds for later harvest as their primary food supply throughout the year. Through triangulation, visual cues and memory, the birds recover as many as thirty thousand seed caches over the course of a year. However, they leave some seeds buried which ultimately germinate and start new pines.
Without the nutcrackers, whitebark pines cannot reproduce. Without the trees, the nutcrackers can't survive. As a result of the perfect symbiosis, an entire ecosystem thrives. Yosemite's beauty blossoms out of the most complex interrelationships. Copyright, © 2008, James McGrew