[Wikipedia] Ecology: The whitebark pine is an important source of food for many granivorous birds and small mammals, including most importantly the Clark's nutcracker (Nucifraga columbiana), the major seed disperser of the pine.[5] Clark's nutcrackers each cache about 30,000 to 100,000 seeds each year in small, widely scattered caches, usually under 2 to 3 cm (3⁄4 to 1+1⁄4 in) of soil or gravelly substrate. Nutcrackers retrieve these seed caches during times of food scarcity and to feed their young. Cache sites selected by nutcrackers are often favorable for germination of seeds and survival of seedlings. Those caches not retrieved by the time the snow melts contribute to forest regeneration. Consequently, whitebark pine often grows in clumps of several trees, originating from a single cache of two to 15 or more seeds. (link added by Mary Ann Machi)