Clark's nutcracker
Distinguishing whitebark pine ("Pinus albicaulis"), from the related limber pine ("Pinus flexilis"), also a member of the white pine group, is much more difficult, and usually requires seed or pollen cones. In "Pinus albicaulis", the seed-bearing female cones are long, dark purple when immature, and do not open on drying, but the scales easily break when they are removed by the Clark's nutcracker to harvest the seeds; rarely are there intact old cones in the litter beneath the trees. Its pollen cones are scarlet.