Hi Tweets

This message is forwarded for Richard Fleming, who is not a member of Tweeters.

Brian H. Bell
Birding & Natural History Guide
Woodinville WA
bell asoc at isomedia dot com


August 3, 2007



Tool Use by Clark's Nutcracker



Richard S. Fleming and Gayle Rae Garman



On August 1, 2007, we were hiking above the Sunrise Lodge in Yakima Park in Mount Rainier National Park. Yakima Park is northeast of the summit of Mount Rainier and is located on the south-facing slopes of Sourdough Mountain. The Park is located at 6400 feet and is at the treeline. The Park is an extensive area of dry open meadows with stringers of trees in the meadows. Trees are also present in and around the talus slopes. Stunted trees (krumholtz) are also present among the rocks and along the cliff lines. About 11:20 PDT, we were about a mile west of the lodge crossing a talus slope on the trail to Frozen Lake. Strings of alpine fir and white pine extended up-slope from below. Many of the trees were either dead or the tops were dead. Our attention was directed to trees just below us by the calling of a number of Clark's Nutcracker (Nucifraga columbiana). We watched a bird alight about three feet below the dead top of a fir about 100 feet from us. The bird hopped around inspecting clusters of lichen, cracks in the branch, and under dead bark. Perched on a lateral branch, the bird inspected a cleft between the main stem (about 2" in diameter) and a subsidiary stem (about 1" in diameter). The cleft was about 6 inches from its perch. The two leaders formed an angle of about 15 or 20 degrees. In the cleft there was a cluster of filamentous lichens and debris about two inches in diameter. The bird inspected the branch on which it was perched and broke-off a twig about 2 inches long. Aligning the twig with the axis of its bill, the bird stabbed at and worked the cluster with lateral and vertical strokes of the twig/tool. After a few seconds the cluster came loose in the cleft. The bird placed the twig/tool under one of its feet and then reached out and picked up the lichen cluster. The bird inspected the lichen cluster, did not find any food item, dropped the cluster, and flew off. On this day, the Clark's Nutcrackers were gleaning food items from the lichen clusters and from under the bark of the trees, as well as hammering the cones of live trees for seeds.