Woodworks

Natural History, June, 2001 by Richard Milner

Charles Darwin admired the special adaptations of woodpeckers, citing their stiff tail spines, hard-pointed bills, and shock-absorbent necks. While most of these birds are small and forage by drilling holes in tree bark to extract one grub at a time, the crow-sized pileated woodpecker (Dryocopus pileatus) hacks away at wood on a somewhat larger scale--both to excavate nests for its young and to expose whole colonies of ants. During February and March, a male and female may pound on a dead branch or old tree trunk for as long as a month to excavate a nesting cavity in which to raise three or four chicks. Both parents take turns incubating the eggs and bringing food to the chicks. Males sit on the eggs mainly at night. The parent feeding a chick in the photograph (inset) was spotted in a mixed conifer-hardwood forest in northern Michigan, near the Canadian border.

Although their diet includes some acorns and beechnuts in the fall, pileated woodpeckers eat mostly ants, flying insects, grubs, and some seeds and fruits. Carpenter ants are a special favorite. When the forest floor is blanketed in snow, the birds use their powerful bills to dig out ant nests from tree trunks and tree bases. Jabbing at the wood, they remove chips three to six inches tong. According to some observers, these woodpeckers feed on the sap that runs from the trees' wounds and also eat the insects that are lured by the flow of sugary liquid.

Woodpeckers of this species have been known to rescue endangered eggs. In one documented instance, when a dead tree containing a nesting cavity collapsed, the female retrieved each of her three eggs with her bill and flew them to a hollow in another tree. On his return to the original nesting site two hours later, the male began a frantic search of the area and finally managed to locate his family. The pair soon settled in their new home and resumed their breeding efforts.

After two decades of traveling on assignment for National Geographic, photographer Jim Brandenburg ("The Natural Moment," page 84) decided to settle down next to a million-acre wilderness in his native Minnesota. Coming upon the tracks of a wolf or a lynx gives him even more pleasure, he reports, than did his former adventures in the Namib Desert or the forests of Manchuria. Brandenburg's books include White Wolf: Living With an Arctic Legend (Northword Press). He has established a nonprofit gallery of his work in his hometown of Luverne; the proceeds go to acquiring and preserving the tallgrass prairie near his boyhood farm there (see www.jimbrandenburg.com).