A Bird’s Tale

A most interesting woodpecker

Wed, 07/23/2014 - 5:30pm

    We were watching a massive female grizzly bear with cubs moving through the willow flats below the Jackson Lake Lodge in Grand Teton National Park with high snow-capped peaks towering into the blue sky behind, when a bird darted over our heads with a bold white wing stripe. It was a sapsucker — a red-naped sapsucker, the closely related western counterpart to our own yellow-bellied sapsucker. The truth is that, even for bird lovers, we could not pull ourselves away from watching the grizzlies to enjoy that particular sapsucker. We would have more opportunities to see more red-naped sapsuckers during our recent trip to Yellowstone, but chances were not so good for seeing another mama grizzly with cubs!

    Sapsuckers are particularly interesting among woodpeckers for a number of reasons. As the name suggests, they have the very unique habit of essentially farming trees to harvest the sap. Could it be that humans learned to make maple sugar by watching sapsuckers? Sapsuckers harvest the sap by making “sapwells” — perfect rows of holes or squares that break through just the hard outer bark of trees to the cambium layer where the sap flows. On the coast of Maine, if you look closely at just about any old apple tree, you will see the neatly aligned rows of holes that are clear evidence of years of sapsucker presence.

    In the Boothbay region, yellow-bellied sapsuckers are most common during migration, although they do breed in the area as well. They are particularly common breeders farther north across forested regions of Maine but they have an extensive breeding range that encompasses most of the boreal forest region of Canada. That means that large numbers of those that nest across Canada migrate through Maine and other northern U.S. states as they head south.

    This long-distance migratory behavior is also unusual among woodpeckers. The familiar hairy and downy woodpeckers that we see at our backyard feeders do not migrate. Nor do the crow-sized pileated woodpeckers or the more recently established red-bellied woodpeckers that are uncommon breeders across at least the southern half of Maine. In our area, the only long-distance migratory woodpeckers are the yellow-bellied sapsucker and northern flicker. In winter, yellow-bellied sapsuckers range from the southeastern U.S. south to the Caribbean and Central America south to Costa Rica and Panama.

    Other creatures have learned and evolved to take advantage of the “farming” efforts of sapsuckers. The most well-known are hummingbirds — ruby-throated hummingbirds in our region. Hummingbirds will hover in front of sapsucker wells to sip the sap and sometimes to catch the insects that are also attracted. It is a funny thing to see a hummingbird hovering in front of a tree instead of a flower.

    One behavior that sapsuckers do have that is not different from other woodpeckers is drumming. Instead of singing, they make loud drumming sounds by tapping rapidly with their bill on resonating surfaces (usually hollow trees) to establish territorial boundaries. But yellow-bellied sapsuckers even do this a little differently. Rather than a single rolling drumming sound they have a cadence that slows at the end with clear pauses between raps. They also seem to more enthusiastically experiment with different surfaces from which to drum including stove pipes and other metal surfaces around camps and homes. Many a camp owner has been shocked from a restful sleep at dawn by the rat-a-tat-tat of a lusty sapsucker echoing down a stove pipe into the camp. Rather than let this sound annoy us, we encourage home and camp owners to embrace it as nature on our doorstep — or chimney, as the case may be.

    Jeffrey V. Wells, Ph.D., is a Fellow of the Cornell Lab of Ornithology. Dr. Wells is one of the nation's leading bird experts and conservation biologists. His grandfather, the late John Chase, was a columnist for the Boothbay Register for many years. Allison Wells is a senior director at the Natural Resources Council of Maine. Both are widely published natural history writers and are the authors of the book, “Maine’s Favorite Birds.”