Knocking on Wood

The northern flicker, so often pushed around by more aggressive birds, could use a little help.

by Frank Graham jr.

The tall, stout stub of a dead trembling aspen lingered for several years in sight of our home in Maine. Each spring a couple of northern flickers would excavate a nesting hole in the remains, giving us hope that a pair of those handsome woodpeckers might remain to raise their young. But no dice. Inevitably, the rapid-fire, high-pitched kwik-kwik-kwik-kwik of the flickers would be replaced by the alien twaddle of European starlings.

Exit the flickers. Starlings, those efficient home-busters, had once more taken over from the original residents. Yet moral outrage yields little satisfaction in such a case because the problem is essentially a conservation one. Suitable nesting trees are often in limited supply in a given area. In our coastal region, the short-lived trembling aspens and paper birches that proliferate may succumb before growing to robust size. As they die, their stubs are often toppled by winds and ice storms.

One solution to this housing shortage is to set out artificial homes. It's well known that bluebirds, tree swallows, and purple martins take readily to nesting boxes in much of the country. But flickers? Well, why not? Though they breed in 49 U.S. states and much of Canada, the northern flicker could use some help. "Although still abundant and widespread," Audubon field editor Kenn Kaufman notes in Lives of North American Birds, "recent surveys indicate declines in population over much of the range since the 1960s."

This decline is about 52 percent since 1966. Because of the species' wide range, the exact causes of its woes are hard to pin down. The human penchant for cutting dead snags gets prominent mention from researchers, and as suitable nesting places become rare, competition for them increases. Flickers, which chiefly eat ants, spend a great deal of time pursuing them during the 12 days it takes the birds to excavate a nest. Unfortunately, when they take a break from nest building, starlings, squirrels, even kestrels notice their absence and appropriate the nests.

Northern flickers make good neighbors. They consume prodigious numbers of ants and other terrestrial insects, and visit backyards in modest numbers instead of overwhelming them the way starlings, grackles, and house sparrows often do. Flickers make good neighbors for birds, too, and can often be seen hammering away at an anthill while robins feast on the worms driven to the surface by the commotion.

The northern flicker was created as a species in 1973 when the American Ornithologists' Union lumped the yellow-shafted flicker of northern and eastern North America with the red-shafted flicker of the West. The two forms, distinguished mainly by the colors of their wing linings, interbreed where they overlap on the Great Plains. A smaller species, the gilded flicker, lives in the Southwest.

Feeding on ground-living ants seems a perversity in birds so beautifully designed to extract grubs from tree trunks and limbs. Like all woodpeckers, flickers are built on a unique plan: The strong, four-toed feet found in most family members, as well as their stiff tail feathers, support the birds as they move up tree trunks or hold them in place as they chisel into the wood with their rugged, pointed bills. A recipe for becoming punch drunk, surely. But the woodpecker's thickened skull and powerful neck muscles cushion its brain from the pounding.

Another woodpecker feature is the long, pale tongue. For most woodpeckers, the tongue functions as a spear, probing deep beneath the bark and drawing out prey with the help of backward-pointing barbs near its tip. In flickers, by contrast, a flattened tip on the extensible tongue is used to maneuver eggs, pupae, and adult insects from the soil.

Still, trees are essential for northern flickers, which sometimes feed on berries or insects among the foliage; excavate their nests in any suitable trunk, stub, or stump; and roost in crevices or cavities. If good nesting trees aren't available, well, that's where we pro bono carpenters are in demand.

Field editor Frank Graham Jr. is a longtime contributor to Audubon.





© 2002  NASI

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Northern Flicker


Tape measure; carpenter's square; pencil; power or hand saw; power hand drill with attachments (2 1/2" keyhole saw, 3/8"-diameter drill bit, 3/32" bit [to predrill holes], Phillips-head screwdriver bit); claw hammer; miter box, for 5-degree cut (optional).


  • 1' x 10' piece of unpainted, rough-cut (on both sides) wood, such as white pine. Remember that while rough-cut (unplaned) lumber is truly 1" thick and 12" wide, planed lumber is either 3/4" thick (both sides are smooth) or 7/8" thick (one side is smooth) and 11 1/4" wide and should not be used to make this box.
  • 16 coated or galvanized (to prevent rusting) 2" Sheetrock (drywall) screws or 2" ring-shank (ribbed) wood siding nails.
  • Two 2" galvanized finishing nails; four 1 1/2" galvanized finishing nails.
  • One right-angle screw; one eyelet screw with galvanized washer.


(1) Trim a 3"-wide strip off the length of the board. You'll have a board 9" wide and 10' long.

(2) Working from the left end of the board, measure then cut a 22"-long piece for the front (22" x 9"). Next cut a 31"-long piece for the back (31" x 9"), then a 12"-long piece for the roof (12" x 9"). The back edge of the roof and the top edge of the front will fit better if they're cut at a 5-degree angle.

(3) Next measure and cut the sides. On the edge closest to you, mark a point 21 3/4" from the left end of the board, then a second mark 24" to the right of the first. On the edge away from you, mark a point 23 3/4" from the board's left end, then a second mark 22" to the right of the first. Draw a diagonal line connecting the first set of marks and cut there. Repeat with the second set of marks. The side pieces will have angled top edges.

(4) Next measure and cut a 3/4"-wide strip (3/4" x 9") and set it aside. It will be attached later where the roof meets the back.

(5) With the remaining lumber, saw a 7" x 7" piece for the bottom of the box.

(6) Using the keyhole saw, drill a centered 2 1/2"-diameter hole in the front piece. The upper edge of the hole should be 2" from the front's top edge.

(7) With the 3/8" drill bit, drill three ventilation holes in a line about 3" below the slanted edge of the longer (non-pivoting) side. Drill five 3/8" drainage holes in the bottom piece-one near each corner and one in the center.

(8) Measure 2" up from the bottom of the back and mark where the bottom edges of the sides will be attached. Using five screws or nails, attach the side with the ventilation holes to the back.

(9) Attach the front to the same side with five screws or nails.

(10) Position the floor and fasten it with two screws each to the front, the non-pivoting side, and the back; recess the floor 1/4" from the bottom edge of the front, side, and back to create a drip edge.

(11) Using the carpenter's square, mark the locations (exactly opposite each other) for the pivot nails near the tops of the front and back. Attach the remaining side with the 2" finishing nails (this side is shorter at the top to enable it to swing out freely); add the angle screw at the bottom of the front to secure this side.

(12) Attach the roof and secure it to the top edge of the front with the eyelet screw and washer. Last, using the four 1 1/2" finishing nails, attach the 3/4"-wide strip of wood to the back of the box above the roof. It should be placed so it just touches the roof-this strip and the eyelet screw are what hold the roof in place-but be sure that it doesn't interfere with removing the roof.

Hanging the Box

Be careful when mounting this heavy nest box 6 to 20 feet up on a live or sound dead tree, wooden post, or metal pipe. Attach it to the tree or post with two 3" lag screws centered at the top and bottom of the back piece. (Use a couple of U bolts for a metal pipe.) Face the box away from the prevailing weather in a semi-open, partly sunny area. Make sure the flickers are able to see the box easily. Hang the box by March 1 (earlier in the deep South). Consider wrapping a 30"-wide sheet of aluminum below the box on the trunk or pole to discourage climbing predators. It is crucial that you pack the box tightly from bottom to top with wood chips or shavings (not cedar, which irritates the nestlings) so that the flickers can "excavate" a cavity. Regular monitoring is crucial to discourage starlings.

René Laubach has been director of the Massachusetts Audubon Society's Berkshire Wildlife Sanctuaries since 1985. He and his wife, Christyna, wrote The Backyard Birdhouse Book (Storey Books, 1999), from which these instructions were adapted.