G. S. Agersborg (1881) mentions a nest that “was in the angle formed by the shares of an upturned plow” in South Dakota. And E. A. Stoner (1915) flushed a red-headed woodpecker from a blue jay’s nest in Iowa. “The nest was eight feet up in an oak sapling and was a typical Blue Jay’s but was found to contain three pure white and unmistakably Woodpecker eggs.”
Eggs.—Major Bendire (1895) writes: “The number of eggs to a set varies from four to seven, sets of five being most frequently found, while occasionally as many as eight eggs have been taken from a nest. Mr. R. C. McGregor records taking a set of ten eggs of the red-head, varying in size from ordinary down to that of the song sparrow. Incubation varied from fresh in the smallest egg to advanced in the larger (Oologist, vol. 5, p. 44, 1888).”
If the first set of eggs is taken, another set will be completed within the next 10 or 12 days, usually in the same hole. Like the flicker, this woodpecker is very persistent in its attempt to raise a brood and will keep on laying, if repeatedly robbed. C. C. Bacon (1891), of Bell, Ky., reports taking six sets of eggs, 28 eggs in all, from the same nest in a single season, after which the birds drilled a new hole in the same tree and raised a brood of four young; this persevering pair drilled two holes and laid 32 eggs before they succeeded in raising a brood.
The eggs vary in shape from short ovate to rounded ovate, are pure white in color, and somewhat glossy when incubated. The measurements of 54 eggs average 25.14 by 19.17 millimeters; the eggs showing the four extremes measure 27.18 by 19.30, 26.16 by 20.57, 23 by 18.20, and 23.11 by 17.78 millimeters.
Young.—Incubation is said to last for about 14 days. Both sexes assist in this duty, as well as in the care of the young. As an egg is laid each day, and, as incubation often begins before the set is complete, the young may hatch on different days.
Mr. DuBois writes to me that one nest that he watched held newly hatched young on June 11; they were in the nest on July 7 but had left before 2 p. m. on the 9th, making the period in the nest approximately 27 days. He says: “The newly hatched, naked young have extremely long necks, longer in fact than their bodies. The four young all faced inward, each toward a point to the right of the center of the nest; and when in repose, each neck crossed the necks of the two others at right angles to its own—like woof and warp in a loom. A little noise on my part made all four of them stretch their necks straight upward; but when they collapsed, their necks became again interwoven. Each lowered its head to its own right side of the one opposite it. There were egg shells still in the nest.”
Julian K. Potter (1912) says of a nest that he watched at Camden, N. J.:
The old birds fed the young at varying intervals, sometimes going to the nest once in every three or four minutes for a half hour, then not appearing again for fifteen or twenty minutes. * * *
The young birds left the nest about June 25. On that day I saw them out in the open, quite able to take care of themselves, although the parents fed them occasionally. [This pair raised a second brood that season, and had young on July 30.] Meanwhile the young of the first brood were being very much misused by their parents, and were driven away whenever they came in sight; in fact they were persecuted to such an extent that they must have been driven from the locality, for I was unable to find them after July 30.
Some writers have said that only one brood is raised in a season, and others that two broods are raised only in the southern part of the breeding range. But Mr. DuBois reports two broods in Minnesota; and Mr. Potter one brood one season and two broods the next season for his pair in New Jersey.