6 BULLETIN 174, UNITED STATES NATIONAL MUSEUM 



from a blind which we built on April 9 in the top of an adjacent rock elm, twenty 

 feet distant from the nest. On April 9, we located a second pair of Ivorybills in 

 the vicinity of a fresh hole about fifty feet up in a dead oak, some two miles to 

 the south of the nest in the maple. The following morning, however, the nest 

 was occupied by a black squirrel and the birds had disappeared. 



Briefly summarizing our five-day vigil at the occupied nest, we learned that 

 the birds took turns sitting on the eggs, working in approximately two-hour 

 shifts when not alarmed, but changing places more frequently when disturbed. 

 Activities usually commenced about six o'clock in the morning, three-quarters 

 of an hour after Cardinals and Carolina Wrens started singing. At this time 

 the female relieved the male after his having spent the night on the eggs. Activi- 

 ties ceased about four o'clock in the afternoon when the male relieved the 

 female on the eggs and went in the nest for the night. This was nearly three 

 hours before dark, whicli came about seven o'clock. 



Eggs. — According to Bendire (1895) : 



The eggs of the Ivory-billed Woodpecker are pure china white in color, close 

 grained, and exceedingly glossy, as if enameled. They vary in shape from an 

 elongate ovate to a cylindrical ovate, and are more pointed than the eggs of 

 most of our Woodpeckers. They appear to me to be readily distinguished from 

 tliose of the Pileated Woodpecker, some of which are fully as large. From three 

 to five eggs are laid to a set, and only one brood is raised in a season. * * * 



The average measurement of thirteen eggs is 34.87 by 25.22 millimetres or 

 about 1.37 by 0.99 inches. The largest egg measured 36.83 by 26.92 millimetres, 

 or about 1.45 by 1.06 inches; the smallest, 34.54 by 23.62 millimetres, or about 

 1.36 by 0.93 inches. 



The eggs described by Hoyt (1905) measured 1.46 by 1.09 and 1.43 

 by 1.07 inches in the first set and 1.43 by 1.10 and 1.43 by 1.08 inches 

 in the second set. 



From my own experience and the observation of others, it seems to 

 me that the number of eggs laid by the ivorybill would not normally 

 exceed three, and one or two of these are often infertile. Frequently, 

 if the bird is successful in rearing any offspring at all, a single young- 

 ster is the result rather than two or three. Allen and Kellogg (1937) 

 describe three nests in which no young were successfully reared, al- 

 though at least some of the eggs apparently hatched, while Scott 

 (1888), Beyer (1900), and Tanner (1937 and 1938 MS.) each report 

 single young, and in the type set of three eggs (Ralph collection, 

 Lafayette County, Fla.) two were infertile, and both of Hoyt's sets 

 contained two eggs each. On the other hand, J. J. Kuhn reports 

 seeing one pair of ivorybills with four young in 1931 and again in 

 1936 in the same forest where Allen and Kellogg made their studies. 

 In 1932, 1933, and 1934 he observed a pair of ivorybills with two 

 young. 



Plumages. —'^0, far as I have been able to find, no one has ever 

 published a description of the natal or juvenal plumages of the ivory- 

 billed woodpecker. The probability is that natal down is absent, 

 although Scott (1888), who found a nest containing one young in 

 Florida March 17, 1887, says: "The young bird in the nest was a fo- 



