90 LIFE HISTORIES OF NORTH AMERIOAJST BIRDS. 



feet, I failed to find any of these birds nesting there, though they were met 

 with by me at various times in the vicinity, and sometimes even quite a distance 

 away from the mountains. They are only summer residents in that region, 

 but an occasional straggler remains in sheltered locations throughout the 

 winter. I am inclined to think that this bird is much more common in the 

 Rocky Mountain region. 



Mi\ Denis Gale, of Gold Hill, Colorado, kindly furnished me with the 

 following observations regarding this subspecies. He writes as follows: 



"My observations have been that this subspecies invariably selects for its 

 nesting site a living aspen tree. I have never met with it in any other. This 

 tree favors the mountain gulches and low, sheltered hillsides, at an altitude of 

 from 7,000 to 10,000 feet. Above this point they do not attain sufficient size, 

 and are mostly dwarfed and scrubby. Here in Colorado Sphyrapicus varius 

 nuchalis is seldom found above 9,000 feet or much below 8,000 feet. The 

 aspen tree is short lived, and ere much of a growth is attained, a cross section, 

 in the majority of instances, will show a discolored center of incipient decay, 

 involving half or two-thirds of its entire diameter, with a sound, white sap zone 

 on the outer circumference, next to the bark. This sound, healthy zone nourislies 

 the tree until the decayed core discovers itself in some withered limbs, and 

 frequently the top of the tree manifests the canker. 



" Such trees the Red-naped Sapsucker selects for its nesting site, and with 

 great perseverance chisels through this tough, sound zone, from 1 to IJ inches 

 in thickness, commencing with a very small hole and gradually extending its 

 circumference with each stage of the deepening process, working from the lowest 

 center out, till the exact circumference of the intended aperture of entrance is 

 attained. In thus radiating in circles from the central point the minute chips 

 are chiseled out with considerable ease. This mode of working is observed 

 until the tough zone is worked through; what remains then is comparatively 

 easy work; the soft, soggy, lifeless inside is worked into and downward with 

 greater facility, and a roomy, gourd-shaped excavation quickly follows, the 

 female doing the excavating from beginning to end, and, according to exigencies, 

 completes it in from six to ten days. 



"Some idea of the vitality and toughness of this zone of sap in a live 

 aspen may be realized when it is stated that in a tree used consecutively for 

 three or four years, if undisturbed, as is the general custom of Spliyrapicus 

 varius nuchalis, the entire aperture will be almost closed by the recuperative 

 agency of the sap which quickly heals and closes up the wound. No other 

 Woodpecker will face such a formidable task. Picus villosus harrisu comes next 

 as a borer; then follows Sphyrapicus thyroideus. Both of these species nest 

 sometimes also in apparently live aspens, but upon close inspection such trees 

 will be found to be badly decayed. 



"Sphyrapicus varius nuchalis usually insists upon a new excavation each 

 year. The height of the nesting sites from the ground varies from 5 to 30 

 feet; the full set of eggs is four or five in number; sometimes a smaller num- 



