2 28 Bendire 071 the Habits of the Ge7ins Sfhyrapicns. [July 



mencing with a very small hole and gradually extending its 

 circumference with each stage of the deepening process, work- 

 ing from the lowest centre out, till the exact circumference of 

 the intended aperture of entrance is attained. In thus radiat- 

 ing in circles from the central point, the minute chips are 

 chiselled 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 downwards, 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 tree may be realized, when in a tree used consecu- 

 tively three or four years, which if undisturbed is the general 

 custom of S. varius mickalis, the entire aperture will be almost 

 closed by the recuperative agent in the sap of the tree to heal 

 and close up the wound. No other Woodpecker will face such 

 a formidable task. Piciis villosus harrisii 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. 



"6". varius nuchalls usually insists upon a new excavation 

 each year. The height of nesting-sites from the ground varies 

 from five to thirty feet ; the full set of eggs is four or five in num- 

 ber, sometimes a smaller number of eggs mark a full set, presum- 

 ably the nest of one of last year's young birds. Fresh eggs may 

 be looked for in Colorado from June i to 15, and should the 

 first set be taken, a second one may generally be found in from 

 ten to fifteen days later ; and as a rule the second nesting-site 

 will not be greatly distant from the first one. Several nests of 

 this species may be found within a short distance of each other 

 in the same aspen grove." 



Two sets of four eggs each of this species, taken by Mr. Gale 

 and kindly presented to the National Museum, Washington, 

 D. C, measure as follows: ist set, taken June, 18S4, four eggs, 

 .91 X .675.90 X .685.89 X .68, .88 X .64 inches; 2nd set, taken 

 June I, 1SS7, .90 X .69, .90 X .69, .90 X .68, and .89 X .65. 

 A set of three eggs taken by the writer in the Blue Mountains, 

 Grant County, Oregon, June 12, 1877, measures, .90 X .^<,i 



