156 BULLETIN 174, UNITED STATES NATIONAL MUSEUM 



chiefly by the circumstance of our having seen in collections many specimens of 

 thyroideus with a red streak on the throat and marked as males, while the 

 type specimen of williamsunl had a white streak on the throat and was said to 

 be a female. We were thus entirely misled by the erroneous identification of 

 the sex in these specimens. We gave the matter up, however, only after shooting 

 a very young specimen of what was undoubtedly tvilUamsoni, and another of 

 thyroideus, both of which very closely resembled the adults of the same 

 forms, a circumstance which at once convinced us that the differences could not 

 depend on age ; so we finally concluded that the two must be distinct. 



All observers seem to agree that this woodpecker is confined to the 

 liigher elevations in the mountains among the pines, in sharp con- 

 trast to the haunts of the red-breasted sapsucker at lower levels among 

 the deciduous trees. 



Joseph Grinnell (1908) , referring to the San Bernardino Mountains, 

 in southern California, says: "This Williamson sapsucker appeared 

 to be restricted to the Canadian zone and upper edge of Transition. 

 We found it only among the tamarack pines on the slopes and ridges of 

 San Gorgonio peak, and among the silver firs, tamarack and yellow 

 pines around Bluff lake. In the former locality the species was com- 

 mon for a Avoodpecker, especially around Dry Lake, 9,000 feet altitude, 

 where several nests were found." 



CouHship. — Charles W. Michael (1935) noted the mating behavior 

 of a male Williamson's sapsucker, which had just left a fresh nest-hole, 

 as follows : 



He sounded his harsh call several times. Seemingly in answer to his call 

 the female appeared. This was the first we had seen of the female. The female 

 examined the nest hole, flew up on a branch and uttered a series of low notes. 

 The male joined her, alighting a foot away and uttering a series of low chuckling 

 notes. While giving these notes he strutted along the limb with wing-tips and 

 tail jerking rapidly. As he approached his mate she crouched low on the limb 

 and the mating act was accomplished. The act lasted several seconds before 

 the birds separated to perch side by side on a limb. After a minute or so the 

 female flew off through the woods and the male went into the nest hole. In 

 about five minutes the female came to the nest hole and again uttered her soft 

 coaxing notes. The male came out of the hole and both birds flew to a limb 

 where again the mating act was consummated. The male returned to the nest. 

 In our two-hour watch the female only went to the nest hole to call the mate out. 



Nesting. — Dr. Grinnell (1908) says of its nesting in the San Ber- 

 nardino Mountains : 



Tamarack pines were selected as nest trees, usually old ones with the core 

 dead and rotten but with a live shell on the outside. In one found June 22, 

 1905, there were four holes drilled one above the other about eighteen inches 

 apart, and one of these holes contained three small young and two infertile 

 eggs. * * * Later on in the same day another nest was found similarly 

 located containing four half-fledged young. A nest with half-grown young was 

 found in the same locality, June 14, 1906; and on June 26 of the same year 

 a nest twenty feet up in a half-dead tamarack held five two-thirds-grown 

 young and one rotten egg. So that a full set of eggs probably varies from 



