226 BULLETIN 174, UNITED STATES NATIONAL MUSEUM 



BALANOSPHYRA FORMICIVORA MARTIRENSIS Grinnell and Swarth 

 SAN PEDRO WOODPECKER 



HABITS 



The acorn-storing woodpecker of the Sierra San Pedro Martir, 

 northwestern Baja California, has been separated and described by 

 Grinnell and Swarth (1926) under the above name, to which they 

 have added the long common name "San Pedro Martir acorn-storing 

 woodpecker." Its distinguishing characters are given as follows: 



Most nearly like B. f. hairdi. Distinguished from that species primarily by 

 shorter wing, and by slightly shorter and notably weaker, more slender bill ; 

 also by average differences in head markings as set forth below. * * * 



The relatively feeble bill of this bird, as compared with that of the upper 

 California hairdi, is the most conspicuous character of this subspecies. In bill 

 structure it is closely similar to B. f. aciileata, of Arizona. 



The character of the head markings in the female is suggestive again of 

 aculeata, the red area being usually more nearly square, as in that form, 

 rather than shorter than wide, as in hairdi. The white frontal band averages 

 slightly narrower than in hairdi, an approach toward the condition in angusti- 

 frons, of the Cape San Lucas region. The yellowish white (more dilutely 

 yellow than in hairdi) U-mark on the lower throat in both sexes averages very 

 much narrower in our specimens of rnartlrensis than in a large series of hairdi 

 usually only about half the width of the former as in the latter. This we are 

 not quite confident of as a real character, in that there is a chance that "make" 

 of specimen (whether or not the skin of the throat was stretched) affects the 

 width of the white band. * * * 



In character of the markings on the feathers of the breast there is no de- 

 parture from the condition in hairdi. The upper breast is broadly and solidly 

 black, the black band not penetrated posteriorly with white streaks to such an 

 extent as in aculeata and angustifrons. 



The range is given as, "so far as now known, onl}' parts of the 

 Sierra San Pedro Martir, in northern Lower California, between lat- 

 itudes 30° and 31°30"; altitude 5,800 to 7,200 feet; life-zone mainly 

 Upper Sonoran (live-oak association), but also Transition locally or 

 sporadically." 



The eggs are similar to those of other races of the species. The 

 measurements of 12 eggs average 26.19 by 18.35 millimeters; the 

 eggs showing the four extremes measure 25.1 by 19.4, 19.0 by 18.5, 

 and 22.8 by 16.8 millimeters. 



ASYNDESMUS LEWIS (Gray) 

 LEWIS'S WOODPECKER 



Plate 29 

 HABITS 



My first impression of this curious and interesting woodpecker 

 was of a large, black bird that looked more like a crow than a wood- 

 pecker and that flew with the strong, steady flight of a crow or a 



