546 U.S. NATIONAL MUSEUM BULLETIN 23 7 part i 



Eggs. — The olive sparrow usually lays four or five eggs, sometimes 

 only three. They are white, unspotted, and quite glossy; in shape 

 they vary from rounded ovate to ovate. The measurements of 45 

 eggs average 21.8 by 16.2 millimeters; the eggs showing the four 

 extremes measure 24-2 by 17.3, 19.9 by 16.0, and 21.7 by 15.0. 



Plumages. — F. M. Chapman (1914) writes: 



Few birds show less change of plumage than does this bush-haunting sparrow. 

 The male resembles the female; there is practically no difference between the 

 winter and the summer dress, and after the post-juvenal molt the bird of the year 

 cannot be distinguished from its parents. 



The Juvenal, or nestling plumage, however, is strongly streaked with fuscous 

 both above and below. At the post-juvenal molt apparently only the wing- 

 quills and tail feathers are retained, and the bird passes into its first winter 

 plumage, which, as just remarked, resembles that of the adult. 



There appears to be no spring molt, and summer birds differ from winter ones 

 only in being more worn. 



Witmer Stone {in Rhoads, 1892, footnote) thus describes the fully 

 fledged young: "The young have the feathers of the head and inter- 

 scapulum centered with black and bordered with ochraceous. Be- 

 neath, the breast and flanks are tinged with olivaceous and are marked 

 with dark longitudinal markings; belly yellowish-white." 



Food. — G. B. Sennett (1879) says the olive sparrow "feeds upon 

 larvae and seeds, especially the seeds of the wild-tomato." Sutton 

 (1951) describes "two in plain enough sight under a fallen branch, 

 kicking away like Httle towhees; another off in the shrubbery, in- 

 visible but scratching noisily; and two more in a vine, a short way 

 above the ground, busily preening their wings." 



Voice. — R. T. Peterson (1941) says: "Song, a series of dry notes all 

 on one pitch, starting off dehberately and trailing off into a Chippy- 

 like rattle. 'Also an insect-like buzz as the birds chase each other 

 through the thickets' (Irby Davis)." George M. Sutton (1951) 

 writes: "For the first time we heard the full song of the Olive Sparrow — 

 a simple, deliberate series of unmusical chips, somewhat suggestive 

 of the song of a Swamp Sparrow (Melospiza georgiana) ." 



Field marks. — E, R. Blake (1953) characterizes the olive sparrovv' 

 as "an olive-backed sparrow with a prominent hrown eye-streak, 

 and two dull hrown crown-strijpes. A strip of bright yellow on the 

 edge of the wing helps verify the identification." Mr. Bent (MS.) 

 writes that the species "may be recognized by its plain, grayish, 

 olive-green upper parts, brighter on the wings and tail, and dull 

 whitish under parts. There is no conspicuous field mark that is 

 visible at a distance. The brown stripes on the head, the white 

 eye-ring and the yellow edge of the wing are noticeable only at short 

 range." Peterson (1941) adds that the bird is about the size of a 

 house sparrow, and that its olive-green back gives it some resemblance 



