RUSTY SONG SPARROW 1543 



again on Feb. 8, together in the trap) but that each then returned to a 

 particular area in which it attacked and pursued others of the species. 

 This territorial behavior persisted even in a late-February and early- 

 March period of cold and snow, during the sunny intervals. Song 

 first became frequent on March 13, courtship of females was first noted 

 on March 17, and by March 27 the three banded males all had mates 

 that were carrying nest material. 



Song posts of males are 10 to 15 feet high (Jewett et al., 1953). 



Nesting. — On Mandarte Island, B.C., Tompa found that the breed- 

 ing season "normally extends from the second half of March to late 

 July." As many as three broods are raised by some pairs. 



In Washington, eggs have been found as early as April 2, and a fresh 

 set of four eggs has been recorded on July 16. Gabrielson and Jewett 

 (1940) set extreme dates of fresh eggs as April 15 and July 10 in Oregon. 

 G. W. Gullion (1951) states that breeding dates of song sparrows in 

 the southern Willamette valley, Oregon, range from Feb. 28 to Aug. 

 13; the subspecies is not identified but is inferred from the locality to 

 have been jnorphna. 



Nests are said to be very well concealed, and are located both on the 

 ground in grass or tules or by a log, in shrubs such as blackberries, 

 in trees such as spruces, and in brush piles. The seasonal pattern 

 of nest location already described for melodia and many other races, 

 in which the elevated nests are to be expected later in the season, 

 prevails in morphna. Heights are rarely greater than 5 feet, more 

 commonly 1 or 2 feet (Jewett, 1916; Gabrielson and Jewett, 1940). 

 William H. Kobbe (1900) measured an elevated nest made of grasses 

 and found its external diameter was 5 inches, its internal diameter 

 3 inches, its external depth 3}£ inches, and internal depth 2 inches. 

 The same author, as well as Alexander Wetmore (quoted in Jewett 

 et al., 1953), described nest construction in terms closely resembling 

 descriptions of nests of melodia. Hughes (1951) found a most unusual 

 nest on April 16; it was the previous year's nest of a Swainson's thrush, 

 6% feet high in a yew. 



Eggs. — The measurements of 40 eggs average 20.2 by 15.1 milli- 

 meters; the eggs showing the four extremes measure 21.8 by 15.2, 20.3 

 by 16.0, 18.0 by 14.2, and 18.8 by 18.8 millimeters. 



Young. — Song has been noted in young of the year as early as July 9, 

 in a bird that could not have been more than 2 months old. William 

 E. Sherwood (1929) felt that the first songs he heard were subdued in 

 volume, but within a few minutes the songs had become indistinguish- 

 able from those of an adult. This early beginning of song correlates 

 well with Tompa's observation of the onset of territorial behavior 

 after the post-ju venal molt. 



