854 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



Nesting. — Nicholson (MS.) considered the ideal nesting habitat to 

 be a damp, but not flooded, salt marsh dotted with small open ponds. 

 Formerly the Indian Kiver marshes had dense patches of low, thick 

 salt grass or hay {Distichlis spicata), tangled plots of knee-high pickle- 

 weed (Salicornia and Batis), large stretches of waist-high bunch grass 

 (Spartina backcri), and various-sized stands of the bayonetlike black 

 rush {Juncus roemarianus). In the 1920's the birds built occasionally 

 in the bunch grass and under blown-over black rush, but he found 

 most nests then in the dense patches of succulent pickleweed, placed 

 usually just below the weed tops and from 10 to 20 inches above the 

 damp ground. The small, neat, open cups were made entirely of 

 dry grass blades and stems mth a few dead pickleweed stems mixed 

 in. By the late 1930's he found the birds nesting almost exclusively 

 in the low salt hay and seldom more than 3 to 5 inches off the ground. 



With the flooding the salt hay and pickleweed have now disap- 

 peared from the impoundments, and the birds nest today in the high 

 Spartina and Juncus, usually from 5 to 15 inches above the water. 

 One nest I measured was 4 inches high and 5 inches in outside dia- 

 meter; the inside of its cup was 3 inches wide and 2}i inches deep. 

 Until the young hatch and the parents are actively engaged in feeding 

 them, the nests are very hard to find. They are usually well concealed 

 in thick vegetation, and the incubating female rarely flushes directly 

 from her eggs. Hunting nests in the sharp-tipped Juncus may aptly 

 be termed searching for a ball of hay in a needlestack, and no prudent 

 man attempts it without wearing glasses or goggles to protect his eyes. 



Eggs. — The eggs of the dusky seaside sparrow are ovate to short- 

 ovate, have very little gloss, and are practically indistinguishable from 

 those of A. maritima. The usual set is three or four, and rarely five. 

 The ground color is dirty-white or very pale bluish-white, speckled 

 and spotted with dark reddish browns such as "sorghum brown," 

 "Mars brown," "russet," "chestnut," or "auburn," occasionally 

 Avith underi3dng spots of "light purplish gray," which are often 

 lacking. The spottings are usually sharp and distinct, but at times 

 may be somewhat clouded. Generally the eggs are marked profusely 

 with a tendency to concentrate toward the large end, where the spots 

 may be confluent. The measurements of 65 eggs average 19.9 by 

 15.0 millimeters; the eggs showing the four extremes measure 21.6 by 

 16.2, 20.7 by 16.8, 18.6 by 14.5, and 19.3 by 14.2. 



Nicholson (MS.) claims the eggs of the dusky show larger areas of 

 ground color and vary more in spotting then those of the other sea- 

 side sparrows. He notes four the commonest clutch size, five having 

 been found only four times, but three eggs also common, and two 

 fairly frequent, especially late in the season. He reports finding nests 



