410 BULLETIN 2 03, UNITED STATES NATIONAL MUSEUM 



the upright twigs of a close branch. The nest was thin, but very 

 neat; the principal material was the wiry old stems of the slender 

 knot-weed {Polygonum tenue), circularly interlaced, and connected 

 externally with rough linty fibres of some species of Asclepi<is, and 

 blended with caterpillars' webs." 



In the Carolinas, where the northern pine warbler breeds abun- 

 dantly, the nests are always built in pines at heights varying from 

 8 to 80 feet above the ground, but more commonly between 30 and 

 50 feet up. Arthur T. Wayne (1910) has found nests in South Caro- 

 lina as high as 135 feet in the tallest pines. The nest may be saddled 

 on a horizontal limb, concealed in the needles at the end of the 

 branch, or hidden in a bunch of cones near the top. 



Eggs. — The pine warbler lays from 3 to 5 eggs in a set, but usually 

 4. These are ovate or short-ovate and are practically lusterless. The 

 ground color is white, grayish white, or greenish w^hite, and is speckled, 

 spotted, or blotched with a wide variety of browns, such as "bay," 

 "chestnut," "auburn," "argus brown," "Brussels brown," "Ptout's 

 brown," "liver brown," or "chestnut-brown," with undertones of "light 

 brownish drab," "brownish drab," or "vinaceous-drab." The spot- 

 tings are usually concentrated at the large end, where a loose wreath 

 may be formed by numerous brown specklings, or a solid band of bold 

 blotches or cloudings may be produced. In some cases the drab mark- 

 ings are the more numerous, with a few scattered spots of the darker 

 browns or with a few scrawls of black. Occasionally, on eggs that 

 are spotted with "Brussels brown" or "Front's brown," the undertones 

 may be a "buffy citrine," instead of the usual drabs. The measure- 

 ments of 50 eggs average 18.1 by 13.5 millimeters; the eggs showing 

 the four extremes measure 20.0 by 14.0, 19.1 by 14.2, and 16.5 by 12.6 

 millimeters (Harris). 



Young. — The period of incubation does not seem to be definitely 

 known. Several observers have noted that the male shares with the 

 female the duties of incubation. Both parents are industrious and 

 devoted in the care and feeding of the young. In a nest watched by 

 Dr. T. S. Roberts (1936), "they brought spiders and insects of various 

 kinds, including large green larvae, caterpillars, and flies, many so 

 small they could scarcely be seen even at close range. The supply 

 was gathered almost entirely from among the foliage and cones of 

 the jack-pines near by, and the birds could often be seen dragging 

 the larvae from between the scales of the latter. The larger insects 

 were killed and mashed by pounding them on a large limb before they 

 were brought to the young. The parents came and went rapidly, 

 often once or twice a minute. They sometimes fed the same bird 

 several times in succession." 



Plumages. — Dr. Dwight (1900) calls the natal down sepia-brown, 

 and describes the juvenal plumage as "above, drab, shading to hair- 



