MANGROVE YELLOW WARBLER 193 



There are now six beautiful nests of this warbler in the Thayer 

 collection in Cambridge, all collected by Brown near La Paz on dates 

 ranging from May 15 to June 2; all were placed in the red man- 

 groves, either on horizontal branches, mostly near the ends, or in 

 forks; the heights from the ground or water varied from 2 feet to 

 10 feet. The largest and handsomest nest was 10 feet up on a hori- 

 zontal branch ; it is a very neat, compactly woven cup, made of soft, 

 fine, light buff plant fibers, mixed with plant down, green moss that 

 looks like down (probably the "light green fern down" referred to 

 above or algae) ^ a few gray lichens and many whitish flower clusters; 

 it is lined with very fine fibers, apparently from the mangroves, and 

 plenty of feathers; it measures externally 3 inches in diameter and 

 2^4 inches in height; the inner diameter at the top of the in-curved 

 rim is 1% inches and the cup is near 2 inches deep. The smallest 

 nest measures only 2i^ inches in outside diameter. The shallowest 

 nest is only ly^. inches high and Vy^ deej) inside. 



These nests are all works of art and quite distinctive ; all the mate- 

 rials are smoothly and compactly felted, being tightly plastered to- 

 gether, as if glued on when wet. The light color and compactness 

 suggest certain hummingbirds' nests. Most of the nests seem small 

 for the size of the birds. 



Eggs. — Three eggs seems to form the Usual set for the mangrove 

 warbler ; in the Thayer series there are five sets of three and one set 

 of two. Ed. N. Harrison (MS.) says that "it seems that one egg is 

 a set as often as two." Most of the eggs in this series are ovate, but 

 some are short ovate ; they have only a very slight gloss. They are 

 white or creamy white, speckled, spotted or blotched with shades of 

 "mummy brown," "bone brown," "Front's brown," or "clove brown," 

 with undertones of "light mouse gray," "deep mouse gray," "Quaker 

 drab," or "drab-gray." The browns are frequently so dark as to 

 appear almost black, but some eggs are spotted with lighter shades, 

 such as "cinnamon brown" and "snuff brown." On the more lightly 

 marked types the most prominent markings are the grays, with only a 

 few scattered brown spots. Often a loose wreath is formed around 

 the large end, where the spots are usually concentrated. 



The measurements of 32 eggs average 17.9 by 13.4 millimeters ; the 

 eggs showing the four extremes measure 19.5 by 13.2, 17.9 by 14.6, 

 17.0 by 13.2, and 18.3 by 12.9 millimeters (Harris). 



Plumages. — Although I have examined a large series of mangrove 

 warblers, I have seen no downy young and no summer birds in juvenal 

 plumage. But Dr. Chapman (1907) describes the young female as 

 "above grayish olive-green, rump brighter; tail blackish, externally 

 greenish, webs of all but central narrowly margined with yellow; 

 wings and their coverts blackish, quills margined, coverts tipped with 



