Allen on an Inadequate "Tlieory of Birds' Nests." 27 



the Woodpeckers, some of the Swallows, the Wood-Duck, the Hooded 

 Merganser and the Buffle-head, the females are much paler and duller 

 colored than the males. In many other instances the colors are in the 

 highest degree adapted for concealment under every circumstance, 

 and especially in a sitting female bird, as, for instance, in the Brown 

 Creeper, the Wrens, some of the Titmice, the Swifts, and various 

 others.' 



2. The burrowing species embrace the Prairie Owl, the King- 

 fishers, two species of Sand Martin or Bank Swallow, the Petrels, 

 various species of Auks and Puffins, and some of the Guillemots. 

 The Kingfishers possibly excepted, almost none of these have bright 

 or conspicuous colors, while in several the colors could scarcely be 

 better adapted for concealment. Especially is this the case with the 

 Owl and Sand Martins, with their dull neutral tints. 



3. Among the comparatively few species that build a covered 

 or domed nest are the ground-building Golden-crowned Wagtail or 

 " Oven-Bird, " the Dipper or Water-Ousel, the Meadow Lark, the 

 common Quail, and several Warblers. The first two of these have 

 tints peculiarly adapted for concealment, and the colors of the dorsal 

 area in the others are likewise "protective." Among the species 

 building covered nests in reeds, bushes, or low trees, are Marsh 

 Wrens, some of the other Wrens, the smaller Tits (genera Psaltri- 

 pai'us, Auriparus, etc.), several of the Warblers (family Sylvicolidce), 

 the Magpie, and perhaps a very few others. Of these the Wrens and 

 Tits are all obscurely or protectively colored, and have no " surpris- 

 ingly gay and conspicuous " tints. Some of the Warblers are more 

 brightly colored, and a few have rather conspicuous markings ; but 

 these features are almost wholly confined to the male, the females 

 being of comparatively dull and obscure tints. The Magpie has 

 showy colors and a very long tail, and the bulky nest, wholly con- 

 cealing the sitting bird, may be useful in hiding these otherwise be- 

 traying features. The species which build hanging, purse-shaped, or 

 subpensile nests are the Orioles and Vireos. In the case of the 

 former the nest is most illy adapted for protection from the most 

 dangerous foes of the species, the predatory Crows, Jays, and 

 Cuckoos, being often a conspicuous object, with, so far as the 

 United States species are concerned, no compensating feature of 

 security. Here again, while the males are in some instances arrayed 

 in " strikingly gay and conspicuous colors," the females do not to 

 any great extent share their bright hues, the sexual differences in 



