Allen on an Inadequate “Theory 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- 
parus, 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 Yireos. 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 
