170 FRANCIS H. HERRICK 



seems tame and humdrum compared with the guarding, fighting, 

 luring, and kindred outbursts of energy, which so commonly 

 attend the breeding cycle of birds. 



It seems to be the aim of the bird, when possessed of the 

 breeding impulses, to find a hole in which to deposit its eggs, 

 or barring this, to make one for itself, " building around a hole," 

 as it were, as Pycraft says of the quaker parrot. But in many 

 cases this protective pocket becomes a graceful, symmetrical 

 " cup," or " saucer," as true as if thrown on a potter's wdieel, 

 or a nicely modelled "purse," "hammock," or "stocking," 

 suspended to adequate supports, or a neatly molded and arched 

 " oven," or even an excavated chamber, with entrance tube 

 or tunnel, when underground, often running five or ten feet 

 clear from the surface. 



Speaking in general, it is undeniably true that the bird's 

 nest is built primarily for protection, which is directed either 

 to the eggs, to the eggs and young, or to the eggs, young, and 

 adult combined. But the ultimate or adequate protection 

 secured is not dependent upon the structure of the nest alone, 

 which so far as the adult and young are concerned, is often a 

 trap and a snare which leads to their destruction. 



We will now consider some of the more obvious ways in which 

 the nest ministers to this prime need, leaving a fuller discussion 

 of certain factors for a later section. It is useless to generalize 

 when it is so obvious that the elements of the protection secured 

 vary with the species, it being now the nest-structure, now its 

 position, or again keen instincts or other bodily powers which 

 tip the scale of protection to the side of safety for the adult, 

 its progeny or both. 



To cite a few cases in illustration of this phase of the question 

 of protection: in the tropical hornbills {Bucerotidae) the nest is 

 the strong factor in ensuring the safety of all concerned, for the 

 sitting female is barricaded against attacks from outside enemies 

 in a wdiolly exceptional manner, though suggesting indeed a habit 

 of the European nuthatch, of partly closing its nest-hole with mud, 

 or the American red-bellied nuthatch in smearing its entrance 

 with pitch; in the hornbill the doorway is both smeared and 

 plastered up with mud and a glutinous secretion until it is reduced 

 to a small opening, but just large enough to admit the food, 

 which is passed in by the males, and to improve the chances 



