PHYSICAL FEATURES OF BIRDS. 



263 



the toilet. In the nesting season, it is always more 

 brightly colored than at any other season of the year; 

 and some birds have it adorned in some way, with an 

 outgrowth of feathers, perhaps, near it and accentuating 

 its beauty at the nuptial season. 



FIG. 101. Fissirostral bill of a 

 swallow. 



FIG. 102. Fissirostral bill of 

 chimney-swift. 



The shape of the bill is indicative of the food habits 

 of the tribe of birds. The long, thin, pointed bill indi- 

 cates the insect and worm 

 eater; the short, stout con- 

 ical bill belongs to the seed 

 eaters; the stout, hooked bill 

 indicates the flesh eater, 

 which tears its victim, fish, 

 mouse, rabbit, or decaying 

 carcass; the American cross- 

 bill cuts out the pine seeds 

 from the cones, more effect- 

 ively than it could be done with a pair of scissors. 



FIG. 103. Hooked and cered bill 

 of a hawk. 



A few birds, as the owls, snap the mandibles together 

 if they are frightened or angry. All birds use the bill 

 as a toilet accessory, while performing the curious duty 



