44 



CIVIC BIOLOGY 



(For three years past rewards aggregating over f:3000 for discovery 

 and report of undisturbed nesting pairs or colonies of passenger pigeons, 

 anywhere in Xorth America, have remained unclaimed, and no tangible 

 evidence has been received of pigeons killed or even seen during this 

 time. This is commonly accepted as proving the species extinct in the 

 wild state. One old bird still survives in the Cincinnati Zoological Gar- 

 den. If nesting pigeons are ever found, they should be most carefully 

 safeguarded, and all protective agencies, private, state, and national, be 



focused on their preservation 

 and increase.) 



Mourning dove Zenai- 

 (liira macr&ura caroHnentig. 

 Every effort is now being- 

 made to save this species in 

 New England. It is abun- 

 dant in the South and Middle 

 West. 



FIG. 20. Young red-shouldered hawks 



Order Raptores (raptor, 

 " a robber ") hawks, 

 eagles, owls. The hawks 

 and owls furnish perhaps 

 the most complicated and 

 difficult problem con- 

 nected with our bird life. 

 By many of the best authorities the majority are accounted 

 among our most valuable birds, on account of the great num- 

 bers of noxious mammals field mice, gophers, rats, etc. 

 which they destroy. Most of the hawks, too, feed largely on 

 insects when they are abundant, and take comparatively few 

 birds, either tame or wild. In determining the value of birds 

 in this class, however, it is always an open question whether 

 the few insectivorous birds, which may form only 1 or 2 per 

 cent of the hawk's total food, if allowed to live, might not 

 have done much more valuable work than the sum total of the 

 predacious species. We must leave questions of this kind to 

 be worked out from practical experience and observation. 



