BIRDS 239 



and then, blown aside from its regular path of migration, 

 or otherwise astray; these are visitants. As to the rela- 

 tive importance, numerically, of these various categories 

 among the birds which may be found in a certain region, 

 and thus form its bird-fauna, we may illustrate by refer- 

 ence to a definite region. Of the 351 species of birds 

 which have been found in the State of Kansas (a region 

 without distinct natural boundaries, and fairly represen- 

 tative of any Mississippi valley region of similar extent), 

 51 are all-year residents, 125 are summ.er residents, 36 

 are winter residents, 104 are migrants, and 35 are rare 

 visitants. 



The all-year residents and the summer residents, com- 

 prising about one-half of the species to be found in a 

 locality are the only ones which breed there, and which 

 thus present opportunity for observations on their nest- 

 building habits and care of the young. Numerous sug- 

 gestive questions present themselves in connection with 

 breeding in addition to the simpler ones already pro- 

 pounded in Chapter III. Why is it that some species 

 nest early and some late .'' Can the character of the food 

 of the young have anything to do with this .'' If so, how .'' 

 Does the condition of the particular trees, bushes or other 

 favorite sites for nests help determine the nesting time ^ 

 Why should some birds raise but one brood a year, and 

 others two or even three .'' Does the fact that a bird is 

 an all-year resident or only a summer resident have any 

 influence in determining its nesting time and the number 

 of broods it rears .'' Compare the habits of the various 

 breeding species of the locality, and find out if the 

 summer residents have any breeding habits in common 

 as distinguished from the all-year residents. 



Observe the behavior of the birds in courting time. 

 Do the males have " singing contests," as is sometimes 

 reported.'' Do they fight with each other ,'' Do the rnales 



