58 Proceedings of the 



but I never found evidence of the breeding of these birds 

 in such places. 



Ranch buildings. — Two birds alone seem to have utilized 

 man-made stuetures in their nest building — fho Barn 

 Swallow and the AVestern Lark Sparrow — the latter but 

 once to my knowledge as described under the discussion 

 of that species. The swallow is probably dependent on 

 man for its presence in the region but the sparrow is able 

 to find and does find nesting sites of various sorts over 

 most of the region and is not dependent on human &id. 



Planted groves. — No data are at hand to indicate the* ef- 

 fect of artificial groves on the species of birds occurring 

 in the locality. Only in their artificial nature do such 

 groves differ from some of the woodland or some of the 

 natural groves of trees in the valley, and the very j-res- 

 enee of the latter would tend to minimize the effective- 

 ness of the former in their influence on bird life w^re such 

 influence present. As stated in the note on woodland, 

 such effects are not noticeable and at present I am unable 

 to offer any discussion of this particular habitat. 



In examining the above notes it must, of course, be 

 borne in mind that the divisions do not hold during mi- 

 grations, at which times the birds wander over a wide 

 range of territory. Witness the occurrence of the King- 

 bird, Black-headed Grosbeak and Brown Thrasher miles 

 from the river valley in a hackberry grove. Even during 

 breeding time, some of the species frequent situations 

 where they do not nest, for example the Mourning Dove, 

 Sennett Nighthawk and Great Blue Heron. 



Owing to the merging of the Prairie and Sandhill re- 

 gions on the Reserve, some difficulty is experienced in as- 

 signing the proper region to certain of the species of 

 birds, especially in the case of the migrants which because 

 of the proximity of the two faunal areas, may be found 

 in both of them within the space of a very few minutes. 

 In the case of the breeders it is not so difficult and some in- 

 teresting comparisons may be brought out by tabulating 

 the forms somewhat as follows: 



Birds common to both Sandhills and Prairie in the state 

 which preferred Prairie when both regions were avail- 



