180 



range of southern forms uii the vaHeys of our streams is as though the 

 great spread tingers of two mighty liauds were interloclced. tlie one rep- 

 resenting the extension of life soutliward and the other the projection of 

 soutliern birds rorthward. 



The region of the Lower Waliasli. witli its bottoms, cypress swamps 

 and ponds, was the liome of many southern birds whicli found there the 

 northern limit of their range. Among these congenial surroundings were 

 noted such southern forms as the White Ibis (Guara alba). Wood Ibis 

 (Tantalus loculator), Yellow'-crowned Night Heron (Nycticorax violaceus). 

 Little Blue Heron (Ardea ctendea). Snowy Heron (Ardea candidiesima), 

 American Egret (Ardea egretta) and Florida Cormorant (Phalacrocorax 

 dilophus floridanus). Some of these there made their homes and reared 

 their young. Other birds ranged farther up the stream and it, and other 

 water-courses, are now known to Ite routes along which certain species 

 move to breeding grounds farther nortli. 



The extreme effect of a river on the disirihution of a 1)ird is illustrated 

 in the case of the Prothonotary Warl)ler. Prior to lS7.j. it was regarded 

 as solely a bird of the Southern States, yet its actual range was then, 

 without doubt, practically the same as we now know it. In that year 

 Mr. E. W. Nelson observed it to be conuiion in the Lower Wabash Valley 

 in Illinois (Bull. Essex Inst. Vol. IX, 1S7T. p. 34). In 1S7S. Mr. Will- 

 iam Brewster found it abundant in Knox and Gibson counties, Indiana 

 (Bull. Nutt. Orn. Club, Vol. Ill, 187S. p. 155). The natural liaunts of 

 these I)irds are the swampy woods and the thickets along water-courses 

 or about ponds or lakes. As one suitable locality after another was dis- 

 covered farther northward, it was found to be occupied by these birds. 

 They were reported from Vigo, Clinton and Carroll counties and from 

 just over the State line near Danville, Illinois. They extended up the 

 Mississippi Uiver, sending off numljers of migrants up the different river 

 courses. Some ascended the Kaskaskia and others the Illinois (Loucks 

 Bull. 111. Lali. N. IL. Vol. IV, 1894). The Kankakee, a tributary of the 

 latter stream, comes into northwest Indiana from the west and becomes 

 quite a factor in its influence upon bird life. At Momence, Illinois, its 

 course is blocked by an outcrop of stone. Above this, it is a sluggish 

 stream, at times widening into lakes. Much of its course is bordered by 

 woods. ;Marshes and sw'amps alternate with thickets and sloiighs along 

 its valley. Amid such attractive surroundings, Prothonotary Warblers 

 find summer (juarters and are characteristic birds. Tliey likely reach 



