1910 J HowEhh, Notes on Birds of Southeastern Missouri. 381 



in this State. It at least deserves to be called 'locally common,' 

 or else considered as 'increasing in abundance.' The develop- 

 ments as regards this situation for the next few years will un- 

 doubtedly be of great interest/ 



NOTES ON THE BIRDS OF THE SUNKEN LANDS OF 

 SOUTHEASTERN MISSOURI. 



BY ARTHUR H. HOWELL. 



The field work of the Biological Survey for the season of 1909 

 included a collecting trip in the ' Sunken Lands ' and swampy river 

 bottoms of southeastern Missouri — a region famous for the vast 

 numbers of waterfowl which stop there on their migratory flights, 

 and interesting also as the summer home of several rare birds, 

 notably Bachman's and Swainson's Warblers. 



The characteristics of this region have been described in several 

 articles by Mr. O. Widmann." It is perhaps sufficient to note 

 here that the lakes and swampy areas, which cover a large part of 

 seven counties in Missouri and portions of Tennessee, Kentucky, 

 and Arkansas, were formed by a subsidence of the land following 

 a series of earthquakes in 1811-1812. Evidences of this subsid- 

 ence are still seen in the presence in some of the lakes of dead 

 stubs of old cypresses standing in deep water far from the present 

 shore line. This swampy region forms a northward extension 

 of the Lower Austral Zone, and for that reason a study of its 



' Not only are Canvas-backs becoming more numerous, but Greater Scaups and 

 Redheads have also noticeably increased lately. They are now seen and shot in 

 some ponds on Cape Cod and in Plymouth County, which they never frequented 

 before; and in some localities, where they formerly were met with only occasion- 

 ally, they are now becoming quite common, so that their arrival during the fall 

 migrations can be depended upon with a reasonable degree of certainty. This 

 flight, or rather change in the migratory route, seems to include these three varie- 

 ties of ducks. The question is whether this condition is only temporary or whether 

 it is to be permanent. 



s Auk, XII, 1895, pp. 350-355; XIV. 1897, pp. 305-309; 'Birds of Missouri." 

 Trans. Acad. Sci. of St. Louis, XVII, No. 1, 1907, pp. 14-16. 



