PLAN OF THE WORK xix 



by an ever-increasing number of enthusiastic field students, whose 

 acknowledged leader for the past forty odd years has been William 

 Brewster. Mr. Brewster contributed to the first edition of the ' 'Hand- 

 book" data on Cambridge birds of much value; but, since that time, 

 he has fortunately embodied his life studies in his " Birds of the Cam- 

 bridge Region" (Memoir No. 4, Nutt. Orn. Club), beyond question 

 the most important local work on American birds which has as yet been 

 published. The data from the Cambridge region given in this edition 

 of the "Handbook" are quoted, by permission, from Mr. Brewster's 

 book, where the exact limits of the area covered will be found stated. 



None of the additional records were contained in the first edition 

 of the "Handbook." Those from Ohio were supplied by Professor 

 Lynds Jones, of Oberlin, long the authority on the birds, of that State. 

 They cover Lorain and Erie Counties. The dates, Professor Jones 

 states, are "median dates of first arrival." 



B. T. Gault, who has contributed the notes from Glen Ellyn, writes: 

 "The dates given are extreme [thus contrary to the plan followed by 

 other contributors], excepting in isolated cases of extra-limital species. 

 My observations really cover the township of Milton, but every bird 

 listed, except Gallinula galeata, Strix varia, and Aquila chrysaetos, has 

 been noted within the corporate limits of the village of Glen Ellyn." 



The records from southeastern Minnesota were supplied by Dr. 

 Thomas S. Roberts, for many years the leading authority on the birds 

 of Minnesota. -They are based, in the main, on observations made in 

 the vicinity of Minneapolis. 



Nests and Eggs. The brief descriptions of nests and eggs are based 

 on the collections of the American Museum of Natural History, supple- 

 mented by the use of Baird, Brewer, and Ridgway's "History of North 

 American Birds," Davie's "Nests and Eggs of North American Birds," 

 Ridgway's "Manual," and Bendire's "Life Histories of North American 

 Birds." In describing the eggs, the color chart was used when possible; 

 but it was designed with particular reference to the plumages of our 

 birds, and is of less assistance in describing their eggs. The measure- 

 ments of eggs are mostly from series of measurements made by Mr. H. 

 B. Bailey, accompanying the Bailey collection in the American Museum, 

 supplemented by reference to the works mentioned above. 



Nesting Dates. The dates following the descriptions of nest and eggs 

 are designed to indicate when the nesting season of the species in ques- 

 tion begins at various localities. They are the earliest dates I have found 

 for the taking of full sets of (presumably) fresh eggs of the first laying. 

 These records were compiled chiefly from the data accompanying the 

 collections of the United States National Museum (to which I have 

 kindly been given access by Dr. C. W. Richmond), those of the Ameri- 

 can Museum of National History, and the collection of Mr. J. P. 

 Norris, Jr., to whom I gratefully express my indebtedness. The "Cam- 

 bridge" records are all extracted, by permission, from Brewster's 

 "Birds of the Cambridge Region," while for those from "SE. Minn." 



