xviii PREFACE. 



they were two hundred years ago. These changes consist 

 mainly in the great decrease in numbers of the representa- 

 tives of all the larger species, not a few of which are already 

 extirpated where they were formerly common ; a few of the 

 smaller species of both classes have doubtless increased in 

 numbers. Two causes operate unfavorably upon the larger 

 ones ; the disforesting of the country and the sporting pro- 

 pensities of the people, everything large enough to be shot, 

 whether useful or otherwise, being considered as legitimate 

 game. . . . Many of the water-fowl that are now only transient 

 visitors, as the Canada Goose, the several species of Mergan- 

 ser, Teals, Black Duck and Mallard, undoubtedly once bred 

 in this State, as did also the Wild Turkey and the Prairie 

 Hen. ... In comparatively recent times, geologically speak- 

 ing, probably other causes, as climatic, have been operating 

 to effect a gradual northward migration, in certain species at 

 least. These changes are of great interest, not only generally, 

 but in a scientific point of view, and we shall be able to trace 

 them and their causes only by comparing, from time to time, 

 exhaustive faunal records of the same localities. 



" In a district so little diversified as that portion of Massa- 

 chusetts lying east of the Connecticut River, it is perhaps 

 a little unexpected that marked discrepancies should occur 

 in the observations made at adjoining localities by equally 

 competent naturalists, in respect to the relative abundance of 

 certain species. As every experienced observer must have 

 noticed that the birds of passage, as many of the Warblers 

 especially, vary greatly in numbers in different years, and in 

 the time occupied by them in passing a given locality, it is 

 less surprising that at different points they should vary in 

 abundance the same year. Among the birds that regularly 

 breed in the district in question, there are some that are not 

 equally common at all points. . . . 



" Birds, as probably other animals, are not quite so invari- 

 able in their habits as has been commonly supposed, nor in 

 the precise character of their notes and songs, or the situation 

 and materials of which they compose their nests. Hence one 

 should not rashly question the accounts given by usually re- 



