430 General Notes. Uuly 



row being pinkish brown in one case and deep olive green in another. 

 There seems to be no record of the names of the artists who were respon- 

 sible for these plates. — Witmer Stone, Academy of Natural Sciences, 

 Philadelphia. 



Observations on the Shifting Range, Migration and Economic 

 Value of the Bobolink. — The inclusion of the Bobolink among the birds 

 protected by the recently consummated treaty with Canada for the pro- 

 tection of migratory birds, resulted in an immediate demand for an inves- 

 tigation of its present-day economic status, which was carried on in the 

 states from New Jersey south to Florida, inclusive, in August to October, 

 191S. A few points were brought forcibly to the writer's attention which 

 perhaps are not wholly realized by ornithologists in general. First, as 

 to the shifting of breeding grounds by the Bobolink, for to my mind that 

 is what is occurring. The trend of the bird's breeding range to the north- 

 west is unmistakable; for instance in the first edition of the A. O. U. 

 Check-List, the Western limit of the breeding range was given as the Great 

 Plains; in the second edition, 1895, as Nevada, Idaho and Alberta, and 

 in the third edition, 19.10, as British Columbia. Now unless there has 

 been a considerable increase in the numbers of the species, the population 

 of eastern breeding grounds must have fallen off, and this latter condition 

 is one of which New England observers in particular complain. Rice 

 growers in the South who have the best opportunity of judging the abun- 

 dance of the species contend that the bird is less numerous than formerly. 

 Putting these two things together, a vastly extended range and no increase, 

 possibly a decrease in number of individuals, diminution of the Bobolink 

 population somewhere is inevitable. This condition has actually been 

 observed in the northeastern states, completing the cycle of evidence that 

 a shift in range has occurred. 



The persistence of birds in maintaining migration routes is particularly 

 exemplified by the Bobolink. After extending its range westward, over 

 hundreds of miles and across two mountain systems, the species with insig- 

 nificant exceptions returns to the Atlantic Coast before turning to the south. 

 The main fall migration path seems to converge into a funnel not far south 

 of the breeding range through which the birds pour in a narrow stream 

 along the coast of southern North Carolina, South Carolina and Georgia, 

 expanding again so as to cover the whole breadth of peninsular Florida. 

 Even farther north, before this migration stream is definitely formed, the 

 birds are much more abundant near the coast than inland as in the wild 

 rice marshes on tidewater from New Jersey to Virginia. Not only do the 

 vast majority of Bobolinks seek a narrow track along the Atlantic seaboard 

 for their southward migration, but they reach all parts of it almost simul- 

 taneously. Florida seems to form an exception to this statement, but in 

 Georgia and South Carolina both the earliest dates (July 13-19) of fall 

 migration and the bulk arrivals (August 15-21) are as early as those for 

 the vicinity of Philadelphia. At a plantation on Goose Creek, South Caro- 



