9 Miscellaneous Circular 18, U. S. Dept. of Agriculture. 
Ornithologists’ Union in 1909, with the result that the American 
Bird Banding Association was organized in New York City on 
December 8 of that year. This organization continued to advance 
the work, during the last few years of its existence under the auspices 
of the Linnaean Society of New York, until it outgrew the resources 
available. The work done under the direction of this association 
(Cleaves, 1913), together with the development of the method of 
systematic trapping (Baldwin, 1919), demonstrated the great pos- 
sibilities of extensive operations. And, as it was realized that the 
information resulting from banding migratory birds, particularly 
waterfowl, would be of much value in the administration of the 
migratory-bird treaty act, the work was taken over by the Biological 
Survey in January, 1920. 
Bi534M 
Fig. 1.—Typical trapping station, showing well-placed trap and gathering cage inside 
of guard fence. (Photograph by S. Prentiss Baldwin.) 
This method of research is receiving attention along these two 
principal lines: First, the banding of fledglings, as formerly prac- 
ticed; and second, the systematic trapping and banding of adults. 
The latter is being given special emphasis, for, since it is the re- 
turns from banded birds that furnish the information desired, it is 
obvious that the method that will yield the largest number of returns 
should be intensively developed. Nothing has been found more sat- 
isfactory for the accomplishment of this object than systematized 
trapping. As the banding of fledglings, however, has the advantage 
of affording valuable information on the ages of birds, the Biological 
Survey desires to encourage this activity also, particularly as applied 
to those species which can be trapped readily as adults, or which, 
for any reason, are likely to be reported as “ dead returns.” 
_ With the establishment of a well-connected chain of trapping sta- 
tions (fig. 1) throughout the United States and Canada, regular 
