10 BULLETIN 217, U. S. DEPARTMENT OF AGRICULTURE. 
drowned. It also developed that very weak birds should be separated 
from the others. Under more favorable conditions the percentage 
of recoveries could be markedly imcreased. California sportsmen 
will be interested to know that at present this appears to be the only 
measure that will prove successful on Tulare Lake. It is even possi- 
ble that birds once cured may become to a greater or less extent im- 
mune, and will not readily be affected again. | 
In order to obtain data on this possible immunity and oh the sub- 
sequent longevity of birds which have recovered from the poisoning, 
aluminum bands were placed upon the legs of 270 of the birds released 
during the past summer. Hach band bears a number on one side 
and on the reverse the inscription ‘‘ Notify U.S. Dept. Agr., Wash., 
D. C.” By this means the birds may be identified should any of 
them be found or captured.t Already reports have been received 
concerning more than 20 of these birds. Should more of these bands 
be secured it is hoped they will be forwarded to the Department of 
Agriculture with full information as to date taken and attending 
circumstances. 
1 Vaiuable information in another line of investigation will be forthcoming from these bands. At present 
knowledge of the routes of migration followed by waterfowl is based upon observation as to the dates of 
arrival or departure of the birds in various localities. These, properly tabulated, show the movement of 
the species in question asa whole. The actual lines of flight pursued by individual birds are almost entirely 
unknown. The importance of information on this point can not be overestimated. 
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WASHINGTON : GOVERNMENT PRINTING OFFICE: 1915 
