National Association of Audubon      Societies 
 
 
     For the Protection of Wild Birds and Animals 
 
            1775 Broadway, New York, N. Y. 
 
 
 
 
 
                                               April Ist, 1938. 
 
Professor Aldo Leopold, 
1532 University Avenue, 
Madison, Wisconsin. 
 
Dear Aldo: 
 
          I have just received reports concerning a paper-which 
Karl Lagler, who is working on the fish predation project at 
the Institute of Fisheries Research at Ann Arbor, gave at a 
recent meeting.   It was rather disquieting, as I was given to 
understand that the paper dealt with the feeding habits of the 
Kingfisher, yet most if not all of the data was ýobtained from 
the stomachs of Kingfishers killed at fish hatcheries. Such 
data on any species of fish-eating bird we know to be absolutely 
valueless as it is obvious that the only food the birds could 
take in such a location would be the species raised at the 
hatchery.   Certainly no research project is needed to deter- 
mine such facts. 
 
          Of course, what we do need to know is the feeding 
habits of these various fish-eating birds as they exist norm- 
ally in natural wild habitats.  To what extent Mr. Lagler is 
obtaining such information I don't know, but without it his 
report won't be of much value in the direct appraising of the 
effect of fish-eating birds on fish. i 
 
          I shall have to confess that I have been worrked 
right along about the whole project Mr. Lagler is working on, 
because I know if it is from a biased or distorted angle it 
will be used by sportsmen to prove all manner of charges against 
fish-eating birds, when in reality the report would actually 
justify'no such charges if carefully read and weighed on the 
basis of the evidence presented. 
 
          As you are a member of the Technical Committee, whom 
I assume have jurisdiction over these projects sponsored by the 
American Wildlife Institute, I certainly would appreciate your 
keeping a careful eye on the whole thing to see that Mr. Lagler 
doesn't set forth as significant data food habit studies made on 
birds killed at fish hatcheries.