318 BOARD OF AGRICULTURE. [Pub. Doc. 



During the progress of the work on the gypsy moth by the 

 State Board of Agriculture in Massachusetts more than a 

 thousand men have been employed, among whom there are, 

 or have been, many who know the common birds. Some of 

 these men are keen-eyed observers. In the early history 

 of the work, when it was seen that birds were feeding on the 

 gypsy moth caterpillars, all those men employed who knew 

 birds were requested to watch the birds and report the re- 

 sults of their observations. There were eleven such ob- 

 servers on the force at that time. Others have joined the 

 force from time to time, until the number whose experiences 

 have been recorded has been increased to thirty-eight. 

 Some of these observers have seen birds feeding on the cat- 

 erpillars of the gypsy moth for only one season, others have 

 been in the employ of the Board for six, seven or eight years, 

 and have made observations during each year. The condi- 

 tions have been such that most of the birds could be observed 

 within a few feet or a few yards. Those which could not be 

 so readily approached were watched with the aid of good 

 field or opera glasses, and where there appeared to be doubt 

 birds were shot and the contents of their stomachs carefully 

 analyzed. 



Much was learned by experience in the earlier observa- 

 tions which has been turned to good account in conducting 

 those made during the last three years. The value of such 

 observations may be questioned by those who rely solely 

 upon the examination of the stomach contents to determine 

 the food of birds. But for the purpose for which these ob- 

 servations are made they are, if skilfully conducted, quite as 

 serviceable as stomach examinations. In fact, one must 

 supplement the other. 



Were one to follow the birds about through the fields and 

 woods no doubt some interesting facts might be learned in 

 regard to their food, but it is not in this way that a series of 

 accurate observations can be made. Birds are attracted to 

 localities where insects are plentiful, preferring often to go 

 some distance to such localities, where food is abundant and 

 readily obtained, rather than to search for less abundant 

 species near their nesting places. For our purpose, then, 

 the method pursued is to find an outbreak of hairy cater- 



