292 Wild Bird Guests 



or evergreen. Each area should be selected with 

 a view to making a yearly census of it and for 

 that reason it would be best to select an area not 

 likely to change very much for several years 

 at least. Otherwise, when there were found to 

 be changes in the bird population, it would be 

 difficult to tell if these changes were due to an 

 increase or decrease in the number of birds or 

 simply to changed conditions in that particular 

 neighborhood. 



The height of the breeding season is the time to 

 make these bird censuses, because the spring 

 migration is over, the fall migration has not 

 begun, so that the birds which you see in any 

 locality are all likely to be birds which belong 

 to that locality and which have their homes 

 there. At Washington, D. C, latitude 39 

 degrees, the 30th of May is about the time to 

 begin; farther south one should begin a little 

 earlier, and farther north somewhat later of 

 course. In the latitude of Boston, the 7th or 8th 

 of June would be about right, while in Maine 

 the middle of that month would be early enough. 



The plan recommended by Mr. Henshaw and 

 which has proved very successful for several 

 years, is to begin at daylight and zig-zag back 

 and forth across the whole area, counting the 

 male birds, which at this hour and season should 



