iSSs-J Bird Migration. Iig 



If you are in a position to observe the lines of flight of birds, 

 have you noticed whether or not such lines are influenced by the 

 topography of the country, and if so, to what extent? 



if a mountain intercepts the line of flight, what kinds of birds 

 pass around it, and what kinds pass over it? 



What localities in your neighborhood are sought as resting- 

 places by the various kinds of migrating birds? Can you give any 

 reason for this selection ? 



What kinds ot birds generally move in flocks, and what kinds in 

 pairs or singly ? 



Are you familiar with any kinds of birds in which the males and 

 females, and old and young, fly in separate flocks? In many spe- 

 cies the males arrive m advance of the females, hence it is impor- 

 tant to note the sex of the first coiners, and the date at which the 

 opposite sex is first seen. 



Have you observed from year to year any increase or decrease 

 in the numbers of any kind of bird known to you? If so, do you 

 attribute such change to altered conditions in the bird's breeding 

 grounds? If not, can you assign a cause? 



Have you observed the increase or decrease of one species to 

 affect the numbers of another species? If so, can you explain the 

 fact ? 



Has any kind disappeared altogether, and if so, can you assign 

 a cause for this disappearance ? 



Among the birds which are now common about your station is 

 there any kind that was formerly rare or absent? If so, can 3-011 

 explain the fact? 



Among the birds which breed regularly in your vicinity have 

 you ever observed an individual which by some personal pecu- 

 liarity (such as the presence of white or dark feathers where they 

 do not belong, or by some deformity) could readily be distinguished 

 from others of its kind? If so, has this bird returned to the same 

 place to nest } r ear after year? 



In recording arrivals and departures it is highly important to 

 distinguish between the movements of irregular stragglers, of the 

 advance guard or 'van,' and of the principal mass or 'bulk' of 

 the species. For this purpose observers are requested to note : — 



1. When the species is first seen. 



"2. When it is next seen. 



3. When it becomes common. 



4. When the bulk departs. 



5. When the last individual is seen. 



In addition to the above data, which all observers are requested 

 to furnish, the Committee particularly desires exact records of 

 eveiy increase and decrease in the numbers of a given species over 

 a given area ; for it is only by the knowledge of the daily fluctua- 

 tions of the same species in the same place that the progress and 

 movements of a 'flight,' or 'bird-wave,' can be traced. Such data 

 can be contributed by experienced observers only, and in their 

 procurement much time must be spent in the field. During the 

 progress of the migratory movement the observer should go over 



