Vol. XI Mackay on Fly Lines. 2A.Z. 



FLY LINES. 



BY GEORGE H. MACKAY. 



'Fly Lines' and 'Lines of Flight' are so closely con- 

 nected that it might seem reasonable to include them under one 

 heading. Yet, judging from my observations of some of the 

 water birds during their sojourn on the New England coast, I 

 can say that Fly Lines do not convey to me the same meaning as 

 do Lines of Flight, for the reason that the former appear to be 

 influenced by the peculiar local surroundings and weather con- 

 ditions of the locality where they occur, while I recognize as 

 Lines of Flight those general migratory movements from north 

 to south, and vice versa, over particular sections of the country 

 or along certain coasts, in contradistinction to other portions 

 where such movements do not occur. While it is true that in 

 some instances Lines of Flight seem to change their character 

 temporarily so as to very properly come under my interpretation 

 of Fly Lines, I can scarcely say I have. ever noticed Fly Lines 

 (with one exception) to assume the definite character so distinc- 

 tive of Lines of Flight during a migratory movement. I am free, 

 however, to state, in regard to the above exception, that I have 

 observed Scoters flying under the temporary local conditions ot 

 Fly Lines which I am certain embraced a migratory movement, 

 as I shall have occasion to instance later on. It is of little im- 

 portance, however, as for as the subject matter is concerned, 

 whether one or both terms are considered as essential in defining 

 such movements. Therefore permit me to use that of my title 

 in describing what I desire to communicate, because it is the one 

 with which I am most familiar. 



The expression 'ocean lanes' is often applied to those invisi- 

 ble, broad, open ways traversed by the ocean steamships in passing 

 to and from this country to Great Britain, and it seems fairly well 

 to convey the meaning. Fly Lines are also invisible pathways, 

 pursued not only by migratory but by sojourning water birds in 

 New England. This unmarked temporary way is always sub- 

 ject to change, sometimes more than once in a day, as it is deter- 

 mined largely by weather conditions ; but whatever the conditions, 



