Vol. XT Mackay on Fly Lines. 2A.Q 



It would seem, especially during inclement, windy weather, 

 that most creatures shrink from a struggle with the elements, for 

 a variety of reasons ; as a result their movements are deflected to 

 leeward. But such conditions are not essential, for I have noticed 

 similar results during ordinary weather when there was but little 

 wind, the position of the Fly Line being changed perceptibly. 

 Such changes are apparently brought about by the wind coming 

 from a different quarter, the Fly Line being deflected almost invari- 

 ably to leeward, even though there may be scarcely wind enough 

 to make a ripple on the water. I interpret it that the birds are 

 enabled to fly in the direction they wish to go with greater ease 

 by so changing their course. It would also seem that some so- 

 journing birds, after becoming accustomed to certain localities, 

 evince a preference for particular routes by their continuous 

 use when passing to and from places they are accustomed to 

 frequent, thus adopting what I designate as their Fly Line. In 

 instances where salt water Ducks are in the habit of frequenting 

 ponds having an opening into the ocean, they usually show a 

 preference for passing in and out over such opening, apparently 

 feeling safer when flying over the water. Should there be no 

 opening they are apt to select the narrowest part of the beach 

 separating the pond from the ocean, over which to cross, regard- 

 less of the wind. The topography of certain localities also has 

 much to do with influencing the direction of the Fly Lines of some 

 of the water birds when passing over the land. The American 

 Golden Plover ( Charadrius dominions) especially will follow 

 undulations, and shape its course so as to follow the depressions 

 and valleys. These illustrations, I think, indicate that the move- 

 ments of some of the water birds are not left to chance, but actu- 

 ated by purpose. 



It is not to be inferred that Fly Lines are easily discovered, 

 though sought after with perseverance, for the reason that their 

 location, favorable weather conditions, and time of flight, are 

 usually matters of conjecture * hence unless one is a good deal in 

 the field, as well as on the alert, instances may occur which will 

 escape the observer's notice. In thus directing attention to the 

 subject, and communicating what I have gleaned, I desire to 

 assist others who may be interested in the matter by giving them 

 the aid of my own experience. 



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