Migration in War-time 



PIPER was met with over Arras, towards the 

 end of March 1917, at an elevation of 12,000 

 feet, and other Limicoline birds at 9,500 and 

 10,000 feet ; WHIMBREL were observed at 4,000 

 feet, and HERONS at between 2,500 and 3,000 

 feet (Ibis, 1919, pp. 321-5). War-time does 

 not offer the most favourable conditions for 

 the solution of the question at what height 

 birds fly when migrating, but the following 

 advertisement was published in February 

 1919: "Any notes on the flight of migira- 

 tory birds made in the air would be highly 

 appreciated. Where possible the species, 

 height, and velocity of flight, time of day, 

 and year would add greatly to value. Single 

 or even negative notes would be most accept- 

 able " (Times, n .ii .19). With the return of 

 peace and a more general use of the aeroplane 

 we may expect many interesting facts and 

 discoveries concerning the question of bird 

 migration, which is, at present, quite un- 

 solved. 



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