^ 17ITH TJNCLE SM'S NATUKALISt^ 



FOR BROADCAST ttSE ONLY 



AmOUNCM^Ti Now let^d hesir what Uncle Sarf' s Naturalists of the United States 

 Department of Agricult1ii*e hsLVe to say about our wild life. Today we will catch 

 some facts on the wing -"— • this time about birds 



Since man took to the air, birds have lost some of their big reputation 

 as flyers. 



Mr. Frederick C. Lincoln, of the United States Biological Survey, tells 

 me that airplane and automobile speedometers have had a lot to do with paring 

 down the speed ratings of birds. Accurate measurements of bird flights have 

 cut down many of the old estimates considerably. 



Not so many years ago, Mr. Lincoln says, some birds were credited with 

 making tremendous speed. That was not a mere popular fancy, either. The notion 

 Was shared by many scientists and experienced sportsmen who had made a practice 

 of estimating how fast the birds move. 



It was rather generally held that laany birds normally flew 100, 150, 180, 

 and even 240 miles an hour. Of course, some birds do get up and move through 

 the air, especially when they are scared. But accurate timing of birds in full 

 flight, Mr. Lincoln declares, shows that often old claims were several jumps 

 ahead of the true speeds. 



!7ith the advent of the automobile, it became easy to check up on such 

 birds as sparrows, and horned larks, smd warblers,, and thrushes, and wrens, and 

 other weak-winged birds which often fly low along the road parallel to motor 

 traffic. 



Readings of speedometers soon showed that some of those birds that had 

 been supposed to travel from 40 to 60 miles an hour, normally make only about 

 18 to 25 miles an hour.. 



Stronger flying, stream-line-model birds such as the moiirning-dove were 

 fotmd to move at the rate of 30 to 35 miles an hour. 



i7ith the help of the airplane, many checks have been made on higher fly- 

 ing birds, such as ducks and geese. Instead of moving ordinarily at rates of 

 liO to 150 miles an hour, as some folks had figured, ducks and geese were found 

 to fly conmonly at 40 to 60 miles an hour. 



