SHORT-EARED OWL 169 



Pennsylvania and New Jersey: 29 records, March 14 to May 30; 

 15 records, March 29 to April 11. 

 Indiana, Illinois, and Iowa: 8 records, March 20 to April 28. 



ASIO FLAMMEUS FLAMMEUS (Pontoppidan) 

 SHORT-EARED OWL 



Plates 38-40 



HABITS 



Contributed by Charles Wendell Townsend 



The short-eared owl is one of the most cosmopolitan of birds, as it 

 is found in every continent except Australia. In its habits it differs 

 from most owls in preferring open plains, marshes, and sand dunes to 

 thick forests, where it is almost never seen, and in the fact that it 

 frequently hunts by day. Although it sometimes takes small birds, its 

 feeding habits in general are of great value to man, for its favorite food 

 consists of rodents. When field mice or voles increase so as to become 

 veritable plagues, various owls, especially of this species, have been 

 known to congregate in the infested region and to have done great 

 service in destroying the pests. There are several such records in 

 various counties in England extending back to the sixteenth century. 

 Such a plague of mice is described by Hudson (1892) as occurring in 

 South America in 1872-73, when short-eared owls wore most important 

 agents in stopping the plague. Notwithstanding their proved value, 

 ignorant and thoughtless gunners continue to shoot these beneficial 

 birds, and their numbers are diminishing. 



Courtship. — The remarkable courtship flight and song of this bird 

 have been well described by A. D. DuBois (1924), who not only made 

 observations on the song at night, but on both the song and flight by 

 day. The song consisted of a series of toots "repeated fifteen to 

 twenty times, at the rate of four toots per second, in a low-pitched 

 monotone." The sound seemed 



to come from all directions. Finally, upon gazing upward, I discovered the owl 

 directly overhead, and for a time was able to watch him, with the field-glass, 

 in the fading light. He was flying at a great elevation; so great in fact that it was 

 difficult to see him at all without the aid of the field-glass. For the most part his 

 flight was with slow, silent flapping wings, although he sometimes soared. His 

 course led in easy curves which kept him in the same general locality. His song, 

 on this occasion, was made up of 1G to 18 toots. Now and then he made a short 

 slanting dive which terminated with an upward swoop. The dive was accom- 

 panied by a peculiar fluttering noise * * * a sound as might be produced 

 by a fluttering small bird imprisoned in a box, or by the flutter of a small flag in a 

 very strong wind. 



Later, DuBois observed the flight in full sunlight and was able to 

 solve the mystery of the "fluttering flag." "When the owl began 



13751—38 12 



