8 1 9 
THE EYES OF THE BURROWING OWL 
The food of these owls consists almost entirely of mice, gophers, 
and similar mammals, as well as of small reptiles and insects. Of 
these a family of owls, commonly ten in number, will consume 
enormous quantities; each member disposing of his own weight 
of pabulum in twenty-four hours! 
According to Knowlton and Ridgway (i) the Burrowing Owl is 
more or less migratory, and after a return to its usual habitat mates 
(probably for life) and then arranges its underground nest. The 
contour of these nesting burrows varies; they are usually about 15 
inches wide and from 5 to 10 feet in length. They enter the ground 
in a diagonal direction for a few feet and then turn at an angle either 
to the right or to the left. The nesting chamber (12 to 18 inches in 
width), placed at the highest part of the burrow, is mostly lined 
with dry dung, but sometimes with hair, feathers, or dried grass. 
The eggs are six to twelve (generally eight) in number; their 
color, when unsoiled, is glossy white. 
It must be remembered that while the great majority of these 
owls dig their own burrows, many of them, especially the northern 
varieties, make use of the abandoned holes of certain mammals, 
notably of the prairie dog, fox, badger, skunk, and ground squirrel. 
Doubtless in the latter instances the Burrowing Owl may enlarge 
or otherwise alter the size, length, and other dimensions of the newly 
acquired hole. 
The Burrowing Owl is not over-clean in his habits; the nesting 
chamber and the remainder of the burrow are often filthy and foul 
smelling. 
The writer has studied the habits of the North American and 
Florida subspecies, with special attention to the eyes and eyesight 
of the bird. From these observations he concludes that this owl, 
like all the others, is a true night bird, adapting itself with but slight 
success to daylight conditions. In spite of the fact that Bendire and 
Hudson refer to the animal as a diurnal owl, their accounts of its 
habits really bear out the writer’s contention of a nocturnal animal 
with fairly good day vision, yet distinctly embarrassed, uncertain, 
and confused w r hen the eyes are exposed to bright sunlight. Stress 
is laid by a number of observers upon the fact that this owl is seen 
at all times of the day standing guard, often on a little mound of 
earth in front of his burrow entrance, forgetting that, as a much 
