THE EYES OF THE BURROWING OWL 
820 
more interested householder, he also watches from the same post 
all hours of the night! 
Bendire gives the best account of their habits as observed by a 
daylight student of their habits: 
“When not unduly molested, they are not all shy, and usually allow 
one to approach them near enough to note their curious antics. Their 
long, slender legs give them a rather comical look — a sort of top-heavy 
appearance. Should you circle around them they will keep you constantly 
in view, and if this is kept up it sometimes seems as if they were in danger 
of twisting their heads off in attempting to keep you in sight. They bunt 
tbeir prey mostly in the early evening and throughout the nigbt y more rarely 
in the daytime. As soon as the sun goes down they become exceedingly 
active and especially so during the breeding season.” 
As one result of a rather extensive study of the visual apparatus 
of this interesting owl, the writer has never seen anything to convince 
him that the bird ever performs an act requiring distinct diurnal 
vision. Certainly the northern bird is decidedly nocturnal, occasion- 
ally using his eyes, but at a disadvantage, during daylight hours. 
This conclusion is confirmed in a noteworthy fashion by a com- 
parison of the fundus oculi of this owl with the same picture in 
owls entirely nocturnal in their habits, and indeed with certain 
other evidence (especially that they all show orange or reddish 
fundi) constantly found in night animals. 
These facts have been fully stated by G. Lindsay Johnson (2) 
as regards the mammalia; and by the writer (3) for the avian eye. 
As in all owls, the eyeballs are set well in front and surrounded 
by more or less plainly marked, uniform and complete facial disks 
(that probably act as reflectors into the eye of the diffused and 
faint rays of evening light). 
Strigiform eyes more closely than those of any other order re- 
semble human eyes; and they preserve, as in man, about the same 
relation to other facial organs and are so placed as to obtain binocular 
vision in front. Structurally, of course, birds’ eyes are quite different, 
especially in the morphology of the eyeball, in the possession by the 
owl of a pecten instead of retinal vessels, in the covered optic nerve 
and in many other particulars which it is not proper to specify here. 
Slonaker (4) and the writer (5) have pointed out that all the 
owls are exceptions to the rule that the retinal area of distinct vision 
