Evening star. [volume] (Washington, D.C.) 1854-1972, 1910-07-10
OWLS SENSITIVE EAR.
The Variations in the Different
Species-Keenness of Sight.

From the London Times.
Most night-feeding birds, such as the
various species Of wild duck and waders,
depend mainly on the sense Of touch, and
although an extraordinary sensitiveness
must be developed in their bills to enable
them to distinguish what is edible as they
probe or dibble in the ooze, the process is
largely mechanical. Owls, however. re-
quire tine keenest and most mobile percep-
ton in order to capture the same prey Of
mice and birds in the dark which kestrels
and sparrowhawks hunt by day. 1t IS
probable that they depend even more
upon hearing than upon sight. The tufts
OF feathers which distinguished the
short-eared and long-eared owls and are
developed still more imposingly In the
great eagle owl Of northern Europe are
OF course no more ears than they are
most remarkable organs.
The facial disk of feathers which gives
them their characteristic appearance
serves as a kind OF sounding board or
sounds and transmit them to the orifice
Of the true ear, which Is concealed In
the small feathers behind the eye. Even
in the barn owl. which possesses the
least complicated arrangement Of this
kind the orif1ce OF the ear is covered
by remarkable flap Of the skin: while
in the other species there are striking
differences in the size and shape OF this
orifice and it's covering flap on the two
sides of the head.
deliberately specialized apparatus has still
to be discovered; but it is a natural In
ference that two ears of widely different
structure must give the owls which pos
sess them power Of localizing SOUND
which is of the greatest use to them when
hunting small creatures in the dark. 1t
Is, therefore, all the more surprising that
the barn owls ears have not this diner
ence Of structure, although the power OF
instantly locating the rustic OF the run
ming mouse must be almost Indispensable.
For catching small birds. which are the
especial prey of the wood owl. keenness
of sight rather than of hearing must be
necessary, since they are chiefly caught
eye is developed in most Of the owls al
most as remarkably as the ear. In the
short-eared OWL which is day-f1yins
species. the eye is corresponding!y re-
duced. 1t has also far less conspicuous
facial disk. and this might also seem to
be naturally explained as result Of its
diurnal habits, with the consequent re-
duction Of the need for acute hearing,
If 1t were not for the marked difference
OF the structure Of its two ears. which Is
even greater than in the case of the
wood owl.
Owls have great variety OF nocturnal
calls and cries. They range from the hiss
ing Of the young white owls as they wait
for food and the low, swapping note which
often falls from the darkness around the
treetops on silent nights to the brown
owls full-throated tu-whit-tu-whoo and
the white owls wild screech. Brown owls
boot more persistently in autumn and
winter than in the summer, and the long
drawn cry sounds louder and more reso-
nant from among the naked aises than
when it Is softened and half stifled by the
roof Of verdure. The white owls screech
is heard more seldom. but the bird itself
is usually more conspicuous than the
brown owl in a district where they are
. equally common.
It's pale plumage often makes it visible
In flight by night, wholly apart from the
disputed question Of its occasional lumi-
nousness. It sometimes fits abroad in the
earliest dusk Of evening, or even in full
daylight. while in the nights Of spring
and early summer it has characteristic
way Of flying low above the standing
hay fields, as If it were large white
moth seeking the clumps Of glimmering
moon daisies. Though 1t glides past like
the very spirit of silence, a few moments
later its yell may ring through all tho
valley.