Consider this fact : No wild canines have drop ears which may indicate a Darwinian
genetic advantage to erect ears.
Studies done by Warner and
Humphreys on Working Dogs produced the following results:
- tests made by Pavlov workers in Russia and by Engelmann in Germany indicate that dogs
hear sounds too faint to affect human ears. A German Shephard responded to a sound at a distance of 24 meters where a man
could not hear at more than 6 meters.
- Dogs
hear a wider range of pitch. They not only respond to tones within our range of
hearing but also to tones so high they escape our ears altogether. Dogs hear
sounds of fainter intensity and of higher pitch than human ears can.
- In
a test to determine the dog’s ability to identify the position of a sound’s
source, two female Shephards and a male Doberman
were used. Electric buzzers were used and the dogs were rewarded if it went to
the correct buzzer which had sounded but the buzzer sound was so brief that the
dog did not have time to move its head or ears in order to locate the source of
the buzz. When two buzzers were used, and placed a just below the level of the
dog’s ears and at a distance of 5 meters, the dogs were always able to identify
the buzzer correctly providing the buzzers were placed or separated by a
distance of at least ½ meter. When the dog was at a distance of 10 meters away,
it failed. The dog was able to identify correctly when the distance between the
two buzzers was increased to ¾ of a meter. At 20 meters, it was necessary to
separate the two buzzers by 1 ½ meters in order for the dogs to perfectly identify them. Most humans could not equal these
records.
- Erect
eared dogs can localize the source of a sound to within 5 degrees whereas a dog
with a drop ear can only localize the same sound to within 20 degrees.
- Erect
eared dogs can tell with remarkable accuracy the direction from which a sound
comes.
- Dogs
are however, not so good at judging the distance
between themselves and the source of a sound in a straight line.
- Uncropped or drop eared dogs can act as a ‘handle’ for a perpetrator to prevent police
dogs from seizing and holding them until apprehended.
Cropping of ears was done for functional reasons rather than cosmetic reasons. The
structure of a cropped ear would lend to better hearing than an ear that was
folded over just as satellite dishes are pointed upwards, not down, in order to
better catch sound waves. |
