Ears
Republished with permission from Horse Sport
There is hardly a more
spectacular scene than that of a horse, ears pricked forward, listening
and looking at an object with unwavering interest. Ears are an element
of the essential beauty of the horse.
But ears are also multi-functional, finely tuned instruments. They
are not only a means to capture sound waves but they also act as an
alarm system, and are expressive communication tools - barometers
to the horseÆs temperament, mood and focus of attention.
From Ear to Hear
The equine ear is comprised of three parts - the outer, middle and
inner sections.
Sticking out from the top of the horse's head, the outer ear is that
the part of the appendage with which we are most familiar. This outer
ear (or pinna) is made of cartilage that swivels to facilitate the
capture of sound waves from all directions. In the wild, this function
helps to protect the prey animal from predators.
The collected sound waves travel through the long ear canal (eustachian
tube) to the middle ear where a thin membrane, the eardrum (or tympanic
membrane) vibrates. The vibrations travel through a configuration
of bones called the malleus, incus and stape, (the Latin names, derived
from their shape for hammer, anvil and stirrup, respectively) located
in the moist, middle ear (tympanic cavity). They then travel through
another membrane (which is attached to the malleus) on to the fluid-filled
inner ear where other, tiny bones at the base of the skull receive
the sound. Located amongst these bones is the auditory nerve, which
sends the message to the brain where it is translated into sound.
Also located in this area is the vestibular nerve, which plays an
important role in the horse's balance.
The gutteral pouch, the purpose of which is unknown, is an extension
of the eustachian tube.
Do You See What I Hear?
Ears play a major role in the non-verbal language of horses. Ears
are one of the major tools for equine communication. When combined
with other body language signals such as head and neck movement, lips
and teeth activity, tail movement, general stance and vocalizations,
horses can communicate very well with one another. For example, as
it is generally known, a horse whose ears are pinned back is angry
or aggressive. It is believed that pre-historic horses adopted this
posture to prevent their ears from becoming damaged when doing battle
with another horse or a predator and through time it evolved into
a gesture signifying threat.
There is also direct connection between the horse's ears and eyes.
If something has his attention, the horse will point his ears toward
that which he is looking. It is the combination of hearing and the
horse's sight that triggers the horse's flight response system, which,
for equine individuals and herds in the wild, is a survival necessity.
Humans (and even other animals) can pick up on these cues as well.
Once you get to know a horse's subtle, unique ear signals and the
rest of their body language, it will seem that they are practically
talking to you...and in their own way they are.
What's That You Say?
Horses' innate prey status makes them naturally more reactive to sounds
than say, humans or other animals but that doesn't necessarily mean
they have more acute hearing.
In fact, their ears aren't able to readily locate the source of sounds
- they might know the general direction from which a sound originates
but cannot pinpoint the origin (a trait common to prey animals).
A greater-than-normal sensitivity to sounds could be part of the
reason some horses have more of a tendency to spook than others.
Likely in the wild these horses would have been herd leaders or those
more apt to survive. Consider most stallions and their extreme receptivity
to sound. Could this be because it is inherently their role to be
the prime "watchman" and communicator of the herd?
It has also been suggested that horses are responsive to different
levels of sound on an individual basis. That is why some horses will
have a greater reaction to loud noises while others find the snap
of a stick terrifying.
It also may not be the sound itself that will send a horse off in
fright, but rather that the sound is associated with another negative
experience. For example, the swooshing sound of a floor being swept
might bring back memories of being beaten with a broom.
Horses are more sensitive to higher frequencies than humans are. That's
why a good sharp growl or a sharp "hey" may be apt to get
a horse's attention than our human voice is not readily audible to
the horse. Alternatively, they seem to find low, soft tones soothing.
A Pain in the Ear
Signs of ear conditions include:
ò head rubbing, shaking or tossing,
ò head tilting
ò droopy ears
ò onset of head shyness
ò hard to bridle
ò off-balanced
ò heavy buildup of dark wax
ò fluid discharge
ò hair loss from rubbing the ears
A horse's ears should be checked regularly for injury, insect infestation
or tumours. If ear conditions are allowed to develop, the horse may
end up hurting themselves, even seriously, as they bump, scratch and
bang their head in an attempt to alleviate the pain and/or irritation.
They can also end up permanently head shy.
>>>>>> Continued
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