Senses
Vision
Elephant seals have large eyes, each with a spherical lens. These specialized lenses help them in absorbing more light in the dark depths. In addition to these lenses, their eyes also contain high numbers of extremely sensitive rod cells called photoreceptors. Helping these rod cells is a mirror-like layer of reflecting plates behind the retina. By reflecting light back through the retina a second time, the light-gathering ability of the rod cells is increased. Their eyes also have a strengthened cornea which is heavily keratinized, and a protective third eyelid called a nictating membrane. This nictating membrane is transparent and moves horizontally across the eye moistening their eyes with an oily liquid. Not only does this membrane protect their eyes underwater by lessening the friction, but it also removes sand and other debris when they're on land. Because elephant seals have no tear ducts, their eyes run more or less continuously when they're ashore.
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Nictating Membrane
Hearing
The almost invisible ears of an elephant seal are about the size of a pinhole and are located just back from their eyes. Even though no external ear flaps exist, and they have an unusually narrow auditory passage that leads to the eardrum, they hear quite well due to other modifications. The inner ear chamber is proportionately larger than those of other earless seals. In addition, the inner ear, the cochlea, is effectively insulated from the skull so background noise transmitted through the skull cannot reach it.
Although elephant seal hearing appears to be less acute on land, they do have well-developed directional hearing underwater. On land, sounds reach both ears at the same time enabling them to localize where the sound is coming from. However, when they're under water, with the muscles around the ear canal tightly contracted to prevent water from getting in, sounds and vibrations are picked up by the extremely sensitive whiskers or vibrissae, each one of which can move independently of the others. Using these sensitive whiskers, the elephant seal moves its upper lip back and forth to detect movement in water with low visibility. Then, using its substantial nervous system, the elephant seal can send this tactile information from its whiskers to its brain. In other words, elephant seals seem to have a form of echolocation.
Close-Up of Vibrissae
Touch
Female elephant seals are very protective of their personal space and seem to show the least desire in wanting to be in physical contact with other elephant seals except during their annual molt when they will pack themselves in on the beach like sardines in a can. Another exception is during the birthing season when the females constantly sniff and touch their pups. The weaners of both sexes, on the other hand, display great affinity for being in physical contact with one another as do the young and sub-adult males.
Females Packed In
Smell
On land, elephant seals display a keen sense of smell as evidenced by the ability of moms and pups to recognize one another by scent more than by sight or sound. Also, similar to dogs, while inhabiting the beach, elephant seals often wiggle their noses to detect incoming smells. When diving, however, elephant seals keep their nostrils tightly closed.
Mom and Pup Sniffing
