Miraculous Animals: Senses

Suzan Mutlu

Jul 1, 1999

Animals are spectacular creations. Not only do they have their unique shapes, sizes, colors, and attributes, but also they have incredible senses that enable them to survive and communicate in this world, in a very different (and superior) form than human beings. There are hundreds of thousands of different animals, and each type have a different level of sight, hearing, smell, taste, and touch, along with what scientists call "super-natural senses." All animals and insects were created with those senses that best suits their size, attributes, and habitat for their survival. In this article, I will attempt to give a brief description of the different amazing senses animals have to create a better awareness and appreciation of these wondrous creations.

Sight: When we look around, we see several shades of colors and hundreds of thousands of images. Human beings, and several animals, are able to see images when light enters the eye and releases an electrical signal through our the nerves to the brain. These signals are then transformed into the images, or pictures, that we see. All creatures see these images differently; some see images in different outlines in shape, color, clarity, circumstances, and distance.

Dogs, because of their hunting needs, see twice as much as do human beings. In addition, dogs have an outstanding ability to follow movement and to perceive direction, speed, and trajectory. Trajectory is what gives dogs the innate ability to plot an angle and predict an angle of movement. For example, dogs have an astonishing ability to know the exact spot where a moving object will land and know from which angle it will be coming. This is the reason why dogs are such good ball and Frisbee catchers; because they visually know the exact point of impact of an object as it falls back to the ground. Cats, on the other hand, have a different reason for being such good jumpers. Cats' faces are flat between the eyes, a rare feature in the animal world, which makes it easier for them to work together. As a result, a cat can focus sharply and three-dimensionally, an ability that allows it to visually judge distances with great accuracy before jumping.

Rabbits, for example, are one of the few animals that can see all around them (front and back) without turning in either direction. Their eyes are located on the sides of their head, which enables them to see in all directions. Rabbits, frequent preys for predators, are always on the alert, and their eyes are located in the best place to help them see their enemies.

Human beings and wildlife animals have two kinds of vision cells that are located inside the back of the eye: cones and rods. Cones detect colors in bright light, including black, white, and gray. Rods provide sharp vision in dim light, but do not detect colors. Night creatures have more rods than cones, which provide them with sharper vision at night-but with only shades of gray. Also, to assist these creatures in the dark, they have a special layer in the back of their eyes, called the tapetum, which acts as a mirror when light passes through it. If the rod does not detect the light during the first passing, the tapetum reflects the light back to the rod, thus giving the rod a second chance to pick up on the light and see an image. It is this layer that makes some animal's eyes shine in dim light.

An owl's eye, for example, is so sensitive in picking up light, that research shows that an owl can follow a trial lit up by a candle 1,000 feet away (3,600 meters).1

Another amazing sight feature is found in predator birds: "telescopic" eyes that allow them to see by making a far away distant object appear larger. Birds such as the hawk and eagle have the sharpest sight of any animal. These birds have about 1.04 million vision cells in the back of their eyes, which that enables them to see a mouse from as far as one mile away.2 (Human beings have only about 130 million vision cells.)3

Although animals are believed to see colors similar to the way humans do, scientists are not sure how bees and insects see color. Scientists believe that, among some other creatures, bees, birds, and insects can see a color that human beings can not: ultraviolet colors. In addition to red, blue, and yellow, flowers often have ultraviolet patterns that show these birds and insects the way to the plant's nectar and pollen. Such sight makes it possible for these creatures to find and feed on the flowers' nectar and pollen.

However, not all animals have only two eyes. Jumping spiders, for instance, have eight eyes. There are two big eyes in the front, and six smaller eyes on the top of the head slightly toward the sides. The two front eyes are very well developed and act as a pair of binoculars that give the spider a clear image of objects up to one foot (30 cms) away. The little eyes are called secondary eyes. These eyes can spot moving objects and have a built-in reflecting layer that helps the spider to see objects in dim light. The secondary eyes are the eyes that actually measure the distance the spider needs to jump to catch its prey.

Hearing: Just as with other senses, human beings and animals have different levels of hearing. Most animals have only two ears, which helps all of us locate the origin of a sound. Having two ears helps us locate where a sound comes from. Since sound reaches the ears at slightly different times, this makes a sound louder than in one ear. This difference in volume and arrival time in one ear is an indication as to the origin of the sound. Sound is expressed in hertz (cycles per second), which are repetitive vibrations per second. Adult human beings, with a normal hearing ability, can hear from twenty to twenty thousand cycles per second. Amazingly, wolves can hear up to eighty thousand cycles per second, and dogs can hear up to thirty-five thousand cycles per second, almost twice as many as humans.

Cats have a surprising hearing of between fifty to one hundred thousand cycles per second-three to five times than what human beings can hear. In addition, a cat's ear has thirty muscles that control the ear muscles that can rotate 180 degrees. This give cats the opportunity to hear its surroundings without moving its head.

An owl's ear, however, are located at different heights. The difference in height enables an owlit to determine if a noise is coming from a high distance or from the ground. Another interesting feature of many owls is a flat heart-shaped face. The shape of its face functions as a reflector that makes faint sounds louder. These two features enable owls to be the great hunters they are and helps them to hunt in the dark.

Not all animals and insects have "ears"; some have holes in either in their head or in another part of their body, and others have eardrums, such as birds, insects, and fish. Fish's ears, for example, are located under its skin behind its eyes. This way, a fish can pick up on vibrations that pass their skin under the water. Other fish makes some of these noises by vibrating an internal organ or by rubbing their fins together. Fish use these vibrations to communicate with other fish, to mate, to warn other fish, or to swim together in groups.

Smell: Animals with different smelling needs have been created with different noses and different smelling abilities. Among the different abilities and noses, an elephant's nose stands out in many individuals' minds; at least mine. These animals' noses are so amazingly equipped with different functions, it is surprising. An elephant's nose (trunk) and upper lip weighs, on average, 300 lbs. (136 kgs.), and can take up and hold more than one gallon (3.7 lt.) of water at a time for spraying on another animal's back. The trunk is also strong enough to pick up large logs, yet functional enough to gather thin blades to eat. In addition, an elephant can raise its trunk high in the air to smell if any predators are in the area. Another function that I grin at, is that elephants weighing so heavy sink to the bottom of a rivers when they try crossing it; however, they use their noses as snorkels when crossing a deep river by lifting their noses high above the water line to breathe.

Dogs have an astounding sense of smell; they are one of the animals with the best sense of smell. Dogs can pick up odors in concentrations of one part per trillion. A book called Scent, published by veterinarian Dr. Hugo Verbruggen, and dog trainer Milo D. Pearsall, mentions an experiment that illustrates how well dogs can pick up odors. It mentions that if a single gram of butyric acid, a chemical constituent in human perspiration, were released in a ten-story building and evaporated, a human being might be able to smell the odor for a very short moment by sniffing at a window. A dog, in comparison though, would be able to pick up the odor in the same amount if it were to spread over a city the size of Philadelphia anywhere within the city up to an altitude of three hundred feet (90 meters).4 It also mentions that if humans had only ten percent of a dog's smelling ability that dogs have, we would have a totally different understanding of our world we.

Camels are desert animals that have been created with special channels that can hold moisture in the dry desert. Also, when the wind blows, a camel can close its nostrils to keep out the sand and dust.

Ants also fascinate me. These tiny creatures use odors to identify if an ant belongs in their colony or if it is an intruder. In addition, when an ant dies a certain odor is released, and other ants in the colony will carry the dead ant to a burial site. An experiment has been performed by scientists that placed this "dead" odor on a healthy ant. Although the marked ant was struggling and kept returning to the nest, other ants constantly carried this marked ant to their burial grounds in the belief that it was dead.5

Taste: Taste and smell are chemical senses. Although scientists can only guess what an animal can and does taste, they do know that animals have different taste buds. Taste buds are made up of tiny taste cells that enable us to taste sweet, sour, bitter, and salty substances. Mammals have the most taste buds, while birds have the fewest; insects have none. However, these animals and insects have special taste cells to detect the certain foods they need for survival.

Touch: All animals have a sense of touch. Many scientists believe that touch is the most important sense. The sense of touch indicates if we are hurt, cold, hot, and much more. Blind and visually impaired individuals rely on the feeling of touch to read Braille. Many animals and insects, however, have built-in antennas that help them avoid too close physical contact with other insects and help them detect food and surrounding conditions.

A blowfly (any fly that deposits its eggs on meat or wounds), for instance, uses its antennas to determine if the wind conditions are best for flying. If the wind is blowing too fast, the blowfly will wait until the wind calms down. This is an important feature, for this insect would not be able to survive flying in a strong wind.

Many animals and insects rely on the sensing of vibrations. For example, a spider relies on the shaking of its web to understand if it has caught food or if another spider has come to mate. A spider feels the vibrations through its long legs by waiting at the edge of its web. It is understood that when a spider returns to its web, it shakes the web to see how it vibrates. The results will let it know if something has been caught.

It is also interesting that some animals seek and show affection through touch, just like human beings do. Cats, dogs, monkeys, seals, and lions are some examples that show love and affection. As a cat owner, it is interesting to see the understanding of affection through touch. They enjoy being petted and seek for affection. A question asked by people, who have a cat or have been near a cat, is that why do cats purr and what causes this noise. Scientists believe that purring is produced by blood in a large vein in the chest that vibrates and is then magnified by air in the windpipe.6 Someone petting a cat can actually feel this vibration. Cats usually purr when they are happy or when being shown affection. However, the cat's purr is more than a sign of content. Kittens, unlike many animals, are born blind and deaf. The vibration of their mother's purring is a physical sign that the kittens can feel; it is somewhat of a signal to the kittens to be close to the mother and nurse. Also, the kittens' purr is a signal back to the mother that their kittens are getting their milk and are healthy. This is an extraordinary survival mechanism.

"Super-natural senses": There are several sensing abilities that scientists can not explain or categorize due to the several unique senses possessed by several animals and insects. Among them is the mosquito's remarkable sense of heat that leads them to their victims. Female mosquitoes follow have several, however, the most remarkable one is that they can sense temperature differences of less than 1/250th of a degree Fahrenheit. This amazing sense of temperature enables them to land on the warmest and best vein of blood for food.

Another sense scientists have difficulty explaining is that birds, bees, and some other creatures have magnetism. Just as a compass has a magnetic needle that points north, these creatures have natural magnets that help them migrate and find food by using the earth's magnetic field. They have natural tiny crystals of iron oxide, or also called magnetite, made front iron found in their blood. This enables these adorable creations to still find their way even when they can not see the sun.

People for many years have been puzzled how animals can sense an earthquake before its any "obvious" signs. One of the explanations is that animals, as described throughout the article, have unique and even, in some cases, better senses than human beings. Therefore, they are able to pick up on vibrations, sounds, and odors that humans physically can not, which may indicate to them that a disaster is about to occur.

A final note: Besides their senses, animals have a uniqueness and wondrous superiority over other animals the other with their physical attributes and characteristics. For example, some animals see or hear better than other animals, and some animals have unique physical attributes that other animals do not have. If you look at the beautiful and majestic kingdom of animals, you will find that each animal has a different beauty and awe that deserves much appreciation. This is a component that makes this world a fascinating and perfectly created one.

REFERENCES

  1. The National Wildlife Federation "What do Do Animals See, Hear, Smell, and Feel?" (1990).
  2. Ibid
  3. Ibid
  4. Roger A Caras, A Dog is Listening. Summit Books. 1992.
  5. The National Wildlife Federation" What do Do Animals See, Hear, Smell, and Feel?" (1990).
  6. Arline Bleecker, "Why Do Cats Sulk?" Globe Digests. 1998.