It can genuinely take forever to study everything about animals.
Well, practically and more honestly, there is no way we can learn everything about animals, and there are two reasons for that. The first is there is no such thing as forever on Earth. Everything will eventually come to an end.
Secondly, and more importantly, we only know a small percentage of all the organisms on our planet. While scientists estimate there are about 8.7 million species, they only know about a little over one million of those. If you do the maths, at least 6.5 million species are still a complete mystery to us.
But who said we need to learn everything about animals? If we are seeking knowledge, astonishment and amusement, we can get that by learning about animals’ phenomenal abilities that were made possible by their fantastic organs. That is why we have dedicated this article series to demonstrating some amazing organs that many extraordinary animals we are familiar with possess.
In the previous four episodes, we discussed many examples of these majestic organs, such as the cat’s sensitive whiskers, the elephant’s trunk, and the kangaroo’s fantastic pouch. We also learned how the octopus uses its eight limbs and why they have thousands of suckers, in addition to the great white shark’s teeth and the longcomb sawfish.
In this fifth and last article, we are going to highlight three more organs as miraculous as the ones we just mentioned above. So let’s go ahead and finish our journey with the owl’s neck, the hammerhead shark’s hammer-like head, and the hawk’s eyes.
In most cultures, owls represent wisdom. This is not a modern trend, just like how avocados are now directly tied to a healthy lifestyle. Owls representing wisdom go as far back as ancient Greece. In Greek mythology, the goddess of wisdom of the city of Athens was called Athena or Minerva, and she was symbolised by a wide-eyed owl.
That aside, owls look a little (or a lot!) scary to many people. They are always associated with the dark, thanks to being only active during the night, which also gives them an aura of mystery and obscurity. But owls are super distinct as well. They have strong broad wings, flat faces, terrifyingly deep eyes, and sharp curved beaks ready to bite and tear. They are so powerful that they can fight and scare a wolf.
But one organ that is much more majestic and almost shared among all 200 species of owls is their rotating necks.
While we, humans, can turn our heads left to right covering a 180° range, owls are much more flexible. They can move their heads in a broader range of 270°, and this is made possible by their mighty necks.
Before we understand how this happens, let’s first know why. What purpose is this high range of head movement serving?
The owl’s eyesight is generally good in daylight and even better in the dark. But it is the anatomy of the eyes that does not really support full vision. Owls cannot move their eyeballs as we do. A human standing still, stabilising their head, can move their eyeballs to scan a range of 180° horizontally as well as vertically. In order to see a wider range, they can then move their heads and even their entire bodies.
But the owls’ eyeballs are fixed in the eye sockets making the owls see only in front of them. So in order to see around, owls have to rotate their heads. Accordingly, necks needed to become flexible, and they did.
Well, the owls’ has become so incredibly flexible that they can turn 270°.
Humans have seven vertebrae in their necks. Giraffes, whose necks measure up to two metres, also have seven cervical vertebrae. But these are elongated, with each measuring 25 cm. Owls, on the other hand, have a total of 14 vertebrae in the necks.
OK. We know for sure that more cervical vertebrae translate to more flexibility. But are 14 vertebrae enough for such a high range of movement that the owl’s neck is capable of?
Well, the answer is yes as long as the neck is supported by another anatomical feature that makes rotation possible.
So what is that other anatomical feature that the owl has? Well, to understand it, we need to go over some anatomy basics.
In the body, there is an organ called the heart. Connected to the heart is the aorta. The aorta is the body’s largest blood vessel which takes blood from the heart and passes it out to every other organ and part of the body.
The aorta itself branches out to many arteries. Two of these are called the subclavian arteries, from which the vertebral arteries emerge. The vertebral arteries, yes, have something to do with the vertebrae. They run through the spinal cord and join together at the end of the skull. Then they branch out again into the two carotid arteries that enter the brain to supply it with blood.
This junction between the vertebral arteries and carotid arteries is large enough to allow the owl to rotate its head without cutting off the blood supply to the brain.
Another thing that makes this high range of movement possible is related to the vertebrae themselves. The vertebral arteries move through small holes in the vertebrae called the foramina. In humans, the diameter of the foramina is the same as the vertebral arteries, making the neck movement relatively limited.
But in owls, the diameter of the foramina is 10 times that of the vertebral arteries. This provides more space and freedom of movement, allowing the owl to rotate its head up to 270° without cutting off the blood supply to the brain.
Is that not majestic?
In parts three and four of this series, we tackled two very distinctive kinds of sharks. The first one was the great white shark. It is famous for its incredible ectodermal organ, the sharp, movable teeth. These were specially designed to cut big prey into smaller pieces. What is majestic about these teeth is that they fall and get replaced by others, making the shark have up to 35,000 teeth throughout its lifetime.
In part four, we studied the longcomb shark. This species’ majestic organ was the extended, flattened nose with teeth on the right and left sides just like those of a comb. This unique shark uses its saw to forage and defend itself. Unlike the great white shark’s replaceable teeth, the longcomb shark’s teeth are never replaced when lost.
Besides these two shark species, the rest of the shark family is pretty distinct too. And in this very section, we are tackling another different, a little bizarre-looking species. That is the hammerhead shark.
Oh, you are not familiar with it?
Let’s get back to Disney’s Finding Nemo once again. Do you remember Bruce’s two friends? Yes, the hammerhead shark was the one called Anchor. Its strange hammer-like head makes it very recognisable.
Anchor has a flattened head that is extended but not forward like the longcomb shark but instead to the sides, resulting in a hammer shape.
So how did this hammer-like head evolve? And for what purpose?
Well, such a thing was kind of hard to determine because there is no way to study this shark or any other shark species closely. That is simply because sharks do not really have bones. So when they die, they dissolve into the water leaving behind only a few small organs that fossilise. In the case of the great white shark, the teeth are left behind. But in the hammerhead shark, it is the eyes that fossilise.
Only from studying those little eye fossils could scientists suggest that the hammerhead shark evolved from an ancestor that lived in the ocean about 20 million years ago, and it had a hammer-like head as well. According to the DNA tests, those millions of years of evolution contributed to varying the sizes and shapes of the head, which allowed the classification of the hammerhead shark into eight different species.
So why is this hammer-like head special anyway?
We know that evolution mainly happens to improve the lives of animals. It simply allows them to survive and flourish in their natural habitat. Well, this also applies to the hammerhead shark. Scientists believe that it evolved such an odd-looking head to mainly improve vision and look for food more efficiently.
As the eyes are found on the right and left sides of the head, this shark is able to move them up and down, covering a vertical field of 360°. That means this fish is able to see above and below at the same time. The hammerhead shark can also direct both eyes toward one thing to see it more clearly.
Like many other shark species, this hammerhead fish can detect the electric field generated by other marine creatures. This ability enables it to find its preferred food more efficiently. What is special about the hammerhead shark anyways is that its electric field detection ability is much more advanced thanks to its extended head.
For sharks to detect the electric field, they were equipped with electric receptors. This does make sense. Well, the hammerhead shark has more electric receptors than any other shark species.
In addition, these electric receptors are distributed over the large area of the head. This enables the fish to quickly scan a wider area, detect more electric signals from many directions and promptly and accurately locate prey.
Thanks to this incredibly advanced head, this fish is even able to find prey buried under the seabed.
Just like many animals are predators, many birds are predators too. They are called birds of prey or raptors. Owls are powerful birds of prey, and hawks are too. Previously, we have made a story about hawks and we are focusing on them again here.
Hawks, all 270 different species, have many excellent abilities, which made humans use them in a sport called falconry, where humans hunt using trained hawks.
The hawks’ exceptional hunting abilities are enabled by their excellent body organs, from their powerful wings that allow fast flight and deep diving, the strong, curved claws that can carry and fly with large prey, to their pointed beaks, the hawks’ natural biting and tearing machine, and their highly developed eyes that provide sharp eyesight.
Well, it is the eyesight we are tackling in this very section.
The hawk’s eyesight is better than the eyesight of any animal in the entire world as well as us, the permits of the permits.
The hawk also has the ability to see in colour. Such a thing is not available for many other animals or birds. What is also exceptional is that hawks can see ultraviolet light. Besides the fact that we cannot see this light, it is even dangerous to our eyes and can truly damage them.
This great ability to see colours allows the hawk to distinguish or recognise the different shades of one colour. This highly intensifies the raptor’s hunting abilities. When it flies over a certain area, it can better navigate and explore it, easily locate the prey and distinguish it from the surroundings.
If you think about it, seeing in colour is highly beneficial for the hawk’s diurnal nature—this means the hawk is active during the day. If this raptor were a night guy like the owl, such an advantage would be for no use.
Anyways.
This great eyesight is enabled by the hawk’s great eyes that are mounted on each side of the face. This makes the field of vision very wide, actually up to 280°. The hawk’s eyes also have sufficient binocular vision. That means they can be directed toward the same thing to spot it with higher focus, and that thing is, for sure, prey.
In addition, hawks enjoy excellent depth of vision. They can determine the distance between them and the prey and then dive directly towards it to catch it. Furthermore, they see very clearly at long distances.
All of this is allowed by the exceptional anatomy of the hawk’s mighty organ, the eyes.
Simply put, we, hawks and many other birds and animals have a tissue in the eye called the retina. The retina has photoreceptors responsible for detecting the light, converting it into electrical signals, and sending these signals to the brain. The brain, in turn, forms the image of what we just saw.
Miraculously, this happens in mere nanoseconds!
The more photoreceptors there are in the retina, the more accurate the vision is. So the reason why hawks have the best sight in the animal world is that their retinas are the most developed. Compared to our retinas that have 200,000 photoreceptors per one square millimetre, hawks have up to one million per the same area.
Here we get to the end of the fifth and last chapter of this article series, where we explored majestic organs found in extraordinary animals.
In this very article, we discussed three different organs, beginning with the owl’s incredible rotating neck that can move in a wide range of 270°. This is allowed by the amazing anatomy of the owl’s cervical vertebrae, which allow the owl to move its head without cutting off the blood supply to the brain.
Then we moved to the second incredible organ, the hammerhead shark’s odd-looking head. This head looks odd because it is extended on both sides like a hammer and has the eyes mounted on each side. This hammer-like head provides the shark with a 360° vertical vision field. It also has many electric receptors that enable this mighty fish to detect electric fields and precisely locate prey.
Finally, we finished by exploring the fantastic hawk’s eyes. Thanks to a significantly developed retina, hawks can see in colour and their eyes can detect ultraviolet light, which we ourselves cannot detect. Hawks can also see at great distances.
We hope you liked this article as much as we enjoyed writing it for you. Now that you know 12 majestic organs found and 12 extraordinary animals, you can move on and learn about many other great things by checking the World Around Us on our website.
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