- Each type of animal on Earth has evolved a range of senses and skills which allow it to live successfully in its environment. Many of these adaptations are very different from how humans have evolved, and compared to humans some of these adaptations feel like they belong in a superhero comic. Senses such as ultraviolet vision, extra color receptors, and echolocation are very hard for humans to imagine, yet are part of the everyday life of hundreds of species of animals.
- Alula Australis (stars.astro.illinois.edu)
ALULA AUSTRALIS (Xi Ursae Majoris). Ursa Major walks on legs identified by three pairs of close but unrelated stars that the ancient Arabs called the “springs (leaps) of the gazelle” that lie north of Leo Minor. From west to east they are Talitha and Kappa UMa, Tania Borealis and Australis, and Alula Borealis and Australis, the last a bright-end-fourth magnitude (3.78) star better known as Xi UMa.
- Dolphins have pretty good eyesight underwater. As their eyes are located on either side of their head, the dolphin’s range of vision is wider than a human’s, including being able to see objects located behind them.
- Pit vipers, pythons, and some boas have evolved a set of infrared sensitive receptors located in the nose of the snake. This allows them to see the body heat of prey species, much like night vision goggles.
- Dragonflies have compound eyes, which consist of a number of smaller visual units. While houseflies have 6000 compound eyes, dragonflies have up to 30,000. These units present the dragonfly with one picture, not 30,000 little ones.
- The colors humans see are detected by 3 color photoreceptors: red, blue, and green. Most species of dragonflies have many more color photoreceptors, up to 30 in fact. This means they are able to see colors humans cannot even imagine.
- As well as being able to see more colors than humans, dragonflies are able to see ultraviolet light. These rays of light from the sun are invisible to humans, however the dragonfly’s ability to see them helps it hunt its prey.
- Sharks have an unusual organ called the ampullae of Lorenzini. This organ detects electromagnetic fields emitted when animals move. It allows them to see prey hiding in the sand as well as locate swimming prey very efficiently.
- Despite popular opinion, dogs can actually see some color. They have 2 photoreceptors, blue and yellow. This means they are unable to see red and green, so finding a red ball on green grass is a very difficult task for a dog.
- Due to their incredible eyesight, dragonflies experience time differently than humans. Insects like flies and mosquitoes actually move very slowly for dragonflies. They can track a flying object and decide whether it is prey or not in less than 5 hundredths of a second.
- Dragonflies can also see through a polarizing filter, much like when humans wear polarized sunglasses. This ability allows them to view prey that may be hiding underwater even if sunlight is hitting the water.
- Sharks have a layer of crystals located behind their retinas called the tapetum lucidum that allows them to see around 10 times better than a human in low light. However, their depth is limited, as sharks can only see clearly about 50 feet ahead.
- The dragonfly eyes wrap almost all around its head, allowing it to see in all directions at once. With this 360 degree vision, it can see without moving its head. This includes behind it as well as underneath it.