Are your spidey-senses tingling?
The world around us hosts an incredible diversity of environments. For a species to thrive in these environments, they must adapt. However, due to the constant battle between predator and prey, there is a race to detect and escape. Super senses of animals are the product of the antagonistic relationships formed in the natural world.
(Pores in a tiger sharks head which allows it to carry out 'electroperception'.)
Avoiding predators is crucial for survival. This is especially difficult when predators are very well camouflaged. Due to their environment in the bright white snow, reindeer have adapted to see in light on the ultraviolet (UV) spectrum. While many other mammals, including humans, would experience snow blindness – a type of temporary eye damage from the UV reflected by snow – reindeer are immune. This is essential if they are to spot predators and escape. As we all know, the Arctic has immense snow cover all year round. Because of this, the ground reflects a large amount of light back into the atmosphere. Due to the high reflectiveness of the Arctic, 90% of UV light is returned, compared to a few percent of snow free land. Therefore, excellent eyesight is imperative for reindeers. Predators and food sources absorb the UV, and so appear black against the snow. Reindeer are able to pick out camouflaged predators and find hidden food easily due to their super sight.
In the natural world, advance warning of the presence of predators could make the difference between life and death. Famous for their large ears, it isn’t surprising to learn that elephants are capable of infrasonic hearing. Infrasounds are defined as sounds which are below the frequencies detected by human hearing. The ability to hear such frequencies means that elephants have incredible hearing, and as a result are able to stay one step ahead of predators. An example of this is their ability to hear storms over 500km away. This is equivalent to someone in London listening to a storm in Edinburgh! Their abilities are not limited to super hearing; elephants are capable of creating low frequency noises as well. It is hypothesized that the noises are created in a similar way to human singing. Due to the large size of their larynx, or voice box, these noises are incredibly deep. Vibrations of the vocal cords are produced owing to a stream of air created from the lungs. These vibrations create pulses of low frequency sounds, which are used in herd communications.
Prey are often extremely well adapted at staying hidden from predators. Therefore, predators must be equally capable of detecting them. An interesting example of this is electroreception in sharks. Sharks, like many other aquatic hunters, have receptors or pores covering the head and snout region. These allow detection of electrical fields, which can be useful in a number of ways. This is an adaptation unique to aquatic life, because salt water is a better conductor of these fields than air. The mechanism allows sharks to orientate themselves to the Earth’s geomagnetic field, which may be instrumental in their success during migrations across oceans. In terms of finding prey, all moving prey gives off a weak electrical field that can be detected by the sharks, and allows the sharks to locate them. This system also attracts sharks to inanimate objects, especially metals. This is why sharks have been known to attack the metal cages used by divers.
Detecting prey is more problematic when other senses are less developed. This is common, due to a trade-off between the powers of senses. All species must compromise in their adaptations to an environment, because of energy costs. This is why we do not see any species with completely super senses, including humans. This is seen in snakes, which have relatively poor eyesight – but incredibly advanced olfactory systems. Snakes and many other animals possess an organ in their mouths called the Jacobson’s organ. It works by sensing chemicals in the air. A characteristic behaviour of snakes is protruding their tongue. This behaviour is effectively snakes “tasting the air” and collecting chemical particles, which are flicked on to the organ. These chemical cues allow them to effectively visualise their environment.
In the wild, super senses can make the difference between life and death. This is true for both predators and prey. Catching prey and gaining energy from food is as equally important as evading attack. The evolution of heightened senses is due to this continual race between hunted and hunter.