Distraction

Colors and patterns for distraction and escape:

Animals put a lot of time and energy trying to avoid being preyed upon, as examples they can camouflage themselves, or trying to make themselves less interesting, or advertise that they are distasteful or poisonous. But we all know that there are predators in these world, they live and they thrive, which means they must get food somehow. So what happens, if in despite of camouflage or other strategies to avoid attack, a predator spots something and decides to attack? Does this mean there is no escape? Of course there might be. Everyone knows that lots of animals have claws, teeth, and other defense mechanisms to fight of a predator physically, and some also chemically, like a bombarding beetle or a skunk. But did you also know that some animals rely on special colors and patterns as a distraction maneuver? Well, here are some ways animals can actually escape an attack without going into physical interactions and without being dangerous.

One of the most famous strategies is startle display(Wilson 2009). This means that an animal being attacked, suddenly show off some powerful and strong colors or patterns that will cause some kind of reaction in the predators behavior. Usually the flashing of color patterns causes the predator to hesitate for a moment, giving the prey some extra time, although maybe just a second or two, but enough to make an escape. Imagine that you are walking past a door, and someone is hiding behind it, and then suddenly jumps out in front of you shouting, the person doesn't need to be dangerous or be a treat to you at all, but you still will display some kind of reaction like freeze for a second or jump to the side to avoid that person. Basically, when something happens fast, which you don't see coming, your brain needs time to adjust and think about what happens and how you should react. This is kind of the same thing that happens when an animal suddenly goes from for example cryptic colors matching the background, til showing of all sorts of colors in a second. This is likely to be extra useful for animals that are slow or clumsy fliers, such as mantises and stick insects, because they need time to prepare for flight(Langridge 2009)

The peacock butterfly has cryptic colors when in a resting position, but if a threat appears, it will open its wings and flash its amazing colors.
From: <http://en.wikipedia.org/wiki/File:Inachis_io_bottom_side.jpg>, viewed 3 April 2014

 From: <http://www.warrenphotographic.co.uk/26028-peacock-butterfly>, viewed 3 April 2014.

Some patterns are proved to be especially good when it comes to creating a hesitation, and can even make the predator retreat. Eye spots are such patterns(Wilson 2009), they seem to be working great, and the pattern is found among many different animals, but is especially abundant among butterflies and moths. These eye spots are found on the wings, and is usually not visible when the butterfly or moth rests. But if in danger, the wings will be spread out, and suddenly a set of 'eyes' appear. The predator, in these cases often birds, will be very surprised and hesitate and might also pull back for a second. Sometimes the predator actually go for a retreat, and this is thought to be because the spots look like the eyes of an owl. And since owls are predators, many smaller animals then back off. Not only moths and butterflies display this pattern, also frogs, octopuses, stick insects, mantises and caterpillars display it, which seems to strengthen the theory of this strategy as being a successful one. It is obviously a feature that has convergently appeared in different groups of animals, and usually if something like this happens, it is because it has an advantage somehow.

This picture shows a Lo moth with eyespots similar to a big animal like an owl.
Picture from: < http://lepcurious.blogspot.com.au/2011/03/defenses-of-butterflies-eyespots.html > viewed 3 April 2014

Another trick some animals use, is displaying some kind of pattern or colors that look similar to a head or at least something that confuses the predator when it comes to which end is which(Wilson 2009). They might also conceal their real eyes in colors or stripes that makes the eyes less visible and this can create more confusion. Butterflies can for example have eyespots, something that looks like antenna, and a shape that may appear as a head on distance. The prinsiple behind this is to make the predator attack the side that is less vulnerable, and it also makes it possible to get away, because the predator will misjudge the direction the prey might be heading for an escape. Lots of animals can survive another day with a lost peace of their tail, but injuries on their anterior side will often be fatal(if they don't get eaten). Butterflies, fishes and centipedes are some animals that uses this technic to confuse predators. An animal that also uses this technic is a caterpillar that has eyespots making it look like a snakes head, fooling a predator in to believing that it is something entirely different than it actually is, which might scare a predator and make it retreat.

This picture show two caterpillars that has patterns on their head making them similar in appearance to a snake.
Picture from: < http://lepcurious.blogspot.com.au/2011/03/defenses-of-butterflies-eyespots.html > viewed 3 April 2014

This fish show a deflection display, drawing attention away from its head towards it's posterior end. Notice how the real eyes are goes almost unnoticed.
Picture from: <http://www.eplantscience.com/index/general_zoology/deflecting_an_attack.php>, viewed 3 April 2014

Although these technics mentioned seem to work in many cases, there are some drawbacks as well(Langridge 2009). If a predator don't use visual cues, like if the predator have bad/no vision or don't see all colors, it might not have any effect at all, so it comes down to which predator that actually hunts a particular prey.

Another effect you can find, is habituation, which means the predator is exposed to the flashing or the pattern several times and over time learn that this doesn't mean anything, or after a while learn to attack the real anterior end after several times of trial and failures. They get used to the display the prey puts up, and then the startling and frightening effect wears off. This means that it probably works best if the predator is a generalist.

Biography:

Wilson, C 2009, Animal behavior: Animal Defenses, Chelsea House, Infobase Publishing, United States.

Langridge, KV 2009, 'Cuttlefish use startle displays, but not against large predators',

Animal Behaviour, Vol.77, No.4, pp. 847-856, viewed 2 April 2014, < http://www.sciencedirect.com.elibrary.jcu.edu.au/ >.