Background artists: nature’s most successful camouflage tricks
The four most notable mechanisms of camouflage, and some of the animals whose lives depend on them. By Jana Howden.
For many creatures in the animal kingdom, camouflage is a matter of life and death. Whether the hunter or the hunted, camouflage has been observed in countless species, a way to blend into the environment to avoid being spotted by predators, or to stalk prey unnoticed. We take a look at four of the notable mechanisms of camouflage, and some of the animals whose lives depend on them.
Colour matching is one of nature’s most basic methods of camouflage. Animals use colour matching to avoid detection by visually resembling their background. For some animals, like the arctic fox (Vulpes lagopus), the changing of the seasons can see their colour matching change too. During the winter, the foxes develop a white coat, allowing them to blend into the frozen arctic environment. When the snow melts away, the winter camouflage goes too, with the white coat replaced by a grey or brown coat.
Colour matching can be tough for some marine animals, as their background colour changes whether being viewed from above or below. To get around this issue, many species exhibit countershading, in which the upper side of the body is dark and the under side is light. When viewed from below, the light-coloured underside better matches the bright surface of the ocean. When when viewed from above, a dark upper side is harder to see against the blackness of the ocean depths. Even the whale shark (Rhincodon typus), which as the largest of all fish species has relatively few predators, uses this type of camouflage.
While striking patterns and shapes are normally thought to stand out from the crowd, they can also be a means of camouflage. It might seem counterintuitive, but some animals use this bold mechanism – known as disruptive colouration – to better blend into their surroundings. Patterns, spots and stripes can help break up an animal’s appearance and body outline, making them harder to detect.
Looking at the stand-out spots of a leopard (Panthera pardus), you would be forgiven for thinking camouflage was not part of this big cat’s agenda. But living in dense habitats with areas of patchy shadows, a leopard’s spots help it blend into its environment when attempting to launch undetected attacks.
Disruptive patterns can also function by leading predators astray, causing them to misidentify their target. The foureye butterflyfish (Chaetodon capistratus) has lines on its body that break up background colour, as well as a band running through its eye, making it difficult for predators to identify the fish’s head.
It is said that imitation is the sincerest form of flattery, but for some animals it is also critical to their survival. Mimicry involves displaying similarities to another object or creature, whether in appearance, behaviour or even scent.
Native to the waters of southern Australia, the curious appendages of the leafy seadragon (Phycodurus eques) allow this fish to mimic its marine environment. With a body size not much bigger than a teacup, the leafy sea dragon’s dainty accessories lets it blend in with the kelp-covered rocky reefs it calls home.
Some animals mimic the appearance of other more dangerous animals when their own defence mechanisms are lacking. The caterpillar of the spicebush swallowtail butterfly (Papilio Troilus) resembles a snake, which helps to ward off predators.
While invisibility might be considered the stuff of science fiction, for some animals it is not far from reality. Animals that exhibit active camouflage are able to change their colour almost immediately in response to their background environment.
The day octopus (Octopus cyanea) can rapidly produce a range of colour patterns to match its ocean environment. Pigment-containing cells in the animal’s skin known as chromatophores can be modified to create a variety of colours.
Like the day octopus, the broadclub cuttlefish (Sepia latimanus) is also capable of rapid colour and texture change. Bands of circular muscle in the skin of these molluscs allows them to create intricate shapes that can even match the appearance of rocks and seaweed.