Background matching

Tonkin bug-eyed frog camouflaged on moss
The tonkin bug-eyed frog matches its mossy habitat very well

Most people associate camouflage with colouration and patterning that resembles the environment in which an animal is found. This means that prey or predators may often overlook an individual unless searching very thoroughly. Animals that lie on the sea bed often have a sand-like colouration and pattern, for example the eastern angel shark, while forest species such as the kakapo often have mottled and green or brown colouration to match the lighting and colours of the habitat.

Many species in cool or seasonal habitats have different summer and winter colouration to reflect the changing environment. For example, the snowshoe hare has a white coat in winter to camouflage itself against the snow, but has a brown coat in spring and summer when white would make it very obvious.

Some animals take this form of camouflage to the extreme and may be transparent or semi-transparent which allows them to blend into the background in different habitats or from many perspectives.

Disruptive camouflage

Bengal tiger resting in grass
The tiger’s striped pattern makes seeing its outline more difficult

A different way in which an animal’s pattern and colouring can conceal it from predators, or allow it to trick prey, is disruptive camouflage. This form of camouflage involves a pattern of light and dark patches, stripes or spots, which often appear to make the individual more obvious, not less. However, these patterns can help to disrupt the outline or shape of the animal, which can prevent an observer from recognising it as a threat or potential prey item. For example, the stripes of a tiger or the pattern of a camouflage grouper can make it harder to see the animal's outline.

Mimicry

Leaf-tailed gecko on forest floor
The satanic leaf-tailed gecko closely resembles a dead leaf

Another way for an animal to avoid being recognised is to mimic the appearance of another object or species. For instance, many animals mimic the appearance of background material such as dead leaves. An excellent example of this type of mimicry is the satanic leaf-tailed gecko. Other animals mimic dangerous species, for example the wasp hoverfly looks similar in appearance to a wasp and the cuckoo may mimic the Eurasian sparrowhawk. Some species even mimic behaviour as well as appearance. For example, some stick insects and mantises sway to look like sticks moving in the wind, although this motion may also help them to see prey.

Adaptive camouflage

camouflaged Common octopus resting
The common octopus can change colour and shape to blend into its environment

Background matching camouflage can sometime be quite restrictive. For instance, if an individual moves from one habitat to another it may no longer blend into the background. Some species get around this problem with active or adaptive camouflage, changing their colour, pattern, shape and texture in response to their environment and needs.

Chameleons are well known for being able to change their colour and pattern within minutes using pigments in their skin. However, cuttlefish, squid, octopuses, and flounders probably have some of the best active camouflage. Changing colours and patterns almost instantly, they can even create moving flashing displays on their skin. This ability is not only used to camouflage the individual, but is also used in communication.

Octopuses are so flexible that they can combine mimicry with this active camouflage, allowing them to take both the shape and colour of objects around them.

Other types of camouflage

Plains zebra herd running away from the Mara River
One theory is that a zebra’s stripes may disrupt the observer’s estimation of speed, direction, or size

Motion dazzle

One problem with many of the other camouflage mechanisms is that once an individual moves it becomes easy to see. However, motion dazzle camouflage, which uses light and dark patterns and stripes, may be able to disguise the direction, speed, or size of a moving animal and help to prevent its capture. One group of animals often said to use motion dazzle camouflage is zebras, although there are also many other suggestions for the reasons behind the zebra’s striped pattern. Another species that may use motion dazzle camouflage is the adder, whose zig-zag pattern and quick movements may make it harder to catch.

Countershading

A number of species use countershading as a form of camouflage, which typically involves the animal being darker on top and paler underneath. This helps an animal to blend in with a darker background such as the ground or sea floor when viewed from above, or to blend in with the paler, brighter sky when viewed from below.