Animal coloration

Animal colouration is the general appearance of an animal resulting from the reflection or emission of light from its surfaces. Some animals are brightly coloured, while others are hard to see. In some species, such as the peafowl, the male has strong patterns, conspicuous colours and is iridescent, while the female is far less visible. There are several separate reasons why animals have evolved colours. Camouflage enables an animal to remain hidden from view. Animals use colour to advertise services such as cleaning to animals of other species; to signal their sexual status to other members of the same species; and in mimicry, taking advantage of the warning coloration of another species. Some animals use flashes of colour to divert attacks by startling predators. Zebras may possibly use motion dazzle, confusing a predator's attack by moving a bold pattern rapidly. Some animals are coloured for physical protection, with pigments in the skin to protect against sunburn, while some frogs can lighten or darken their skin for temperature regulation. Finally, animals can be coloured incidentally. For example, blood is red because the haem pigment needed to carry oxygen is red. Animals coloured in these ways can have striking natural patterns. Animals produce colour in both direct and indirect ways. Direct production occurs through the presence of visible coloured cells known as pigment which are particles of coloured material such as freckles. Indirect production occurs by virtue of cells known as chromatophores which are pigment-containing cells such as hair follicles. The distribution of the pigment particles in the chromatophores can change under hormonal or neuronal control. For fishes it has been demonstrated that chromatophores may respond directly to environmental stimuli like visible light, UV-radiation, temperature, pH, chemicals, etc. colour change helps individuals in becoming more or less visible and is important in agonistic displays and in camouflage.

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related concepts (71)

Related lectures (11)

Countershading

Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the top or upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish, and insects, both in predators and in prey. When light falls from above on a uniformly coloured three-dimensional object such as a sphere, it makes the upper side appear lighter and the underside darker, grading from one to the other.

Eyespot (mimicry)

An eyespot (sometimes ocellus) is an eye-like marking. They are found in butterflies, reptiles, cats, birds and fish. Eyespots could be explained in at least three different ways. They may be a form of mimicry in which a spot on the body of an animal resembles an eye of a different animal, to deceive potential predator or prey species. They may be a form of self-mimicry, to draw a predator's attention away from the prey's most vulnerable body parts. Or they may serve to make the prey appear inedible or dangerous.

Albinism

Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and reddish pink or blue eyes. Individuals with the condition are referred to as albinos. Varied use and interpretation of the terms mean that written reports of albinistic animals can be difficult to verify. Albinism can reduce the survivability of an animal; for example, it has been suggested that albino alligators have an average survival span of only 24 hours due to the lack of protection from UV radiation and their lack of camouflage to avoid predators.

Animal cell mechanics ME-480: Mechanobiology: how mechanics regulate life

Explores the mechanics of animal cells, including actin assembly and retrograde flow.

Reflection at Metal Surfaces and Optical Constants of Metals PHYS-201(d): General physics: electromagnetism

Explores reflection at metal surfaces and optical constants of metals.

Introduction to Biology: Fundamentals and Sources ENV-103: Biology

Introduces fundamental aspects of living beings, biochemistry, and cell biology, emphasizing the importance of macromolecules, molecular evolution, and metabolism.