Skip to main content

Unit information: The Biology of Colour in 2020/21

Unit name The Biology of Colour
Unit code BIOL30014
Credit points 10
Level of study H/6
Teaching block(s) Teaching Block 4 (weeks 1-24)
Unit director Dr. How
Open unit status Not open

Recommended: Sensory Biology (Y2), Behavioural Ecology (Y2), Green Planet (Y2)



School/department School of Biological Sciences
Faculty Faculty of Life Sciences


Historically, the external appearance of organisms has been mainly of taxonomic or aesthetic interest to humans. Only recently has colouration been investigated from the standpoint of production, perception and function, tackling questions such as how and why colour patterns have evolved across nature, how do sensory systems detect and process this information, and how are colour patterns produced.

The forces that drive the evolution of colouration are diverse, including the need to communicate or to hide from others, the need to defend against the elements, and a variety of others that we are only just appreciating. A complete understanding of colouration involves quantifying colour, sensory limitations, and uncovering the diverse evolutionary forces shaping colouration in nature.

In this unit, we survey this rapidly developing field from these multiple perspectives, extending principles covered in second year units to understand issues as diverse as sexually selected ornamentation; colouration involved in anti-parasite and antipredator defence; leaf, fruit and flower colour; colouration as a deceptive mechanism; and the import of colour for humans in the sports arena. Throughout the unit we particularly emphasise the need to understand receiver sensory systems, comparative aspects of colouration in nature, and how methodology has been used to address the study of colouration.

While most units take a ‘field’ and study diverse topics within that field using similar methods, our unit takes a topic and studies it in radically different ways, promoting a recognised strength of the University of Bristol.

Intended learning outcomes

By the end of this unit, students will be able to:

1. Describe modes of colour production in the natural world;

2. Define how animals and plants sense light and describe the role of sensory systems in the evolution of colouration;

3. Describe and explain how signalling, protective colouration and environmental factors drive the evolution of colouration in animals and plants;

4. Illustrate how research methods can be applied at various spatial scales (ranging from photons to ecological networks) to study animal and plant colouration.

5. Evaluate the strength of evidence presented in scientific papers relevant to the theories of colouration.

6. Apply knowledge from the above, supported by examples from the literature, to propose novel hypotheses and experiments.

Teaching details

Lectures, directed reading, research and/or problem-solving activities; and independent study.

Assessment Details

Summative written assessment, with one essay question to be selected from a choice of two.

Reading and References


This is a fast-moving field, taught mainly from the primary literature, and so many of the key papers will change year-on-year. Nonetheless a good introduction to all aspects of the field can be found in

Marshall, N.J. (2010) Why are animals colourful? Sex and violence, seeing and signals. Colour: Design and Creativity. 8: 1-8.

Caro, T., Stoddard, M.C. and Stuart-Fox, D., (2017). Animal coloration: production, perception, function and application. Theme issue of Philosophical Transactions of the Royal Society B. (15 papers on many aspect of colouration)

Kelber, A, Vorobyev, M, and Osorio, D (2003) Animal colour vision – behavioural tests and physiological concepts. Biological reviews. 78: 81-118.

Further Reading:

As a summary of colouration in nature and society:

  • Cuthill IC, Allen WL, Arbuckle K, Caspers B, Chaplin G, Hauber ME, Hill GE, Jablonski NG, Jiggins CD, Kelber A, Mappes J, Marshall J, Merrill R, Osorio D, Prum R, Roberts NW, Roulin A, Rowland HM, Sherratt TN, Skelhorn J, Speed MP, Stevens M, Stoddard MC, Stuart-Fox D, Talas L, Tibbetts E, Caro T (2017) The biology of color. Science 357:eaan0221
  • Cronin, T.W., Johnsen, S., Marshall, N.J., and Warrant, E.J. 2014. Visual Ecology. Princeton University Press