Animal coloration is influenced by a multitude of factors including the chemical and physical properties of pigments, skin, feathers and scales; the biophysics of light; the visual systems and cognitive abilities of predators, prey, mates and rivals; and the development, behaviour, life-history and ecology of animals. We need to study it from the scale of particles and molecules to communities and landscapes.
In the Stuart-Fox Lab, we primarily study the evolution and diversity of animal coloration because it provides rich insight into biological processes generating current diversity. This page provides details of our research areas.
1. Adaptive significance of colour change
Stemming from four years working on chameleons in South Africa, I am fascinated by the function, mechanisms and evolution of colour change.
Current project: “The adaptive significance of animal-visible and near-infrared colour change in bearded dragon lizards”
We are studying the extent of colour change in these different parts of the spectrum, the relationship between them and their adaptive significance.
Primary investigators: Viviana Cadena (Postdoctoral fellow), Katie Smith (PhD student)
Collaborators: John Endler (Deakin University)
Warren Porter (University of Wisconsin, Madison)
Michael Kearney (University of Melbourne)
Funding: Australian Research Council (DP120100105)
2. Colour polymorphism and speciation
Colour polymorphic species, in which multiple, genetically determined, discrete colour forms coexist within an interbreeding population, have provided many insights into evolutionary processes. Theory suggests that the processes generating and maintaining the different colour forms can promote speciation. We recently showed that in birds, colour polymorphism is associated with increased speciation rates (Hugall and Stuart-Fox 2012 Nature).
Current project: “Polymorphism and speciation”
We are studying geographic variation in polymorphism among populations as well as processes maintaining polymorphism within populations of the tawny dragon lizard.
Primary investigators: Claire McLean (Post-doc), Maddy Yewers (PhD student)
Collaborators: Adnan Moussalli (Museum Victoria)
Sarah Pryke (Australian National University)
Funding: Australian Research Council (DP1092908)
More information about our research on colour change can be found in this post:
– Colour variation speeds up evolution
3. Visual ecology and signalling
What are the adaptive functions of animal coloration and what processes generate the spectacular colour differences that often characterise adaptive radiations? A focus of our research is how the environment (including human habitat modification) influences the kinds of colour patterns animals use for both communication and camouflage.
Current project: “Environmental effects on signal design in gliding lizards”
Primary investigator: Danielle Klomp (PhD student)
Collaborators: Terry Ord (UNSW)
Funding: National Geographic Society
More information about our research on visual ecology and signalling can be found in this post:
– Colour change evolved for communication
4. Sexual selection, female ornamentation and mating strategies
An interest in visual signals necessarily entails an interest in sexual selection. We have explored a range of topics in this general area including the dynamics of male-male contests; the evolution of sexual dimorphism; the costs of copulation; the evolution of multiple mating; and the evolution of conspicuous signals and behaviours used by females to avoid unwanted courtship and copulation attempts. One example of this is our research into female Lake Eyre dragons (Ctenophorus maculosus), who deter male courtship by lying on their backs displaying prominent orange patches on their belly and throat [see People and Publications pages for more detail on specific projects].
5. Macroevolution and comparative analyses
We complement studies of micro-evolutionary processes with studies identifying macro-evolutionary patterns. We have used phylogenetic comparative approaches to address diverse topics, including the correlates of species richness, the evolution of sexual dimorphism in body size and ornamentation, the evolution of signal complexity and the relationship between sexual selection and ecological generalism [see People and Publications pages for more detail on specific projects].