The colour of success: does female mate choice rely on male colour change in the chameleon Furcifer pardalis?

Colour change is involved in various functions ranging from thermo- and hydroregulation to camouflage and communication. The role of colour change in communication has received increased attention over the past few decades, yet has been studied predominantly in the context of intrasexual competition. Here, we investigate the role of colour change in mate choice in an animal that can change its colour, the panther chameleon (Furcifer pardalis). We conducted behavioural experiments and colour analysis to investigate whether colour changes, including in the UV range, are involved in mate choice. This study presents evidence of female mate choice for specific aspects of colour change in courting males, both in the visible (i.e. human visible range: 400-700 nm) and the UV range. Females chose males exhibiting more saturation changes regardless of the body region and spectral range. In addition, females chose males showing fewer brightness changes at the level of the lateral line and males showing lower hue changes at the level of the bands and the interbands, in the visible range. At UV wavelengths, selected males showed more brightness changes and higher maximum brightness. These results suggest that male colour change is important in female mate choice in the panther chameleon.