Figure 1.

Bufo luetkenii exhibit dramatic sexual dimorphism and dynamic colour change. (a) A typical male B. luetkenii photographed at the edge of a mating aggregation in the early morning. (b) A typical male in amplexus with a female, photographed later on the same day. (c) Average reflectance spectra for the dorsal surface of 10 males measured early in the morning (yellow solid line) and the same 10 males measured 4 h later (dashed brown line). (d) Average reflectance spectra for the dorsal surface of 30 males (solid blue line) and 10 females (dashed red line). Vertical bars show s.e.