Is ultra-violet fluorescence a trait related to breeding in the mongolian racerunner (Eremias argus; lacertidae, reptilia)?

Ornamental traits such as ultraviolet (UV) fluorescence and reflectance can provide reliable signals indicating the bearer’s condition as a potential mate. UV fluorescence is widely found in nature and used for multiple functions, such as indicating female maturity in arachnids and acting as a signal enhancer in many insects. Lizards can display a broad range of colours, but the function of some of their ornamental traits remains unclear. Here, we report the presence of UV fluorescence in female Eremias argus specimens, a small lizard inhabiting Mongolia, China and the Korean Peninsula. Based on our observation, combined with the literature on the breeding behaviour of the species, we provide two hypotheses, assigning the use of UV fluorescence to: 1) an indicator of females’ body conditions and 2) signal efficacy backup. To verify our hypotheses, we suggest a protocol with three serial trials under low light and enhanced UV light conditions.