Step by Step Examination of Tail Movement Sequences Reveals Functional Differentiation in Signals of Spotted Toad-Headed Agamas Phrynocephalus guttatus (Gmelin, 1789) (Reptilia: Agamidae)

Phrynocephalus lizards are well-known for their remarkable tail movements. Possible function of such displays still remains unclear. We present a new approach for studying displays of Phrynocephalus, analyzing them as a sequence of movements. Here, we describe four tail movements of Phrynocephalus guttatus on the basis of observations on the population from the surroundings of Astrakhan, Russia. We found that movement sequences are structured and two main stereotyped patterns for movement sequences are suggested to distinguish depending on function they perform — aggressive or submissive. We also explain differences in preference and structure of movement sequences for lizards of different sex and age groups from the point of their social status.