AGE STRUCTURE AND GROWTH OF THE SPOTTED TOADHEAD AGAMA, PHRYNOCEPHALUS GUTTATUS (REPTILIA, SAURIA, AGAMIDAE) IN TEREK SAND MASSIF (EASTERN CISCAUCASIA)

Abstract

Background. The spotted toadheaded agama is one of the most widely distributed species of the genus. Until now, attempts have been made to determine the age and growth of this lizard only by selecting of size groups or individual tagging. The purpose of the study is to estimate the age structure of the population and the growth characteristics of the spotted toad-head agama in Terek Sand Massif using the method of skeletochronology. Materials and methods. 81 lizards were caught in the vicinity of the Peschaniy settlement in Kursk district Stavropol Krai. The body length (SVL) and tail length (LT) were measured. To determine the age with skeletochronology method, the phalange of third finger from hind right limb was used. After these procedures, the animals were released into the nature. Results. Most of the captured lizards were young animals (39,5 %) and adult males (39,5 %). Adult females were 21,0 %. In accordance to the age determined by the method of skeletochronology, there were juveniles (39,5 %), yearlings (39,5 %), two-year-olds (19,8 %) and three-year-olds (1,2 %). In the group of adult males, the absolute majority were yearlings (96,9 %), and there was only one two-year-old lizard (3,1 %). In adult females, the majority of individuals were two years old (88,2 %) and only one specimen was one year (5,9 %) and three years (5,9 %) old. The length of lizard’s body at different age was statistically significantly different. The largest sizes had the oldest animals. Conclusions. Lizards of this species grow intensively throughout their lives, differing well in body length in different age groups. For this reason, it is possible to distinguish individuals of different age groups by size with high confidence.

Keywords

• the spotted toadhead agama
• phrynocephalus guttatus
• age
• growth
• skeletochronology
• terek sand massif
• eastern ciscaucasia