Age structure of the population of Anguis colchica orientalis (Reptilia, Anguidae) in the Talysh Mountains

Abstract

The paper presents the results of studying the age and growth of the eastern slow worm (Anguis colchica orientalis) in the upper reaches of the Tangeru River (Astara district, Republic of Azerbaijan). Lizards (8 males and 6 females) were caught from March to August in 2011–2019. Their age was determined by the number of lines of arrested growth (LAG) on the cross sections of the tail vertebrae. Sections of the mandibular bone were also examined in three dead individuals. The number of LAG on the mandibular bone sections and the caudal vertebra coincided. The studied animals were aged from 1 to 10 years. The average age of males and females was 4.86 and 5.33 years, respectively. More than half of the males (5 individuals) were 4–5 years old, and a third of the females (2 individuals) were six years old. The life expectancy after the first wintering in females and males was 6.70 (S = 0.84) and 5.93 years (S = 0.82), respectively. It is noted that age determination by cross-sections of the tail vertebrae in slow worms is possible and allows conducting studies on live lizards.