Age structure and growth of Bufo verrucosissimus (Amphibia, Anura, Bufonidae) in the Caucasian State Nature Biosphere Reserve (Russia) at the end of the XX century

Abstract

Bufo verrucosissimus is an endangered species in the Russian Federation. One of the largest protected areas where B. verrucosissimus is preserved is the Caucasian State Nature Biosphere Reserve. The paper presents data on age structure and growth of B. verrucosissimus collected in the Caucasian State Nature Biosphere Reserve in 1987–1990 and stored in the collection of Sochi National Park. The age of 16 females and 51 males was determined using the method of skeletochronology. The age of adult females was 6–10 years (on average 7.9 years), and males 2–9 years (on average 5.8 years). Females were statistically significantly superior to males in average age. In terms of body length, significant differences between males and females where noted in groups of seven- and ten-year-old animals. The body length of studied animals (60.8–116.4 mm for females and 61.2–86.3 mm for males) corresponds to the size of adult toads from other localities in the North Caucasus. Females grow evenly throughout their lives, while the growth of males slows down significantly after reaching puberty. Males were able to reach the maximum body length faster than females (the growth coefficient was 0.722 for males and 0.163 for females). According to the von Bertalanffy equation, the maximum possible body length was 130.9 mm for females and 74.6 mm for males.