The European common spadefoot, Pelobates fuscus, has not been observed in Moscow since the end of the 20th century. The species is listed in the Red Data Book of Moscow (2017) as endangered or completely extinct. The paper presents new findings of P. fuscus on the territory of the city, namely, in the “Moskvoretskiy” Natural-Historical Park and the “Kosinskiy” Natural-Historical Park in August 2020.

The paper discusses the finding of a Meadow lizard (Darevskia praticola praticola) melanist in the Stavropol Region. Information about the clutch and offspring from this female melanist is given.

The daily diet of in local populations in the Khoper river floodplain is considered. The absence of gender differences in their daily diet is shown. Most of prey is made up of animals weighing 10–25 mg and having body lengths of 8–18 mm. Hymenoptera (70.8%) and Coleoptera (52.1%) predominate by the number of specimens and by biomass, respectively. The number of daily caught invertebrates usually does not exceed 15. The lowest feed consumption is in April and October, while the highest one is in the summer months.

Histological features of the dorsal (DS), throat (TS) and tail skins (caudal skin, CS) were examined in Salamandrella keyserlingii females of the aquatic and terrestrial morphotypes. Using histological and statistical methods, sexual differences in the relative areas of epidermis, strata compactum and spongiosum, connective tissue in the whole, granular and mucous glands were measured. In the aquatic phase, males, in comparison with females, have larger areas of the connective tissue in TS and DS, a larger area of the epidermis in CS, but smaller areas of the granular glands in the upper part of CS and elements of the connective tissue in the lower part of CS. In the terrestrial phase, sexual differences were weakly expressed. Females, in comparison with males, have larger areas of the connective tissue in the whole and its stratum spongiosum in the upper part of CS. Elements of the connective tissue made the greatest contribution to the formation of sexual differences of the skin in S. keyselingii.

The paper presents the results of our long-term (August 2014–October 2016) observations of changes in some properties of the poisonous secretion of eastern steppe vipers of the nominative subspecies Vipera renardi renardi (Christoph, 1861) during their postembryonic ontogenesis. The poisonous secretion of newborn vipers differed from the venom of adult snakes by an increased protease activity and the absence of any L-amino acid oxidase activity; all newborns had colorless venom. Adults produce venom either colorless, where no L-amino acid oxidase activity is detected, or yellow, where it is detected. It was found that the enzymatic activity of the venom of young vipers between their first and second winterings corresponded to the level of adults. After the second wintering, young vipers showed statistically insignificant seasonal changes in the activity of proteases and L-amino acid oxidase.

The paper discusses the distribution of Nikolsky’s pitviper, Gloydius caucasicus, in Azerbaijan. According to the authors’ own research results, literature data and museum collections, 32 findings of this species in the Jalilabad (1 locality), Yardymly (11 localities), Lerik (10 localities), Lenkoran (10 localities) and Astara (5 localities) administrative districts are presented. All the known findings of the pitviper are located within 10–1,980 m above sea level in the Lenkoran lowland, the mountain forest belt of the Talysh Mountains, as well as in the mountain-xerophytic steppe of the Yardymly, Deman and Diabar intermountain depressions. The species is recorded on the territory of “Hirkan” National Park and Zuvand regional reserve. G. caucasicus is a rare snake species in Azerbaijan. The main threat to the pitviper in the region is habitat loss. To preserve the species in the northwestern periphery of the habitat, the authors recommend creating a specially protected natural area in the Jalilabad and Yardymly districts on the Alashar-Burovar Ridge. It is also necessary to include G. caucasicus into the Red Data Book of the Republic of Azerbaijan in the category “Vulnerable species” (VU).

The paper provides new information on the distribution of rare and endangered snakes over the Stavropol Region, namely, Eryx jaculus, Dolichophis caspius, Elaphe sauromates, and Platyceps najadum.

For the first time, the amplitude-frequency and temporal characteristics of the acoustic signals (the distress one and two types of advertisement calls) of the Crimean gecko (Mediodactylus danilewskii) were analyzed. The distress call is a rather long one (usually around 150–350 ms, but sometimes up to nearly 1 s), with a peak frequency of 6.86 kHz in both males and females. The upper harmonics of this type of signal lie in the ultrasonic region of the frequency spectrum. The short advertisement call has a different duration in males and females, namely, about 23 ms and 35–40 ms on average, respectively. The peak frequency of this type of signal is 4.82 kHz in both sexes. Some frequency parameters of the acoustic signals are characterized by lower values in males than those in females, despite the larger body sizes of the latter. E.g., 35% and 11% of the total distress call energy is below 4 kHz in males and females, respectively. The average value of the fundamental frequency of short advertisement calls in males and females is 1.75 kHz and 3.33 kHz, respectively, while the limits of variability of this parameter in representatives of both sexes almost do not overlap. The prospects of using bioacoustics for solving important issues of the Mediodactylus (kotschyi) superspecies taxonomy are discussed. We assume that the male long advertisement call, which is a sequence with a duration of 4 to 9 s consisting of 24–44 clicks with an average peak frequency below 4 kHz following each other at a rate of 6.4–9.1 clicks/s, will be most informative for these goals.

Lantz’s newt, or the Caucasian smooth newt, Lissotriton lantzi, is an endemic species for the Caucasian mountain-forest belt. In North Ossetia–Alania, only 4 findings of this newt are known in the Prigorodniy, Alagirskiy and Irafskiy districts. Since 1983, there has been no new information about any findings of L. lantzi in this region. On August 4, 2020, L. lantzi larvae were caught in a lake on the left shore of the Urukh River in the Irafskiy district. Newts live here in a beech forest at an altitude of 810 m. The authors assume that L. lantzi in North Ossetia–Alania inhabits the entire forest belt in the range of altitudes of 700–1000 m above sea level.

Characteristics of the meristic features of the external morphology of young and adult snakes (the Colubridae family) of three species, namely, the grass snake Natrix natrix, the dice snake N. tessellata and the Pallas’ coluber Elaphe dione, living in the Samara region, are described. For the first time, a comparative analysis was carried out of a number of morphological characters of uneven-aged snakes, namely: newborns obtained in laboratory conditions, juvenile specimens, and adult snakes captured in nature. It was revealed that those morphological features which remained unchanged during the snake's life (the number of Ventr., Scd., Lab. and Temp. scales) significantly differred in specimens of laboratory and natural origin. Statistically significant differences were also found between young and adult specimens of the dice snake from nature.