Volume 103, Nº 7 (2024)

The present study is based on the oribatid mite material collected from the Pinar del Río Province, Cuba. A list of 22 species, belonging to 17 genera and 13 families, is presented. Nine species are reported from Cuba for the first time. Two new species are described from aquatic plants: Tyrphonothrus pinarensis Ermilov sp. n. (Malaconothridae) and Scheloribates (Topobates) rioensis Ermilov sp. n. (Scheloribatidae). The tritonymphal instar of T. pinarensis is described.

A new species of bristletail, Allopsontus stepposus sp. n., is described from the western Crimea. In the structure of the antennal flagella, the chaetotaxy of the maxillary and labial palps, the sensory field on the fore femora, the abdominal sternites and parameres, it seems to be especially similar to A. tauricus Kaplin 2024, described from a nearby area in western Crimea. These two species are clearly distinguished by the pattern formed by differently colored scales on the dorsal side of the abdomen, as well as the color and shape of the paired ocelli. The species also differ in the width to length ratio of the paired ocelli, the structure of the 3rd article of the labial palp, and the size of the apical angle of the abdominal sternites.

Results of a study on the reproductive potential of the Taimyr wild deer in the 1987–2021 are presented. The material for the population analysis was formed by empirical samples of altogether 3695 females 2 to 17 years old each and the initial data from aerial surveys of the Taimyr population. The potential fecundity of the species in this part of the circumpolar distribution range (northern Central Siberia) in 1987–1990 averaged 0.412 ± 0.015 female fetuses per mature female. The potential fecundity, both male and female fetuses, totaled 82.4 fetuses per 100 adult females. The realized reproduction of the population in July 1988 amounted to 75.08 calves, vs 75.31 calves per 100 mature females in July 1990. Hence the infant mortality before calving for that monitoring period was 8.6–8.9%. Given the controlled use of the population resources in 1966–1990 (Soviet period), the linear regression equation for adult females was y = 4.6704x + 140.08 thousand (R² = 0.5342, Ᾱ =5.2%), the linear trend in the numbers of underyearling calves in the period 1975–1990 being y = 5.15x + 73.9 thousand (R² = 0.84, Ᾱ = 2.76%, r = 0.24, p < 0.05). The maximum “yield” of 142.5 thousand calves was noted for the Taimyr population in the summer of 1988. The potential fecundity of the Taimyr deer decreased in 1996–1998 and amounted to 0.339 ± 0.0362 female fetuses per adult female, vs 0.379 ± 0.0013 in 1999–2006, the realized fecundity in the postnatal period in 2002–2007 was found to be 0.295 ± 0.009 females per adult female, or 59.03 calves (males + females) per 100 adult females; this can be interpreted as elimination from spring to autumn of more than 16 calves per 100 adult females (mortality rate 21.3%). Using a linear regression for the 32-year interval between 1990 and 2021, the numbers of adult deer females dropped to y = –14.36x + 231.14 thousand (R² = 0.48, Ᾱ = 2.4, r_xy= 0.89, p < 0.01 (t_p = 4.36, p < 0.01)). The predicted abundance of adult females based on a completed point forecast for the summer of 2022 is estimated at 116.23 thousand heads, vs 101.86 thousand for the summer of 2023. The trend equation for the juvenile group of Taimyr deer showed the following quantitative characteristics in the 1990–2021 interval: y = –21.35х + 175.51 thousand (R² = 0.95, Ᾱ = 2.9, r_xy = 0.98, p < 0.01 (t_p = 11.01, p < 0.001)). Changes in the characteristics of the natal group are negative, as the existing rates of reproduction in the population do not balance its decline. There is a clear trend towards a decrease in the biotic potential of the Taimyr population at the current rates of reproduction in its migration flows and a further decline in the productivity of the species in that part of the circumpolar distribution range.

The purpose of the study was to establish the order and nature of the development of the Baikal seal (Pusa sibirica Gm.) in different areas of the rookery on Dolgiy Island, Ushkanyi Islands, Lake Baikal, also determining whether there was a correlation in the number of animals in different rookeries, as well as the time and daily dynamics of their development. We also wanted to identify differences in the functioning of rookeries subject to anthropogenic influence vs rookeries where it was absent, and to assess the ecological capacity of all rookeries on Dolgiy Island. The material for the present study were still images obtained using eight camera traps monitoring different sections of the coast on the northern side of the island. The cameras automatically took photographs of the shore every 3–4 hours during May to June 2022. The study showed that Baikal seals, a few days after the northern part of the lake had been completely cleared of drifting ice, almost simultaneously started approaching the island in all rookery areas. Within three days, a few haulouts were formed. In early June, the numbers of seals were rapidly increasing everywhere, but the natural dynamics of the numbers were interrupted on June 7 by the appearance of an extraordinary disturbance factor (a boat) at the rookery. A significant part of the seals left all rookery areas and only after 1–2 days the numbers of seals began to recover at the expense of other individuals. In the second ten days of June, the numbers of seals in five areas fluctuated greatly, remaining 2–3 times lower than the initial one, and in the third ten days it dropped even more. In the other three areas, the dynamics were somewhat different, this to be explained by an insignificant ecological capacity of these areas, an order of magnitude lower than that of the first five. The numbers of seals in June 2022 in the areas differed significantly, since the area and nature of the substrate available to the seals were not the same, but there was a close positive correlation between the numbers of seals in neighboring areas. In all rookery areas, regardless of their ecological capacity, close daily dynamics of the numbers of seals were noted, this indicating the actual existence of a certain order of seals coming onto land during the day (seals can be present at the rookery all the day round). We assessed the ecological capacity of each site (they totalled 2400 individuals) and, taking into account the unexplored locations, the possible capacities of all rookeries on the northern side of Dolgiy Island could be estimated at 2600–2700 individuals. No differences in the behavior of seals in rookeries that were subject to anthropogenic influence vs rookeries where it was absent could be revealed, since the behavior of Baikal seals in small and large haulouts is apparently not the same.