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Vol 104, No 8 (2025)
ARTICLES
Helminth communities of herring gulls (Larus argentatus) at the Murman coast of the Barents Sea: composition, analysis, approaches to assessment
Abstract
The parameters of helminth species richness, abundance, between-species associations and the diversity of infracommunities and compound communities were studied in 4 areas of the Murman coast, Barents Sea, based on 106 adult herring gulls, Larus argentatus. 40 species of helminthes, including 15 digeneans, 16 cestodes, 7 nematodes and 2 acanthocephalans were revealed. 11 helminth species were recorded in birds in all areas of the coast. The number of helminth species in infracommunities ranged from 1 to 10, while completely identical infracommunities in terms of species composition were extremely rare. Helminth infracommunities of herring gulls at the Murman coast could be classified as unstable and unpredictable. No significant differences in diversity were found between the compound communities in different areas of the coast. The highest values of abundance and evenness indices were characteristic of the compound community of gulls from the urban population. Stable and widespread species associations are dominated by helminthes with marine life cycles, but in some areas, a combination of environmental conditions might include species with freshwater life cycles. The ratio of the number of species variants in infracommunities to the number of host individuals infected with helminthes has been proposed to term as a “Diversity Saturation Index”.
Russian Journal of Zoology. 2025;104(8):3-22
3-22
New faunistic and taxonomic data on oribatid mites (ACARI, ORIBATIDA) from the Can Gio biosphere nature reserve, Vietnam
Abstract
A list of 40 oribatid mite (Oribatida) species belonging to 34 genera and 20 families, collected from the mangroves in the Can Gio Biosphere Nature Reserve, southern Vietnam, is presented. One new species of Polyxylobates (Haplozetidae) is described: P. paradiversiporosus Ermilov, Salavatulin et Khaustov sp. n. The new species differs from the known representatives of the genus in the number of notogastral setae and the absence of a translamella. A new generic diagnosis of Polyxylobates is provided.
Russian Journal of Zoology. 2025;104(8):23-31
23-31
Bryocamptus (Bryocamptus) timoshkini sp. n. (Copepoda, Harpacticoida, Canthocamptidae) from Lake Baikal
Abstract
An illustrated description of females and males of a new species of the genus Bryocamptus Chappuis, 1929 is presented: Bryocamptus (Bryocamptus) timoshkini Alekseeva et Krivorotkin sp. n. Individuals of the new species were found in the coastal zone of a small bay near Zolotoy Utes Cape (depth 5–10 m), located at the western shore of the southern basin of Lake Baikal. The structure of individuals of the new species was studied using scanning electron and light microscopy. This is the first representative of the genus Bryocamptus to be found in Lake Baikal, in which the females show three-segmented P2 and P3 endopods, vs; two-segmented endopods of these legs in the females in the remaining Baikalian species of this genus. An updated checklist of Baikalian harpacticoids is given, one that includes 75 species (65 endemic) belonging to 9 genera and 9 subgenera (only one subgenus is endemic).
Russian Journal of Zoology. 2025;104(8):32-49
32-49
The population of the common grass snake (Natrix natrix Linnaeus, 1758, Colubridae, Reptilia) in the city of Moscow. 1. A history of formation and the features of spatial structure.
Abstract
The distribution, a history formation and the population dynamics of Natrix natrix in Moscow within the MKAD ring road have been studied. The features of distribution and the causes of abundance depression of the Common grass snake in the late 1990s to early 2000s are considered. The stages of the formation of the urban population over the past 30–40 years and the peculiarities of its spatial differentiation into separate micropopulations and groupings in the conditions of isolation and fragmentation under the anthropogenic impact are highlighted. Based on the cadastral map compiled of the current distribution of Natrix natrix in Moscow and the distribution of its locations, micropopulations and smaller groupings of the Common grass snake have been identified, forming the spatial and temporal structure of the population. The abundance of snakes and its possible dynamics in relatively isolated parts of the population is estimated. A potential of the micropopulations has been determined, and a forecast for the colonization of new territories by the Common grass snake given.
Russian Journal of Zoology. 2025;104(8):50-65
50-65
Lesser Black-backed Gulls, Larus fuscus fuscus (Laridae, Charadriiformes) on Lake Onega (The Red Data Book of the Russian Federation)
Abstract
The material on the biology and population dynamics of the globally endangered Lesser Black-backed Gull (Larus f. fuscus) in the islands of Lake Onega, all collected between 1974 and 2024, are summarized. The study presents the distribution of the birds across the area, data on the timing of arrival, nesting biology, and post-nesting movements. Long-term population trends and the factors influencing changes are analyzed. The primary nesting sites of the Lesser Black-backed Gull are located in the Kizhi skerries and Kondopoga Bay, both in the northwestern skerry region of the lake. Birds typically arrive between the middle and last third of April, with egg-laying commencing in early to mid- May. The average clutch size is 2.47 ± 0.03 eggs (n = 530). The hatching period varies annually within a three-week range, depending on April and May air temperatures (rs = –0.53, p < 0.01). Due to rising spring temperatures, hatching gradually shifts to an earlier period (2 days in 10 years). The population peaked in 1985, with 210 individuals recorded in the Kizhi skerries. The numbers declined until the late 1990s, then recovered in the 2000s, but have been decreasing again since 2012, reaching just 25 individuals in 2024. Annual fluctuations negatively correlated with water levels in the primary wintering areas of the eastern subspecies in the Sudd Wetlands and Lake Victoria (rs = –0.52, p < 0.01). This indirectly supports the hypothesis that some mature birds remain in Africa during summer (Cherenkov et al., 2014) and indicates that their numbers may depend on the state of wintering habitats. There was no strong interspecific competition between the Lesser Black-backed Gull and the Herring Gull: the abundance of these species correlated (rs = 0.63, p < 0.01), and long-term trends had a similar direction. A more significant role is played by local factors associated with visits to the islands by people during the nesting period. The flow of tourists arriving by water routes is constantly growing, and the conservation of large gull colonies without protection strengthening is hardly feasible even within the Kizhi Federal Nature Reserve.
Russian Journal of Zoology. 2025;104(8):66-78
66-78
Changes in the abundance of the arctic skuas (Stercorarius parasiticus (l., 1758)) and the great skuas (Stercorarius skua (Brunnich, 1764)) (Stercorariidae) on the Murman islands as a response to the dynamics of trophic conditions in the southwestern Barents sea
Abstract
Based on the results of long-term monitoring on the Murman Islands, southwestern Barents Sea, the population dynamics of the Arctic skuas (Stercorarius parasiticus) and the Great skuas (S. skua) were determined. Both species were found to have reached their highest numbers at the end of the second decade of the 2000s and, starting with 2018, a rapid decline in the numbers of Arctic skuas was observed (by 71% by 2024), as well as the complete disappearance of Great skuas by 2022 on two of the three Murman archipelagos. The nesting biology of both species in the Murman conditions was studied during observations, mainly of individually tagged individuals. 45 Arctic skuas and 5 Great skuas were tagged. The maximum duration of continuous nesting of the Arctic skua on the Seven Islands archipelago was found to be 10 years; for the Great skua it amounted 5 years. The breeding success in 1991–1995 was 1.6 chicks/pair for the former, and two times lower for the latter. A comparative analysis of the trophic relationships of both species showed that Arctic skuas obtained most of their food as fish and crustaceans through kleptoparasitism on seabirds, while Great skuas preyed on eggs, chicks, and adult seabirds in adjacent areas. The population development crisis of both species in recent decades was established to have been caused by immense deterioration of the trophic conditions in the coastal waters of Murman. The root cause is a change in the oceanographic conditions in the North Atlantic and adjacent seas.
Russian Journal of Zoology. 2025;104(8):79-87
79-87
Analyses of m1 anteroconid diversity in the field vole (Microtus agrestis, Arvicolinae, Rodentia)
Abstract
A study of 75 left first lower cheek teeth of the Field vole from five collection sites using the morphotypic method and geometric morphometric method revealed a significant correlation between morphogenetic and Procrustes distances in relation to the distribution of morphotypes, while there was no significant correlations observed between the distances calculated with the use of different methods in relation to the geographic distribution of the samples. Nonparametric multivariate two-way analysis of variance (PERMANOVA) showed that the contribution of morphotype diversity to the overall variability is three times greater than contribution of the geographic factor. As a way to organize the diversity geometric morphometric method, that cannot duplicates the classical morphotypic method, but they can be used as complementary method.
Russian Journal of Zoology. 2025;104(8):88-99
88-99
Methods of Zoological Investigations
Photodocumentation in seabird surveys: how to do them right?
Abstract
Seabirds being at the top of trophic chains are an excellent indicator that can provide us with information about the condition of these chains. By monitoring the numbers and breeding success of seabirds in colonies, we obtain data on trends in bird populations and can judge on the condition of marine ecosystems as a whole, albeit direct observations of which are extremely laborious and sometimes impossible at all. The only thing we need is to regularly count birds and monitor them in colonies. However, complete censuses of birds in colonies are costly in terms of both material resources and the involvement of a large number of specialists. This task can be performed by using photographic equipment in counts throughout the whole colony or at relatively small representative monitoring plots. During route surveys at sea from various kinds of watercraft, photographing the encountered seabirds, and marine mammals, is necessary, since among seabirds, especially in the Southern Ocean, where many species look similar, the identification is only possible based on photographs. This paper mainly instructs how to correctly set up photographic equipment, as well as which kind of settings in cameras affect the image quality and what should be done to obtain photographic material suitable for further biological processing.
Russian Journal of Zoology. 2025;104(8):100-113
100-113
Testing a non-invasive method of stress assessment in the wild boar (Sus scrofa L., 1758; Artiodactyla)
Abstract
The possibility of applying a non-invasive method of stress assessment in the Wild boar (Sus scrofa L., 1758) based on the overall concentrations of immunoreactive substances bound by antibodies to cortisol (C–IRS) in animal feces was investigated using the ELISA test system “Cortisol” (“Khema”, Russia). A physiological validation of the method showed that the measurements taken from the animal feces reflected the hormone-producing function and secretory activity of the adrenal cortex. Two samples of feces from wild boars living in semi-free conditions in the Republic of Karelia (LLC “Hunting Farm Chyornye Kamni”, Sortavala District) with high (n = 14) and low (n = 11) levels of stress factor exposure were compared. Fecal samples were collected at feeding sites in two enclosures for semi-free animal keeping. At the time of the study, repairs were being conducted in the first enclosure, and traces of predators (wolves) were found. Additionally, the long-term average density of wild boars in the first enclosure was significantly higher than in the second (14.1 and 1.57 individuals/km2, respectively). Wild boars from the first enclosure showed higher concentrations of C–IRS in their feces compared to those from the second, indicating a higher level of stress among the wild boars in the first enclosure. Potential causes of anxiety for the animals may include high population density, the presence of predators, and anthropogenic influences (repair work, vehicle traffic). The results of the study demonstrated that analyzing the C–IRS concentrations in the feces of wild boars is suitable as a non-invasive method for animal stress assessment and can be used in monitoring studies of wild boar populations.
Russian Journal of Zoology. 2025;104(8):114-120
114-120