On November 15, the first practical lesson on identifying microscopic algae and invertebrates in hydrobiological samples was held at the IEE RAS Laboratory of Aquatic Communities and Invasions under the guidance of Anna Nikolaevna Neretina. In 60 minutes, the participants got acquainted with the main groups of hydrobionts that inhabit continental water bodies, with the structure of the dichotomous identification key, learned to identify algae and cladocerans to the species level using pictures. An important result of the lesson can be considered the establishment of the species affiliation of the invertebrate animal, displayed on the avatar of the IEE RAS chat "Mysterious Worlds in a Drop of Water". This animal, similar to Darth Vader from "Star Wars", is called Scapholeberis mucronata (O.F. Mueller, 1776) (scapholeberis mucronata). Scapholeberis is a representative of neuston. It attaches itself with the ventral edges of the valve to the surface film of water, but can also deftly crawl along the surface of aquatic macrophytes.

Fig.1: Presentation slide: damage/wounds On October 28, Pavel Viktorovich Chukmasov, Junior Researcher at the Institute of Ecology and Evolution of the Russian Academy of Sciences, spoke online to the participants of the Competition for specialized classes about the variety of injuries and skin damage in marine mammals and shared a method for analyzing images. Fig.2: Presentation slide: damage of the tail fin, damage of the pectoral fin Marine mammals living in various waters are exposed to a variety of hazards, including various types of skin damage and injuries, which can be of both natural and anthropogenic origin. Fig.3: Presentation slide: parasites Studying and monitoring these injuries is of great importance for assessing the state of a species or population in a certain water area. At the end of the lecture, the children were given the task of analyzing an archive of photographs and identifying animals with skin injuries and determining the nature of their occurrence. This task will not only be practical, but also a learning moment, contributing to the development of analytical skills and a deep understanding of the problems associated with the protection of marine ecosystems.

Fig. 1. Experiment site A team of scientists from the Laboratory of Soil Zoology and General Entomology of the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences and the Institute of Biology of the Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences have jointly traced the pathways of invertebrates falling from tree crowns into the soil food web in temperate forests using an isotopically labeled analogue of arthropod rain. Most invertebrates living in the aboveground layer of forests eventually fall to the soil surface and become prey for soil predators and saprophages. The extent of this vertical subsidy to detrital food chains in various forest types has been previously studied, but its significance for the diet of various groups of soil animals remains unappreciated. The work used 15N-labeled Collembola grown in the laboratory to trace the pathways of invertebrates falling from tree crowns (“arthropod rain”) into the soil food web. The simulation experiment was conducted in a mixed spruce forest at the Malinki biogeocenological station of the Institute of Ecology and Evolution of the Russian Academy of Sciences (Fig. 1). The design of the experiment included the introduction of several model plots of Folsomia candida springtails from a laboratory culture into the soil, previously labeled with 15N under laboratory conditions (Fig. 2). Live or dead springtails were added once to field mesocosms in an amount equivalent to the average daily flow of arthropod rain in a given forest type (19 mg dry w. m-2). Fig. 2. Experimental mesocosms on the work site Trapping of soil populations in experimental and control plots by standard soil-zoological methods was carried out on the 8th and 22nd days after treatment. In total, about 15,000 invertebrate specimens were processed, isotope analysis was performed for 1,251 samples (individual or containing several specimens of the same species). After adding live springtails, the isotope label was most often detected in predatory trombidiform (83% of samples) and mesostigmatic (85%) mites, spiders (58%), predatory centipedes (45%) and beetles (29%). Among non-predatory groups, the isotope label was recorded in thrips (27%), springtails (24%) and oribatids (18%). An increase in 15N values ​​was also recorded in a number of representatives of the fauna of the litter-soil complex (symphylans, ants, diplurans, millipedes, pholcidae, etc. Fig. 3). Fig. 3. Distribution of δ15N values ​​of the most numerous taxa of soil animals after addition of 15N-labeled analogue of arthropod rain. Boxplots – control values; large symbols – labeled samples, small symbols – unlabeled. When dead springtails were added to the mesocosms, the label was found in predators and saprophages in approximately equal proportions (21-25%). This study contributes to the emerging view that soil food webs are not entirely "detrital" but derive a significant portion of their energy from green plants. Unlike other forms of aboveground subsidy in soil food webs, such as litterfall, root exudates, honeydew, etc., which are mainly processed by microorganisms, arthropod rain is directly consumed by animals, mainly higher-order consumers. We found an unexpectedly high frequency of incorporation of aboveground subsidy into the forest soil food web, suggesting that this source of energy and nutrients may contribute significantly to the maintenance of the abundance (and possibly diversity) of soil predators. The work was supported by the RSF project 22-14-00363 The full results of the study can be found in the article: Rozanova, O.L., Tsurikov, S.M., Kudrin, A.A., Leonov, V.D., Krivosheina, M.G., Fedorenko, D.N., Tanasevitch, A.V., Rybalov, L.B., Tiunov, A.V. Incorporation of the 15N-labeled simulated arthropod rain in the soil food web. Oecologia 205, 587–596 (2024).

Fig.1: Siberian maral during the autumn rutting period Researchers from Lomonosov Moscow State University and the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences studied the use of rutting calls by male Siberian maral Cervus canadensis sibiricus as indicators of individuality and competitive advantages of males fighting for harems of females with rival males. During the rutting season, male deer scream a lot. They use these screams to attract females and to scare off other males - potential competitors. What features of the screams carry information about the quality, size and age of the male? This is known for European subspecies of red deer. Females choose males with low formant frequencies in the scream; such screams sound more bassy to the ear. However, the screams of the Siberian maral are very high-pitched, and low formants cannot be manifested in them. Scientists had to find out what acoustic features encode the status of males and how they are related to the individual characteristics of the maral's rutting screams. Observations and sound recordings were conducted at the Kostroma Reindeer Husbandry Center (http://kostroma-hunter.ru/), an antler farm that breeds marals brought from three reindeer farms in Altai. The Center’s 70-hectare enclosure housed a herd of 22 adult males (aged 5-10 years), 34 adult females (aged 2-10 years), 20 young males (aged 2-4 years), and 18 young marals under one year old. The enclosure marals are wary of humans, but not afraid of them or aggressive towards them, which allowed us to approach the animals at a distance of 30-40 m during data collection. All adult animals were individually tagged with ear tags. The marals were free to roam throughout the enclosure; females could move from one harem to another at will. Fig.2: Non-aggressiveness and tolerance towards humans allow observation and recording of maral sounds from a close distance. Fourteen adult males were making rutting calls and trying to win their own harems. A male was considered to be in a harem if he managed to maintain a harem of five or more females for at least two days. During the 15 days of observations covering the period of peak rutting activity, there was only one harem in the enclosure for three days, two harems for nine days, three harems for two days, and four harems for one day. Six harem males maintained a harem for an average of 5.2 days and never became a harem male again after losing it. Fig.3: The harem male tries to monopolize the females. Fig.4: A screaming harem male. The tag with the individual number is clearly visible. In the acoustic structure of male rutting calls, both features of the harem status of the male and features associated with his individuality were found. Compared to peripheral males that also emitted rutting calls but failed to win the harem, the calls of harem males were shorter and higher in terms of the minimum fundamental frequency (one of the features determining the general contour of the call). After winning the harem and changing the status from a harem contender to a harem male, each male shortened his own calls, decreased their initial and maximum fundamental frequency, and increased the minimum fundamental frequency. Evaluation of the acoustic parameters using multivariate statistics methods showed that for 78.9% of calls, the male status was determined correctly based on the call structure. This value was significantly higher than the random level. Thus, rutting calls reliably encode the status of a male as a harem one, a contender for a harem, or a peripheral one who will not be able to win a harem this season. Fig.5: Spectrograms of rutting calls of five peripheral males that failed to win the harem and five harem males, first in the status of contenders (before winning the harem) and then harem males (after winning the harem). Individuality features in male calls were much weaker than status features. Only 53.2% of calls were correctly assigned to the males that produced them. This finding is consistent with long-term data on the analysis of the acoustic structure and censuses of male European red deer based on their voice (the so-called "roar" censuses). Long-term data show that such censuses are unreliable and do not reflect the real number of males in the census sites. Although the calls of European red deer and Siberian marals are individualized, they cannot serve as a vocal "signature" (the so-called vocal signature) for each specific male due to their high intra-individual variability. However, these calls reliably mark the status of males as harem holders. The study also showed that status and individuality features in male calls are encoded by different acoustic parameters. The results of the study were published in Q1 of the Journal of Zoology (London): Sibiryakova O.V., Volodin I.A., Volodina E.V., 2024. Rutting calls of harem-holders, harem-candidates and peripheral male Siberian wapiti Cervus canadensis sibiricus: Acoustic correlates of stag quality and individual identity. Journal of Zoology.

Fig.1: Walrus with a satellite transmitter installed. Photo by: Svetlana Artemyeva The population of Atlantic walruses (Odobenus rosmarus rosmarus) living on the Franz Josef Land archipelago remains one of the least studied. In the summer-autumn of 2020-2021, satellite transmitters were installed on 26 walruses on the islands of the archipelago and on Victoria Island to study their movements and assess the use of the water area. In addition, 65 macrobenthos samples were collected in the study region to assess the distribution of walrus food resources. IEE RAS employees, together with colleagues from the Arctic Research Center, Lomonosov Moscow State University Marine Research Center, and the University of Edinburgh, estimated the speed of animal movements: on average, walruses covered a distance of 29 ± 13.5 km/day at an average speed of 1.2 ± 0.6 km/hour. The speed of movement and the distance traveled statistically differed among males, females and the young. Such differences were noted for the first time and are probably related to the fact that immature individuals have difficulty accessing convenient resting places and the most nutritious areas, and in search of both they have to cover large distances. This is also confirmed by the analysis of the depths of movement: younger walruses were more often recorded in waters with depths greater than 100 m. Fig.2: Distance traveled per day by walruses of different age and sex groups (mature females, mature males, immature animals). N(an) is the number of animals used in the analysis, N(d) is the number of tracking days. The individuals tagged on Victoria Island remained in the vicinity of the island, and the walruses tagged on the Franz Josef Land archipelago actively moved between the islands, using the entire water area. In their movements, the animals used known rookeries, but the use of the entire water area of ​​the archipelago by individual animals was shown for the first time. It was also shown for the first time that Victoria Island is so important for the movement of walruses that the animals did not move more than 60 km from it. One walrus tagged on the Franz Josef Land archipelago moved to the Novaya Zemlya archipelago in 5 days at the end of November, which may indicate a connection between the FJL walruses and the Kara-Barents Sea walruses. Perhaps the transition was caused by ice, which began to cover FJL at that time. Fig.3: Movements of walruses in August-December 2020-2021. The inserts show the movements of walruses tagged on Victoria Island and the transition of a walrus to Novaya Zemlya. The study area was characterized by a high average biomass of macrobenthos. The bivalve mollusc Hiatella arctica dominated the macrobenthos biomass and was probably the main food resource for walruses. Peak biomass values ​​were recorded at a depth of 62 m, but the highest density of stations with high biomass values ​​was located at depths of 15-30 m. Fig.4. Species and phylum composition of macrobenthos The publication was prepared as part of the work on the topic “Study and monitoring of walrus and polar bear as indicators of the sustainable state of marine Arctic ecosystems” within the framework of the Biodiversity Conservation Program of PJSC NK Rosneft. The work was published in the journal Marine Mammal Science (Q1, IF= 2.0): The movement patterns and foraging resources of Atlantic walruses (Odobenus rosmarus rosmarus) in Franz Josef Land archipelago and connectivity with the Kara-Barents Sea population.

Fig.1: Plasticine models with traces of predator attacks. A – model of a caterpillar in Vietnam without damage; B – model of a worm in Khibiny with traces of mammal bites; C – model of a worm with traces of bird beaks; D – model of a worm with traces of arthropod jaws. One of the most pressing issues in modern ecology is the interaction of soil and terrestrial food webs. The former are detrital, that is, based on dead organic matter, while the latter are grazing, based on the green parts of plants. Direct trophic (food) links between terrestrial and underground communities are varied, but they are rarely taken into account in food web models. Earthworms are one such link: they live in the soil and feed on dead organic matter, but often leave their usual environment and crawl to the surface, where they become victims of a variety of terrestrial predators, from beetles to thrushes and badgers. This phenomenon is widely known, but quantitative data on how terrestrial predators affect earthworm populations are virtually nonexistent. Fig.1 Attack rates on the model per day (means and 95% confidence intervals) for all predators combined, and for arthropods, birds, and mammals separately. Models were deployed either on soil (“worms”, blue diamonds) or on plants (“caterpillars”, red circles) in different ecosystems, from left to right: alpine tundra, mixed forest, and tropical monsoon forest in the dry and wet seasons. Different letters indicate statistically significant differences. To study this issue, specialists from the Institute of Ecology and Evolution RAS conducted an experiment with plasticine models of worms and caterpillars. This approach has been used for a couple of decades to assess the predator load on herbivorous animals, but it has not yet been applied to soil communities. The essence of the method is simple: plasticine models resembling worms or caterpillars in shape and size are placed in model biotopes; various animals try to attack them and leave traces of their bites on the plasticine. The damage on the models clearly shows which predators (arthropods, reptiles, birds, mammals) tried to eat them. The work used plasticine models of two types: "worms" on soil (a total of 2208 models) and "caterpillars" on vegetation (1668 models). The work was conducted in the monsoon forest of Vietnam (Cat Tien National Park), in a mixed forest in the Moscow region (the Malinki biological station of the IEE RAS), and in different variants of mountain tundra in the Khibiny Mountains (Murmansk Region, N.A. Avrorin PABSI). It turned out that in the forests of Vietnam and the Moscow region, arthropods most often attack the worm models, while in the Khibiny tundra, mammals do so. In almost all cases, predators attack the worm models more often than the caterpillar models. As expected, the highest level of attacks was recorded in Vietnam during the wet season. The results of the study emphasize that underground resources can be important for maintaining terrestrial food webs, and even the simplest tools can help study this phenomenon. The work was carried out within the framework of the RSF project No. 22-14-00363. The article was published in the journal Applied Soil Ecology: Vinogradov D. D., Sotnikov I. V., Tiunov A. V. (2024) Plasticine models confirm high predator pressure on surfaced earthworms in different ecosystems. Applied Soil Ecology, 202: 105594. Related materials: RAS: "Plasticine models of worms help in environmental research" Agro XXI: "How plasticine worms help in environmental research"

On October 30, the second meeting with schoolchildren on parasitology was held at the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences. Lyudmila Alekseevna Limantseva, PhD in Biology, research fellow, and Maria Sergeevna Plykina, postgraduate student, junior research fellow at the Laboratory of Phytoparasitology of the IEE RAS, spoke about parasites that live on plants. The lecture mainly focused on nematodes that affect plants. Nematodes are the second most diverse group in the animal kingdom after insects. They also discussed species diagnostics of nematodes and the features of individual methods. In the second part of the meeting, they discussed in more detail how nematodes affect medicinal crops using mint as an example. In the practical part, schoolchildren were able to independently isolate Ditylenchus destructor nematodes from an infected potato tuber. They also examined various soil nematodes under a microscope: they practiced distinguishing phytophages from other trophic groups, distinguishing larvae and adult individuals, and among the latter, distinguishing females and males. During an informal discussion, they learned what work on phytoparasitology is being carried out at the Institute.

Whales of the same species, born in another part of the world, feed in summer and autumn in different areas of the Far East on different bottom organisms to accumulate fat reserves before long-distance migration. Specialists from the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences obtained new data during a laboratory analysis of biopsy samples. This year, they continued their research into the planet's most ancient cetaceans in Kronotsky Bay. The first expedition of the Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences to study gray whales started in the waters of the Kronotsky Nature Reserve in early summer 2022. This year, scientists received interesting information from the results of laboratory tests of a biopsy that was performed two years ago. It turned out that in order to accumulate fat reserves, gray whales that feed in different areas, due to the natural features of their feeding grounds, eat different foods. "We have conducted extensive work with gray whales in the coastal waters of Sakhalin, Kamchatka and Chukotka. Including collecting biopsy samples for several years. The process is as follows: we carefully approach the whale in a boat and shoot it with a crossbow. At the end of the arrow there is a small sampler, in which skin and subcutaneous fat remain after the shot. Usually, whales do not react to the shot at all or react weakly. And they do not even move away from us. We send the collected samples to the laboratory for lipid and isotope analysis," explained Matvey Mamayev, head of the expedition, leading engineer of the Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences. Laboratory studies have shown that food chains are longer in Chukotka, meaning they include more elements. Gray whales feed there mainly on several species of amphipods and ammodytes. In Kamchatka and Sakhalin, food chains are shorter, with other types of crustaceans, specific species of polychaete worms, and bivalves predominating in the whales' diet. In Chukotka, gray whales are more successful in fattening, as can be seen from the higher lipid content in the fat samples of Chukotka whales. But samples from Kamchatka are characterized by a high content of cholesterol esters, which is a secondary form of energy storage in whales, which is associated with differences in nutrition and/or internal needs of the body to store these lipids in Kamchatka. This September, the IEE RAS staff conducted work in the northern part of Kronotsky Bay. They identified 20 gray whales from fresh photographs. The researchers encountered most of them every day, observed them feeding in the bay and moving around it. Many of the animals had previously been encountered on Sakhalin. The collected data confirmed the close connection between different feeding areas in the waters of the Northern Pacific Ocean. In the future, it will be necessary to determine the fatness of the whales from photographs - that is, how successfully they were able to accumulate fat this year before their long migration to wintering grounds and reproduction sites. These are presumably the warm waters of Mexico and California, where the animals practically do not feed. The specialists will also compare the success of whale feeding in different areas. "It is important for us to develop cooperation with leading research institutes. For example, with the IEE RAS, in the field of gray whale research and other areas. Our long-term partnership helps solve many problems in the scientific field. We exchange experience, new research ideas, methods, develop a wide range of skills, conduct comprehensive work to study amazing marine mammals - gray whales, observing them in their natural habitat," said Olga Solovey, head of the scientific department of the Kronotsky State Nature Reserve. The research was conducted jointly with the Kamchatka branch of the Pacific Institute of Geography of the Far Eastern Branch of the Russian Academy of Sciences, the Chukotka Arctic Scientific Center and the Institute of Biology of the Karelian Scientific Center of the Russian Academy of Sciences. The gray whale is listed in the Red Books of the International Union for Conservation of Nature and the Russian Federation. Related materials: Aquaculture: "Scientists have identified the characteristics of gray whale feeding" EcoTourismExpert: "Ученые провели исследования рациона редких серых китов из разных частей света" Зелёная Россия: "Нелишние килограммы, или как обитатели заповедных территорий страны готовятся к зиме" Минприроды: "Нелишние килограммы, или как обитатели заповедных территорий страны готовятся к зиме"

On November 1, at the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, the competition participants listened to a lecture titled “Report from the shore of a reservoir: an overview of the customs and habits of aquatic inhabitants,” prepared by Anna Nikolaevna Neretina, a research fellow at the Laboratory of Ecology of Aquatic Communities and Invasions. At the lecture, the audience was introduced to the heroes and villains of continental water bodies, and the features of their biology and role in communities were described. Participants who attended the lecture in person had the opportunity to hold a homemade plankton net with a handle made of bamboo, and also learned how to use images of water fleas in the interior design of a modern research laboratory.

More than a year ago, on July 14, 2023, in the Bolshoy Thach Nature Park (Western Caucasus), as part of the Program for the Restoration of the Persian Leopard in the Caucasus, a female leopard named Achipse was released, but her collar stopped responding after a few days. Specialists feared for the life of the animal and tried to find the collar by the VHF signals it emitted, but these searches yielded no results. On November 4, 2024, a resident of the city of Sochi, Igor Zavrazhin, found a discarded collar in the mountains, 59 km from the place where the leopard was released, called the phone number indicated on it and handed it over to the project specialists. Employees of the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences determined that the collar belonged to the female leopard Achipse. The collar's self-release system worked 440 days after the leopard was released. This means that the "lost" Achipse has successfully survived the past winter and has been actively moving around. More detailed information about the cat's life and activity is yet to be "pulled" from the collar and deciphered by the members of the monitoring group at the IEE RAS. IEE RAS thanks Igor Valerievich Zavrazhin for his attentiveness and responsible attitude to the discovery, which will allow us to collect valuable data necessary for the successful restoration of the population of the Persian leopard in the Caucasus. The program for the restoration of the Persian leopard in the Caucasus is being implemented by the Ministry of Natural Resources of Russia with the participation of the Sochi National Park, the Caucasus Nature Reserve, the Federal State Budgetary Institution "Zapovednaya Ossetia-Alania", the Moscow Zoo with the assistance of the International Union for Conservation of Nature (IUCN). Scientific support for the Program is provided by the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IPEE RAS) in cooperation with the A.K. Tembotov Institute of Mountain Ecology of the Russian Academy of Sciences (IEGT RAS), the Caspian Institute of Biological Resources of the Dagestan Federal Research Center of the Russian Academy of Sciences (PIBR DFRC RAS) and zoologists of the specially protected natural areas. Monitoring of released leopards is carried out with financial support from the Nature and People Foundation. Related materials: Sovetskaya Adygeya: "Female Persian leopard released a year ago has successfully adapted to the mountains of Adygea" TASS: "Female leopard released in Bolshoy Tkhach Nature Park has successfully adapted" Kommersant: "Sochi resident finds collar of Persian leopard released in 2023" Komsomolskaya Pravda: "Achipse is alive! A Sochi resident found a collar of a female leopard in the forest, which was long considered dead" Sochi 1: "Evidence found in Sochi that a female leopard released into the wild more than a year ago is alive" Krasnodar TV channel: "After 440 days: a collar of a female leopard was found in a Sochi forest" Kuban24: "A Sochi resident found a collar in the mountains females of the Central Asian leopard Achipse" AiF: "Female leopard Achipse successfully adapted to the Caucasus Nature Reserve" Kuban News: "A resident of Sochi found a collar of a female leopard Achipse in the forest"