Rhombomys Research Articles

Great Gerbils (Rhombomys opimus) in Central Asia Are Spreading to Higher Latitudes and Altitudes.

The great gerbil (Rhombomys opimus) is a gregarious rodent in Central Asia and is one of the major pests found in desert forest and grassland areas. The distribution changes and migration routes of R. opimus in Central Asia under climate change remain unexplored. This study employed multi-model ensemble, correlation analysis, jackknife method, and minimum cumulative resistance (MCR) model to simulate the potential habitat of R. opimus under current and future (2030 and 2050) climate scenarios and estimate its possible migration routes. The results indicate that the ensemble model integrating Random Forest (RF), Gradient Boosting Machine (GBM), and Maximum Entropy Model (MaxEnt) performed best within the present climate context. The model predicted the potential distribution of R. opimus in Central Asia with an area under the curve (AUC) of 0.986 and a True Skill Statistic (TSS) of 0.899, demonstrating excellent statistical accuracy and spatial performance. Under future climate scenarios, northern Xinjiang and southeastern Kazakhstan will remain the core areas of R. opimus distribution. However, the optimal habitat region will expand relative to the current one. This expansion will increase with the rising CO2 emission levels and over time, potentially enlarging the suitable area by up to 39.49 × 104 km2. In terms of spatial distribution, the suitable habitat for R. opimus is shifting toward higher latitudes and elevations. For specific migration routes, R. opimus tends to favor paths through farmland and grassland. This study can provide guidance for managing and controlling R. opimus under future climate change scenarios.

MORPHOLOGICAL AND GENETIC CHARACTERISTICS OF POPULATIONS OF THE MAIN CARRIER OF PLAGUE RHOMBOMYS OPIMUS LICHT., 1823 IN THE SOUTH OF KAZAKHSTAN

The great gerbil (Rhombomys opimus, Licht., 1823) is the primary carrier of various bacteriological, viral, and rickettsial diseases in Central Asia, Mongolia, and China. Currently, the systematic position of the great gerbil remains unclear. However, understanding the biology of the species that carry various pathogens is crucial for ensuring public safety. According to classical concepts, plague in nature exists as a complex three-part parasitic system: the causative agent of plague (Yersinia pestis), arthropod carriers or vectors (usually fleas and ticks), and warm-blooded hosts. Modern data suggest the presence of a fourth component - soil invertebrates. The most common parasitic triad in recent outbreaks consists of the causative agent of plague (Yersinia pestis), carried by fleas of the genus Xenopsylla, and the primary carrier, the great gerbil. Five populations inhabit the South Balkhash basin, with their northern border limited by Lake Balkhash. The colonies of the Taukum’s population are located on the left bank of the lower reaches of the Ili River, in the sands of the Taukum desert. On the right bank of the Ile River, the largest population, Saryesik-Atyrau, is spread out, with the Lyukkum’s population to the east of it, separated by the Karatal River in the west and the Aksu River in the east. Between the Aksu and Lepsy rivers lies the Aralkum’s population, and at the western point of Lake Balkhash lies the Lepsy-Ayaguz’s population. South of the Balkhash group of populations, four populations of the great gerbil are identified, located along the Ili River above the Kapshagai Reservoir: on the right bank, Prialtynemel’s and Karakum’s populations, and on the left bank, Syugatinian’s and Karadala’s populations, separated by the Sharyn River. Another group is the tenth population of the great gerbil – Dzhungarian’s – located southeast of Lake Alakol. Using morphological methods, craniometric indicators of the above populations were studied, revealing two regional complexes in the Balkhash-Alakol basin: the Balkhash region’s and Dzhungar's. Phylogenetic data combined samples captured in the southern Balkhash region into one cluster. In summary, we have several geographically isolated populations that differ phenotypically and genetically. These populations have evolved alongside specific strains of the plague pathogen and species of flea carriers, resulting in significant differences in resistance to various zoonotic infections.

Genetic diversity of Rhombomys opimus and Meriones meridianus with potential divergence of plague resistance in the Junggar Basin plague focus based on RT1-Db1*exon1

In the Junggar Basin plague focus, Rhombomys opimus and Meriones meridianus live together, and their parasitic fleas have a similar community structure. However, R. opimus has significantly higher positive rates of Yersinia pestis and anti-F1 antibody compared with M. meridianus. In this study, Y. pestis- and antiF1 antibody-negative R. opimus and M. penicilliger were collected in Qitai county, Fukang city and Mulei county of the eastern part of the Junggar Basin. The genomic DNA was extracted from their spleen tissues, and RT1-Db1*exon1 was amplified through PCR procedure and then sequenced. Sequence analysis was performed and molecular diversity parameters were calculated and compared. The results showed that there were significant differences in nucleotide composition, amino acid composition, number and distribution of single nucleotide polymorphism (SNP) sites and number of haplotypes between R. opimus and M. penicilliger. The nucleotide diversity (π) for R. opimus was 0.00420 ± 0.00139, the haplotype diversity (h) was 0.833 ± 0.086, and the average number of nucleotide differences (K) was 2.02564. The π for M. penicilliger was 0.06569 ± 0.02524, and the h was 1.000 ± 0.045, and the K was 10.4444. The fixation index (FST) value between R. opimus and M. penicilliger was 0.9207. Furthermore, the FST value within R. opimus (0.0275) was significantly lower than that within M. penicilliger (0.2106), indicating a greater genetic variation of M. penicilliger compared with R. opimus. In conclusion, the genetic diversity analysis based on RT1-Db1*exon1 showed that M. penicilliger had higher gene polymorphism and greater genetic differentiation compared with R. opimus in the Junggar Basin plague focus, which might be associated with the low infection rate of Y. pestis.

Effects of Great Gerbil Disturbance on Photosynthetic Characteristics and Nutrient Status of Haloxylon ammodendron.

Rodents, such as those that feed on plants and nest in plant roots, can significantly affect the growth and development of desert plants. The aim of this study was to investigate the effects of Rhombomys opimus disturbance on the photosynthetic characteristics and nutrient status of Haloxylon ammodendron at different growth stages in the Gurbantunggut Desert. The effects of great gerbil disturbance on the photosynthetic characteristics of H. ammodendron at different growth stages were investigated by measuring the gas exchange parameters, instantaneous water use efficiency, and chlorophyll fluorescence parameters of H. ammodendron at different ages (young, middle, and adult) under the disturbance of great gerbils. The soil nutrients in the assimilated branches and rhizosphere of H. ammodendron at different growth stages were tracked to reveal the relationship between the H. ammodendron nutrient content and gerbil disturbance. The results showed that great gerbil disturbance decreased the organic carbon content in the rhizosphere soil of adult H. ammodendron and increased the total nitrogen content in the rhizosphere soil and the nitrogen and potassium contents in the assimilated branches at each growth stage. The net photosynthetic rate and instantaneous water use efficiency of H. ammodendron decreased at each growth stage, and the maximum photochemical efficiency and non-photochemical quenching parameters of the young H. ammodendron decreased. However, the actual photochemical efficiency and photochemical parameters of the middle H. ammodendron increased. It was concluded that the disturbance of great gerbils decreased the photosynthetic capacity of H. ammodendron and increased the content of total nitrogen in the soil and nitrogen and potassium in the plant. This study revealed that the Gurbantunggut Desert great gerbil and H. ammodendron do not have a simple predation relationship. It laid a foundation for the study of the moderate disturbance threshold and better use of the mutually beneficial relationship between the two.

Genotyping, bionomics and host-feeding behavior of Phlebotomus spp. (Diptera: Psychodidae) in Iran

The main goal of the current study was to investigate the molecular systematics and host–vector interactions of sandfly species (Phlebotomus spp.) in Iran. Sandflies were collected using CDC light traps, sticky traps, and BG-Sentinel traps at seven trapping sites in Iran during 2019 and 2020. The source of blood meals was identified using primer pairs specific to either the 16S rRNA or the mitochondrial cytochrome b (cytb) genes. A total of 736 blood-fed female sandflies were collected. Six species of the genus Phlebotomus (Ph.) and four species of the genus Sergentomyia (Se.) were identified using molecular identification techniques. The most abundant sandfly species were Ph. papatasi (38.45 %) and Se. sintoni (36.28 %). Blood meal analysis identified 19 different host species, specifically, 15 mammalian and four bird species. The most common blood meal sources were Rattus norvegicus, followed by Homo sapiens, Bos primigenius f. taurus, Ovis orientalis f. aries, Meriones persicus, Gallus gallus f. domestica, Rhombomys opimus, and Canis lupus; other host species had incidences of less than 5 %. We observed that Ph. major complex and Se. sintoni had mostly mammalophilic blood-feeding behavior, while Ph. papatasi and Ph. sergenti had mostly anthropophilic and ornithophilic blood-feeding preferences, respectively. The current results confirmed cytb is a suitable gene for regular species level identification, and that phylogenetic analyses of cytb allowed for clear demarcation of sandfly species.

The great gerbil (Rhombomys opimus) as a host for tick species in Gurbantunggut Desert

BackgroundRodents play an important role in the life cycle of ixodid and argasid ticks, particularly as hosts of larvae and nymphs. The great gerbil (Rhombomys opimus), the preferred prey item of several carnivores (e.g. the red fox and marbled polecat), is the dominant rodent species in the Gurbantunggut Desert in northwestern China. The aim of this study was to investigate tick species associated with different hosts in the habitat of great gerbils, including wildlife and livestock.MethodsDuring 2018–2023, ticks were removed from 326 great gerbils, two red foxes (Vulpes vulpes), three marbled polecats (Vormela peregusna), 35 pastured sheep (Ovis aries), and one long-eared desert hedgehog (Hemiechinus auritus) in the Gurbantunggut Desert. Ticks were identified according to standard morphological keys. Then, they were further analyzed by molecular and phylogenic methods based on two mitochondrial markers, 16S rDNA and cytochrome c oxidase subunit I (COI) genes.ResultsA total of 889 ticks were collected, representing five species. These included Hyalomma asiaticum (n = 425: 24 larvae, 79 nymphs and 322 adults), Rhipicephalus turanicus (n = 153: 2 nymphs and 151 adults), Haemaphysalis erinacei (n = 298: 4 larvae, 7 nymphs and 287 adults), Ixodes acuminatus (n = 7: 4 nymphs and 3 adults) and Ornithodoros tartakovskyi (6 adults). Based on COI sequences, molecular and phylogenetic analyses showed that (i) I. acuminatus from great gerbils and marbled polecats clustered with I. acuminatus reported from Europe; (ii) O. tartakovskyi found in northwestern China belonged to an independent clade; (iii) Hy. asiaticum, R. turanicus and Ha. erinacei had 100% sequence identities to conspecific ticks sampled previously in China.ConclusionsThe great gerbil is an important host for the developmental stages of I. acuminatus, O. tartakovskyi, Ha. erinacei, Hy. asiaticum and R. turanicus, thus supporting the life cycle of several tick species which, as adults, parasitize predators (red fox and marble polecat) as well as pastured sheep and hedgehogs in the Gurbantunggut Desert. Ixodes acuminatus and O. tartakovskyi were found for the first time on great gerbil and marbled polecat, respectively.Graphical

Contribution to the knowledge of beetles (Coleoptera) inhabiting rodent burrows in Turkmenistan

Animal burrows contain peculiar ecosystems. The rodent burrows are often inhabited by many arthropod species, including beetles (Coleoptera). During our research in Turkmenistan (1976–1988) beetle communities of the burrow of two gerbil species (Meriones libycus and Rhombomys opimus) were studied. A total, 56 beetle species from 11 families were found in gerbil burrows. Among those, 11 species (19.6%) are bothrobionts: Aleochara jacobsoni, Atheta flagellicornis, Coprophilus dimidiatipennis, Sunius nidicola (Staphylinidae), Erebidus vlasovi, Pholioxenus phoenix (Histeridae), Onthophagus psychopompus, Ontho¬phagus vlasovi, Orodaliscus transaralicus (Scarabaeidae), Attagenus duplex (Dermestidae) and Cryptophagus quadrimaculatus (Cryptophagidae).

Epizootiology and biological characteristics of echinococcosis in agricultural animals, dogs, wild carnivores, and rodents in the Western region of the Republic of Kazakhstan.

Echinococcosis is one of the most dangerous parasitic diseases common to humans and animals. In Kazakhstan, echinococcosis is widespread in animals. This study aimed to estimate the prevalence and biological characteristics of echinococcosis in agricultural animals, dogs, wild carnivores, and rodents in the Western region of the Republic of Kazakhstan. The study analyzed slaughtered carcasses of cattle (2500), sheep (4200), pigs (250), horses (91), and camels (45). Furthermore, the study analyzed 144 dogs (herding, rural, and urban), 41 wild carnivores (wolves, red foxes, and corsac foxes), and 339 wild rodents (great gerbils, tamarisk jirds, little ground squirrels, yellow ground squirrels, and muskrats). Postmortem and vital examination methods were used in the helminthological studies of dogs, wild carnivores, and rodents. In agricultural animals, localization and intensity were determined by counting echinococcal cysts in parenchymatous organs. Extensiveness of invasion (EI) averaged 19.2% in cattle, 27.5% in sheep, 5.6% in pigs, and 13.3% in camels. Echinococcal cysts mainly affected the liver in sheep (45.4%) and the lungs in cattle (35.5%). The fertility of echinococcal cysts decreased with age in animals. Acephalocysts were registered mainly in cattle. The highest invasiveness of Echinococcus granulosus was found in herding dogs with an EI of 12.5%. Experimental infestations of dogs showed that maturation of echinococcal eggs occurred by days 36-40 and maturation of segments by day 50. Studies of wild carnivores and rodents showed the presence of E. granulosus (imago stage) in wolves, Alveococcus multilocularis (imago stage) in red foxes and corsac foxes, and A. multilocularis (larval stage) in great gerbils and muskrats. Our data provide evidence of high epizootiological danger for the population and significant damage caused by E. granulosus to animal husbandry in the region. Studies on the spread of echinococcosis suggest the possibility of controlling the situation with human and animal diseases and show the importance of this issue.

Rodents as vehicle for delivery of transgenic bacteria to make paratransgenic sand fly vectors of cutaneous leishmaniasis in field condition

Vector-borne diseases, among them leishmaniasis, cause more than 700,000 deaths annually. The lack of an effective vaccination and the increasing resistance of sand flies to insecticides require the urgent development of innovative approaches to contain the disease. The use of engineered bacteria that express anti-parasite molecules (paratransgenesis) shows much promise. However, a challenge for implementation of this strategy is to devise means to introduce modified bacteria into sand flies in the field. In this study, we use rodent food bait as a delivery strategy to introduce two mCherry-fluorescent bacteria, Serratia AS1 and Enterobacter cloacae, into adult sand flies in field settings. Bacteria-infected food was provided to Rhombomys opimus rodents. These bacteria transiently pass through the rodent alimentary tract and are delivered to larval habitats with the rodent feces. The feces are ingested by sand fly larvae and, in the case of Serratia AS1, are trans-stadially transmitted to adults. This is the first report of targeting delivery of Serratia AS1 in a paratransgenic system to control transmission of leishmaniasis under field condition. This novel strategy shows promise for delivering transgenic bacteria to Leishmania vectors in the field.

Tacheng Tick Virus 1 and Songling Virus Infection in Great Gerbils (Rhombomys opimus) in Northwestern China.

Tacheng tick virus 1 (TcTV-1) and Songling virus (SGLV) were originally found in human patients in China who had had tick bites. Tamdy virus (TAMV) was detected for the first time in a tick-infested person from Kyrgyzstan in 1973. In this study, 276 great gerbils (Rhombomys opimus) were collected in Xinjiang Uygur Autonomous Region in northwestern China. The total RNA of individual spleen samples was extracted, and the viral L segments of TcTV-1, SGLV, and TAMV were detected by nested reverse transcription PCR. Overall, 2.9% (8/276) and 2.2% (6/276) of spleen samples tested positive to the viral L segments for TcTV-1 and SGLV, respectively; TAMV was not detected in any samples. The SGLV from the great gerbils shared 93.7% (236/252 nucleotide [nt]) and 94.0% (78/83 amino acid [aa]) identities to SGLV detected in patients infected with SGLV in northeastern China. The TcTV-1 in great gerbils was closest to TcTV-1 from a patient in China, with 98.5% (797/809 nt) and 98.9% (265/268 aa) sequence identities. This is the first molecular evidence for the presence of TcTV-1 and SGLV in great gerbils. High genetic diversity in SGLV was observed among geographical locations. Multiregion surveillance of Tamdy orthonairoviruses in more wildlife species is necessary.

Genomic analysis of Leishmania turanica strains from different regions of Central Asia.

The evolution in Leishmania is governed by the opposite forces of clonality and sexual reproduction, with vicariance being an important factor. As such, Leishmania spp. populations may be monospecific or mixed. Leishmania turanica in Central Asia is a good model to compare these two types. In most areas, populations of L. turanica are mixed with L. gerbilli and L. major. Notably, co-infection with L. turanica in great gerbils helps L. major to withstand a break in the transmission cycle. Conversely, the populations of L. turanica in Mongolia are monospecific and geographically isolated. In this work, we compare genomes of several well-characterized strains of L. turanica originated from monospecific and mixed populations in Central Asia in order to shed light on genetic factors, which may drive evolution of these parasites in different settings. Our results illustrate that evolutionary differences between mixed and monospecific populations of L. turanica are not dramatic. On the level of large-scale genomic rearrangements, we confirmed that different genomic loci and different types of rearrangements may differentiate strains originated from mixed and monospecific populations, with genome translocations being the most prominent example. Our data suggests that L. turanica has a significantly higher level of chromosomal copy number variation between the strains compared to its sister species L. major with only one supernumerary chromosome. This suggests that L. turanica (in contrast to L. major) is in the active phase of evolutionary adaptation.

Epidemiological Study and Reservoir Identification of Cutaneous Leishmaniasis From Ardestan in Isfahan, Iran (2015-2016)

Background and aims: Cutaneous leishmaniasis (CL) has been considered one of the most common serious parasitic diseases. Some cities in Iran are known as the center of this important parasitic disease. The World Health Organization (WHO) defines CL as an infectious parasitic disease in the tropics, which can be challenging. The aim of this study was to investigate the epidemiological situation of CL (the identification of parasite, vector, and reservoir) in Ardestan. Methods: This descriptive-analytical cross-sectional study was performed in 2015-2016. Overall, 121 patients with CL who referred to Ardestan Dermatology and Leishmaniasis Center were sampled, and the Leishmania species were determined in the samples using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, following the amplification of the internal transcribed spacer 1 (ITS1) region in the parasite genome. Finally, the vector and reservoir species were detected by zoology experts according to identification keys. Results: The incidence of the disease had the highest (57.8%) and lowest (4.1%) levels in summer and spring, respectively. The disease was prevalent in both women and men but was more common in men (51.2%). The majority of patients (27.3%) were in the age group of 21-30 years, and most of the wounds (71.1%) were nodules. More than one wound on the body was observed in 54.5% of patients, and the disease was prevalent in 13.2% of patients and their family members. Occupationally, students showed the highest disease frequency (32%). The response to treatment with meglumine antimoniate (glucantime) was more effective than the other treatments. The species of the Leishmania vector in the Ardestan region was identified as Phlebotomus papatasi, and the species of the reservoirs in this region were Rhombomys opimus and Meriones libycus. Conclusion: Further research is needed to determine the carriers and reservoirs of the disease in other regions in order to reach a constructive decision for appropriate strategies to control the disease.

PCR Positivity of Gerbils and Their Ectoparasites for Leishmania Spp. in a Hyperendemic Focus of Zoonotic Cutaneous Leishmaniasis in Central Iran.

Various arthropods, including Rhipicephalus sanguineus and Ctenocephalides felis felis have been suggested as secondary vectors of Leishmania spp. many years ago. This study was conducted to determine zoonotic cutaneous leishmaniasis (ZCL) PCR positivity of reservoir hosts and their ectoparasites for Leishmania spp. in Segzi plain in Esfahan Province from October 2016 to October 2017. Microscopic examination and nested PCR were used to detect and identify Leishmania spp. isolated from rodents' ears and ectoparasites, and then, the results were confirmed by two methods, PCR-restriction fragment length polymorphism and sequencing. Totally, 93 rodents (92 Rhombomys opimus and one Nesokia indica) and nine different species of ectoparasites (n=527) including fleas, mites, and ticks were collected during different seasons in the study area. Fourteen R. opimus were positive for Leishmania spp. by microscopic examination while one N. indica and 77 R. opimus were positive by nested PCR. The infection rate of rodents with Leishmania major and Leishmania turanica was 39.79% (n=37) and 15.05% (n=14), respectively. Mixed natural infections with L. major and L. turanica were seen in rodents. Moreover, 72.22% of fleas (39/54), 75.0% of mites (5/8), and 100% of tick nymph (1/1) were PCR positive for Leishmania parasites. The highest rate of infection with L. major and L. turanica in R. opimus populations was observed in summer and spring, respectively. It is suggested that the role of L. turanica and the probable role of ectoparasites in the epidemiology of disease should be investigated. A Xenodiagnostic test is recommended for future study.

Гнездовые группировки орлов на ключевой орнитологической территории «Чинк Донызтау» в 2022 году

Гнездовые группировки орлов на ключевой орнитологической территории «Чинк Донызтау» в 2022 году

К вопросу о миграциях орла-могильника и степного орла в Туркменистане

A dedicated analysis of spring and fall migration of the Eastern Imperial Eagle (Aquila heliaca) and Steppe Eagle (Aquila nipalensis) in Turkmenistan has never been conducted before. Both species have been considered migratory, although in the last decade some individuals began to overwinter. Wide portions of their flyways pass over Turkmenistan. Both species are more often found and concentrated in the southern half of the country and areas containing an abundance of Great Gerbil (Rhombomys opimus) and Libyan Jird (Meriones erythrourus), especially in population outbreak years. The migrating Imperial Eagle may be encountered almost everywhere, preferring areas in various open habitats in the flat parts of the country. It is difficult to estimate the total number of migrating Imperial Eagles, as well as Steppe Eagles, because it is rarely possible to record them over large areas during migration. We have put together the few known facts: a migrating flock of 26 individuals was recorded on April 28, 1939, near the Karabogazgol Strait (Isakov, Vorobyev, 1940); after detailed observations in 1949–1958 the Imperial Eagle was recorded twice in Badkhyz (Sukhinin, 1971), and only once in 1984–1997 (Bukreev, 1997); 37 Imperial Eagles have been observed in a flyway on October 20, 1976, in the delta of the Murghab River (in the Karakum lowlands), 36 km north of the village of Chashgyn. In the South-Eastern shore of the Caspian Sea there were 2 sightings over the period of 1977–1991: in October 1977 (3 individuals near Maloye Delili Lake) and March 1979 (2 individuals near Cheloyuk settlement) (A.A. Karavaev, unpublished data); In Central Kopetdagh in 1990–2010 this eagle was recorded only 7 times, with 1–2 birds observed each time, for a total of 27 birds (Efimenko, 2010), including once a flock of 9 individuals (Efimenko N.N., unpublished data); In the Western Kopetdagh in 2009–2018 it was also recorded 7 times, usually 1–2 individuals, with one observation of 6 individuals at one time (March 6, 2015) (Khodjamuradov, Rustamov, 2010; 2019). Although Steppe Eagles can be found throughout Turkmenistan, they migrate mostly over the western and southeastern parts of the country. The first flyway is predominantly over the Western Kopetdag and then through Southern Ustyurt (territories surrounding Karabogasgol bay and Sarakamysh lake), while the other goes through the broader Badkhyz corridor further along the edge of the Southeastern Karakum and Karabil to the southern half of the Sundukly Desert (Tallimerjen massif). Individual migrant streams can be traced along the foothills of the Bolshoi Balkhan and Maliy Balkhan, Kopetdag and/or across the Karakums. At the same time, birds can be seen everywhere in small groups and even singly (as if in isolation, but parallel to the main stream), crossing the flat portion of Turkmenistan in a broad front. Compared to the Imperial eagle, there are considerably more recorded sightings of Steppe Eagles (detailed analysis is given in the report).

Орёл-могильник на юго-востоке Казахстана в 2022–2023 годах: распространение, численность, угрозы

Орёл-могильник на юго-востоке Казахстана в 2022–2023 годах: распространение, численность, угрозы

Современный статус степного орла в Казахстане

Современный статус степного орла в Казахстане

Актуальные проблемы сохранения балобана в республике Казахстан

Актуальные проблемы сохранения балобана в республике Казахстан

О ситуации с балобаном в Южном Прибалхашье на юго-востоке Казахстана

The Saker Falcon (Falco cherrug) has been a breeding and wintering species in the southern shore of Lake Balkhash region for the last two decades. There is a publication describing the first known case of the Saker Falcon nesting there in 2013 and the wintering of a pair in the transition landscape of wetland to desert biome landscape of this geographical area (Zhatkanbaev, 2014). By the end of 2017, the nesting population of the species numbered at least 20 pairs. Saker Falcons nested both in the Ile River and Karatal River floodplain areas, and their nests were located directly in the desert areas of the Ile-Karatal interfluve. Here pairs occupied nests of both Long-Legged Buzzards (Buteo rufinus) and unoccupied old nests of Golden Eagles (Aquila chrysaetos) and Brown-Necked Ravens (Corvus ruficollis), often located on the power transmission poles of 35kV power lines. In February 2015, a pair of Saker Falcons was able to drive a pair of Long-legged buzzards out of their nest, which had been continuously occupied for the previous 4 years, and the buzzards were forced to occupy and renovate an old dilapidated nest 200 m away from the main nest. The pair of Saker Falcons then successfully hatched chicks in the Long-Legged buzzards’ nest. The main prey item of Saker Falcons in the southern shore of Lake Balkhash in the period of 2013–2023 was the Great Gerbil (Rhombomys opimus). Interestingly, in May 2015, adult Saker Falcons had fed their nestlings with Rooks (Corvus frugilegus), including whole carcasses. They had been hunted in the nesting colony in Karaoy village 22–25 km away, causing considerable disturbance in the Rook colony. Additionally, among the prey species of the Saker Falcon were the Steppe Agama (Trapelus sanguinolentus) and fish, namely carp (Cyprinus carpio). It also fed on carrion. After setting Reconyx and Bushnell camera traps, it was observed that on March 22, 2017, a male Saker Falcon flew into a rather dense thicket of trees, mainly consisting of Poplar (Populus deversifolia), and, descending to the ground, managed to grab an adult Muskrat (Ondatra zibethicus) and fly away with it. During nesting of Saker Falcons in the southern shore of Lake Balkhash, the fact of cainism among Saker Falcon nestlings was established, when on May 15, 2017, one of them was observed on the ground, eating another nestling that died, apparently as a result of electric shock (the nest of falcons was located in an abandoned nest of a Brown-necked raven built on a power transmission pole), whereas 5 healthy, fully feathered nestlings had been observed in the nest the day before. In 2021, the abundance of Great gerbil, the main local prey species of the Saker Falcon, was depressed, and as a possible effect of this, the relative abundance and occurrence of the Saker Falcon was extremely low in spring and summer of that year. Another possible reason for the decrease in the number of nesting pairs of Saker Falcons in this region could be the ongoing pressure of spontaneous illegal falcon capture in Kazakhstan, as news of such facts are still published both in the media and on social networks. In late summer and fall of 2022, adult Saker Falcons started to reappear in their former breeding areas, and were observed near Brown-necked raven nests on power transmission poles. Possibly, the same breeding pairs of Saker Falcons gravitated to such old and newly built Brown-necked raven nests after their removal by power engineers. In late July, late August, and early September 2023, individual falcons as well as pairs were observed near power transmission poles with Brown-necked raven nests.

Polygenic plague resistance in the great gerbil uncovered by population sequencing.

Pathogens can elicit high selective pressure on hosts, potentially altering genetic diversity over short evolutionary timescales. Intraspecific variation in immune response is observable as variable survivability from specific infections. The great gerbil (Rhombomys opimus) is a rodent plague host with a heterogenic but highly resistant phenotype. Here, we investigate the genomic basis for plague-resistant phenotypes by exposing wild-caught great gerbils to plague (Yersinia pestis). Whole genome sequencing of 10 survivors and 10 moribund individuals revealed a subset of genomic regions showing elevated differentiation. Gene ontology analysis of candidate genes in these regions demonstrated enrichment of genes directly involved in immune functions, cellular metabolism and the regulation of apoptosis as well as pathways involved in transcription, translation, and gene regulation. Transcriptomic analysis revealed that the early activated great gerbil immune response to plague consisted of classical components of the innate immune system. Our approach combining challenge experiments with transcriptomics and population level sequencing, provides new insight into the genetic background of plague-resistance and confirms its complex nature, most likely involving multiple genes and pathways of both the immune system and regulation of basic cellular functions.