Spermophilus Fulvus Research Articles

Measuring Docility, Boldness, and Exploration in the Free-Living Yellow Ground Squirrel Spermophilus fulvus Licht. (Sciuridae)

Studying intraspecific variation in animal behavior is one of the key trends in recent biology. Comparative behavioral studies of different species require developing an adequate methodology for every new species. We performed three types of behavioral tests with juveniles of the yellow ground squirrel, a large hibernating rodent. Docility tests with an estimation of the time and intensity of the animal locomotor activity in a bag showed low repeatability and appeared to be inappropriate for this species since most of the pups demonstrated freezing behavior. Boldness tests with an action camera installed near the squirrel’s burrow were more promising, but the juveniles still did not emerge aboveground for a long time after they escaped to their burrows, remained vigilant, and did not explore the new object. Test results indicate that yellow ground squirrels are very shy and cautious, which may be a persistent behavioral trait of this species.

Inheritance of signs of parent species by hybrids of Russet, Yellow and Speckled ground squirrels (<i>Spermophilus</i>, Sciuridae, Rodentia)

The inheritance of size, color and bioacoustic characteristics of Russet (Spermophilus major), Yellow (S. fulvus) and Speckled (S. suslicus) ground squirrels in hybrids differing in their genetic status were studied. In a hybrid population of Russet and Yellow ground squirrels, 10 individuals of S. major, 10 individuals of S. fulvus and 40 hybrids of S. major × S. fulvus were analyzed; in a hybrid population of Russet and Speckled ground squirrels, 11 individuals of S. major, 11 individuals of S. suslicus and 24 hybrids of S. major × S. suslicus were analyzed. Hybrid individuals different in genetic status have been shown to demonstrate differentiation in the vector space of the variability range of the parental species. At the same time, both a shift in some categories of hybrids towards one of the hybridizing species and a significant deviation are noted. The results obtained indicate an increase in the level of variability in size, color and bioacoustic characters in hybrid populations, associated with the erosion of the divergent hiatus of specific features of the parental forms due to the formation of a differentiated hybrid population. As hybrid individuals with different combinations of parental traits accumulate in the population, the situation arises when a sufficient number of hybrids with an overall combination of parental traits (Hcomb) appear in the hybridogenic population. In the hybrid population of the Russet and Yellow ground squirrels, the proportion of such hybrids, according to our data, is 22.5% (n = 40), and in the hybrid population of the Russet and Speckled ground squirrels it is 12.5% (n = 24). This category of hybrid individuals can be considered as possible material for further microevolutionary events and the process of speciation.

Measuring Docility, Boldness, and Exploration in the Free-Living Yellow Ground Squirrel Spermophilus fulvus Licht. (Sciuridae)

Measuring Docility, Boldness, and Exploration in the Free-Living Yellow Ground Squirrel Spermophilus fulvus Licht. (Sciuridae)

Yellow Ground Squirrel Algorithm (YGSA): A Novel Metaheuristic Algorithm for Global Optimization

In recent years, numerous methods have emerged for optimizing problems inspired by nature. Each of these methods, according to their nature, has applications for solving specific problems with unique characteristics. Given the wide array of optimization problems across various fields, introducing novel algorithms with distinct behaviors can be both appealing and practical. In this article, a nature-inspired meta-heuristic optimization algorithm called Yellow Ground Squirrel Algorithm (YGSA) is introduced. The main idea behind YGSA is to simulate the natural behavior of a yellow ground squirrel in terms of pursuit and evasion from a farmer (the predator) and reaching the nest. The objective of the proposed algorithm is to enhance and attain a more equitable equilibrium between the fundamental stages of exploration and exploitation in contrast to preceding approaches. This balance arises from the fact that the yellow ground squirrel, during its escape, simultaneously tries to increase the distance from the farmer (the predator) and decrease the distance to its nest (burrow). To validate the proposed algorithm, 56 benchmark evaluation functions from various unimodal and multimodal types have been evaluated. The evaluation results are compared with the HBO, EBO-CMAR, FO, SCA, PSO, CS, GSA, MVO, and WSO algorithms. The optimization results for unimodal test functions demonstrate the high exploitation capability of YGSA in approaching the optimal solution, while the optimization results for multimodal test functions indicate the strong exploration ability of YGSA in finding the main optimal region in the search space.

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.

Circadian Activity in Yellow Ground Squirrels <i>Spermophilus fulvus</i> Licht. (Sciuridae): the Pilot Instrumental Study

Animal circadian activity was mostly studied in captivity with artificial environment. We performed pioneer study of daily activity using telemetry for yellow ground squirrels (Spermophilus fulvus), burrowing hibernating rodents. Eight individuals were fitted with glued-on radio transmitters contained accelerometers and light sensors in the wild colony in 2021. Our data showed that S. fulvus was strictly diurnal and active aboveground only during daytime. The squirrels ceased locomotor activity and rested when they entered their burrows. As the season progressed, the duration of aboveground activity decreased. In contrast to similar species with peaks of aboveground activity in the morning and in the evening, yellow ground squirrels didn’t break the activity in midday. Probably, prolonged hibernation and, therefore, time deficiency induced S. fulvus to use day hours as effective as possible.

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

Micronucleus test and assessment of changes in peripheral blood erythrocytes of dominant animal species in the Turkestan region

The article presents the results of a study of peripheral blood erythrocytes of dominant animal species in the Turkestan region. The relevance of this work is due to the construction of a nuclear power plant on the territory of Uzbekistan (Jizzakh region, Lake Tuzkan), since the areas of the Turkestan region fall under the potential influence of nuclear power plants and biota objects require monitoring at the ‘zero stage’ before the construction of a nuclear power plant. The data obtained are of great importance in assessing the impact of technogenic factors on biota. Given the location of uranium deposits in the Turkestan region, the uranium content was determined in samples (bones, soft tissues) of amphibians and fish. It has been established that the concentration of uranium in samples of biological objects is within the normal range. We have carried out work on the analysis of erythrocytes and micronuclei in the following biota representatives: desert lacerta (lat. Eremias intermedia), yellow ground squirrel (lat. Spermophilus or Citellus), lake frog (lat. Pelophylax ridibundus), rudd (lat. Redd pisces), snakehead (lat. Channa argus). According to the results of studies in the desert lacerta (lat. Eremias intermedia) and lake frog (lat. Pelophylax ridibundus), various pathological conditions of erythrocytes and micronuclei were observed in 11% of the total number of blood products studied.

Современный статус степного орла в Казахстане

Современный статус степного орла в Казахстане

Post‐Sovietfire and grazing regimes govern the abundance of a key ecosystem engineer on the Eurasian steppe, the yellow ground squirrelSpermophilus fulvus

AbstractAimGrazing intensity and fire patterns across the Eurasian steppes have changed dramatically over the past decades due to the collapse of the Soviet Union in 1991, and Kazakhstan is now a global fire hotspot. The implications of these changes for ecosystem functioning are largely unclear. We aimed to understand the effects of changed grazing intensity and fire frequency on a key ecosystem engineer, the yellow ground squirrelSpermophilus fulvus, on a very large scale.LocationKazakhstan.MethodsGround squirrels were surveyed in an area of ca. 100,000 ha in the dry steppe of central Kazakhstan, using hierarchical distance sampling at more than 200 random points, stratified by fire frequency and livestock grazing intensity. We modelled abundance as a function of different variables, grouped at the landscape scale (fire and grazing), meso‐scale (soil and vegetation structure) and at burrow scale (plant traits such as palatability, digestibility and nutrient content).ResultsGround squirrels prefer areas of a high wormwood cover (Artemisiaspp.) and high plant species richness, which are moderately grazed, preferably by cattle, with only rare fire occurrence. High squirrel densities were also related to the availability of nitrogen‐rich plants of high nutritional value for herbivores.Main ConclusionsYellow ground squirrels seem to reach their density optima by balancing trade‐offs between optimal foraging in areas of short, nutrient‐rich vegetation and a good visibility of approaching predators. Post‐Soviet changes in grazing pressure, resulting in higher fire recurrence rates due to grass encroachment and litter accumulation (i.e. fuel for wildfire), have likely affected the abundance of burrowing mammals and associated biodiversity across huge parts of the Eurasian steppes and semideserts.

Juvenile survival curves in a solitary ground squirrel with a prolonged hibernation: effects of individual characteristics, environment, and maternal investment.

Juvenile survival is a key life-history influence on population dynamics and adaptive evolution. We analyzed the effects of individual characteristics, early environment, and maternal investment on juvenile survival in a large solitary hibernating rodent-yellow ground squirrel Spermophilus fulvus using Cox mixed-effects models. Only 48% of weaned pups survived to dispersal and 17% survived to hibernation. Early life expectancy was primarily determined by individual characteristics and, to a lesser extent, by the early environment. The strongest and positive predictor of juvenile survival was body mass which crucially affected mortality immediately after weaning. Males suffered higher mortality than females after the onset of dispersal; however, the overall difference between sexes was partly masked by high rates of mortality in the first days after emergence in both sexes. Later emerged juveniles had lower life expectancy than the earliest pups. The overall effect of local juvenile density was positive. Prolonged lactation did not enhance juvenile survival: Pups nursed longer survived shorter than the young nursed for a shorter period. Our findings support the hypothesis that females of S. fulvus cannot effectively regulate maternal expenditures to mitigate the effects of unfavorable conditions on their offspring. The strategy to deal with seasonal time constraints on life history in female S. fulvus suggests an early termination of maternal care at the cost of juvenile quality and survival. This female reproductive strategy corresponds to a "fast-solitary" life of folivorous desert-dwelling S. fulvus and other solitary ground squirrels with prolonged hibernation.

Алматы облысының тау бөктерлерінде мекендейтін сарышұнақтың қорек құрамының ерекшеліктері

The article provides information about features of the chemical and mineral composition of the diet of ground squirrels living in the foothills of the Trans-Ili Alatau. The study was conducted in 2020 on the foothill-steppe, foothill-dry steppe, foothill-desert pastures of festuca-bluegrass-carex, ephemeral-wormwood, sainfoins-bromus-festuca, stipa-bluegrass-wormwood, cereal-wallflower-garlic, wormwood-ceratocarpus. The main research method-the study of the fertility and chemical composition of grasses was carried out by generally accepted methods of zootechnical analysis. It was conducted in the laboratory of KazRILFP LLP (Kazakh research institute of livestock and fodder production). The chemical, mineral and nutritional properties of the food were studied and determined depending on the different growth phases. Samples of natural grasses of foothill areas of Almaty region were studied 5 times during the growing season, from May to September. Results obtained showed that, regardless of the growth zone, the nutritional value of the feed unit and the digestible protein are determined during the tube release period. Later, it decreases slightly during the earing period, and a decrease in the nutritional value of plants occurs during the flowering period and after flowering. Along with the decrease in nutritional value, the content of dry substances and fiber increases. In combination with the level of raw and digestible protein, the carotene content also decreases during the growing season of herbs. In this regard, the change in the composition of the yellow ground squirrel's diet and its value directly depend on the growing season of pasture grasses and the composition of the rodent's diet changes.

Development and characterization of new polymorphic microsatellite markers for Eurasian ground squirrel Spermophilus fulvus (Lichtenstein, 1823)

Development and characterization of new polymorphic microsatellite markers for Eurasian ground squirrel Spermophilus fulvus (Lichtenstein, 1823)

Early predictors of female lifetime reproductive success in a solitary hibernator: evidence for "silver spoon" effect.

Fitness consequences of early-life conditions remain unclear and poorly studied in mammals. Based on long-term observations of yellow ground squirrels (Spermophilus fulvus), we identified early determinants of female fitness by analyzing the effects of early-life individual and environmental characteristics (weaning weight, weight gain rate, date of natal emergence, natal litter size, location of the natal burrow, local density of juveniles, population density and precipitation in the post-weaning period) on lifetime reproductive success (LRS). We found high variation and right-skewed distribution in all five LRS components (survival to adulthood, adult lifespan, and lifetime numbers of weaned litters, weanlings, and yearling offspring). Numbers of litters, weanlings, and adult offspring were correlated with each other and increased with lifespan, confirming that longevity is a better predictor of LRS than fecundity. Survival to adulthood was the most sensitive fitness component to early conditions and was higher in females (a) with greater weaning weight, (b) born further from human settlement and (c) born at lower population density. Population density at birth was the best early predictor of all LRS components and negatively influenced adult lifespan and numbers of weanlings and yearling offspring. Early growth rate positively affected the probability of reproducing after the first hibernation and the number of offspring weaned. Such syndrome of high-quality (heavy and fast-growing) young born in a favourable environment ("a silver spoon effect") with downstream damping fitness consequences has been observed so far in only a few mammalian species.

SARCOCYSTIS IN SOME RODENTS AND BIRDS

Sarkosporidiosis is a chronic animal disease that often results in death. In animals with severe damage to the body by sarkosporidiosis, weakness, tissue depletion and hydremia are observed. Sarcocyst development occurs in muscle cells and tissues. It is known that in vivo predators become infected by eating meat from animals affected by sarcocysts. Sarcocysts secrete toxic substances, sarcocystin and sarcosporiocin, which lead to the death of animals within 5-20 hours. In chronic conditions in animals, salt deposits form around numerous sarcocysts and pronounced skeletal muscle hydremia is also observed. Sarcocystosis can be detected only after the death of animals. The corpses of animals must be examined microscopically, severely damaged corpses should be buried to a depth of 2 meters. When conducting microscopic studies of slices taken from samples of affected animal meat, a diagnosis is established. The proposed work is devoted to study the fauna and cycles of the development of micromorphology of representatives of the genus Sarcocystis of some rodents and birds. To achieve this research, an experiment was conducted with small vertebrates. The goal of our work is to identify the distribution of sarcosporidia of some species of rodents and birds, to study the morphology of the detected sarcosporidia, and their life cycle. The results of the study can be used for the epizootological characterization of sarcocystosis of rodents and birds. The study of the life cycle and specific structure is necessary for the diagnosis of species of the genus Sarcocystis. Yellow ground squirrel, house mouse and chukar can serve as a laboratory example in the study of mammalian and bird sarcocystosis. Ultrastructure materials and the life cycle of sarcosporidia can be used in studying the courses “Parasitology” and “Invertebrate Zoology”. There are 5 articles that were published on materials of this work.

Phylogeny and genetic structure of the Yellow ground squirrel, Spermophilus fulvus (Lichtenstein, 1823), in Iran

Old world ground squirrels (genus Spermophilus) are distributed throughout the Holarctic and Palearctic regions, of which two Iranian species, the Yellow ground squirrel S. fulvus and the Asia Minor ground squirrel S. xanthoprymnus, comprise the southernmost distribution of the genus in the Palearctic. The two species are found in fragmented populations from northeastern to northwestern Iran, with S. fulvus being more common and widespread in the country. The enormous geographical distance (more than 1000 km) between Yellow ground squirrel’s patchy populations in eastern and western Iran has led to ambiguous evolutionary relationships and consequently uncertain conservation planning for the species. We studied the phylogenetic relationships and spatial genetic structure of the isolated populations using the mitochondrial Cytochrome b (cyt b) among 79 individuals. Our phylogenetic analysis found that S. fulvus was divided into three main mtDNA clades in Iran. Molecular dating suggested an ancestral expansion from high latitudes towards Iran during the cold periods (before the Holsteinian temperate period), followed by contraction of populations into interglacial refugia around the Holsteinian temperate period (430-350 Kya), leading to their isolation from their ancestral pool about 427 Kya. Furthermore, we found a non-deep phylogenetic divergence between patchy isolated populations of the species in Iran. A major genetic break was detected between populations of eastern Iran (steppes in Hezar Masjed and Binalud mountains, near Iran-Turkmenistan-Afghanistan borderline) and the others, probably associated with their confinement to interglacial refugia during the Domnitz temperate period (340-300 Kya). However, the recent divergence between northeastern and western populations of Iran probably resulted from their contraction into interglacial refugia in the Saale/Drenthe temperate period (250-190 Kya). These results may suggest that populations of the Yellow ground squirrel in Iran fell under the influence of glacial and interglacial cycles along a longitudinal axis. Finally, we propose the three isolated clades of the Yellow ground squirrel identified in Iran as three ESUs.

Reproductive Decisions in a “Fast-Living” Sciurid: A Case Study of the Yellow Ground Squirrel (Spermophilus fulvus)

The problem of the optimal distribution of time and energy between reproduction and the other vital functions and the choice of optimal reproductive tactics concerns all animals. The sequence of decisions largely determines overall individual reproductive success and fitness. The goal of the study was to summarize the factors determining the reproductive decision of the yellow ground squirrel (Spermophilus fulvus). Despite its relatively large size and extremely long hibernation, the yellow ground squirrels is characterized by rapid growth and maturation, in combination with a short life-span; the life cycle of the yellow ground squirrel proceeds according to the “fast” scenario. Analysis of the relationship between breeding indices of females and their individual characteristics has shown that the reproductive investment and success of females do not depend on the age, body condition, or previous reproductive history of the female. The only factor found to influence female reproduction is the date of emergence from hibernation: the later a female emerges, the lower the offspring mass is and the fewer offspring survive. At the same time, female annual investment in reproduction is very large and close to the mean lifetime reproductive investment estimated for female mammals. With a short life-span (approximately 2–3 years), females do not have the opportunity to distribute the reproductive effort across many breeding attempts, they seem to be able to recover quickly after reproduction. Nevertheless, a substantial portion of mature females (about 30%) annually do not produce litters for unknown reasons. The sex ratio among reproductively active individuals during the mating period is strongly biased toward females. This is due to the lower survival of males, the late maturation of young males in comparison with females, and the fact that, even in adult males, individuals in poor physical condition are not very active and hardly search for sexual partners, i.e., males demonstrate a trade-off in the distribution of costs for somatic processes and reproduction. When there is a surplus of females emerging from hibernation, there are more receptive females in the population than reproductively active males, and operational sex ratio (OSR, the ratio between females and males ready to mate) is skewed toward females. Since females live sparsely and are sedentary during the mating period, the probability of breeding for them depends on the availability of sexual partners: the females’ breeding chances increase with an increase in the local density of males and the proportion of males in the population at the time of the female’s estrus; the only explanation for the large proportion of non-breeding females is the shortage of sexual partners. Thus, the negative effect of the shortage of males on the probability of female reproduction is shown for the first time for a natural population of mammals; this opens a new perspective on the theory of sexual conflict. This phenomenon, which is not so typical of species in which the parental investment of the female far exceeds the male’s investment, is explained by the combination of sociodemographic conditions and the life-history patterns of the yellow ground squirrel.

Ixodoid ticks on rodents in the deserts of South Kazakhstan

The tick fauna of rodents was studied in the Muyunkum (Chu-Talas interfluve) and Eastern Kyzylkum deserts and in the west of Betpakdala. Hyalomma asiaticum asiaticum, Haemaphysalis erinacei turanica, and Ornithodoros tartakovskyi ticks were dominant in all the desert regions but the degree of dominance of individual species varied in different deserts. The greatest number of ticks parasitized Rhombomys opimus and Spermophilus fulvus. The ticks parasitizing rodents are vectors of Crimean-Congo hemorrhagic fever, Q fever, tick-borne spotted fevers, and borrelioses.

A shortage of males causes female reproductive failure in yellow ground squirrels.

Sexual conflict theory suggests that female breeding success is strongly influenced by individual life history and environmental conditions and is much less affected by mate availability. Female mating failure due to a shortage of males remains poorly studied and understood. We present data on the effects of male availability on female breeding success in a wild colony of yellow ground squirrels (Spermophilus fulvus). A female's probability of breeding increased with the local density of males and was higher with higher male-biased operational sex ratio (OSR) but was independent of local female density, female age, and body condition, which are factors commonly assumed to influence female reproduction. The positive effect of male availability (as measured by OSR) on female breeding success was consistent across the years, and we conclude that male limitation contributes to female mating failure. This pattern, which is not commonly recorded in species with conventional sex roles, can be explained by a combination of sociodemographic and life history traits (sex differences in age of maturation, female-skewed adult sex ratio and seasonally varying OSR, solitary living at low population density, and low mobility of females combined with mate-searching tactics of males) that are not confined to S. fulvus. Our findings indicate that the role of female mating failure (due to a shortage of males) in shaping mammalian life history may be underestimated.

Nesting Season Diet of Golden Eagles (Aquila chrysaetos) in Western Iran

I studied the diet of the Golden Eagle (Aquila chrysaetos) in western Iran by identifying food items in prey remains, pellets, and video recordings at seven nests during the 2011–2013 breeding seasons. Two methods were used to calculate diet composition: minimum number of individuals of each prey species and estimated biomass for prey items. I identified 316 prey items, which included five species of birds, four species of mammals, and two species of reptiles. Mammals made up the greatest proportion of the diet, 44.0% by frequency and 76.8% by biomass, and birds accounted for 43.7% of the diet by frequency and 17.7% by biomass. Cape hare (Lepus capensis), Chukar (Alectoris chukar), Common Magpie (Pica pica), large-toothed souslik (Spermophilus fulvus) and common fox (Vulpes vulpes) were the most important prey species. The percentage of mammals in the Golden Eagle’s diet in western Iran was lower than in North America, Scotland, the mountains of the Mediterranean, and across Europe and Asia.