Meriones Meridianus Research Articles

Seasonal variation in the diet of Long-eared Owl, Asio otus, in the desert of Northwest China

Abstract Regurgitated pellets (n = 584) of Long-eared Owl (Asio otus) were collected for three seasons from Gansu Endangered Animal Research Center, Gansu Province, China. From these pellets, a total of 1011 individual prey items – representing seven species of rodents and two undetermined species of birds and one undetermined sorex-species – were identified. Long-eared Owls depend mainly on small mammals both based on prey numbers (95.5%) and prey biomass (97.0%). The composition of the diet of Long-eared Owls varied significantly among seasons by frequency and by biomass. The individual species groups indicated significant variation among seasons for Mus musculus, Meriones meridianus, Cricetulus barabensis, Phodopus roborovskii, Dipus sagitta and Rattus norvegicus by biomass. And the difference of seasonal variation of prey items were significant but not for Mus musculus by frequency. Based on prey numbers, Mus musculus was the main food item (50.5%) in its diet; this species was most common in autumn (56.9%) and least common during spring (36.7%). Main prey species, based on prey biomass, was Rattus norvrgicus which comprised 27.5% of total biomass from our pellet samples. The mean length of tibias of mammals in pellets of Long-eared Owls was 18.6 ± 5.4 mm. Long-eared Owls utilize a wide range of prey items in respect to their habitats. Results suggest that Long-eared Owls are selective predators at some levels.

Effects of environmental factors on organ mass of midday gerbil ( Meriones meridianus Pallas, 1773)

We measured and analyzed the organ masses of midday gerbils ( Meriones meridianus Pallas, 1773) to test whether organ masses would respond to the variation in environmental factors. The results showed that organ masses (as expressed in log of organ dry mass) of midday gerbils changed significantly in different environmental gradients. Altitude was the best predictor of variation for heart dry mass, while it was frost-free period for the dry masses of kidneys, liver, and lung. The integrative effect of frost-free period and precipitation explained the 54.9% of the variables for kidney dry mass and 47.7% of the variables for liver dry mass. Precipitation and latitude explained 8.9% of the variables for spleen dry mass. We concluded that environmental factors had an integrative influence on organ masses. Midday gerbils’ heart mass became larger at higher altitude to respond to hypoxia and higher level of energy demand. Primary productivity (surrogated by frost-free period, precipitation, and their interaction) played the most significant role in determining the organ masses of midday gerbils. When encountering unfavorable conditions, midday gerbils had the tendency to grow larger organ masses to promote organ function.

Effects of the Qinghai-Tibet Railway on the community structure of rodents in Qaidam desert region

During July to August in 2007 and 2008, rodents were trapped along Qinghai-Tibet Railway in desert of Qaidam Basin. For accessing the ecological effects of the railway on the community structure of rodents, we organized four unique trapping areas, and three transects were set at different distances from the railway in each area. The results indicated: Dipus sagitta, Allactaga sibirica, Meriones meridianus and Phodopus roborovskii were common species in the study area and no invader was found. There were grazing-disturbed sampling areas on one side of the railway while on the other side this disturbance was insignificant. The result of Chi-square test showed that composition ratio of rodents was significantly different between paired sampling areas, which suggested grazing disturbance could be an important factor in interfering ecological impact of the railway itself. In non-grazing sampling areas, as the vegetation was basically uniform, there was no significant difference of community structure among three transects at 50, 200, 500 m away from the railway. In conclusion, the railway had no clear zone effect on rodent populations correspond to distance.

Chorological structure of the range and genetic variation of the midday gerbil (Meriones meridianus Pallas, 1773)

The midday gerbil ( Meriones meridianus Pallas, 1773) range covers a significant portion of the Eurasian arid zone. This species tends to populate sands at different stages of stabilization and is encountered in various landscapes, from steppes to true deserts, as well as hills up to 1600 m above the see level. According to our data, the yearly average air temperature within the entire range of the midday gerbil is 9 ± 5.7°e , and the average annual precipitation is 180 ± 108 mm. A wide spread of a species under diverse natural conditions is usually characterized by a significant geographical variation. Midday gerbils were found to have a great intraspecific chromosomal variation [5]. M. dahli (Transcaucasia) and M. chengi (China), both of which were earlier assigned to M. meridianus , are now considered to be independent species [9]. Modern methods of molecular and genetic analyses make it possible to study gene genealogies and reconstruct the species range history taking into account the geographical data [1, 7]. Using these approaches supplemented with chorological analysis of the midday gerbil range, we demonstrated genetic similarity of the populations from Kalmykia in Russia to Xinjiang in China and their distinctions (reaching the species rank) from the Turkmenistan‐Uzbekistan and Tyva‐Mongolia gerbils. This is a new contribution to the gerbil taxonomy and the history of biota formation in desert landscapes.

Geographical pattern and historical demography of Midday gerbil Meriones meridianus (Gerbillidae, Rodentia) inferred from the sequences of the mitochondrial DNA control region

Geographical pattern and historical demography of Midday gerbil Meriones meridianus (Gerbillidae, Rodentia) inferred from the sequences of the mitochondrial DNA control region

Parasitic Contact Nets in the Settlings of Tamarisk and Midday Gerbils and their Fleas in the Sands of Volga-Ural Country be­ tween Two Rivers

As a result of transitions of the Meriones genus gerbils and fleas phoresy the parasitic contact nets are formed in their settlements to provide the effective settling of ectoparasites and spreading of plague etiological agent. The contact net covers all the territory occupied by the rodent settlings that do not have spatial disconnection.

Diets of little owls and long-eared owls in Northwestern China

Abstract We compared diets of little owls (Athene noctua) and long-eared owls (Asio otus) in the Minqin Desert in northwestern China. Based on prey numbers, little owls fed mainly on mammals (51.0%) and beetles (46.9%), whereas long-eared owl fed almost exclusively on mammals (96.4%). Based on biomass, both species fed mainly on mammals. Mus musculus, Cricetulus barabensis and Meriones meridianus were the three most common mammals taken by both species. Seasonal variation was found in the diets of both species. Food niche breadth was 3.4 for little owls vs 2.9 for long-eared owls. Dietary overlap between the two species was 49.6%, but varied from 4.0% in April to 96% in January. Dietary overlap of mammals was 97.9%, indicating that both owls fed on similar rodent assemblages. Mean mass of prey was 25.8 ± 22.7 g for long-eared owls and 15.5 ± 22.7 g for little owls. The mean length of tibias of mammals in pellets also indicted that, on average, long-eared owls (18.1 ± 5.6 mm) took larger prey than little owls (16.2 ± 4.7 mm).

Niche characteristics of rodents by diverse disturbance in Alashan desert, Inner Mongolia, China

Four diverse disturbance types, namely, farmland, rotationally grazed grassland, overgrazed grassland and forbidden grazing grassland, were identified in the Alashan desert region of Inner Mongolia. Rodents were sampled in April, July and October in 2002 and 2003 using the trap-day method. Their spatial and temporal niches among the four disturbance types were assessed using the Shannon-Wiener niche breadth index and the Pianka niche overlap index. The Shannon-Wiener niche breadth index was the highest for Allactaga sibirica and Meriones meridianus (0.925 and 0.908, respectively), intermediate for Cricetulus eversmanni, Phodopus roborovskii and Citellus dauricus (0.789, 0.782 and 0.711, respectively), and lowest for Cardiocranius paradoxus (0.003). The Pianka niche overlap indices of six-paired species were the highest and varied from 0.900 to 1.000, suggesting their spatial niche overlapped almost completely. Conversely, the spatial niche overlap index for Meriones unguiculatus, Cardiocranius paradoxus, and Salpingotus kozlovi was zero, thus indicating a complete absence of competition among them. In addition, the temporal niche breadth and overlap indices varied greatly in relation to disturbance types and season. The level of temporal niche overlap in spring and autumn was low while in summer it was high. For all disturbance types and for each season, the temporal niche overlap index of Meriones meridianus and Cricetulus barabansis was always highest but for Meriones unguiculatus and Salpingotus kozlovi always lowest.

Soil biological activity in the Chernye Zemli, Kalmykia, inhabited by gerbils Meriones tamariscinus and M. meridianus

The influence of tamarisk (Meriones tamariscinus) and midday (M. meridianus) gerbils on soil biological activity in the Chernye Zemli, Kalmykia, was studied. Nitrogen fixation, denitrification, and CO2 emission were measured in soil samples from different parts of gerbil burrows. Functional biodiversity of the microbial community was evaluated using multisubstrate testing and comparison of bacterial group composition in samples from gerbil burrows. The impact of gerbils on soil biological activity was mediated by the changes in the group composition of microorganisms.

The diet of the Long-eared Owls, Asio otus, in the desert of northwest China

The contents of regurgitated Long-eared Owls ( Asio otus) pellets collected in Minqin Desert Experimental Research Station of northwestern China were analysed. A total of 303 individuals representing five species of rodents and one of bird were identified in the pellets. By frequency, the most common species taken by Long-eared Owls was Meriones meridianus, followed by Cricetulus barabensis and Phodopus roborovskii. By biomass, Meriones meridianus was the most important species taken, followed by C. barabensis and Rhombomys opimus. Our results suggest that the Long-eared Owls were nocturnal hunters and fed on a wide range of animals with respect to their habitats.

Comparative Morphology of the Arterial Circle of the Brain in Some Species of Mammals

Investigations were performed on 10 adult individuals of chinchilla (Chinchilla laniger), midday gerbil (Gerbillus gerbillus), rabbit (Oryctolagus cuniculus), guinea pig (Cavia porcellus) and Egyptian spiny mouse (Acomys cahirinus). The animals were killed with ether anaesthesia and injected with coloured acryl latex through the abdominal aorta or left heart ventricle. The heads of the animals were fixed in formalin and after decalcification in 5% HNO3, injected arteries of the base of the brain were exposed. The different types of arterial circle of the brain in investigated species were observed. The open type with morphological asymmetry in the anterior part was found in chinchilla. It depended on an unusually strongly developed anterior cerebral artery at the right side. In the midday gerbil the most common form was the closed type of investigated circle, with a lack of typical communicating artery posterior. The morphological asymmetry of the anterior part of the circle without fully developed anterior cerebral artery was found in the rabbit. Typical, the closed type of investigated structure with little individual variability was observed in guinea pig. The most individual variability connected with anterior and posterior part of the Willi's circle was found in the Egyptian spiny mouse where it was difficult to describe the typical arterial circle of the base of the brain.

Effect of Habitat Type and Population Density on the Stress Level of Midday Gerbils (Meriones meridianus Pall.) in Free-Living Populations

New methods of noninvasive evaluation of the endocrine status of animals by the content of hormones in feces were used to study the relationship between the stress level and social (population density) and ecological (habitat integrity) indices in natural populations of midday gerbil in the Southern Kalmykia in 2000. Stress level proved to increase with habitat disturbance but did not depend on population density of animals. The obtained data are discussed in the context of species-specific ecology and social behavior of midday gerbils.

Epidemiology of Helicobacter infection in wild rodents in the Xinjiang-Uygur autonomous region of China.

Helicobacter species were detected in the feces of wild rodents captured in Qiemo and Ruoqiang in the Xinjiang-Uygur autonomous region of China by polymerase chain reaction and 16S rRNA partial sequence analysis. Forty-four wild rodents, including one Przewalski's gerbil (Brachiones przewalskii), three Northern three-toed jerboas (Dipus sagitta), one long-eared jerboa (Euchoreutes naso), 34 midday gerbils (Meriones meridianus), two short-tailed bandicoot rats (Nesokia indica) and three great gerbils (Rhombomys opimus), were examined. Epidemiological studies indicated that Helicobacter spp. were detected in all genera tested; that H. hepaticus, H. apodemus, H. canadensis, and H. winghamensis were widespread in wild rodents; and that the dominant Helicobacter species in rodents differed depending not only on the order or genus of the animal but also on the animal's habitat. H. bilis, H. pylori, H. rodentium and " H. suncus" were not detected in any animals. It appears that the wild rodents tested in this study are not a reservoir of H. pylori infection.

Certain Behavioral Traits of Small Mammals in Abnormal Social Environment

In a social vacuum following a catastrophic decline in population density of small mammals, species-specific adaptive behavioral mechanisms optimizing reconstitution of the spatial and social structure are manifested to a different extent in different species. At the same time, the rate of structure and population recovery depends on specific social organization of a species. The field observation data on the behavior of three species, Pallas' pika as well as Mongolian and midday gerbils, in an experimentally depleted population are presented. Mongolian gerbil living in family groups demonstrated developed adaptive mechanisms of this kind in contrast to two other species with pronounced individual territorialism.

A comparative study on the morphology and topography of the ciliary ganglion in midday gerbil ( Meriones meridianus) and turtle ( Agrionemys horsfieldii)

The morphology and topography of the ciliary ganglia in the midday gerbil and turtle were studied with use of histochemical and histological techniques. The ciliary ganglion of the midday gerbil consisted of two cell agglomerations: the main ganglion and the accessory ganglion. The main ganglion was situated in the orbit and usually closely attached to the nerve for the inferior oblique muscle. The short ciliary nerves arose from the superior end of the main ganglion and reached the orbit. The accessory ciliary ganglion was smaller than the main ganglion. Usually it was attached to short ciliary nerves. The ganglionic neurocytes, 25.97 microm in diameter, were distributed regularly over the entire surface of the main ganglion. They typically had a single clear nucleus. The ciliary ganglion in the turtle formed a characteristic triangular structure on the inferior branch of the oculomotor nerve. The histological examination showed a small number of nerve cells in comparison to the nerve fibres. The neurocytes were placed mainly in the nasal part of ganglion and they had an irregular arrangement. The average diameter of neurons was 23.55 microm. Significant differences in density of ganglionic components in both species were observed. In midday gerbil the cells were densely packed and took up about 80% of a cross-section, while, in the turtle, neurocytes were located mainly in the surface part of ganglion.

Observations on the reproduction biology of Meriones meridianus Pallas, 1773 (Mammalia: Rodentia) in Turkey

The reproduction biology of Meriones meridianus was investigated in the field and laboratory. The distribution in Turkey is confined to a relatively small area in the extreme east of the country. The duration of pregnancy in uncontrolled laboratory conditions was found to last 24–27 days, and average birth weight to be 2.45 g. The litter size was determined to vary between 5 and 7 at birth. The breeding season of this species lasted from May to October. The development of body measurements during the postembryonal period is shown.

Diagnostic Characters and Distribution of Meriones Illiger, 1811 Species (Mammalia: Rodentia) in Turkey

In this study, specimens of Meriones collected from various areas of Turkey were evaluated based on morphological and biometrical characters. It was determined that four species; Meriones tristrami, Meriones vinogradovi, Meriones meridianus and Meriones crassus exist in Turkey. External characters such as the terminal tuft on tail, the colour of ventral hairs, the soles of hind foot and the length of tail, and cranial characters such as the structure of suprameatal triangle, the connection of anterior rim of auditory meatus to squomosal and the projection of mastoid portion of tympanic bullae from supraoccipitals were determined to be useful in distinguishing species of Meriones. The range of M. tristrami in steppes and plains below altitude of 1200 m in Anatolia, M. vinogradovi in vicinity of Kars and Iğdır province, M. meridianus at sandy belts in the north of Ağrı mountain and M. crassus in Southeastern Anatolia were determined.

Discrimination of midday jird's odour by house mice

Responses of three groups of house mice, Mus musculus, of different origins (feral mice, commensal mice and third-generation mice of a laboratory colony from feral parents) to the odour of midday jirds, Meriones meridianus, were studied to examine the role of odour in spatial segregation of these species. Mice that co-habited with jirds avoided the jirds' odour, whereas commensal mice and laboratory-bred mice were indifferent to the jirds' odour. Experiments supported the hypotheses that (1) odours mediate inter-species interactions and (2) intraspecific avoidance of rodents based on odour cue is learned rather than innate.

The fine structure of the parotid gland of the Mongolian gerbil, Meriones meridianus.

The parotid gland of the Mongolian gerbil, Meriones meridianus, was examined by the electron microscopy. A peculiar feature of the serous acinar cells in that mature secretory granules have a bipartite substructure consisting of a centrally-located large dense homogeneous core and the peripheral rim of a less dense, fibrillo-granular matrix. The latter is histochemically revealed to be rich in acid mucosubstance while the former may be mainly composed of zymogenic materials because of its dense homogeneous texture. Such a heterogeneity of granule content is detectable in all the materials examined, regardless of fixation and staining methods and of animal age. Another characteristic feature of the gland is observable in the duct cells, which provide the basal hemidesmosomes attached with microfilaments and the network system of agranular cytoplasmic tubules, closely related to the basal plasma membrane. Functional significance of these structures is discussed.