Field Mouse Research Articles

Climate influences the genetic structure and niche differentiation among populations of the olive field mouse Abrothrix olivacea (Cricetidae: Abrotrichini)

Even when environmental variation over time and space is commonly considered as an important driver of population divergence, few evaluations of intraspecific genetic variation explicitly assess whether observed structure has been caused by or is correlated with landscape heterogeneity. Several phylogeographic studies have characterized the mitochondrial diversity of Abrothrix olivacea, but none has incorporated landscape genetics analyses and ecological niche modeling, leaving a gap in the understanding of the species evolutionary history. Here, these aspects were addressed based on 186 single nucleotide polymorphisms, extracted from sequences of 801 bp of Cytb gene, gathered from 416 individuals collected at 103 localities in Argentina and Chile. Employing multivariate statistical analyses (gPCA, Mantel and Partial Mantel Tests, Procrustes Analysis, and RDA), associations between genetic differences and geographic and climatic distances were evaluated. Presence data was employed to estimate the potential geographic distribution of this species during historical and contemporary climatic scenarios, and to address differences among the climatic niches of their main mitochondrial lineages. The significant influence of landscape features in structuring mitochondrial variability was evidenced at different spatial scales, as well as the role of past climatic dynamics in driving geographic range shifts, mostly associated to Quaternary glaciations. Overall, these results suggest that throughout geographic range gene flow is unevenly influenced by climatic dissimilarity and the geographic distancing, and that studied lineages do not exhibit distributional signals of climatic niche conservatism. Additionally, genetic differentiation occurred by more complex evolutionary processes than mere disruption of gene flow or drift.

Metabarcoding of bacteria and parasites in the gut of Apodemus agrarius

BackgroundThe striped field mouse Apodemus agrarius is a wild rodent commonly found in fields in Korea. It is a known carrier of various pathogens. Amplicon-based next-generation sequencing (NGS) targeting the 16S ribosomal RNA (rRNA) gene is the most common technique used to analyze the bacterial microbiome. Although many bacterial microbiome analyses have been attempted using feces of wild animals, only a few studies have used NGS to screen for parasites. This study aimed to rapidly detect bacterial, fungal and parasitic pathogens in the guts of A. agrarius using NGS-based metabarcoding analysis.MethodsWe conducted 18S/16S rDNA-targeted high-throughput sequencing on cecal samples collected from A. agrarius (n = 48) trapped in May and October 2017. Taxa of protozoa, fungi, helminths and bacteria in the cecal content were then identified.ResultsAmong the protozoa identified, the most prevalent was Tritrichomonas sp., found in all of the cecal samples, followed by Monocercomonas sp. (95.8% prevalence; in 46/48 samples) and Giardia sp. (75% prevalence; in 36/48 samples). For helminths, Heligmosomoides sp. was the most common, found in 85.4% (41/48) of samples, followed by Hymenolepis sp. (10.4%; 5/48) and Syphacia sp. (25%; 12/48). The 16S rRNA gene analysis showed that the microbial composition of the cecal samples changed by season (P = 0.005), with the linear discriminant analysis effect size showing that in the spring Escherichia coli and Lactobacillus murinus were more abundant and Helicobacter rodentium was less abundant. Helicobacter japonicus was more abundant and Prevotella_uc was less abundant in males. The microbial composition changed based on the Heligmosomoides sp. infection status (P = 0.019); specifically, Lactobacillus gasseri and Lactobacillus intestinalis were more abundant in the Heligmosomoides sp.-positive group than in the Heligmosomoides sp.-negative group.ConclusionsThis study demonstrated that bacterial abundance changed based on the season and specific parasitic infection status of the trapped mice. These results highlight the advantages of NGS technology in monitoring zoonotic disease reservoirs.Graphical

Molecular Dietary Analysis of Three Sympatric Mustelidae in Northeast China

Diet analysis is essential to fully understand the biology of a species and its function within the ecosystem, as well as being key in identifying food web interactions and the population dynamics of predators and prey. The understanding of the diet of small to mid-sized carnivores remains generally lacking or uninformative due to the inability for taxonomic resolution based on morphology. The yellow-throated marten (Martes flavigula), Eurasian river otter (Lutra lutra), and Siberian weasel (Mustela sibirica) are three important Mustelidae species in ecosystems of northeast China. Based on fecal DNA and a next-generation sequencing (NGS) approach, we analyzed the vertebrate prey of these three sympatric Mustelidae. Prey included 7 mammalian taxa, 10 fishes, 2 birds, and 2 amphibians, with 85% of the taxa assigned to the species level. In total, twenty-one vertebrate prey taxa were identified from seven yellow-throated martens, eight Eurasian river otters, and two Siberian weasels. Concerning identified dietary species, 10 taxa were consumed by yellow-throated martens, 14 by Eurasian river otters, and 4 by Siberian weasels. Some prey species were identified in more than one species. Amphibians and fishes were the most dominant Eurasian river otter prey categories, whereas Eurasian badger (Meles leucurus), birds, and rodents were the main yellow-throated marten prey; amphibians and rodents were largely contained in Siberian weasel prey. Among prey items, Dybowski's frog (Rana dybowskii) and Korean field mouse (Apodemus peninsulae) were identified in all three Mustelidae species but our analyses suggest potential diet preferences among Mustelidae species. Future studies should focus on understanding the trophic relationships of these three Mustelidae species, providing valuable information for their conservation planning.

A South American Mouse Morbillivirus Provides Insight into a Clade of Rodent-Borne Morbilliviruses.

Morbilliviruses are negative-sense single-stranded monosegmented RNA viruses in the family Paramyxoviridae (order Mononegavirales). Morbilliviruses infect diverse mammals including humans, dogs, cats, small ruminants, seals, and cetaceans, which serve as natural hosts. Here, I report the identification and characterization of novel viruses detected in public RNAseq datasets of South American long-haired and olive field mice. The divergent viruses dubbed Ratón oliváceo morbillivirus (RoMV) detected in renal samples from mice collected from Chile and Argentina are characterized by an unusually large genome including long intergenic regions and the presence of an accessory protein between the F and H genes redounding in a genome architecture consisting in 3'-N-P/V/C-M-F-hp-H-L-5'. Structural and functional annotation, genetic distance, and evolutionary insights suggest that RoMV is a member of a novel species within genus Morbillivirus tentatively named as South American mouse morbillivirus. Phylogenetic analysis suggests that this mouse morbillivirus is closely related to and clusters into a monophyletic group of novel rodent-borne morbilliviruses. This subclade of divergent viruses expands the host range, redefines the genomic organization and provides insights on the evolutionary history of genus Morbillivirus.

Phylogeography of the striped field mouse (Apodemus agrarius Pallas, 1771) in light of new data from central part of Northern Eurasia.

A phylogeographic analysis of A. agrarius based on the complete mtDNA cytochrome b and control region sequences has been performed using data obtained for the first time for the species from large regions of the central part of Northern Eurasia (23 localities of Altai, Western Siberia, and the Urals). The obtained results have demonstrated a complex intraspecific differentiation of A. agrarius, which has manifested not only in the isolation of the isles populations in Southeast Asia (Jeju and Taiwan), but also in the genetic heterogeneity of mainland populations, which has reflected the history of the modern intraspecific genetic diversity formation against the background of changing physiographic conditions of Eurasia in the Quaternary. The divergence of genetic lineages has taken place apparently simultaneously (in mid-Pleistocene) on the territory of the Eastern part of the modern disjunctive range, where all the identified lineages are present today. The demographic history and possible evolutionary scenarios for A. agrarius in the Western part of the range have been considered. TMRC reconstructions have shown that the lifetime of the common ancestor of the lineage that expanded in the Western Palearctic is about 17.7 [95% HPD 13.2–22.5] kyr. This suggests that the transcontinental expansion of A. agrarius is a relatively recent event that has occurred after the LGM.

Rustrela virus infection - An emerging neuropathogen of red-necked wallabies (Macropus rufogriseus).

The rustrela virus (RusV) was recently described as a novel pathogen in a circumscribed area of northern Germany close to the Baltic Sea. Up to now, the virus has been detected in cases of fatal non-suppurative meningoencephalitis in zoo animals of different species and a single wild carnivore as well as in apparently healthy yellow-necked field mice (Apodemus flavicollis). Data regarding the background of this previously undiscovered pathogen, including clinical presentation of the disease, host range and distribution of the virus, are still limited. Here, three euthanized red-necked wallabies (Macropus rufogriseus) from zoos of different areas in northeastern Germany were submitted for necropsy after presenting with apathy and therapeutically unresponsive neurological signs. A moderate to severe, non-suppurative meningoencephalitis was diagnosed in all three cases. RusV was consistently detected via RT-qPCR and RNA in situ hybridization in the brains of all wallabies. Other commonly known neuropathogens could not be detected.

Orthohantaviruses in Reservoir and Atypical Hosts in the Czech Republic: Spillover Infection and Indication of Virus-Specific Tissue Tropism.

ABSTRACTOrthohantaviruses (genus Orthohantavirus) are a diverse group of viruses that are closely associated with their natural hosts (rodents, shrews, and moles). Several orthohantaviruses cause severe disease in humans. Central and western Europe are areas with emerging orthohantavirus occurrences. In our study, several orthohantaviruses, including the pathogenic Kurkino virus (KURV), were detected in their natural hosts trapped at several study sites in the Czech Republic. KURV was detected mainly in its typical host, the striped field mouse (Apodemus agrarius). Nevertheless, spillover infections were also detected in wood mice (Apodemus sylvaticus) and common voles (Microtus arvalis). Similarly, Tula virus (TULV) was found primarily in common voles, and events of spillover to rodents of other host species, including Apodemus spp., were recorded. In addition, unlike most previous studies, different tissues were sampled and compared to assess their suitability for orthohantavirus screening and possible tissue tropism. Our data suggest possible virus-specific tissue tropism in rodent hosts. TULV was most commonly detected in the lung tissue, whereas KURV was more common in the liver, spleen, and brain. Moreover, Seewis and Asikkala viruses were detected in randomly found common shrews (Sorex araneus). In conclusion, we have demonstrated the presence of human-pathogenic KURV and the potentially pathogenic TULV in their typical hosts as well as their spillover to atypical host species belonging to another family. Furthermore, we suggest the possibility of virus-specific tissue tropism of orthohantaviruses in their natural hosts.IMPORTANCE Orthohantaviruses (genus Orthohantavirus, family Hantaviridae) are a diverse group of globally distributed viruses that are closely associated with their natural hosts. Some orthohantaviruses are capable of infecting humans and causing severe disease. Orthohantaviruses are considered emerging pathogens due to their ever-increasing diversity and increasing numbers of disease cases. We report the detection of four different orthohantaviruses in rodents and shrews in the Czech Republic. Most viruses were found in their typical hosts, Kurkino virus (KURV) in striped field mice (Apodemus agrarius), Tula virus (TULV) in common voles (Microtus arvalis), and Seewis virus in common shrews (Sorex araneus). Nevertheless, spillover infections of atypical host species were also recorded for KURV, TULV, and another shrew-borne orthohantavirus, Asikkala virus. In addition, indications of virus-specific patterns of tissue tropism were observed. Our results highlight the circulation of several orthohantaviruses, including KURV, which is pathogenic to humans, among rodents and shrews in the Czech Republic.

Chestnut caching behavior of Chinese white-bellied rats (Niviventer confucianus) and South China field mice (Apodemus draco): effects of seed size and insect infestation

Chestnut caching behavior of Chinese white-bellied rats (Niviventer confucianus) and South China field mice (Apodemus draco): effects of seed size and insect infestation

Dietary niche breadth influences the effects of urbanization on the gut microbiota of sympatric rodents.

Cities are among the most extreme forms of anthropogenic ecosystem modification, and urbanization processes exert profound effects on animal populations through multiple ecological pathways. Increased access to human‐associated food items may alter species' foraging behavior and diet, in turn modifying the normal microbial community of the gastrointestinal tract (GIT), ultimately impacting their health. It is crucial we understand the role of dietary niche breadth and the resulting shift in the gut microbiota as urban animals navigate novel dietary resources. We combined stable isotope analysis of hair and microbiome analysis of four gut regions across the GIT to investigate the effects of urbanization on the diet and gut microbiota of two sympatric species of rodents with different dietary niches: the omnivorous large Japanese field mouse (Apodemus speciosus) and the relatively more herbivorous gray red‐backed vole (Myodes rufocanus). Both species exhibited an expanded dietary niche width within the urban areas potentially attributable to novel anthropogenic foods and altered resource availability. We detected a dietary shift in which urban A. speciosus consumed more terrestrial animal protein and M. rufocanus more plant leaves and stems. Such changes in resource use may be associated with an altered gut microbial community structure. There was an increased abundance of the presumably probiotic Lactobacillus in the small intestine of urban A. speciosus and potentially pathogenic Helicobacter in the colon of M. rufocanus. Together, these results suggest that even taxonomically similar species may exhibit divergent responses to urbanization with consequences for the gut microbiota and broader ecological interactions.

Naturally Fluorescent Field Mouse, Mus booduga (Gray, 1837) and Common House Gecko, Hemidactylus frenatus (Schlegel, 1836) as Model Organisms for Biomedical Studies

Naturally Fluorescent Field Mouse, Mus booduga (Gray, 1837) and Common House Gecko, Hemidactylus frenatus (Schlegel, 1836) as Model Organisms for Biomedical Studies

PREDATION OF A PACIFIC TREE FROG (PSEUDACRIS REGILLA) BY AN AMERICAN ROBIN (TURDUS MIGRATORIUS) ON SAN JUAN ISLAND, WASHINGTON

The diet of the American Robin (Turdus migratorius) consists largely of fruit and invertebrates. Rarely, predation of small vertebrates has also been reported, including attacks on, and/or consumption of, snakes, a skink, fish, shrews, a field mouse, a salamander, and frogs. Few observations have included a prolonged interaction, leaving unanswered questions about how the prey are subdued, killed, and eaten. Here I describe an 8-min encounter between an adult male Robin and a Pacific Tree Frog (Psuedacris regilla), including plausible prey-dropping, pursuit, bill-pouncing, pecking, and beating the frog against the ground. The frog was killed, but not consumed, apparently because it was too large to swallow whole and the Robin failed to open or dismember the carcass. This marks the first reported attack by a Robin on a Pacific Tree Frog, and the first confirmed Robin kill of any frog species.

Chromosomal Aberrations in Large Japanese Field Mice (Apodemus speciosus) Captured in Various Periods after Fukushima Daiichi Nuclear Power Plant Accident.

After the Fukushima Daiichi Nuclear Power Plant accident, we studied the chromosomal aberrations (dicentrics and translocations) in the splenic lymphocytes of wild mice inhabiting Fukushima prefecture. Here, we report the frequencies of chromosomal aberrations in large Japanese field mice (Apodemus speciosus) captured from 2012 to 2016 in a heavily contaminated area. The chromosomal aberrations were detected using newly developed 4-color FISH (fluorescence in situ hybridization) with A. speciosus chromosome 1-, 3-, 4- and 5-specific painting probes. The frequencies of chromosomal aberrations in mice captured in July 2012 and October 2014 were significantly higher than that in the mice inhabiting the non-contaminated control area; however, the frequency of chromosomal aberrations in mice captured in January 2016 was not. The frequency of chromosomal aberrations in individual mice tended to increase with certain dose rates and accumulated doses. Regression tree analyses suggested increasing chromosomal aberration rate in mice exposed to chronic radiation at dose rates of more than 1.1 mGy day-1 and at accumulated doses of more than 200 mGy. It is concluded that ambient dose rates in the most severely contaminated area of Fukushima prefecture and radiation doses to wild mice inhabiting this area decrease with time; consequently, chromosomal aberrations induced by radiation have not been detected 5 years after the accident.

Evaluation of sperm fertilization capacity of large Japanese field mice (Apodemus speciosus) exposed to chronic low dose-rate radiation after the Fukushima accident

Due to the risk of bias in early developmental processes of radio-sensitive germ cells, the effects of radiation on reproductive ability remain unclear. In this study, wild large Japanese field mice (Apodemus speciosus) within the ex-evacuation zone of the Fukushima Daiichi Nuclear Power Plant (FDNPP) exposed to chronic low dose-rate (LDR) radiation since 2011 were examined. We analyzed the in vitro fertilization (IVF) capacity of cryopreserved A. speciosus sperm from 2012 to 2021 using interspecific zona pellucida (ZP)-free and homogenous wild mice oocytes. The radioactivity concentrations of 134Cs and 137Cs were 3,460–37,630 Bq/kg in the Fukushima wild mice. Frozen-thawed sperm showed generally normal acrosomal and nuclear morphology. No significant differences in sperm penetration rate to that of ZP-free mouse oocytes were observed between the control and Fukushima sperm. When frozen-thawed A. speciosus sperm was used for IVF, 44%–90% homogenous wild mice oocytes fertilized and developed a 2-cell embryo. This study was the first to reveal that long-term chronic LDR radiation exposure (0.18–0.59 mGy/d) associated with the FDNPP accident showed no detrimental effect on the IVF capacity of cryopreserved sperm in wild A. speciosus. This study also provides an alternative framework to estimate radiation effects on wild mice reproduction.

Repellent effect of synanthropic house mouse urine odor on small forest mammals.

In this study, we examined the effect of synanthropic house mouse (Mus musculus) urine odor on catching probability of small mammals to live traps. We conducted a series of field experiments in August 2016 and 2017 in a natural forests of the northwestern Moscow Region (Russia). Small mammals were trapped at two 4-ha fields using capture-mark-recapture technique by setting 200 live traps (100 points, 2 traps per point) within each field. One trap in each pair was odorless (control) with bait only, whereas the other one was odor-baited with 20 μL of the urine of a synanthropic house mouse. Further analysis was based on the data collected from 2 rodent species (bank vole Myodes glareolus, herb field mouse Apodemus uralensis) and 3 shrew species (common shrew Sorex araneus, Laxmann's shrew Sorex caecutiens, and Eurasian pygmy shrew Sorex minutus). As a result, only bank voles significantly avoided odor-baited live traps. Using generalized linear mixed models, we showed that the choice of a trap by bank voles depended on their age, whereas the probability of repeated capture to a certain live trap was related to their prior experience. We discuss the possible role of components of synanthropic house mouse urine in the population management of exoanthropic small mammals.

Effects of a forest landscape on the prey composition of the Common Barn-owl Tyto alba in southern Bulgaria

The diet of the Common Barn-owl in a forest- and shrub-dominated hunting area in the Strandzha Mountains, southern Bulgaria, was identified from 516 prey specimens. Shrews (52.9% by number, 26.7% by biomass) and rodents (42.1% N, 71.5% B) were prevalent. Among them, White-toothed shrews, Criocidura sp., (45.3% N, 21.4% B) was the most numerous prey genus. Mice, Apodemus sp., (15.7% N, 29% B) contributed with the largest share to the food biomass due to high predation of Striped field mice, A. agrarius, (12.2% B). The proportions of forest species in diet (Apodemus sp, Sorex sp., and dormice liridae) increased with the higher proportion of forest habitats (forests and shrublands cover more than 25% of the area) in most Barn Owl hunting territories in southern Bulgaria.

Diversity of Borrelia burgdorferi sensu lato in ticks and small mammals from different habitats

BackgroundIxodid ticks are important vectors for zoonotic pathogens, with Ixodes ricinus being the most important in Europe. Rodents are hosts of immature life stages of I. ricinus ticks and are considered main reservoirs for tick-borne pathogens, e.g. Borrelia burgdorferi. The aim of this study was to analyse the prevalence as well as genospecies and sequence type (ST) diversity of Borrelia burgdorferi sensu lato in ticks and small mammals from central Germany and to elaborate on the influence of environmental and/or individual host and vector factors on Borrelia prevalence.MethodsAfter species identification, 1167 small mammal skin samples and 1094 ticks from vegetation were screened by B. burgdorferi sensu lato real-time polymerase chain reaction, and positive samples were characterized by multilocus sequence typing. Generalized linear (mixed) models were used to estimate how seasonality, small mammal species/tick life stage and habitat affect individual infection status.ResultsIn total, 10 small mammal species and three tick species, Ixodes ricinus, Ixodes inopinatus (both considered members of the I. ricinus complex) and Dermacentor reticulatus, were investigated. Borrelia DNA was detected in eight host species, i.e. the striped field mouse (Apodemus agrarius), the yellow-necked field mouse (Apodemus flavicollis), the wood mouse (Apodemus sylvaticus), the water vole (Arvicola amphibius), the bank vole (Clethrionomys glareolus), the field vole (Microtus agrestis), the common vole (Microtus arvalis), and the common shrew (Sorex araneus). Two species were Borrelia negative, the greater white-toothed shrew (Crocidura russula) and the pygmy shrew (Sorex minutus). The average prevalence was 6.2%, with two genospecies detected, Borrelia afzelii and Borrelia garinii, and at least three STs that had not been previously reported in small mammals. Borrelia prevalence in small mammals did not differ between seasons. Six genospecies of Borrelia—Borrelia afzelii, Borrelia valaisiana, Borrelia garinii, Borrelia lusitaniae, Borrelia spielmanii, and Borrelia burgdorferi sensu stricto—and 25 STs of Borrelia, of which 12 have not been previously described at all and five have not been previously reported in Germany, were detected in 13% of I. ricinus complex ticks. Prevalence was highest in adult females (25.3%) and lowest in nymphs (11.4%). Prevalence was significantly higher in ticks from grassland (16.8%) compared to forests (11.4%).ConclusionsThe high level of small mammal diversity in this region of Germany seems to be reflected in a wide variety of genospecies and STs of B. burgdorferi.Graphical abstract

Ehrlichia, Coxiella and Bartonella infections in rodents from Guizhou Province, Southwest China

Rodents are generally recognized to be the reservoir hosts of a great many zoonotic pathogens. In some areas of China, rodent-borne pathogens, as well as the role of rodents in the natural cycle of these pathogens, are still poorly investigated. To increase our knowledge on the distribution and epidemiology of rodent-borne bacterial pathogens, 81 rodent liver samples were collected in three locations of Guizhou province located in Southwest China, and screened for the presence of Ehrlichia, Coxiella, and Bartonella in them. A putative novel Ehrlichia species was identified in 5 Berylmys bowersi samples (100%, 5/5). Its 16S rRNA, gltA, and groEL genes have highest 99.84%, 89.11%, and 98.02% identities to those from known Ehrlichia species, and form distinct clades in the phylogenetic trees. Herein we name it “Candidatus Ehrlichia zunyiensis”. Bartonella was tested positive in 8 A. agrarius (striped field mouse), 2 A. chevrieri (Chevrier's field mouse), 1 R. norvegicus (Norway rat), 1 N. confucianus, and 1 N. lotipes, with a total positive rate of 16.05% (13/81). Sequence analysis indicated high genetic diversity in these Bartonella strains. Unexpectedly, two Coxiella strains were identified from the rodents (1 Niviventer confucianus and 1 Mus pahari). Genetic and phylogenetic analysis indicated that both of them are closely related to the Coxiella endosymbiont of ticks. This result supported previous conjectures that vertebrate hosts such as rodents may play a role in the preservation and transmission of Coxiella endosymbiont of ticks.

Epidemiological Manifestation of Combined Natural Foci of Tularemia, Leptospirosis and Hemorrhagic Fever with Renal Syndrome: Mixed Infections

Epidemiological Manifestation of Combined Natural Foci of Tularemia, Leptospirosis and Hemorrhagic Fever with Renal Syndrome: Mixed Infections

Asymmetric competition for seeds between two sympatric food hoarding rodents: implications for coexistence.

Asymmetric competition occurs when some species have distinct advantages over their competitors and is common in animals with overlapping habitats and diet. However, the mechanism allowing coexistence between asymmetric competitors is not fully clear. Chinese white-bellied rats (Niviventer confucianus, CWR) and Korean field mice (Apodemus peninsulae, KFM) are common asymmetric competitors in shrublands and forests west of Beijing city. They share similar diet (e.g. plant seeds) and activity (nocturnal), but differ in body size (CWR are bigger than KFM), food hoarding habit (CWR: mainly larder hoarding; KFM: both larder and scatter hoarding), and ability to protect cached food (CWR are more aggressive than KFM). Here, we tested seed competition in 15 CWR-KFM pairs over a 10-day period under semi-natural enclosure conditions to uncover the differences in food hoarding, cache pilferage, and food protection between the 2 rodents, and discuss the implication for coexistence. Prior to pilferage, CWR harvested and ate more seeds than KFM. CWR tended to larder hoard seeds, whereas KFM preferred to scatter hoard seeds. Following pilferage, CWR increased consumption, decreased intensity of hoarding, and pilfered more caches from KFM than they lost, while KFM increased consumption more than they hoarded, and they preferred to hoard seeds in low and medium competition areas. Accordingly, both of the 2 rodent species increased their total energy consumption and hoarding following pilferage. Both rodent species tended to harvest seeds from the source, rather than pilfer caches from each other to compensate for cache loss via pilferage. Compared to CWR, KFM consumed fewer seeds when considering seed number, but hoarded more seeds when considering the seeds' relative energy (energy of hoarded seeds/rodent body mass2/3 ) at the end of the trials. These results suggest that asymmetric competition for food exists between CWR and KFM, but differentiation in hoarding behavior could help the subordinate species (i.e. KFM) hoard more energy than the dominant species (i.e. CWR), and may contribute to their coexistence in the field.

Stability of the Population System of B Chromosomes of the Korean Field Mouse Apodemus peninsulae (Mammalia, Rodentia) in the Southern Baikal Region: 35 Years of Observations

Stability of the Population System of B Chromosomes of the Korean Field Mouse Apodemus peninsulae (Mammalia, Rodentia) in the Southern Baikal Region: 35 Years of Observations