Small Mammals Research Articles

Seasonal variation in the ultrasonic vocal activity of Humboldt's flying squirrel (Glaucomys oregonensis).

Most mammals rely on vocal communication to increase survival and reproductive success. While the functions of audible vocalizations have been well-studied across mammal species, ultrasonic vocalizations in small mammals outside of bats are less understood. North American flying squirrel species (Glaucomys spp.), including the newly described Humboldt's flying squirrel (Glaucomys oregonensis), produce numerous call-types that extend into the ultrasonic range. To investigate the potential function of ultrasonic call-types in the Humboldt's flying squirrels, we used ultrasonic recorders to record squirrels in the wild across multiple seasons to determine if there are temporal and seasonal patterns in nightly vocal activity and rates of different call-types. We recorded Humboldt's flying squirrels in two geographic locations - Humboldt and San Bernardino counties-in California from 2018 to 2022 in the summer and winter across multiple study areas. We found that although seasonal weather conditions differ between locations, flying squirrels in Humboldt and San Bernardino had similar vocal activity patterns across nightly active periods between locations and between summer and winter. Nightly activity patterns of when the three main chirp-like call-types (arc chirps, tonal chirps, upsweeps) were given varied between seasons in both geographic locations, and these call-types were given at greater rates in the summer in San Bernardino, but rates did not vary by season in Humboldt. Trills, the most structurally complex of the four main call-types, were produced more in the summer than in winter, and also differed in their nightly activity patterns, in both geographic locations. Flying squirrels may use certain call-types earlier or later in the nightly active period due to their potentially varying functions, and may produce more trills in the summer coinciding with the breeding season. Further understanding of the function of different call-types can provide insight into social, foraging, and antipredator behavior of this nocturnal and elusive species.

The influence of sample size and sampling design on estimating population-level intra specific trait variation (ITV) along environmental gradients.

Understanding the relationship between intraspecific trait variability (ITV) and its biotic and abiotic drivers is crucial for advancing population and community ecology. Despite its importance, there is a lack of guidance on how to effectively sample ITV and reduce bias in the resulting inferences. In this study, we explored how sample size affects the estimation of population-level ITV, and how the distribution of sample sizes along an environmental gradient (i.e., sampling design) impacts the probabilities of committing Type I and II errors. We investigated Type I and II error probabilities using four simulated scenarios which varied sampling design and the strength of the ITV-environment relationships. We also applied simulation scenarios to empirical data on populations of the small mammal, Peromyscus maniculatus across gradients of latitude and temperature at sites in the National Ecological Observatory Network (NEON) in the continental United States. We found that larger sample sizes reduce error rates in the estimation of population-level ITV for both in silico and Peromyscus maniculatus populations. Furthermore, the influence of sample size on detecting ITV-environment relationships depends on how sample sizes and population-level ITV are distributed along environmental gradients. High correlations between sample size and the environment result in greater Type I error, while weak ITV-environmental gradient relationships showed high Type II error probabilities. Therefore, having large sample sizes that are even across populations is the most robust sampling design for studying ITV-environment relationships. These findings shed light on the complex interplay among sample size, sampling design, ITV, and environmental gradients.

The discovery of novel variants reveals the genetic diversity and potential origin of Seoul orthohantavirus.

Seoul orthohantavirus (SEOV) has been identified as one of the main causative agents of hemorrhagic fever with renal syndrome (HFRS) in China. The virus was found circulating in rodent populations in almost all provinces of the country, reflecting the wide distribution of HFRS. Here, using the direct immunofluorescence assay (DFA) and real-time quantitative reverse transcription PCR (qRT-PCR) approach, we performed screening in 1784 small mammals belonging to 14 species of three orders captured in the main areas of HFRS endemicity in Yunnan province (southwestern China) and identified 37 SEOV-positive rats (36 Rattus norvegicus and 1 Rattus tanezumi). A 3-year surveillance of HFRS epidemics and dynamics of rodent reservoir density and virus prevalence implied a potential correlation between them. The subsequent meta-transcriptomic sequencing and phylogenetic analyses revealed three SEOV variants, among which two are completely novel. The ancestral character state reconstruction (ACSR) analysis based on both novel variants and documented strains from 5 continents demonstrated that SEOV appeared to originate near the southwestern area (Yunnan-Kweichow Plateau) of China, then could spread to other regions and countries by their rodent carriers, resulting in a global distribution today. In summary, these data furthered the understanding regards genetic diversity and the potential origin for SEOV. However, the expanding endemic foci in the province suggest that the virus is spreading over a wider region and is much more diverse than previous depicted, which means that increased sampling is necessary.

Bat consumption by holostean fishes in the Eocene Lake Messel: insights into the trophic adaptability of extinct gars and bowfins.

Direct evidence of trophic interactions between extinct species is rarely available in the fossil record. Here, we describe fish-mammal associations from the middle Eocene of Messel (Germany), consisting of three specimens of holosteans (one Atractosteus messelensis (Lepisosteidae) and two Cyclurus kehreri (Amiidae)) each preserved with a bat specimen (Palaeochiropteryx tupaiodon) lying in close contact with its jaws. This suggests that these fishes probably died after failed swallowing attempts, with the bat wing membrane entangled in their jaws resulting in a fatal handicap. Based on data from modern gars and bowfins, A. messelensis and C. kehreri may have opportunistically attacked drowning and dying individuals or scavenged on floating/sinking carcasses. This hypothesis is also supported by the unusually high number of bat specimens preserved in the deposits of the Eocene Lake Messel, suggesting that this group of small mammals may have represented a substantial food source for generalist feeders. This is the earliest case of chiropterophagy and the first known evidence of bat consumption by lepisosteid and amiid fishes, emphasizing the high trophic variability and adaptability of these groups throughout their evolutionary histories. The newly described associations provide important information for reconstructing the Eocene Lake Messel palaeoecosystem and its trophic web.

Effects of Peromyscus spp. (Rodentia: Cricetidae) presence, land use, and ecotone on Ixodes scapularis (Acari: Ixodidae) ecology in an emergent area for tick-borne disease.

As the range of Ixodes scapularis Say expands, host abundance and land use can play important roles in regions where ticks and their associated pathogens are emerging. Small mammal hosts serve as reservoirs of tick-borne pathogens, with Peromyscus leucopus Rafinesque often considered a primary reservoir. A sympatric species Peromyscus maniculatus Wagner is also a competent reservoir and is notoriously difficult to differentiate from P. leucopus. Anthropogenic land use can alter host and habitat availability, potentially changing tick exposure risk. We tested the hypotheses that tick infestation and pathogen prevalence differ between the two Peromyscus spp. and that host-seeking I. scapularis density and pathogen prevalence differ across land use and ecotone gradients. We live trapped small mammals and collected ticks across 3 land-use classifications and ecotones in Maine, an emergent area for tick-borne disease. We tested each small mammal and tick sample for Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti. While both Peromyscus spp. serve as hosts for immature ticks, P. leucopus exhibited a higher tick infestation frequency and intensity. We did not detect any significant difference in pathogen infection prevalence between the two species. The density of I. scapularis nymphs and the density of infected nymphs did not differ significantly between land-use types, though did differ across ecotones. We also noted a significant north/south gradient, with higher tick densities and pathogen prevalence at the southern end of the study area. Our study highlights the potential variability in tick density and pathogen prevalence across fine spatial scales within an emerging region for tick-borne disease.

Diversity, abundance and habitat association of small mammals in Maze National Park, Ethiopia

We investigated species composition, relative abundance, habitat association and density of small mammals in Maze National Park, Ethiopia. Data were collected using the capture-mark-recapture technique in three representative habitat types (grassland, bushland and riverine forest) from November 2021 to August 2022. Descriptive statistics and indices for diversity and evenness were used to analyse the data. A total of 679 rodents and insectivores were collected during a span of 2 646 trap nights. Of these, 534 (76.64%) individuals were newly captured, while 145 (23.36%) were recaptures. Overall trap success was 20.18%. Five species of rodents were captured: four from the family Muridae (Mastomys natalensis, Arvicanthis niloticus, Rattus rattus and Lemniscomys macculus) and one (Xerus rutilus) from the family Sciuridae; and one insectivore species (Elephantulus rufescens) from the family Macroscelididae. Mastomys natalensis (178; 33.3%) was the most abundant, while X. rutilus (1; 0.2%) and E. rufescens (1; 0.2%) were the least abundant. Small mammal species varied significantly with habitat types (χ2 = 6.101, df = 2, p ≤ 0.05), with the highest count in the bushland habitat (197; 36.89 %) and the lowest in riverine forest (152; 28.46%). The bushland and riverine forest habitats supported the highest (H’ = 1.04) and the lowest (H’ = 0.506) diversity of small mammal species, respectively. A relatively high number of small mammal species were caught during the wet season (n = 336) compared to the dry season (n = 198). Future studies using more trapping grids covering additional habitat types and genetic analyses for small mammal species confirmation are necessary for a better understanding of the Park’s small mammal fauna.

New Additions to the Mammal List Documented in the Portuguese Red Data Book.

This study outlines the procedures used for collecting, processing, and categorizing data on 16 new mammal species for mainland Portugal, belonging to four taxonomic groups: Eulipotyphla (1), Chiroptera (4), Rodentia (2), and Cetacea (9). Data collection and processing encompassed field and lab work and bibliographic compilation. Data categorization involves, whenever possible, the assessment of the approximate number of mature individuals in populations, the extent of occurrence, and the area of occupancy. The approach employed led to the classification of eight out of the 16 species into an IUCN category: two non-volant small mammals and one bat species were designated as Vulnerable, requiring ongoing monitoring; one rodent and three cetaceans were assigned to Data Deficient due to insufficient available information; and a single bat species was classified as Least Concern due to the high abundance of local populations. For small mammals and bats, alterations to natural systems and climate change emerged as the most relevant threatening factors, while for cetaceans, human activities such as fishing, commercial shipping, and tourism were identified as the primary survival risks. It is recommended to maintain action programs that assist in defining strategic orientations for the implementation of conservation measures on a case-by-case basis.

Is chewing efficiency in small herbivorous mammals a function of body size?

Is chewing efficiency in small herbivorous mammals a function of body size?

Variations in risk‐taking behaviour mediate matrix mortality's impact on biodiversity under fragmentation

The impact of fragmentation on biodiversity is driven by more than the spatial configuration of suitable habitat patches. Habitat is embedded in the surrounding anthropogenic land cover, known as the matrix, which plays a key role in species movement and connects the fragmented habitat. Whether the matrix is a barrier or a conduit to movement depends on the mortality of the moving individuals. However, individuals differ in their behavioural response to the risk posed by the matrix, with the willingness to enter the matrix depending on an individual's risk‐taking behaviour. This individual‐level behavioural variability is rarely considered but represents an additional mechanism shaping inter‐ and intraspecific competition as well as evolutionary behavioural responses. We used an individual‐based model to scale up from individual foraging movements to the resulting community structure of a competitive small mammal community in differently fragmented landscapes. The model interactively considers extrinsic matrix conditions, given as a certain mortality rate, and individual differences in intrinsic movement decisions when moving into the matrix. The model was used to investigate consequences of fragmentation and matrix mortality for species and behavioural diversity. Low matrix mortality resulted in a positive effect of fragmentation on species diversity. At the same time, it led to a high average risk‐taking behaviour. While this was an important adaptive response to fragmentation, it also led to a loss of intraspecific diversity. High matrix mortality reversed the effect of fragmentation, leading to a drastic loss of species with increasing fragmentation. High mortality risk reduced average risk‐taking, especially at high fragmentation. Study findings suggest that the feasibility of movement in the matrix can influence species diversity and evolutionary responses of movement‐related behavioural traits in fragmented landscapes. The matrix may thus play a key role in reconciling contrasting empirical results and provides a promising tool for future biodiversity conservation.

Feline Encounters Down Under: Investigating the Activity of Cats and Native Wildlife at Sydney's North Head.

Cats (Felis catus) are widespread across Australia, including within natural and protected areas, and in many areas, cats, including owned domestic cats, are not restricted in where or when they can roam. In Australia, cats have contributed to the decline of many native species and continue to be a problem for governments. North Head, Manly, is home to an endangered population of Long-nosed Bandicoot (Perameles nasuta) and the only mainland breeding colony of Little Penguin (Eudyptula minor) in New South Wales (NSW). Camera traps were installed for a 5-week period across North Head to determine the spatial and temporal distribution of cat activity. As well as capturing instances of cats, the cameras detected native animals such as birds, possums, Long-nosed Bandicoots and other small mammals. An analysis of the camera images showed cats could be found within protected areas of the headland (where cats are prohibited) and along the boundary with the adjacent suburban area of Manly. Cats were mostly detected during the night. There were high occurrences of overlap between cats and Long-nosed Bandicoots (Dhat 0.82), possums (Dhat 0.88) and other small mammals (Dhat 0.67). These findings indicate that cats are active across the Manly headland at the same time as native animals, both within protected areas where cats are prohibited and in adjacent residential areas, and this could have implications for these populations.

Quantification of wildlife visits to pig farms via camera traps in Japan

Infectious diseases in livestock not only cause significant economic losses but also affect food security. Although wildlife may be involved in these infectious diseases by serving as reservoirs, research has primarily focused on livestock and related species. Moreover, while these species represent a potential threat in wildlife-borne infectious diseases, comprehensive surveys of the presence of various species are limited. In this study, we aimed to quantitatively investigate the occurrence of various mammals and birds at three pig farms in Japan. We conducted camera trap surveys from October 15, 2020, to March 24, 2022, and determined the relative abundance index inside and outside the sanitary control zone. Wild boar (Sus scrofa), sika deer (Cervus nippon), and Japanese serow (Capricornis crispus) were photographed only outside the sanitary control zone. In contrast, small and medium-sized mammals, such as feral cats (Felis catus), raccoons (Procyon lotor), and rodent species (Muridae), and birds, such as the rufous oriental turtle dove (Streptopelia orientalis) and crows of the genus Corvus, were photographed both inside and outside the sanitary control zone. This comprehensive quantitative evidence suggests that various mammals and birds may be in indirect contact with livestock, highlighting the need to improve biosecurity at livestock farms. Moreover, while fences are effective against large mammals, they are inefficient against small to medium-sized mammals and birds. Therefore, the results of this study provide important insights into enhancing biosecurity on livestock farms by strengthening physical fencing, disinfecting clothing and equipment, and complying with standards of hygiene management.

Plateau zokor disturbance enhances soil bacterial diversity and reduces network complexity

Rodent disturbances are considered as the key factors that affect grassland ecological restoration worldwide. Although the impact of rodent disturbances on plant diversity and ecosystem functions has been extensively studied, our understanding of how such activities shape soil bacterial community networks and their functional roles remains limited. In this study, we employed 16S rRNA sequencing to investigate soil bacterial communities between undisturbed alpine meadow and zokor mounds at different successional stages. Additionally, we analyzed the co-occurrence networks and potential functions within the alpine meadow ecosystem. The results revealed that (1) the disturbance by plateau zokors altered the soil bacterial community structure, increased bacterial diversity and reduced network complexity. Also, there were synergistic interactions among key species in the soil bacterial co-occurrence network; (2) soil organic carbon (SOC) and total nitrogen (TN) were identified as the key environmental variables that shape soil bacterial communities; (3) functional predictions based on FAPROTAX indicated that the disturbance by plateau zokors significantly affected the functional groups involved in carbon (C) and nitrogen (N) cycling. Overall, these findings significantly enhance our understanding of how small mammal activities influence the soil nutrient cycling and bacterial community in the Qinghai-Tibet Plateau (QTP) alpine meadow.

Prevalence and genetic diversity of Bartonella spp. in wild small mammals from South Africa.

Bartonella spp. are intracellular bacteria associated with several re-emerging human diseases. Small mammals play a significant role in the maintenance and spread of Bartonella spp. Despite the high small mammal biodiversity in South Africa, there is limited epidemiological information regarding Bartonella spp. in these mammals. The main aim of this study was to determine the prevalence and genetic diversity of Bartonella spp. from wild small mammals from 15 localities in 8 provinces of South Africa. Small mammals (n = 183) were trapped in the Eastern Cape, Free State, Gauteng, Limpopo, Mpumalanga, Northern Cape, North West, and Western Cape provinces of South Africa between 2010 and 2018. Heart, kidney, liver, lung, and spleen were harvested for Bartonella DNA screening, and prevalence was determined based on the PCR amplification of partial fragments of the 16S-23S rRNA intergenic spacer (ITS) region, gltA, and rpoB genes. Bartonella DNA was detected in Aethomys chrysophilus, Aethomys ineptus, Gerbillurus spp., Lemniscomys rosalia, Mastomys coucha, Micaelamys namaquensis, Rhabdomys pumilio, and Thallomys paedulcus. An overall prevalence of 16.9% (31/183, 95% CI: 12.2%-23%) was observed. Bartonella elizabethae, Bartonella grahamii, and Bartonella tribocorum were the zoonotic species identified, while the remaining sequences were aligned to uncultured Bartonella spp. with unknown zoonotic potential. Phylogenetic analyses confirmed five distinct Bartonella lineages (I-V), with lineage IV displaying strong M. coucha host specificity. Our results confirm that South African wild small mammals are natural reservoirs of a diverse assemblage of Bartonella spp., including some zoonotic species with high genetic diversity, although prevalence was relatively low.IMPORTANCESmall mammals play a significant role in the maintenance and spread of zoonotic pathogens such as Bartonella spp. Despite the high small mammal biodiversity in southern Africa including South Africa, there is limited epidemiological information regarding Bartonella spp. in these mammals across the country. Results from our study showed the liver and spleen had the highest positive cases for Bartonella spp. DNA among the tested organs. Bartonella elizabethae, B. grahamii, and B. tribocorum were the three zoonotic species identified and five distinct Bartonella lineages (I-V) were confirmed through phylogenetic analyses. To the best of our knowledge, this study presents the first extensive nuclear diversity investigation of Bartonella spp. in South African small mammals in South Africa.

Mining metagenomic data to gain a new insight into the gut microbial biosynthetic potential in placental mammals.

Mammals host a remarkable diversity and abundance of gut microbes. Biosynthetic gene clusters (BGCs) in microbial genomes encode biologically active chemical products and play an important role in microbe-host interactions. Traditionally, the exploration of gut microbial metabolic functions has relied on the pure culture method. However, given the limited amounts of microbes being cultivated, insights into the metabolism of gut microbes in mammals continued to be very limited. In this study, we adopted a computational pipeline for mining the metagenomic data (named taxonomy-guided identification of biosynthetic gene clusters, TaxiBGC) to identify experimentally verified BGCs in 373 metagenomes across 53 mammalian species in an unbiased manner. We demonstrated that polyketides (PKs) and nonribosomal peptides (NRPs) are representative of mammals, and the products derived from them were associated with cell-cell communication and resistance to inflammation. Large carnivores had the highest number of BGCs, followed by large herbivores and small mammals. We also observed that the large mammals had more common BGCs that aid in the biosynthesis of a variety of natural products. However, small mammals not only had fewer BGCs but were also unique to each species. Our results provide novel insights into the mining of metagenomic data sets to identify active BGCs and their products across mammals.IMPORTANCEThe gut microbes host numerous biosynthetic gene clusters (BGCs) that biosynthesize natural products and impact the host's physiology. Historically, our understanding of BGCs in mammalian gut microbes was largely based on studies on cultured isolates; however, only a small fraction of mammal-associated microbes have been investigated. The biochemical diversity of the mammalian gut microbiota is poorly understood. Metagenomic sequencing contains data from a vast number of organisms and provides information on the total gene content of communities. Unfortunately, the existing BGC prediction tools are designed for individual microbial genomes. Recently, a BGC prediction tool called the taxonomy-guided identification of biosynthetic gene clusters (TaxiBGC) that directly mine the metagenome was developed. To gain new insights into the microbial metabolism, we used TaxiBGC to predict BGCs from 373 metagenomes across 53 mammalian species representing seven orders. Our findings elucidate the functional activities of complex microbial communities in the gut.

Extreme Body Condition Index Values in Small Mammals.

The body condition index (BCI) values in small mammals are important in understanding their survival and reproduction. The upper values could be related to the Chitty effect (presence of very heavy individuals), while the minimum ones are little known. In this study, we analyzed extremes of BCI in 12 small mammal species, snap-trapped in Lithuania between 1980 and 2023, with respect to species, animal age, sex, and participation in reproduction. The proportion of small mammals with extreme body condition indices was negligible (1.33% with a BCI < 2 and 0.52% with a BCI > 5) when considering the total number of individuals processed (n = 27,073). When compared to the expected proportions, insectivores and herbivores were overrepresented, while granivores and omnivores were underrepresented among underfit animals. The proportions of granivores and insectivores were higher, while those of omnivores and herbivores were lower than expected in overfit animals. In several species, the proportions of age groups in underfit and overfit individuals differed from that expected. The male-female ratio was not expressed, with the exception of Sorex araneus. The highest proportion of overfit and absence of underfit individuals was found in Micromys minutus. The observation that individuals with the highest body mass are not among those with the highest BCI contributes to the interpretation of the Chitty effect. For the first time in mid-latitudes, we report individuals of very high body mass in three shrew species.

Verifying the Diet of the Slender Racer, &lt;i&gt;Orientocoluber spinalis&lt;/i&gt; (Peters, 1866), Rare, Threatened, and Endangered Across Northeast Asian Countries

Understanding the diet of a species provides important information on various aspects of its ecology. Diet studies are few on the reptile species, of which observation frequency is very low, due to the great difficulty of sampling. We investigated the diet of Orientocoluber spinalis, a long and slender small grassland snake with high rarity and a high extinction risk across northeast Asian countries, by applying regurgitated stomach content analysis and metabarcoding analysis using a developed O. spinalis blocking primer. Among 19 diet samples, which were mainly collected on islands along the west coast of the Korean Peninsula, we determined the food sources of 13 samples, which consisted of four small vertebrate species, the Tsushima smooth skink (Scincella vandenburghi), mountain grass lizard (Takydromus wolteri), Japanese keelback (Hebius vibakari), and lesser white-toothed shrew (Crocidura shantungensis). Among them, O. spinalis most frequently fed on S. vandenburghi (10 of 13 cases). Our results show that O. spinalis mainly forages small reptiles and mammals in grasslands adjoining to lowland forests and could be beneficial for conservation in the field and rearing of this vulnerable species in the facilities.

Retinal neuroanatomy of two emerging model organisms, the spiny mouse (Acomys dimidiatus) and the Mongolian gerbil (Meriones unguiculatus)

Current research using animal models to investigate retinal cell biology and model retinal degenerative diseases largely utilize small mammals that are nocturnal and lack the ability to restore lost vision. In contrast, the Mongolian gerbil (Meriones) is a diurnal rodent with good photopic vision, and the spiny mouse (Acomys) is a small desert-dwelling rodent with remarkable regenerative capabilities. The goal of this study was to identify antibodies that detect retinal cell classes in Meriones and Acomys, and to describe the retinal anatomy of these two species in comparison to outbred laboratory mice (Mus musculus). Immunohistochemistry was performed on retinal sections with antibodies for various retinal cell types. Sections were imaged by light, fluorescence, and confocal microscopy. Cell density, morphology, and placement were compared between species qualitatively and quantitatively. Our analyses revealed a classic assembly of retinal cells in Meriones and Acomys, with a few deviations compared to Mus. Meriones displayed the highest density of cones and Acomys the lowest. A higher density of bipolar cell bodies in the proximal portion of the inner nuclear layer was observed in both Acomys and Meriones compared to Mus, and both species exhibited an increase in amacrine cell density compared to Mus. Our results provide a foundation for future research into the visual system adaptations of these interesting species.

The Specificity of Epizootic and Epidemiological Processes in Natural Foci of Hemorrhagic Fever with Renal Syndrome and Tick-Borne Encephalitis in Russia, as the Basis for the Prospects of Creating a Combined Vaccine for the Prevention of These Infections.

Hemorrhagic fever with renal syndrome (HFRS) and tick-borne encephalitis (TBE) are the most common viral diseases in Russia. HFRS is caused by six different types of hantaviruses: Hantaan, Amur, Seoul, Puumala, Kurkino, and Sochi, which are transmitted to humans through small mammals of the Muridae and Cricetidae families. TBE is caused by viruses belonging to five different phylogenetic subtypes. The similarities in the ecology of HFRS and TBE pathogens is presented here. Hantavirus-infected small mammals can transmit the virus to uninfected animals, and ticks can also transmit hantavirus to other ticks and mammals. Hantavirus transmission from ticks to humans is possible only hypothetically based on indirect data. Over the past 23 years, 164,582 cases of HFRS (4.9 per 105 people) and 71,579 cases of TBE (2.5 per 105 people) were registered in Russia. The mortality rate was 0.4% (668 cases) in HFRS and 1.6% deaths (1136 cases) in TBE. There were 4030 HFRS (2.5%) and 9414 TBE (13%) cases in children under 14 years old. HFRS and TBE cases were registered in 42 out of 85 Russian regions; in 18-only HFRS, in 13-only TBE, and 12 had no reported cases. The prospects of applying a combined vaccine for HFRS and TBE prevention are shown in this paper.

Island living indirectly affects hair glucocorticoid levels in a small mammal

Island living indirectly affects hair glucocorticoid levels in a small mammal

Association between Outlying Values in Body Condition Indices in Small Mammals and Their Habitats

Habitat type and habitat change are very important factors in the body condition of small mammals that inhabit them. The response can be positive, increasing, or the opposite, decreasing body condition. We analyzed outliers of the body condition indices (BCIs) of 12 species trapped in nine different habitats during 1980–2023 in Lithuania, a mid-latitude country. Mixed and fragmented habitats, as well as commensal habitats, could be considered the least suitable for small mammals, based on the highest proportions of underfit and low proportions of best-fit individuals. On the contrary, meadows and disturbed habitats (landfills and cormorant colonies) had the highest proportions of best-fit individuals, while the proportion of under-fit individuals was much lower than expected. We found outliers in the BCI in all species, except for the under-fit harvest mice (Micromys minutus), and in all habitats, though not numerous. The presence of the highest BCI in yellow-necked mice (Apodemus flavicollis) and bank voles (Clethrionomys glareolus) in the disturbed habitats studied and in house mice (Mus musculus) in commensal habitats may be related to the resources provided by these habitats. Our results demonstrate the feasibility of using retrospective small mammal morphometric data to analyze their relationship with habitat.