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Despite the lasting aversion many hold towards rats and mice owing to historical associations with diseases such as the plague, there exists a growing consensus among researchers advocating for a reappraisal of these creatures. A noticeable trend is emerging in Western Europe, wherein rodents are increasingly viewed as urban neighbors, challenging the prevailing negative perceptions. To explain the ongoing shift, we use examples from medicine, popular culture, science, and exhibitions. The recognition of rats and mice as sentient and intelligent beings necessitates human stewardship in the context of urban coexistence. We conclude that understanding the ecology and behavior of rats and mice in urban environments, as well as human behavior change, is a prerequisite for achieving harmonious urban coexistence.

Roof rats (Rattus rattus) are a successful invasive species worldwide because of their ability to exploit their commensal relationship with humans. They are opportunistic feeders that use a wide range of natural and anthropogenic food sources. Because some rodent control methods, such as traps and rodenticides, threaten non-target wildlife species, understanding the diets of roof rats can help develop targeted approaches to better control these pests. Our aim is to use stable isotope analysis and stomach contents analysis to determine the diets of roof rats collected in agricultural, urban, and suburban areas in California. We hypothesized that diets of roof rats trapped in agricultural areas would contain crop plants and food resources associated with the agricultural environ­ment (arthropods, mollusks), whereas those from urban and suburban areas, e.g., schools, residential zones, would consume a broader range of food sources, including anthropogenic foods such as pet food, trash, and produce from gardens and fruit trees. To date, we have obtained roof rat carcasses from control efforts across the state, including our own trapping in southern California. Rats were frozen until they could be dissected in the lab. From each rat, we removed the gastrointestinal tract and took a small sample of ear tissue for stable isotope analysis; all tissues were stored in 95% ethanol. Ear tissue samples were dried, cut into small pieces, and weighed before sending them to the UC Davis Stable Isotope Facility for stable carbon (C) and nitrogen (N) isotope analysis. Stomachs were dissected under a dissecting microscope and food items were identified using reference keys. Preliminary analyses of stomach contents revealed significant amounts of what appears to be plant material, seeds, arthropod parts, and rodenticide bait, as well as many roundworms. Isotopic analysis of ear tissue of 64 rats from four Central Valley counties and urban/suburban rats from three southern California counties (n = 65) and Yolo County (n = 14) showed that δ13C values of rats from urban settings were significantly enriched compared to rural rats (Figure 1; F = 4.52, d.f. = 1, 141, P = 0.053), which is consistent with an urban diet containing more anthropogenic foods. δ13C values of urban roof rats were also much more variable (coefficient-of-variation, CV = 8.7%) than that of rats from agricultural areas (CV = 3.6%), which showed remarkably little variation within a site, indicative of feeding on a concentrated, shared resource. δ15N of rats differed significantly between agricultural counties (F = 195.9, d.f. = 3, 60, P

The diet of a single Maghreb Owl Strix mauritanica (family Strigidae) was examined within its natural habitat at Kahf Lakhal cave on Jbel Moussa, a mountain in northern Morocco. The two distinct batches of pellets collected contained a total of 190 prey items. Pellet analysis revealed a diet comprised of four primary taxonomic classes of prey: mammals, insects, birds and reptiles. We identified 29 prey species, representing 21 families. Mammals were the most prominent component, accounting for 49.5% of the diet items and included at least nine distinct species. Insects constituted 28.9% of the diet, representing at least eight species; birds comprised 20%, representing at least 11 species; and reptiles were represented by a single species (3.4%). Numerically, the most frequently captured prey species were the common bent-wing bat Miniopterus schreibersii (22.1%), black rat Rattus rattus (8.4%) and European rhinoceros beetle Oryctes nasicornis (7.9%). In biomass, black rats were the biggest component of the owl's diet (31.8%), followed by Barbary Partridges Alectoris barbara and hares Lepus sp. (each 11.9%); together these three species comprised more than half the estimated biomass of the prey types consumed by the owl. This investigation significantly improves our knowledge of the diet of the Maghreb Owl in the North African region. [ABSTRACT FROM AUTHOR]

Background: The common cat tapeworm, Hydatigera taeniaeformis, is widely distributed across many regions of the world but its global genetic diversity, ecology, and other biological features are not fully understood. The predator-prey relationship of felids and rodents sustains the transmission in both sylvatic and synanthropic or urban settings. This study was carried out in three urban market centres in Tamale, Ghana to determine the prevalence of H. taeniaeformis infection in urban rats and characterise the local population genetics using the mitochondrial nad1 gene sequences. Methods: From January to May 2023, rats were captured and euthanized to identity and isolate the H. taeniaeformis metacestodes. The full mitochondrial nad1 gene was amplified, sequenced and used to characterise the cestode population. Results: In total 64/80 rats from the three market centres were found naturally infected with metacestodes of H. taeniaeformis. Averagely, infected rats harboured two cysts with one exceptional case of 25 cysts in one liver. Each cyst harboured one metacestode. The DNA sequences revealed four haplotypes in a star-like distribution network across the three market centres. All four haplotypes were found to be unique, clustered with H. taeniaeformis sensu stricto (s.s.) global isolates and had only marginal variation among themselves. Conclusion: This is the first account of the genetic variability within H. taeniaeformis in Ghana and would contribute to ongoing and future studies on African regional biogeographic distribution of the common cat tapeworm. [ABSTRACT FROM AUTHOR]

Simple Summary: Heterakis spumosa Schneider, 1886 is a parasite commonly found in rodents, primarily associated with the black rat Rattus rattus and the brown rat R. norvegicus, two global invasive rodent species, and the house mouse Mus musculus. This parasite originated probably from Asia, and has been reported in various rodent species, but molecular information from its putative native region is still lacking. Our sampling efforts across Southeast Asia allowed us to collect and analyze this species from two localities in Lao PDR and five localities in Thailand. Additionally, specimens from Europe were included in the analysis. All specimens were analyzed using mtCOI gene and nuclear ribosomal ITS1. Our findings revealed the presence of two distinct clades of H. spumosa, with no discernible association with hosts and geographical localities. Heterakis spumosa, a parasitic worm infecting rodents, is globally prevalent in black rats, brown rats, and house mice. It is hypothesized to originate from Asia due to its widespread presence in Southeast Asia in various Murinae. Previous molecular studies focused on European, African, and Japanese specimens, but none included samples from the putative native range. Rodents were collected between 2008 and 2015 across various localities in Southeast Asia and Europe, identified by morphology or genetic barcoding. Viscera were examined or preserved for later inspection. DNA was extracted from H. spumosa. PCR amplification targeting the mtCOI gene and ITS1 region was conducted in this study using newly designed primers (based on Heterakis reference sequences). PCR amplicons were subsequently sequenced and analyzed. In this study, the phylogenetic analysis using ITS1 sequences revealed that Heterakis samples from Thai and Laotian rodents belong to the species H. spumosa, exhibiting low genetic variation compared to samples from other regions. Genetic distance calculations using mtCOI sequences confirmed the marked distinction of H. spumosa from other Heterakis species. Our phylogenetic analyses using partial mtCOI and ITS1 sequences have significantly enhanced our comprehension of the genetic diversity and evolutionary history of the nematode H. spumosa. [ABSTRACT FROM AUTHOR]

Retinitis pigmentosa (RP) is a genetic blinding disease with over 80 causative genes. Disease progression varies between patients with similar genetic backgrounds. We assessed the association between environment, gut microbiota, and retinal degeneration in the RP rat model Royal College of Surgeons (RCS). The rats were born and raised for two generations under specific pathogen-free (SPF, n = 69) or non-SPF conditions (n = 48). At the age of four weeks, SPF rats had significantly shorter dark-adapted a-wave and dark and light-adapted b-wave implicit times by electroretinogram (p = 0.014, p = 9.5*10−6, p = 0.009, respectively). The SPF rats had significantly less photoreceptor apoptosis at ages four, eight, and twelve weeks (all p < 0.022), significantly thicker debris zone at age 14 weeks, and smaller hypofluorescent lesions in SPF rats at ages 10–16 weeks, especially in the inferior retina. The non-SPF rats had significantly higher microbiota alpha diversity (p = 0.037) and failed to present the age-related maturation of Proteobacteria, Spirochaetes, Actinobacteria, and Bacteroidetes seen in SPF conditions. Specific microbial amplicon sequence variants were reduced in rats with more severe retinal degeneration. Our data suggest an environmental effect on retinal deterioration in RCS rats. These findings may lead to the development of novel microbiome-related interventions for retinal degeneration. [ABSTRACT FROM AUTHOR]

Introduction: Enterocytozoon bieneusi is one of the most important zoonotic pathogens, responsible for nearly 90% of human infections. Its host spectrum is broad in China, encompassing humans, non-human primates, domestic animals, wildlife, and wastewater. Wild rodents have the potential to act as carriers of E. bieneusi, facilitating the parasite’s transmission to humans and domestic animals. Methods: The present study involved the collection of 344 wild rodents, representing nine species, from three provinces in China. The prevalence and genotypes of E. bieneusi were determined through amplification of the ITS gene. Evolutionary analysis was conducted using Mega 5.0 with the neighborjoining method (Kimura 2-parameter model, 1,000 replicates). Results: Among the sampled wild rodents, 41 (11.92%) were tested positive for E. bieneusi. Rattus flavipectus exhibited the highest prevalence (11/39), while Bandicota indica and Rattus rattus sladeni showed no infections (0/39 and 0/5, respectively), highlighting significant differences. Environmental factors strongly influenced E. bieneusi infection; rodents residing in lake beaches (10.27%, 15/146) and fields (19.95%, 18/95) were more susceptible compared to those in mountainous areas (7.77%, 8/103). The study identified four known genotypes (D, Type IV, SDD5, PigEBITS7) and five novel genotypes (HNRV-1 to HNRV-3, GXRL-1, GXRL-2) in the investigated wild rodents, with Genotype D exhibiting the highest prevalence. Discussion: Remarkably, this study reports the presence of E. bieneusi, R. flavipectus, M. fortis, A. agrarius, R. losea, and N. lotipes for the first time. These findings underscore the common occurrence of E. bieneusi infection in wild rodents in China, highlighting its diverse nature and significant potential for zoonotic transmission. Hence, it is imperative to conduct a comprehensive epidemiological investigation of rodent infection with E. bieneusi, particularly focusing on wild rodents that are closely associated with humans. Additionally, developing appropriate measures and monitoring strategies to minimize the risk of infection is essential. [ABSTRACT FROM AUTHOR]

Frequent encounters with the greater bandicoot rats (Bandicota indica) following high rodent damage towards rice crops and lack of information on the species had encouraged this study to be conducted to test the relevance of using first- and second-generation rodenticide in a field efficacy test. This study also attempts to detect any sign of resistance of current rodent pest populations towards chlorophacinone (0.005%) and flucoumafen (0.05%) for the control of field rats predominant rice field agrosystem of the Kedah in northern peninsular Malaysia. Six different treatments over dry and wet rice planting season together with trapping exercise. The observation was evaluated based on the number of active burrows, counting tiller damage due to rodent attack and trapping index. The results indicated that flucoumafen gives better rodent control and has a better impact (p < 0.05) although chlorophacinone is still relevant to be applied (p < 0.05). Treatments during the off-planting season (September-February) are more effective compared to the main planting season (March-August). Rodent control during the early off-planting season is encouraged for better rodent management in the rice field and the use of bait stations to increase the weatherability of the baits. [ABSTRACT FROM AUTHOR]

Synanthropic wild rodents associated with agricultural operations may represent a risk path for transmission of high pathogenicity avian influenza viruses (HPAIVs) from wild birds to poultry birds. However, their susceptibility to HPAIVs remains unclear. In the present study, house mice (Mus musculus), brown rats (Rattus norvegicus), and black rats (Rattus rattus) were experimentally exposed to H5N1 subtype HPAIVs to evaluate their vulnerability to infection. After intranasal inoculation with HA clade 2.2 and 2.3.2.1 H5N1 subtype HPAIVs, wild rodents did not show any clinical signs and survived for 10- and 12-day observation periods. Viruses were isolated from oral swabs for several days after inoculation, while little or no virus was detected in their feces or rectal swabs. In euthanized animals at 3 days post-inoculation, HPAIVs were primarily detected in respiratory tract tissues such as the nasal turbinates, trachea, and lungs. Serum HI antibodies were detected in HA clade 2.2 HPAIV-inoculated rodents. These results strongly suggest that synanthropic wild rodents are susceptible to infection of avian-origin H5N1 subtype HPAIVs and contribute to the virus ecosystem as replication-competent hosts. Detection of infectious viruses in oral swabs indicates that wild rodents exposed to HPAIVs could contaminate food, water, and the environment in poultry houses and play roles in the introduction and spread of HPAIVs in farms. [ABSTRACT FROM AUTHOR]

Male Zucker Diabetic Sprague Dawley rats were housed in standard individually ventilated cages with floor area of 1500 cm2, and were placed in a 'playcage' (a large open cage) for three visits per week from the age of 16–18 weeks. The playcage was introduced in an attempt to reverse the compulsive behaviour that the rats displayed in the individually ventilated cages, with the purpose to increase their well-being and to provide cognitive as well as physical stimulation. After two weeks of periodic stays in the playcage, the rats' repetitive behaviour in their home cage ceased, and the rats displayed signs of happiness and excitement when they were in the playcage. The observations strongly indicate that periodic stays in a larger playcage can be an alternative environmental enrichment for laboratory rats when housing in a larger home cage is not an option. [ABSTRACT FROM AUTHOR]

The ability to recognize and differentiate between conspecifics and heterospecifics as well as their signals is critical for the coexistence of closely related species. In the genus Rattus , species are morphologically similar and multiple species often coexist. Here, we investigated the interspecific recognition and signal differentiation of two sympatric rat species, the brown rat (Rattus norvegicus , RN) and the Asian house rat (Rattus tanezumi , RT). In a two-way choice test, both RN and RT females showed a preference for conspecific male rats to heterospecific ones. RT females showed a significant preference for accessible urine of males of same species to those of other species, but not for the inaccessible urine. On the other hand, there were significant differences in the structural characteristics of the ultrasonic vocalization emitted by males of these two rat species. Sodium dodecyl sulphate‒polyacrylamide gel electrophoresis (SDS‒PAGE) and isoelectric focusing electrophoresis unveiled that major urinary proteins (MUPs) in voided urine were more highly expressed in RN males versus RT males. The interspecific differences of urinary volatile compounds were also discussed. In conclusion, female rats had the ability to distinguish between males of either species. [ABSTRACT FROM AUTHOR]

Eradicating invasive predators from islands can result in substantial recovery of seabirds, but the mechanisms that drive population changes remain poorly understood. Meta‐analyses have recently revealed that immigration is surprisingly important to the recovery of philopatric seabirds, but it is not known whether dispersal and philopatry interact predictably to determine rates of population growth and changes of distribution. We used whole‐island surveys and long‐term monitoring plots to study the abundance, distribution, and trends of 4 burrowing seabird species on Macquarie Island, Australia, to examine the legacy impacts of invasive species and ongoing responses to the world's largest eradication of multiple species of vertebrates. Wekas (Gallirallus australis) were eradicated in 1988; cats (Felis catus) in 2001; and rabbits (Oryctolagus cuniculus), black rats (Rattus rattus), and mice (Mus mus) in 2011–2014. We compared surveys from 1976–1979 and 2017–2018 and monitoring from the 1990s and 2000s onward. Antarctic prions (Pachyptila desolata) and white‐headed petrels (Pterodroma lessonii) increased ∼1% per year. Blue petrels (Halobaena caerulea) and gray petrels (Procellaria cinerea) recolonized following extirpation from the main island in the 1900s but remained spatially and numerically rare in 2018. However, they increased rapidly at 14% and 10% per year, respectively, since cat eradication in 2001. Blue and gray petrel recolonization occurred on steep, dry, west‐facing slopes close to ridgelines at low elevation (i.e., high‐quality petrel habitat). They overlapped <5% with the distribution of Antarctic prion and white‐headed petrels which occurred in suboptimal shallow, wet, east‐facing slopes at high elevation. We inferred that the speed of population growth of recolonizing species was related to their numerically smaller starting size compared with the established species and was driven by immigration and selection of ideal habitat. [ABSTRACT FROM AUTHOR]

Despite the pernicious impacts that invasive black rats Rattus rattus have on island ecosystems, little is known about their effect upon insular reptiles, which are a highly vulnerable but pivotal element of island biota. To bring to light these effects, we evaluated the threat posed by R. rattus on the critically endangered Canarian spotted lizard Gallotia intermedia by analyzing its frequency of occurrence on rat feces, estimating rat abundance and density, and correlating these parameters with previous lizard censuses. We genetically detected that 14.96% of all rat feces contained G. intermedia, with 27.27% of individual R. rattus consuming this lizard. Rat density varied from 0.740 ± 0.474 to 2.183 ± 1.137 rats/ha and was correlated with larger declines of G. intermedia between past censuses and those of 2019. These results confirm for the first time that R. rattus consumes and impacts this endemic and endangered lizard species. From a broader perspective, this is one of the first studies detecting rat impact on a large-sized reptile, which calls for further attention to the interaction between invasive rats and a highly vulnerable but essential component of island ecosystems. [ABSTRACT FROM AUTHOR]

BACKGROUND: The mechanisms that regulate multi‐annual population dynamics of rodent pest species of cereal crops is often unknown. Better knowledge of such aspects can aid pest management and in turn improve food security and human health. The patterns and processes of the population dynamics of Rattus argentiventer, in rice fields of Indonesia, and Rattus tanezumi, in rice fields of the Philippines were assessed in this article. RESULTS: The meta‐analysis of trapping data over 20 years in Indonesia, and 16 years in the Philippines indicated that rodent populations in rice fields did not show a regular multi‐annual pattern. Rattus argentiventer populations in Indonesia responded to less rainfall from the current year. Rattus tanezumi populations in the Philippines responded positively to both rainfall and rainfall anomaly with a 1‐year time lag. CONCLUSIONS: Our study of long‐term population data indicates that certain combinations of rainfall parameters could be useful to predict years when there is higher rodent abundance in rice fields. The key rodent pest species in rice fields in Indonesia (R. argentiventer) and the Philippines (R. tanezumi) differ, and the populations of each species respond differently to rainfall anomalies. Other factors such as crop cover and water availability may also be important and should be considered in future work. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rat eradication from islands is a very effective tool that can free entire ecosystems from the pressure of alien predators. In this study we present the case study of Ventotene (Ponziane Archipelago, central Italy), which to date is the island with by far the greatest number of human inhabitants ever freed from the negative implications of rats. Rat eradication was carried out in the framework of the Life PonDerat project, co‐financed by the European Union. Besides considering the conservation benefits due to the removal of rats, we also considered the socio‐economic and pathogenic impacts from introduced rats. RESULTS: The overall economic cost of the rats was quantified to be at least €18 500 per year to the residents of the island. Several zoonotic pathogens were detected in the rat population prior to eradication. A reduction in the rodenticide distributed over time on the island was also estimated. Identifying the origin of the rat population allowed for the development of more targeted and effective biosecurity measures. The eradication effort was challenged by the presence of domestic animals and variability in support for baiting in urbanised areas. CONCLUSIONS: The results of this study open up new perspectives on island restoration projects. We demonstrated the cost‐effectiveness of the action, including ecosystem restoration, reduction of rat impacts in agricultural systems, and improving overall health and food safety. Our findings will have implications for similar interventions on other islands, potentially bringing significant benefits. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Habitat loss, fragmentation, and degradation of habitats are among the most pervasive impacts on species persistence. Mammals may vary in their response to these impacts, both in abundance and in physiological parameters. Herein, we verified how habitat quality influenced the small mammal nutritional status and stress levels among five semi‐deciduous forest remnants in the Brazilian Cerrado. To assess species' physiological responses, we used body condition as an indicator of nutritional status and neutrophil/lymphocyte (N/L) ratio as an indicator of chronic stress in Gracilinanus agilis and Rhipidomys macrurus. We sampled 264 animals belonging to the following species: G. agilis, Didelphis albiventris, Akodon montensis, Oligoryzomys spp., Rattus rattus, R. macrurus, Oecomys cleberi, Hylaeamys megacephalus, and three unidentified rodent species. We found no negative effect of reduced habitat quality on the body condition of G. agilis and R. macrurus, however, the N/L ratios of these species were lower only in high‐quality habitats, demonstrating that this parameter is an accurate indicator of chronic stress. Based on preliminary analysis, we also reported an impoverished fauna, mainly dominated by generalist species, in low‐quality habitats. Thus, we conclude that short‐term reduction in habitat quality leads to increased stress levels, which can in turn lead to future population declines and culminate in biotic homogenization. [ABSTRACT FROM AUTHOR]

Introduction: Blastocystis is one of the most critical intestinal protozoans in various hosts, including humans and mice. To determine the status of Blastocystis infection in wild rodents in China. Methods: A total of 344 faecal samples were collected from seven wild rodent species from three provinces, and the small subunit ribosomal RNA (SSU rRNA) genes of Blastocystis were amplified to determine their prevalence and subtypes. Results: Of the 344 samples, 54 (15.70%) were detected as Blastocystis-positive. The prevalence of Blastocystis was 26.14% (40/153), 7.95% (7/88), and 6.80% (7/103) in wild rodents from Hunan Province, Yunnan Province, and Guangxi Province, respectively. The prevalence of Blastocystis in different wild rodent species varied from 0.00% (0/13) in Mus musculus to 40.00% (2/5) in Rattus rattus sladeni. The prevalence of Blastocystis in samples from the lake beach area (27.40%, 40/146) was significantly higher than in those from the mountain (6.80%, 7/103) and field regions (7.37%, 7/95). The prevalence in different seasons was 26.14% in summer (40/153), 7.95% in autumn (7/88), and 6.80% in winter (7/103). Moreover, a total of two Blastocystis subtypes were identified in the investigated wild rodents, including ST4 and ST5. Discussion: The present study discovered the existence of Blastocystis infection in Rattus favipectus, Microtus fortis, Apodemus agrarius, Bandicota indica, Rattus rattus sladeni, and Rattus losea, expanding the host range of this parasite. The findings also demonstrate that wild rodents may be an important potential infection source for Blastocystis infection in humans and other animals. [ABSTRACT FROM AUTHOR]

Co‐invasion, characterized by the simultaneous introduction of hosts and parasites with the latter establishing themselves in native hosts, is a phenomenon of ecological concern. Rattus rattus, a notorious invasive species, has driven the extinction and displacement of numerous avian and mammalian species and serves as a key vector for diseases affecting both humans and wildlife. Among the parasites hosted by R. rattus are fleas, which exhibit obligate parasitic behaviour, a generalist nature and high prevalence, increasing the likelihood of flea invasion. Simultaneously, invasive species can serve as hosts for native parasites, leading to potential amplification or dilution of parasite populations in the environment. In Chile, R. rattus has been present since the 17th century because of the arrival of the Spanish colonizers through the ports and has spread throughout urban, rural and wild Chilean territories. This study aims to evaluate whether co‐invasion of native fleas of invasive rats occurs on native rodents in Chile and to determine whether black rats have acquired flea native to Chile during their invasion. For this, we captured 1132 rodents from 26 localities (20° S–53° S). Rattus rattus was found coexisting with 11 native rodent species and two species of introduced rodents. Among the native rodents, Abrothrix olivacea and Oligoryzomys longicaudatus exhibited more extensive sympatry with R. rattus. We identified 14 flea species associated with R. rattus, of which only three were native to rats: Xenopsylla cheopis, Leptopsylla segnis and Nosopsyllus fasciatus. These three species presented a higher parasite load in black rats compared to native fleas. Leptopsylla segnis and N. fasciatus were also found associated with native rodent species that cohabit with R. rattus. The remaining species associated with R. rattus were fleas of native rodents, although they were less abundant compared to those associated with native rodents, except for Neotyphloceras pardinasi and Sphinctopsylla ares. Although there has been evidence of flea transmission from rats to native species, the prevalence and abundance were relatively low. Therefore, it cannot be definitively concluded that these fleas have established themselves in native rodent populations, and hence, they cannot be classified as invasive fleas. This study underscores R. rattus’ adaptability to diverse environmental and geographical conditions in Chile, including its capacity to acquire fleas from native rodents. This aspect has critical implications for public health, potentially facilitating the spread of pathogens across various habitats where these rats are found. [ABSTRACT FROM AUTHOR]

In recent years, the transmission of viruses from wildlife to humans has raised significant public health concerns, exemplified by the COVID-19 pandemic caused by the betacoronavirus SARS-CoV-2. Human activities play a substantial role in increasing the risk of zoonotic virus transmission from wildlife to humans. Rats and mice are prevalent in urban environments and may act as reservoirs for various pathogens. This study aimed to evaluate the presence of zoonotic viruses in wild rats and mice in both urban and rural areas, focusing on well-known zoonotic viruses such as betacoronavirus, hantavirus, arenavirus, kobuvirus, and monkeypox virus, along with other viruses occasionally detected in rats and mice, including rotavirus, norovirus, and astrovirus, which are known to infect humans at a high rate. A total of 128 animals were captured, including 70 brown rats (Rattus norvegicus), 45 black rats (Rattus rattus), and 13 house mice (Mus musculus), and feces, lung, and liver were collected. Among brown rats, one fecal sample tested positive for astrovirus RNA. Nucleotide sequencing revealed high sequence similarity to both human and rat astrovirus, suggesting co-presence of these viruses in the feces. Murine kobuvirus (MuKV) was detected in fecal samples from both black (n = 7) and brown (n = 6) rats, primarily from urban areas, as confirmed by sequence analysis. These findings highlight the importance of surveillance and research to understand and mitigate the risks associated with the potential transmission of pathogens by rodents. [ABSTRACT FROM AUTHOR]

Pheromones and olfactory communication play vital roles in sex recognition and mate choice in rodents. Asian house rats (Rattus tanezumi) (RT) often startle easily, making behavioral measurements difficult to carry out accurately in the laboratory. Here, the behavioral and olfactory preferences of the female RT between males and females were not observed using a conventional two‐choice device; we then explored the neuro‐immunohistochemical evidence in the brains of RT females. We found that male urine elicited significantly higher c‐fos expression in the accessory olfactory system and sex‐related brain regions in females than female urine did. On the other hand, the differences of volatile compounds and major urinary proteins (MUPs) in both voided urine and preputial glands (PGs) of the RT were detected using gas chromatography–mass spectrometer, sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, isoelectric focusing electrophoresis, and liquid chromatography–electrospray ionization mass spectrometry. We found that PG‐derived 1‐(4,5‐dihydro‐2‐thiazolyl)‐ethanone and total MUPs were more abundant in males versus females, suggesting these sexually divergent components might activate the female's accessory olfactory system. In conclusion, the neuro‐immunohistochemical evidence indicated that potential sex pheromones might exist in RT; however, the strength of the chemical signal might be too weak to cause behavioral responses in females. [ABSTRACT FROM AUTHOR]

The present study was carried out to determine the chemistry of the preputial gland (PG) of mature male black rats and its role in sexual and social communication. 50% PG extracts from male rats of different age groups were prepared using n-hexane and dichloromethane and tested against black rats of different age groups and sexes. Results revealed that mature females were highly attracted towards and mature males were highly repelled from preputial gland extract of mature male rats for five and two days, respectively. Comparison of gas chromatography linked mass spectrometry analysis of fresh and eight days old PG extract revealed that 13 pheromonal compounds (.+/-.)-.alpha.-tocopherol acetate; acetophenone; undecane; dodecane; tridecane; tetradecane; heneicosane; docosane; squalene; cholesterol; octadecanal; palmitic acid; stigmastan-3,5-diene) were exclusively present in fresh extract but absent in eight days old preputial gland extract. These 13 compounds are already reported to have role in sexual and social communication in other mammals, insects and reptiles. They might be used by mature male rats for sexual and social communication. In the future, these identified compounds can be used in fixed proportions individually and in various combinations after testing their efficacy to develop a stable lure to increase the trappability and acceptability of antifertility agents and rodenticide-based baits for the management of black rats. [ABSTRACT FROM AUTHOR]

Niche partitioning is a common strategy species use to avoid competition for limited resources, allowing them to coexist. Rodent species often reduce competition by spatial segregation and trophic differentiation, but behavioural differences, particularly related to foraging, can also be important. Therefore, temporal segregation can also be an important mechanism for species coexistence, as it helps them avoid sub‐optimal habitats. We found three rodent species (the native Octodon degus and O. lunatus, and the exotic Rattus rattus) foraging on endemic palm Jubaea chilensis seeds, a highly valuable but limited resource. We hypothesized that these rodent species could coexist by segregating foraging in time, showing behavioural differences. To test this, we used camera traps to monitor the fate of J. chilensis seeds and rodent activity at 25 feeding stations. From 596 photographic records, we identified 128 as O. degus, 232 as O. lunatus and 236 as R. rattus. Octodon degus had a diurnal activity, while O. lunatus and R. rattus were nocturnal, showing significant temporal segregation. However, we found no spatial association among these rodents. We found significant behavioural differences in decision and handling times and seed removal rates, with O. degus having the greatest seed removal rate. Nevertheless, we found some nocturnal O. degus records in which the three rodent species were co‐foraging, which may suggest that the resource is limited but valuable enough to shift from exploitation to interference competition. Our results suggest that temporal and behavioural differentiation are more important than spatial segregation and trophic differentiation. Thus, niche partition over multiple dimensions might allow for species coexistence. [ABSTRACT FROM AUTHOR]

The present study, conducted from August to November 2022 in district Okara, Pakistan, focused on assessing the bacterial characterization in oral saliva swabs of black rats (Rattus rattus). DNA extraction was performed using the QIAamp DNA Microbiome kit, and the 16S rRNA gene was amplified using universal primers to amplify variable regions (V) V1 to V8 of 1380 bp. The identified bacterial phyla were as follows: Proteobacteria 98%, Firmicutes 1%, Actinobacteria 0.4%, and Bacteroidetes 0.05%. The bacterial classes included Gammaproteobacteria 95%, Alpha Enterobacterales 3%, and Bacilli 1%. The relative abundance of different bacterial orders was Pseudomonadales 40%, Enterobacterales 30%, Xanthomonadales 25%, Sphingomonadales 3%, Lactobacillales 1%, Micrococcales 0.4%, and Bacteroidales 0.05%. The identified families followed the order of Pseudomonadaceae 40%, Enterobacteriaceae 30%, Xanthomonadaceae 25%, and Sphingomonadaceae 3%. The percentage distribution of Pseudomonas was 40%, Stenotrophomonas 25%, Sphingomonas 3%, Pantoea 2%, and Porphyromonas 0.05%. This knowledge enhances our understanding of bacterial infections in rodents, serving as crucial baseline data for bacterial species. The high prevalence of potentially pathogenic bacteria like Pseudomonas suggests a significant risk of zoonotic diseases that could affect both local wildlife and human populations. It is crucial that future studies should focus on identified bacterial communities in other rodent species and small mammals to compare their roles in disease ecology. This ongoing research could identify specific species that are particularly significant in zoonotic transmission, thereby guiding future studies and public health measures. [ABSTRACT FROM AUTHOR]

Background Methods and Results Conclusions Angiostrongylus cantonensis, commonly known as the rat lungworm, is a metastrongyloid nematode found primarily not only in tropical and subtropical regions but also in temperate areas and considered the leading cause of eosinophilic meningitis in humans. Synanthropic rodents such as Rattus norvegicus and Rattus rattus are the most frequent definitive hosts of this parasite.The presence of this parasite was detected in the pulmonary arteries of three specimens of R. norvegicus in the city of Buenos Aires representing the species' southernmost known record in natural hosts. Species confirmation was achieved through partial sequences of 18S and COI genes. By comparing the COI gene sequences with those available in GenBank through the construction of a haplotype network, we obtained that the analysed specimen presents high similarity with those reported in Japan and Southeast Asia.All infected rats were captured in an area surrounding a port with significant import and export activity, suggesting that A. cantonensis may have been introduced through commercial ships. Specifically, the parasite was detected in a neighbourhood with vulnerable socio‐economic conditions and in a nature reserve, which exhibit biotic and abiotic characteristics conducive to sustaining high‐density rat populations, scattered waste, areas of spontaneous vegetation, debris accumulation and flooded areas or lagoons offering suitable habitats for intermediate hosts such as snails. Thus, the close proximity of the port to these sites creates a favourable ecological context for the establishment of A. cantonensis. This study shows the need to conduct research to detect A. cantonensis in non‐endemic areas but with the characteristics that promote its arrival and development of its life cycle in order to implement control measures to prevent expansion of this parasite and its transmission to humans and other animals. [ABSTRACT FROM AUTHOR]

Small terrestrial mammals are major hosts of infectious agents responsible for zoonotic diseases. Astroviruses (AstVs)–the cause of non-bacterial gastroenteritis mainly affecting young children–have been detected in a wide array of mammalian and avian host species. However, understanding the factors that influence AstV infection within and across hosts is limited. Here, we investigated the impact of land use changes on AstVs in terrestrial small mammals in rural northeastern Madagascar. We sampled 515 small mammals, representing seven endemic and four introduced species. Twenty-two positive samples were identified, all but one of which were found in the introduced species Mus musculus and Rattus rattus (family Muridae), with a positivity rate of 7.7% (6/78) and 5.6% (15/266), respectively. The non-introduced rodent case was from an endemic shrew-tenrec (family Tenrecidae). We found the highest positivity rate of AstVs infection in brushy regrowth (17.5%, 7/40) as compared to flooded rice fields (4.60%, 8/174), secondary forest (4.1%, 3/74), agroforest (3.6%, 1/28), village (2.61%, 3/115), and semi-intact forest (0%, 0/84). A phylogenetic analysis revealed an association between AstVs and their rodent host species. None of the viruses were phylogenetically related to AstVs previously described in Malagasy bats. This study supports AstV circulation in synanthropic animals in agricultural habitats of Madagascar and highlights the need to assess the spillover risk to human populations in rural areas. Author summary: This article describes the diversity of Astroviruses (AstVs) shed by Malagasy terrestrial small mammals and explores the impact of habitat degradation on positivity rate in animal reservoirs. Using a sample of 515 terrestrial small mammals from northeastern Madagascar, we show that AstV infection is almost exclusively restricted to rats and mice, suggesting that AstVs from terrestrial mammals were introduced to Madagascar. A phylogenetic analysis including AstVs sequences from Malagasy small mammals reveals a strong structuring of AstV sequences within host species, indicating limited host switching of these viruses among small mammals. Finally, positivity rates show that some habitat types are particularly conducive to AstV infection in reservoirs, such as rice fields where mice exhibit maximal infection. Altogether, presented data encourage the need for assessing the actual exposure of the local human population to the AstVs in small mammals, especially rice-field farmers. [ABSTRACT FROM AUTHOR]

Eradication of invasive alien species (IAS) is often proposed to restore invaded ecosystems, with information on subsequent ecosystem recovery key to conservation policies. Although ants perform major ecological functions in the ecosystem, their response to IAS eradication has received relatively little monitoring. This study investigated ant response to iceplant (Carpobrotus spp.) and black rat (Rattus rattus) eradications on the small Mediterranean island of Bagaud (Var, France). Ant communities were monitored over a ten-year period, including two years before eradications, at six different sites: two invaded by iceplants, two under high rat pressure, and two native vegetation sites without intervention. We found inter-annual variations in ant communities but no before-after eradication trend at both native vegetation and rat eradication sites. However, there was a clear increase in ant species richness and abundance score after the iceplant eradication. A core of common Mediterranean species, including Pheidole pallidula, Messor bouvieri, and Plagiolepis pygmaea, increased their foraging activity after the removal. As xerophilous and thermophilous species they would benefit from the return of native vegetation with possibly warmer and dryer microclimatic conditions, but also from habitat and resource diversification. The trend was even stronger on the denser and thicker iceplant eradication patch. Our results emphasize the relevance of implementing ant monitoring to evaluate the effectiveness of such restoration and conservation strategies. [ABSTRACT FROM AUTHOR]

The black rat (Rattus rattus) is a unique model for studying exploratory tactics due to its enormous colonizing potential. Considerable behavioral variability and consistent interindividual differences might help populations inhabit new environments and persist there even under intense pressure. Additionally, the affinity of the black rat for climbing might be another advantage, widening their potential niche. In this study, we describe the exploratory tactics of the black rats when introduced to a novel environment. In the first experiment, we tested 12 rats and calculated repeatability of their behaviors across 12 sessions of an enriched open-field test. We concluded that climbing is a highly repeatable behavior that serves as an important source of interindividual variability. In the second experiment, we tested 24 black rats in a unique L-shaped arena. Each rat was tested twice. We found that the majority of rats distributed their activity evenly, exploring each part of the apparatus for a similar amount of time, thus maximizing their chances of finding resources. Nevertheless, these "even" explorers still greatly differed in their level of activity, orderliness and affinity for climbing, generating large variability. In contrast, the minority of rats concentrated their activity only on a section of the new environment and were therefore characterized as selective explorers. Overall, we concluded that a combination of such exploratory tactics as well as a bias for even explorers enables black rats to quickly colonize new environments and persist there even under unfavorable conditions. [ABSTRACT FROM AUTHOR]

Aim: The rat lungworm, Angiostrongylus cantonensis, has recently been found in the city of Valencia, parasitizing rats, Rattus norvegicus and Rattus rattus, its natural definitive hosts. This is the first finding of this zoonotic nematode in continental Europe. After informing local and national health authorities, the collection of local terrestrial snails took place with the aim of elucidating their potential role as intermediate hosts of A. cantonensis. Methods and Results: A total of 145 terrestrial snails, belonging to the species Cernuella virgata, Cornu aspersum, Eobania vermiculata, Otala punctata, Pseudotachea splendida, Rumina decollata and Theba pisana, were randomly collected between May and December 2022 in public gardens, parks and orchards in six districts of Valencia, in five of which A. cantonensis had been reported previously in rats. Once collected and identified, the snails were frozen at −20°C. Subsequently, the DNA was isolated and screened by PCR using specific primers targeting the A. cantonensis COI gene. Seven individual snails, belonging to the species C. virgata, C. aspersum and T. pisana, were positive, for an overall prevalence of 4.8%. The PCR product from one of them was sequenced by Sanger sequencing. Conclusions: The three positive terrestrial snail species are among the edible species that are frequently included in various dishes in Spain. C. virgata is reported as a previously unrecorded intermediate host and should be added to the list of more than 200 species of terrestrial snails that have been reported worldwide as intermediate hosts of the rat lungworm. Considering that these terrestrial snails may release infective larvae of A. cantonensis on leafy green vegetables on which they feed and during their handling and preparation for consumption, prophylactic measures to prevent human neuroangiostrongyliasis in Valencia and other regions to which this zoonotic parasite may spread are recommended. [ABSTRACT FROM AUTHOR]

Predator–prey interaction is a major force driving natural selection. Yet, the identification of species preying on, or consuming, aposematic species is largely unknown. Here, I conduct a study evaluating the role of the exotic Rattus rattus as a consumer and possible predator of the aposematic and toxic Salamandra salamandra. I used camera traps to investigate the response of R. rattus towards S. salamandra carcasses in two insular populations, Ons and San Martiño (NW Spain), which show remarkable contrasting behaviour (nocturnal vs. diurnal activity) and demographic and phenotypic differences. This study unveils R. rattus consumes S. salamandra despite its aposematic colour pattern and toxicity. The high number of salamander carcasses consumed or taken by rats throughout each island (90%–100%) and the lack of other possible predator–prey interactions points to R. rattus as an efficient consumer of S. salamandra in these insular environments, which might exert a high predation pressure on both islands. Yet, the drivers underlying the behavioural and phenotypic differences in these insular populations should be further investigated. [ABSTRACT FROM AUTHOR]

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Negative interactions among invasive predators, competitors and native species can often disrupt ecosystem services, particularly when keystone species are affected. The Key Largo woodrat (Neotoma floridana smalli) is an endangered ecosystem engineer, endemic to protected hammocks on the northern third of the island of Key Largo, FL, USA. Invasive predator control efforts have assisted in woodrat recovery, but less is known about how a potential competitor, the black rat (Rattus rattus), interacts with the woodrat. We conducted camera trap surveys at supplemental nest sites throughout the range of the woodrat and used multi-species occupancy models to investigate factors influencing woodrat and black rat co-occurrence. Supplemental nest sites were surveyed each year over a three-year period, during which the population of black rats within the protected hammock declined precipitously. Woodrats and black rats occurred at similar levels in the first survey with occupancy probabilities of 22.8 % and 15.6 %, respectively. Both species occurred at fewer sites in the second survey, but while woodrats later rebounded, black rats were only detected twice in the final survey. There was evidence of species avoidance between the rodents based on a species interaction term, and they exhibited opposing relationships with predictor variables of both detection and occupancy probabilities. As the occupancy of black rats decreased, the relationship between woodrats and distance from developed areas also weakened. Following the black rat decline, woodrats recolonized an area previously dominated by black rats, where they had been presumed extirpated for 2–3 decades. Our results indicate that black rat competition restricted occupancy of Key Largo woodrats, hindering recovery efforts that previously concentrated on invasive predator removal, demonstrating the need to consider influences of both invasive predators and competitors in species recovery programs.

Background: Considering the expected increase in the elderly population and the growing emphasis on aging-related biomedical research, the demand for aged laboratory animals has surged, challenging established husbandry practices. Our objective was to establish a cost-effective method for environmental enrichment, utilizing the liver as a representative organ to assess potential metabolic changes in response to differing enrichment levels. Methods: We conducted a six-month study involving 24 male Sprague Dawley rats, randomly assigned to four environmental enrichment groups. Two groups were housed in standard cages, while the others were placed in modified rabbit cages. Half of the groups received weekly playtime in an activity focused rat housing unit. We evaluated hormone levels, playtime behavior, and subjective handling experience. Additionally, liver tissue proteomic analysis was performed. Results: Initial corticosterone levels and those after 3 and 6 months showed no significant differences. Yet, testosterone levels were lower in the control group by the end of the study (p = 0.007). We observed 1871 distinct proteins in liver tissue, with 77% being common across groups. In gene ontology analysis, no specific pathways were overexpressed. In semiquantitative analysis, we observed differences in proteins associated in lipid metabolism such as Apolipoprotein A-I and Acyl-CoA 6-desaturase, which were lower in the control group (p = 0.024 and p = 0.009). Rats in the intervention groups with weekly playtime displayed the least amount of reported distress during inspection or upon room entry and were less prone to accepting treats. Removing animals from their enclosure was most effortless for those in the large cage group. Over time, there was a decrease in conflicts among rats that interacted only twice weekly during playpen time. Discussion: In summary, refining husbandry practices for aging rats is both simple and budget-friendly, with no apparent adverse effects on stress levels, animal development, or relevant metabolic changes in the liver. [ABSTRACT FROM AUTHOR]

While the impacts of black (Rattus rattus) and brown (Rattus norvegicus) rats on human society are well documented--including the spread of disease, broad-scale environmental destruction, and billions spent annually on animal control--little is known about their ecology and behavior in urban areas due to the challenges of studying animals in city environments. We use isotopic and ZooMS analysis of archaeological (1550s-1900 CE) rat remains from eastern North America to provide a large-scale framework for species arrival, interspecific competition, and dietary ecology. Brown rats arrived earlier than expected and rapidly outcompeted black rats in coastal urban areas. This replacement happened despite evidence that the two species occupy different trophic positions. Findings include the earliest molecularly confirmed brown rat in the Americas and show a deep ecological structure to how rats exploit human-structured areas, with implications for understanding urban zoonosis, rat management, and ecosystem planning as well as broader themes of rat dispersal, phylogeny, evolutionary ecology, and climate impacts. [ABSTRACT FROM AUTHOR]

Research Highlight: Badou et al. (2023). Maritime international trade and bioinvasions: A three‐year long survey of small mammals in Autonomous Port of Cotonou, Benin. Journal of Applied Ecology, https://doi.org/10.1111/1365‐2664.14557. Highly connected points are probably the entry point for many of the introduced species around the world. This is the case of the Port of Cotonou in Africa, where the authors evaluated the population dynamics of small mammals present in the Autonomous Port of Cotonou, in Benin, Africa. Two main zones of the port were assessed: the industrial port, with warehouses, storage rooms, restaurants, garages and open areas, among other uses, and the artisanal port, with rooms where fresh fish and fishing gears are stores, along with the fresh fish market. Using traps, they were able to find that three of the '100 most invasive species' are present at the study area: the house mice (Mus musculus), black rat (Rattus rattus) and Norway rat (Rattus norvegicus). Two native species were also found, Mastomys natalensis and Crocidura olivieri. The authors found clear trends in the species preferences and co‐occurrences. Norwegian rats and house mice prefer industrial‐like environments, so they are mostly found in the industrial port. The Black rats, on the other hand, are present almost exclusively in the artisanal port. They were also able to determine that control efforts should be carefully planned to show long‐term effective results, involving decision makers and stakeholders at every step of the management process. [ABSTRACT FROM AUTHOR]

The present study aimed to detect the parasitic fauna associated with black rats (Rattus rattus) from southeastern Algeria. It showed the presence of seven species of parasitic fungi namely Penicillium sp. (Prevalence Pr=91.3%), Aspergillus niger (Pr=91.3%), Alternaria sp. (Pr=58.7%), Cladosporium sp. (Pr=87%), Microsporum sp. (Pr=19.6%), Trichophyton sp. (Pr=21.7%) and Chrysosporium sp. (Pr=10.9%), noting that saprophytic fungi were the most recorded. On the other hand, according to the richness (S), adults (S = 7) and sub-adults (S = 7) of black rats were the most infested, with leaning for males compared to females, considering all the isolated species as satellites except the Chrysosporium sp. (2.9%) which is presented as a rare species. Concerning parasitic bacteria, aged rats were the most infected followed by adults and sub-adults where total coliforms were present in all individuals of the three classes tested. However, fecal streptococci were noted with a similar infestation rate in all age groups. Unlike this, clostridium sulfite-reducer (CSR) was mostly recorded on aged rats. Concerning the endoparasites found in the intestines of black rats, the pinworms (Syphacia muris, Syphacia obvelata, and Aspiculuris tetraptera) were more abundant than the other species. Hence, the current study allowed us to demonstrate that black rats can be considered an important reservoir of several microorganisms that can hold germs and represent a threat to biomedical and veterinary public health. [ABSTRACT FROM AUTHOR]

Carrion acts as a hotspot of animal activity within many ecosystems globally, attracting scavengers that rely on this food source. However, many scavengers are invasive species whose impacts on scavenging food webs and ecosystem processes linked to decomposition are poorly understood. Here, we use Australia as a case study to review the extent of scavenging by invasive species that have colonised the continent since European settlement, identify the factors that influence their use of carcasses, and highlight the lesser‐known ecological effects of invasive scavengers. From 44 published studies we identified six invasive species from 48 vertebrates and four main groups of arthropods (beetles, flies, ants and wasps) that scavenge. Invasive red foxes (Vulpes vulpes), domestic dogs (Canis familiaris), feral pigs (Sus scrofa), black rats (Rattus rattus) and feral cats (Felis catus) were ranked as highly common vertebrate scavengers. Invasive European wasps (Vespula germanica) are also common scavengers where they occur. We found that the diversity of native vertebrate scavengers is lower when the proportion of invasive scavengers is higher. We highlight that the presence of large (apex) native vertebrate scavengers can decrease rates of scavenging by invasive species, but that invasive scavengers can monopolise carcass resources, outcompete native scavengers, predate other species around carcass resources and even facilitate invasion meltdowns that affect other species and ecological processes including altered decomposition rates and nutrient cycling. Such effects are likely to be widespread where invasive scavengers occur and suggest a need to determine whether excessive or readily available carcass loads are facilitating or exacerbating the impacts of invasive species on ecosystems globally. [ABSTRACT FROM AUTHOR]

AbstractRepeated use of rodenticides for rodent pest management leads to the development of bait shyness and resistance in rodents. Therefore, using pheromones for rodent management could be a significant step forward. The present study was conducted to determine the response of house rats towards odour of faecal extracts of conspecifics of different age groups and sexes. Rats of different maturity groups and sexes were exposed to 20% faecal extract of mature and immature male and female rats. Results indicated that faecal extract of estrous stage mature females has a significant attractant/repellent effect on mature rats of opposite/same sex, respectively. Gas chromatography-linked mass spectrometry of the faecal extract of estrous female rats identified 62 compounds, of which 16 were already reported in other animals as pheromonal compounds and might be used in communication by house rats. In the future, these identified compounds can be used in a fixed proportion after testing their efficacy to develop a stable lureto increase the trappability and acceptability of antifertility agents and rodenticide-based baits for the management of house rats. [ABSTRACT FROM AUTHOR]

We outline issues with a recent publication by Mein and Williams (2023), which is primarily based on the morphology and quantification of osteocyte lacunae, microscopic cavities that house cells (osteocytes) which sustain bone tissue in living vertebrates. Using 26 rats (Rattus rattus) of unreported age and sex, the authors propose a method whereby post-mortem bone degradation on a short timescale can be quantified by analysing subtle shape changes of osteocyte lacunae. However, a lack of consideration is given to the natural variation and other biological factors influencing osteocyte lacunar morphology; the proposed diagenetic composition of lacunae is not determined; and the methods employed, including the animal model used, are unfit for the purpose of the study. Given these issues, we believe the conclusions presented by the authors should be treated cautiously and not extended to forensic investigations of post-mortem interval, particularly in humans. [ABSTRACT FROM AUTHOR]

Cutaneous leishmaniasis is of particular importance in southern Iran. This study aimed to investigate the infection of rodents with Leishmania major in an urban area of Fars Province, located in southern Iran. Rodents were trapped and samples from the liver, spleen, and skin were collected. Impression smears were prepared from these tissues and any skin lesions and were examined microscopically. In addition, a portion of the samples were preserved for subsequent DNA extraction. A total of 41 rodents belonging to three species were caught from 10 trapping stations in gardens or houses within the area. The caught rodent species were Rattus rattus (n = 25, 60.97%), Mus musculus (n = 15, 36.58%), and Meriones persicus (n = 1, 2.5%). Leishmania amastigotes were seen in the spleen tissue smear of 6 (2.43%) of the rodents, including 4 of R. rattus and 2 of M. musculus. Skin lesions were observed on the muzzles of two R. rattus and one M. musculus. Samples taken from these lesions tested positive for Leishmania infection. Leishmania DNA was detected in 18 (43.9%) rodents, including 11 R. rattus, 6 M. musculus, and one M. persicus, based on DNA sequencing of the ITS2 gene and PCR of the kDNA. Phylogenetic reconstruction revealed that the parasite infecting the rodents was L. major. The detection of Leishmania infection in these rodents in urban areas raises concerns about the urbanization of cutaneous leishmaniasis caused by L. major. This urbanization poses unique challenges for control and prevention efforts. [ABSTRACT FROM AUTHOR]

Immunity is the body's defense mechanism against invaders. Thus, in the event that infections manage to penetrate the skin or mucous membranes, the immune system acts as the body's natural defensive mechanism. This investigation sought to determine if almond seeds may benefit hepatic rats' immune and histological systems. In this study, the animal was kept in a cage during the trial. Prior to the trial, for a week, the rats were housed in groups of six and given a standard diet. The first set of rats were negative normal controls (C-ve) and were given nothing except a baseline diet for twenty-eight days. The survival rats (n=24) were inoculated with carbon tetrachloride (Ccl4). There were three groups given different amounts of (5%, 10%, 15% almond seed), Nonetheless, one group was given the disease diagnosis before the experimental diet was even given. The findings revealed mostly significant differences among all groups contrasted with the C+ ve group. But no significant differences were observed between G3, and G4 for Monocell Immune Distribution (MID) and Granulocytes (GRAN). The highest recovery was in rats fed 15% almond seed powder in (WBC), (LYM), (MID), (GRAN), (IgG) and (IgM). Different doses of almond seeds are indicated for boosting immunity in hepatic cases. [ABSTRACT FROM AUTHOR]

From July 2020 to June 2021, 248 wild house mice (Mus musculus), deer mice (Peromyscus maniculatus), brown rats (Rattus norvegicus), and black rats (Rattus rattus) from Texas and Washington, USA, and British Columbia, Canada, were tested for SARS-CoV-2 exposure and infection. Two brown rats and 11 house mice were positive for neutralizing antibodies using a surrogate virus neutralization test, but negative or indeterminate with the Multiplexed Fluorometric ImmunoAssay COVID-Plex, which targets full-length spike and nuclear proteins. Oro-nasopharyngeal swabs and fecal samples tested negative by RT-qPCR, with an indeterminate fecal sample in one house mouse. Continued surveillance of SARS-CoV-2 in wild rodents is warranted. [ABSTRACT FROM AUTHOR]

Accurate detection of invasive rodents is essential to guide appropriate management responses, including effective control. Due to the arboreal behaviour of some invasive rodent species, above-ground monitoring may provide managers with a clearer picture of rodent presence. Numerous ground-based rodent monitoring tools have been tested and compared, but how these tools perform in an arboreal context is unknown. Our study sought to compare the strata-specific detection capability of three widely applied rodent monitoring tools using a nested design. Over two month-long periods, we deployed 180 monitoring stations at the ground, mid-storey and canopy across 30 sites within a National Park forest. Each monitoring station consisted of a camera trap, chew card and tracking tunnel positioned to detect rodent presence. Device agreement was high, with all devices detecting rodent presence at 50% of stations. Chew cards were the most sensitive above-ground tool, implied by positive rodent detection 90% of the time, while tracking tunnels and camera traps generated a positive detection 74% and 75% of the time respectively. Low equipment costs also made chew cards the most cost-effective method. Detection performance differed according to the strata in which the device was deployed, thus a combination of methods that includes camera traps and chew cards was most effective when implementing a three-dimensional rodent monitoring network in forests. While not all methods are equal, traditionally ground-based rodent monitoring devices can be used to effectively monitor arboreal rodent activity. We provide evidence-based guidance for invasive rodent monitoring in an arboreal context to support future invasive rodent population control or eradication programs. [ABSTRACT FROM AUTHOR]

Purpose: Rodents are one of the most abundant and diverse species of mammals and have recently been identified as carriers of numerous human pathogens. The current study was conducted to assess the prevalence, subtype (STs) distribution, and zoonotic potential of Blastocystis spp. in various species of rodents in Shiraz, southwestern Iran. Methods: For this aim, a total of 120 fresh fecal samples were collected from Mus musculus (n = 40), Rattus norvegicus (n = 40), and Rattus rattus (n = 40) in various municipality districts of Shiraz (6 out of 10 districts) between February and November 2020. Upon detecting parasites using light microscopy, a DNA fragment of the Blastocystis SSU rDNA gene was amplified using conventional PCR. Results: By employing direct wet mount examination, 8 out of 120 fecal samples (6.7%; 2 from house mice, 3 from black rats, and 3 from brown rats) tested positive. Similarly, 5% (2/40) of house mice, 7.5% (3/40) of black rats, and 7.5% (3/40) of brown rats tested positive using the molecular method. Phylogenetic analysis revealed that the Blastocystis infecting different rodent species in Shiraz belonged to two potentially zoonotic STs (ST1 and ST4). Accordingly, rodents should not be overlooked as potential reservoirs of zoonotic Blastocystis infections. Different sampled urban districts and their statistical association with reported prevalence rates were analyzed separately. Conclusion: Overall, the issue of the frequency and ST distribution of Blastocystis in urban rodents of Iran is still open to question and for a proper understanding, wider and more comprehensive studies are needed. [ABSTRACT FROM AUTHOR]

Organisms must regulate their behavior flexibly in the face of environmental challenges. Failure can lead to a host of maladaptive behavioral traits associated with a range of neuropsychiatric disorders, including attention deficit hyperactivity disorder, autism, and substance use disorders. This maladaptive dysregulation of behavior is influenced by genetic and environmental factors. For example, environmental enrichment produces beneficial neurobehavioral effects in animal models of such disorders. The present study determined the effects of environmental enrichment on a range of measures related to behavioral regulation using a large cohort of male, outbred heterogeneous stock (HS) rats as subjects. Subjects were reared from late adolescence onwards either in pairs in standard housing with minimal enrichment (n = 200) or in groups of 16 in a highly enriched environment consisting of a large multi-level cage filled with toys, running wheels, and shelters (n = 64). Rats were subjected to a battery of tests, including: (i) locomotor response to novelty, (ii) light reinforcement, (iii) social reinforcement, (iv) reaction time, (v) a patch-depletion foraging test, (vi) Pavlovian conditioned approach, (vii) conditioned reinforcement, and (viii) cocaine conditioned cue preference. Results indicated that rats housed in the enriched environment were able to filter out irrelevant stimuli more effectively and thereby regulate their behavior more efficiently than standard-housing rats. The dramatic impact of environmental enrichment suggests that behavioral studies using standard housing conditions may not generalize to more complex environments that may be more ethologically relevant. [ABSTRACT FROM AUTHOR]

Context: Invasive rodents pose a substantial threat to biodiversity and are a leading cause of species decline and extinction on islands. Population suppression using ground-based methods is common practice, though arboreal behaviour of rodents may render control programs less effective. Aims: We aimed to quantify species-specific invasive rodent activity (Rattus rattus , R. exulans , Mus musculus) across three forest strata to determine the prevalence of arboreal rodent behaviour in a system that has undergone extensive long-term rodent baiting, and therefore assess the suitability of solely ground-based baiting in this system. Methods: We calculated rodent presence at the ground, mid-storey, and canopy using three detection methods (camera traps, chew cards and tracking tunnels) deployed for 30-day periods across three structurally distinct forest types (canopy heights ranged from 3.5 to 16.7 m). We developed continuous rodent activity indices for each method, which we paired with density estimates. Strata-specific species composition was determined using camera trap images. Key results: Rodent presence was recorded equally across all strata, with R. rattus dominating above-ground strata. Rodent densities differed significantly between forest types, which was largely consistent with activity indices. Conclusions: Our findings offer an additional explanation for reduced efficacy of long-term ground-based control programs: arboreal behaviour may exacerbate the reduction in efficacy often associated with long-term control. Implications: Effective management of invasive rodent species on islands is a global conservation challenge. Our findings suggest above-ground control may be required in some long-term suppression programs or eradication campaigns, particularly in the presence of the black rat. Introduced rodents are highly destructive island invaders the world over. Control programs are usually ground-based, however our study found that black rats (Rattus rattus) dominated the forest mid-storey and canopy, casting doubt on the effectiveness of solely ground-based programs. Including above-ground control in the conservationist's rodent control arsenal may improve outcomes for island biodiversity. [ABSTRACT FROM AUTHOR]

Objective: Osteoarthritis (OA) is a disease with high prevalence and an unmet medical need for disease modifying treatments. In rat models, OA-like subchondral bone and cartilage changes can be induced by instability surgery with different severity levels. Factors which determine structural changes additionally comprise the study duration and activity-impacted joint loading. Methods: A medial meniscal tear (MMT) or anterior cruciate ligament transection with partial meniscectomy (ACLT+pMx) was induced unilaterally in rats housed in a rat colony cage (RCC), allowing high activity levels including jumping and stair climbing. In parallel, ACLT+pMx rats were housed in Type IV cages. The time course of OA-related changes was investigated at 4, 8, 12, and 16 weeks after surgery by micro-CT, gait analysis and joint diameter measurements. Results: Gait disturbance was observed after 2 weeks and to a similar extend in all models. The increase in ipsilateral joint diameters peaked after 2 weeks and were more pronounced after ACLT+pMx compared to MMT-surgery, but independent of housing. Micro-CT analysis revealed that increases in osseous tibial width were most distinct after ACLT+pMx in RCC and progressed continuously until week sixteen. In contrast, osseous tibial width of ipsilateral joints in MMT RCC and ACLT+pMx Type IV groups did not increase further after week twelve. In contralateral joints, this parameter was not affected, regardless of the model or caging. However, a significant increase in bone volume fraction and trabecular thickness was observed over time in the femur and tibia of both ipsilateral and contralateral knees. Here, the medial tibial compartment of the operated joint was most affected and linear changes were most pronounced in the ACLT+pMx RCC group. Conclusion: Increased movement of animals in colony cages leads to robust structural changes in subchondral bone after surgically induced joint instability over time, while in regular Type IV housing maximal changes are reached in week twelve. The new insights into the differentiation of the models, particularly with respect to the linear progression of bone changes in ACLT+pMx in the RCC, may be useful for the design of chronic OA-studies within a longer lifespan and therefore supporting the development of novel therapies. [ABSTRACT FROM AUTHOR]