Using clotted, pelleted blood samples for direct molecular detection of Bartonella spp. in small mammal wildlife surveillance studies.

OBJECTIVE: Bartonella are emerging bacterial zoonotic pathogens. Utilization of clotted blood samples for surveillance of these bacteria in wildlife has begun to supersede the use of tissues; however, the efficacy of these samples has not been fully investigated. Our objective was to compare the efficacy of spleen and blood samples for DNA extraction and direct detection of Bartonella spp. via qPCR. In addition, we present a protocol for improved DNA extraction from clotted, pelleted (i.e., centrifuged) blood samples obtained from wild small mammals. RESULTS: DNA concentrations from kit-extracted blood clot samples were low and A260/A280 absorbance ratios indicated high impurity. Kit-based DNA extraction of spleen samples was efficient and produced ample DNA concentrations of good quality. We developed an in-house extraction method for the blood clots which resulted in apposite DNA quality when compared to spleen samples extracted via MagMAX DNA Ultra 2.0 kit. We detected Bartonella in 9/30 (30.0%) kit-extracted spleen DNA samples and 11/30 (36.7%) in-house-extracted blood clot samples using PCR. Our results suggest that kit-based methods may be less suitable for DNA extraction from blood clots, and that blood clot samples may be superior to tissues for Bartonella detection.

Multivariate analysis of craniodental morphology in mouse-eared bats (Chiroptera, Vespertilionidae, Myotis) from Vietnam.

This study conducted biostatistical multivariate analyses on 23 craniodental morphological measurements from 209 specimens to study interspecific variations amongst 15 bat species of the genus Myotis in Vietnam. Univariate and multivariate analyses demonstrated that the studied species can be divided into four groups as follows: extra-large-sized species (M.chinensis), large-sized species (M.pilosus, M.indochinensis and M.annectans), medium-sized species (M.altarium, M.hasseltii, M.montivagus, M.horsfieldii, M.ater, M.laniger and M.muricola) and small-sized species (M.annamiticus, M.aff.siligorensis, M.rosseti and M.alticraniatus). Our data revealed that the main craniodental features contributing to the variations in distinguishing Myotis species are the width of the anterior palatal, least height of the coronoid process, length of the upper and lower canine-premolar, zygomatic width and width across the upper canines and lower premolar-molar length. Based on patterns of morphological differences, we conducted comparisons between morphometrically closely resembling species pairs and further discussed additional characteristics that are expected to support the taxonomy and systematics of Vietnamese Myotis bats.

Genetic diversity and prevalence of emerging Rickettsiales in Yunnan Province: a large-scale study.

BACKGROUND: Rickettsia and related diseases have been identified as significant global public health threats. This study involved comprehensive field and systematic investigations of various rickettsial organisms in Yunnan Province. METHODS: Between May 18, 2011 and November 23, 2020, field investigations were conducted across 42 counties in Yunnan Province, China, encompassing small mammals, livestock, and ticks. Preliminary screenings for Rickettsiales involved amplifying the 16S rRNA genes, along with additional genus- or species-specific genes, which were subsequently confirmed through sequencing results. Sequence comparisons were carried out using the Basic Local Alignment Search Tool (BLAST). Phylogenetic relationships were analyzed using the default parameters in the Molecular Evolutionary Genetics Analysis (MEGA) program. The chi-squared test was used to assess the diversities and component ratios of rickettsial agents across various parameters. RESULTS: A total of 7964 samples were collected from small mammals, livestock, and ticks through Yunnan Province and submitted for screening for rickettsial organisms. Sixteen rickettsial species from the genera Rickettsia, Anaplasma, Ehrlichia, Neoehrlichia, and Wolbachia were detected, with an overall prevalence of 14.72%. Among these, 11 species were identified as pathogens or potential pathogens to humans and livestock. Specifically, 10 rickettsial organisms were widely found in 42.11% (24 out of 57) of small mammal species. High prevalence was observed in Dremomys samples at 5.60%, in samples from regions with latitudes above 4000 m or alpine meadows, and in those obtained from Yuanmou County. Anaplasma phagocytophilum and Candidatus Neoehrlichia mikurensis were broadly infecting multiple genera of animal hosts. In contrast, the small mammal genera Neodon, Dremomys, Ochotona, Anourosorex, and Mus were carrying individually specific rickettsial agents, indicating host tropism. There were 13 rickettsial species detected in 57.14% (8 out of 14) of tick species, with the highest prevalence (37.07%) observed in the genus Rhipicephalus. Eight rickettsial species were identified in 2375 livestock samples. Notably, six new Rickettsiales variants/strains were discovered, and Candidatus Rickettsia longicornii was unambiguously identified. CONCLUSIONS: This large-scale survey provided further insight into the high genetic diversity and overall prevalence of emerging Rickettsiales within endemic hotspots in Yunnan Province. The potential threats posed by these emerging tick-borne Rickettsiales to public health warrant attention, underscoring the need for effective strategies to guide the prevention and control of emerging zoonotic diseases in China.

Density of a cryptic Australian small mammal: The threatened Julia Creek dunnart (Sminthopsis douglasi).

Globally, hundreds of mammal species face the threat of extinction in the coming decades, and in many cases, their ecology remains poorly understood. Fundamental ecological knowledge is crucial for effective conservation management of these species, but it is particularly lacking for small, cryptic mammals. The Julia Creek dunnart (Sminthopsis douglasi), a threatened, cryptic carnivorous marsupial that occurs in scattered populations in the central west of Queensland, Australia, was once so poorly studied that it was believed extinct. Sporadic research since its rediscovery in the early 1990s has revealed that S. douglasi is distributed across land at risk from many threats. Fundamental knowledge of S. douglasi population density is urgently required to inform conservation management at key sites, yet the species has historically proven hard to detect. Indeed, the status of the largest known population of S. douglasi, in Bladensburg National Park, is unknown. Here, we conducted a population study on S. douglasi at two sites within Bladensburg National Park via live mark-recapture surveys during 2022 and 2023. From likelihood-based spatially explicit capture-recapture (SECR) modelling we provide the first estimates of density and population size for S. douglasi. Live trapping resulted in captures of 49 individual S. douglasi (with 83 captures total, including recaptures). We estimated S. douglasi to occur at a density of 0.38 individuals ha-1 (0.25-0.58) at one site and 0.16 individuals ha-1 (0.09-0.27) at another site, with an estimated mean population size in suitable habitat at Bladensburg National Park of 1211 individuals (776-1646). Our S. douglasi density estimates were similar to that reported for other threatened small mammals in Australia. We also found evidence of extreme S. douglasi population fluctuations over time at Bladensburg National Park, which is of concern for its future conservation. Our study has provided the first estimate of density for S. douglasi, a threatened dasyurid species from the Mitchell Grass Downs of central western Queensland, Australia. Our research provides crucial population data to assist the management of this poorly studied species. We demonstrate a method that can be applied to species with low detection probability to ultimately help address the mammal extinction crisis faced by Australia and the rest of the world.

CT findings of an incidental segmental aplasia of the caudal vena cava with azygos continuation in a guinea pig (Cavia porcellus).

Background: Segmental aplasia of the caudal vena cava (CVC) with azygos continuation is a congenital malformation macroscopically described in mammals including humans, dogs, and rodents. It is usually detected as an incidental finding and the final diagnosis is reached by computed tomography (CT), fluoroscopy, or post-mortem dissection. Case Description: A 3-year-old guinea pig (Cavia porcellus) presented with subacute dyspnea. A computed tomographic examination was performed for the evaluation of subtle pulmonary changes previously suspected on conventional radiography, and a segmental aplasia of the CVC with azygos continuation was identified as an incidental finding. Conclusion: According to database negative results, this is the first report describing a segmental aplasia of the CVC and azygos continuation in a guinea pig by CT.

The past, present, and future of predator-prey interactions in a warming world: Using species distribution modeling to forecast ectotherm-endotherm niche overlap.

Climate change has the potential to disrupt species interactions across global ecosystems. Ectotherm-endotherm interactions may be especially prone to this risk due to the possible mismatch between the species in physiological response and performance. However, few studies have examined how changing temperatures might differentially impact species' niches or available suitable habitat when they have very different modes of thermoregulation. An ideal system for studying this interaction is the predator-prey system. In this study, we used ecological niche modeling to characterize the niche overlap and examine biogeography in past and future climate conditions of prairie rattlesnakes (Crotalus viridis) and Ord's kangaroo rats (Dipodomys ordii), an endotherm-ectotherm pair typifying a predator-prey species interaction. Our models show a high niche overlap between these two species (D = 0.863 and I = 0.979) and further affirm similar paleoecological distributions during the last glacial maximum (LGM) and mid-Holocene (MH). Under future climate change scenarios, we found that prairie rattlesnakes may experience a reduction in overall suitable habitat (RCP 2.6 = -1.82%, 4.5 = -4.62%, 8.5 = -7.34%), whereas Ord's kangaroo rats may experience an increase (RCP 2.6 = 9.8%, 4.5 = 11.71%, 8.5 = 8.37%). We found a shared trend of stable suitable habitat at northern latitudes but reduced suitability in southern portions of the range, and we propose future monitoring and conservation be focused on those areas. Overall, we demonstrate a biogeographic example of how interacting ectotherm-endotherm species may have mismatched responses under climate change scenarios and the models presented here can serve as a starting point for further investigation into the biogeography of these systems.

Application of lidar to assess the habitat selection of an endangered small mammal in an estuarine wetland environment.

Light detection and ranging (lidar) has emerged as a valuable tool for examining the fine-scale characteristics of vegetation. However, lidar is rarely used to examine coastal wetland vegetation or the habitat selection of small mammals. Extensive anthropogenic modification has threatened the endemic species in the estuarine wetlands of the California coast, such as the endangered salt marsh harvest mouse (Reithrodontomys raviventris; SMHM). A better understanding of SMHM habitat selection could help managers better protect this species. We assessed the ability of airborne topographic lidar imagery in measuring the vegetation structure of SMHM habitats in a coastal wetland with a narrow range of vegetation heights. We also aimed to better understand the role of vegetation structure in habitat selection at different spatial scales. Habitat selection was modeled from data compiled from 15 small mammal trapping grids collected in the highly urbanized San Francisco Estuary in California, USA. Analyses were conducted at three spatial scales: microhabitat (25 m2), mesohabitat (2025 m2), and macrohabitat (~10,000 m2). A suite of structural covariates was derived from raw lidar data to examine vegetation complexity. We found that adding structural covariates to conventional habitat selection variables significantly improved our models. At the microhabitat scale in managed wetlands, SMHM preferred areas with denser and shorter vegetation and selected for proximity to levees and taller vegetation in tidal wetlands. At the mesohabitat scale, SMHM were associated with a lower percentage of bare ground and with pickleweed (Salicornia pacifica) presence. All covariates were insignificant at the macrohabitat scale. Our results suggest that SMHM preferentially selected microhabitats with access to tidal refugia and mesohabitats with consistent food sources. Our findings showed that lidar can contribute to improving our understanding of habitat selection of wildlife in coastal wetlands and help to guide future conservation of an endangered species.

Functional consequences of animal community changes in managed grasslands: An application of the CAFE approach.

In the midst of an ongoing biodiversity crisis, much research has focused on species losses and their impacts on ecosystem functioning. The functional consequences (ecosystem response) of shifts in communities are shaped not only by changes in species richness, but also by compositional shifts that result from species losses and gains. Species differ in their contribution to ecosystem functioning, so species identity underlies the consequences of species losses and gains on ecosystem functions. Such research is critical to better predict the impact of disturbances on communities and ecosystems. We used the "Community Assembly and the Functioning of Ecosystems" (CAFE) approach, a modification of the Price equation to understand the functional consequences and relative effects of richness and composition changes in small nonvolant mammal and dung beetle communities as a result of two common disturbances in North American prairie restorations, prescribed fire and the reintroduction of large grazing mammals. Previous research in this system has shown dung beetles are critically important decomposers, while small mammals modulate much energy in prairie food webs. We found that dung beetle communities were more responsive to bison reintroduction and prescribed fires than small nonvolant mammals. Dung beetle richness increased after bison reintroduction, with higher dung beetle community biomass resulting from changes in remaining species (context-dependent component) rather than species turnover (richness components); prescribed fire caused a minor increase in dung beetle biomass for the same reason. For small mammals, bison reintroduction reduced energy transfer through the loss of species, while prescribed fire had little impact on either small mammal richness or energy transfer. The CAFE approach demonstrates how bison reintroduction controls small nonvolant mammal communities by increasing prairie food web complexity, and increases dung beetle populations with possible benefits for soil health through dung mineralization and soil bioturbation. Prescribed fires, however, have little effect on small mammals and dung beetles, suggesting a resilience to fire. These findings illustrate the key role of re-establishing historical disturbance regimes when restoring endangered prairie ecosystems and their ecological function.

Nutritional Considerations for Juvenile Exotic Companion Animals.

Pediatric exotic companion animal nutrition is a broad topic, spanning small mammals, reptiles, and birds. Little research has been performed focusing on the juvenile life stages of these species because they are largely acquired by clients at the young adult stage. The information that does exist has been compiled by wildlife rehabilitators, commercial breeders, and/or exotic captive breeding programs, such as those that exist in zoologic facilities. In this article, we discuss natural history, feeding strategies, energy requirements, digestive physiology and diet digestibility, and key nutrients of concern as factors for determining an appropriate diet for pediatric exotic species.

Population dynamics of plague vector fleas in an endemic focus: implications for plague surveillance.

Plague is a zoonotic vector-borne disease caused by the bacterium Yersinia pestis. In Madagascar, it persists in identified foci, where it is a threat to public health generally from September to April. A more complete understanding of how the disease persists could guide control strategies. Fleas are the main vector for transmission between small mammal hosts and humans, and fleas likely play a role in the maintenance of plague. This study characterized the dynamics of flea populations in plague foci alongside the occurrence of human cases. From 2018 to 2020, small mammals were trapped at sites in the central Highlands of Madagascar. A total of 2,762 small mammals were captured and 5,295 fleas were collected. The analysis examines 2 plague vector species in Madagascar (Synopsyllus fonquerniei and Xenopsylla cheopis). Generalized linear models were used to relate flea abundance to abiotic factors, with adjustments for trap location and flea species. We observed significant effects of abiotic factors on the abundance, intensity, and infestation rate by the outdoor-associated flea species, S. fonquerniei, but weak seasonality for the indoor-associated flea species, X. cheopis. A difference in the timing of peak abundance was observed between the 2 flea species during and outside the plague season. While the present study did not identify a clear link between flea population dynamics and plague maintenance, as only one collected X. cheopis was infected, the results presented herein can be used by local health authorities to improve monitoring and control strategies of plague vector fleas in Madagascar.

Identification of a Novel Hepacivirus in Southeast Asian Shrew (Crocidura fuliginosa) from Yunnan Province, China.

The genus Hepacivirus contains single-stranded positive-sense RNA viruses belonging to the family Flaviviridae, which comprises 14 species. These 14 hepaciviruses have been found in different mammals, such as primates, dogs, bats, and rodents. To date, Hepacivirus has not been reported in the shrew genus of Crocidura. To study the prevalence and genetic evolution of Hepacivirus in small mammals in Yunnan Province, China, molecular detection of Hepacivirus in small mammals from Yunnan Province during 2016 and 2017 was performed using reverse-transcription polymerase chain reaction (RT-PCR). Our results showed that the overall infection rate of Hepacivirus in small mammals was 0.12% (2/1602), and the host animal was the Southeast Asian shrew (Crocidura fuliginosa) (12.5%, 2/16). Quantitative real-time PCR showed that Hepacivirus had the highest viral RNA copy number in the liver. Phylogenetic analysis revealed that the hepaciviruses obtained in this study does not belong to any designated species of hepaciviruses and forms an independent clade. To conclude, a novel hepacivirus was identified for the first time in C. fuliginosa specimens from Yunnan Province, China. This study expands the host range and viral diversity of hepaciviruses.

Capturing red squirrels (Sciurus vulgaris) on camera: A cost-effective approach for monitoring relative abundance and habitat preference.

Effective methods for monitoring animal populations are crucial for species conservation and habitat management. Motion-activated cameras provide an affordable method for passively surveying animal presence across the landscape but have mainly been used for studying large-bodied mammals. This paper explores the relative abundance and habitat preferences of red squirrels (Sciurus vulgaris) in coniferous forests using cameras and live trapping. The study was conducted in two forests (Newborough and Pentraeth) on Anglesey, North Wales, with a total of 50 sampling locations across four habitat categories. Detailed woodland structure and composition data were gathered around each sampling location. We found a strong positive correlation between the number of individual red squirrels live trapped over 10 days with the number of camera images of squirrels recorded during a previous 5-day period. The time interval between camera deployment and the first recorded image of a red squirrel showed a significant negative correlation with the number of individuals live trapped. Red squirrel relative abundance was negatively related to forest canopy openness, while the presence of Scots pine and increased tree species diversity were positively associated with the relative abundance of squirrels. There was also a strong site difference with lower relative abundance at Newborough compared with Pentraeth, which likely reflects the heavy thinning of mature forest at Newborough reducing tree crown connectivity. The results show that remotely activated cameras are an effective method for monitoring red squirrel populations across varying animal densities. The cameras also provided crucial information on red squirrel habitat preferences that can aid in woodland management and conservation efforts. Cameras have great potential to collect data on the population status of other small mammals, but it is essential that these methods are validated on a species-by-species basis.

Morphology and Mitochondrial Lineage Investigations Corroborate the Systematic Status and Pliocene Colonization of Suncus niger (Mammalia: Eulipotyphla) in the Western Ghats Biodiversity Hotspot of India.

The Indian highland shrew, Suncus niger (Horsfield, 1851), is the least studied soricid species from its original range distribution in Southern India, with several systematics conundrums. Following its discovery in 1851, the species was synonymized with Suncus montanus (Kelaart, 1850) (endemic to Sri Lanka) and subsequently identified as a separate Indian population. However, the systematic status of S. niger from topotype specimens in Southern India has yet to be determined through an integrated approach. Both taxonomy and mitochondrial genetic data (Cytochrome b and 16S ribosomal RNA) were used to re-examine the systematics of S. niger. The mtCytb gene clearly distinguished topotypic S. niger from other Suncus species, with high genetic divergences varying from 8.49% to 26.29%. Further, the Bayesian and maximum likelihood topologies clearly segregated S. niger from other congeners and corroborated the sister relationship with S. stoliczkanus with expected divergence in the late Pliocene (2.62 MYA). The TimeTree analysis also exhibits a strong matrilineal affinity of S. dayi (endemic to India) toward the African species. The current study hypothesizes that the ancestor of the soricids evolved in Africa and that genetic lineages were subsequently shifted by plate tectonic events that subsequently colonized different continents as distinct species during the late Miocene (Tortonian) to the Holocene era. In addition to the new range expansion and elevation records of S. niger in the Central Western Ghats, we propose that additional sampling across its distribution, as well as the use of multiple genetic markers, may be useful in determining the genetic diversity and population structure of this endemic species. The present study also recommends that more molecular data on the Soricomorphs lineages, and estimates of their divergence times, will shed light on the evolution of these small mammals on Earth.

Sedation and Anesthesia in Exotic Animal Critical Care.

Sedation and anesthesia of exotic animals in inherently challenging, but often facilitates the best care for patients. Critical illness or injury adds on another layer of complexity to their management for obtaining diagnostics and providing treatments. This article serves to review some of the more recent literature of sedation and anesthesia within exotics practice, bringing to light some nuances and considerations for when those patients are critically ill or injured.

Discarded bottles entrap endemic small mammals species in a large Mediterranean island.

We examined the entrapment effect of discarded bottles on small mammals, along a road network located in North-Western Sardinia (Italy). On 162 bottles, 49 (> 30%) contained at least one animal specimen (invertebrate or vertebrate) and 26 (16%) entrapped 151 small mammals: insectivorous shrews (Soricomorpha) were more frequently recorded. Larger bottles (66 cl.) showed a higher number of entrapped mammals, but difference was not significant when compared to smaller bottles (33 cl.). Our data highlighted as abandoned bottles represent a threatening factor for small mammals on a large Mediterranean island with over-represented endemic shrews (predators of high trophic level) attracted by insects entrapped in bottles. Correspondence analysis suggest a weak segregation between bottles of different size, related to the abundance of the most entrapped species, the Mediterranean shrew (Crocidura pachyura). This still neglected type of litter, reducing number and biomass of insectivorous mammals of high trophic level and high ecological value may affect the food web in terrestrial insular communities, yet impoverished for biogeographical reasons. However, discarded bottles may represent as low-cost surrogate pitfall traps useful to improve knowledge in poor studied areas. Following the DPSIR (Driving force, Pressure, State, Impact, Response) approach as a framework to select indicator, we suggest as the effectiveness of removal clean-ups could be monitored using both the density of discarded bottles (as indicator of threat pressure) and the abundance of entrapped animals (as indicator of impact on small mammals).

[Prevalence of Echinococcus infection in small mammals captured from Shiqu County, Sichuan Province from 2015 to 2020].

OBJECTIVE: To investigate the prevalence of Echinococcus infection in small mammals in Shiqu County, Sichuan Province from 2015 to 2020, so as to provide insights into echinococcosis control in Shiqu County. METHODS: One setting with frequent activity of small mammals was sampled as the survey site from each of 9 townships where human alveolar echinococcosis was hyperendemic, in Shiqu County, Sichuan Province from 2015 to 2020. Two quadrats measuring 50 m × 50 m were assigned in each survey site during the period between July and August from 2015 to 2020 to capture all small mammals in quadrats, and the species of small mammals were identified by morphological characteristics. All captured small mammals were dissected in the field and Echinococcus infection was identified by visual examinations. The affected organs of Echinococcus - infected small mammals were collected, and Echinococcus infection was detected using PCR assay, with Echinococcus species characterized. The prevalence of Echinococcus infection was calculated in small mammals, and the trends in the prevalence of Echinococcus infection were analyzed during the period from 2015 to 2020. In addition, the prevalence of Echinococcus infection was compared in small mammals using visual examinations and PCR assay. RESULTS: A total of 2 692 small mammals were captured in the survey sites of Shiqu County from 2015 to 2020, and morphology characterized 1 360 Microtus fuscus (50.52%) and 1 332 Plateau pika (49.48%). The prevalence rates of Echinococcus infection were 35.63%, 19.16%, 21.41%, 8.40%, 7.68% and 4.44% by visual examinations and 18.96%, 5.36%, 5.61%, 4.58%, 3.30% and 0.37% by PCR assay in small mammals in Shiqu County from 2015 to 2020, both showing a tendency towards a decline year by year (χ2 = 215.024 and 117.045, both P values < 0.001). The prevalence of Echinococcus infection was significantly higher in small mammals by visual examinations than by PCR assay during the period from 2015 to 2020 except in 2018 (χ2= 33.597, 21.815, 51.373, 17.268 and 9.537, all P values < 0.01). PCR assay detected a reduction in the prevalence of E. multilocularis infection from 10.21% to 0.37% and a reduction in the prevalence of E. shiquicus infection from 8.75% to 0 in small mammals in Shiqu County from 2015 to 2020, both appearing a tendency towards a decline year by year (χ2 = 117.045 and 43.436, both P values < 0.001). In addition, the prevalence of E. multilocularis and E. shiquicus infections reduced from 15.19% to 0.45% and from 8.23% to 0 in M. fuscus, and the prevalence of E. multilocularis and E. shiquicus infections reduced from 7.76% to 0 and from 9.01% to 0 in P. pika in Shiqu County from 2015 to 2020. CONCLUSIONS: M. fuscus and P. pika were dominant species of small mammals in Shiqu County, Sichuan Province from 2015 to 2020, and E. multilocularis infection was mainly found in M. fuscus and E. shiquicus infection mainly found in P. pika. The prevalence of Echinococcus infection appeared a tendency towards a decline in both M. fuscus and P. pika year by year during the period from 2015 to 2020.

The gut microbiome reflects ancestry despite dietary shifts across a hybrid zone.

The microbiome is critical to an organism's phenotype, and its composition is shaped by, and a driver of, eco-evolutionary interactions. We investigated how host ancestry, habitat and diet shape gut microbial composition in a mammalian hybrid zone between Neotoma lepida and N. bryanti that occurs across an ecotone between distinct vegetation communities. We found that habitat is the primary determinant of diet, while host genotype is the primary determinant of the gut microbiome-a finding further supported by intermediate microbiome composition in first-generation hybrids. Despite these distinct primary drivers, microbial richness was correlated with diet richness, and individuals that maintained higher dietary richness had greater gut microbial community stability. Both relationships were stronger in the relative dietary generalist of the two parental species. Our findings show that host ancestry interacts with dietary habits to shape the microbiome, ultimately resulting in the phenotypic plasticity that host-microbial interactions allow.

Vertical stratification patterns of tropical forest vertebrates: a meta-analysis.

Tropical forests harbour the highest levels of terrestrial biodiversity and represent some of the most complex ecosystems on Earth, with a significant portion of this diversity above ground. Although the vertical dimension is a central aspect of the ecology of forest communities, there is little consensus as to prominence, evenness, and consistency of community-level stratification from ground to canopy. Here, we gather the results of 62 studies across the tropics to synthesise and assess broad patterns of vertical stratification of abundance and richness in vertebrates, the best studied taxonomic group for which results have not been collated previously. Our review of the literature yielded sufficient data for bats, small mammals, birds and amphibians. We show that variation in the stratification of abundance and richness exists within and among all taxa considered. Bat richness stratification was variable among studies, although bat abundance was weighted towards the canopy. Both bird richness and abundance stratification were variable, with no overriding pattern. On the contrary, both amphibians and small mammals showed consistent patterns of decline in abundance and richness towards the canopy. We descriptively characterise research trends in drivers of stratification cited or investigated within studies, finding local habitat structure and food distribution/foraging to be the most commonly attributed drivers. Further, we analyse the influence of macroecological variables on stratification patterns, finding latitude and elevation to be key predictors of bird stratification in particular. Prominent differences among taxa are likely due to taxon-specific interactions with local drivers such as vertical habitat structure, food distribution, and vertical climate gradients, which may vary considerably across macroecological gradients such as elevation and biogeographic realm. Our study showcases the complexity with which animal communities organise within tropical forest ecosystems, while demonstrating the canopy as a critical niche space for tropical vertebrates, thereby highlighting the inherent vulnerability of tropical vertebrate communities to forest loss and canopy disturbance. We recognise that analyses were constrained due to variation in study designs and methods which produced a variety of abundance and richness metrics recorded across different arrangements of vertical strata. We therefore suggest the application of best practices for data reporting and highlight the significant effort required to fill research gaps in terms of under-sampled regions, taxa, and environments.

The use of intralipid emulsion therapy to treat status epilepticus in a guinea pig (Cavia porcellus) secondary to severe ivermectin toxicity.

OBJECTIVE: To describe the successful management of ivermectin-induced status epilepticus in a guinea pig (Cavia porcellus) with intravenous lipid emulsion (ILE) therapy. CASE SUMMARY: A 5-week-old, female intact guinea pig was presented to an emergency hospital for status epilepticus 24 hours after oral administration of ivermectin. Approximately 48 hours after exposure, ILE therapy was administered. Within 12-16 hours after ILE therapy, seizures had stopped and the patient's mentation returned to normal. The definitive diagnosis was based on owner history, clinical presentation, and American Society for the Prevention of Cruelty to Animals poison control guidelines. NEW OR UNIQUE INFORMATION PROVIDED: The use of intralipid therapy has been widely documented as a treatment option for numerous toxicities. Its efficacy in treatment for toxicities in both veterinary and human medicines has been well described in various case reports and studies. However, its use and success in small mammals have yet to be documented. In this case report, intralipid therapy is used to successfully treat a seizuring guinea pig that was administered a severely toxic dose of ivermectin. To the authors' knowledge, this is the first report on the successful use of intralipids in a guinea pig from ivermectin toxicosis.

Savviness of prey to introduced predators.

The prey naivety hypothesis posits that prey are vulnerable to introduced predators because many generations in slow gradual coevolution are needed for appropriate avoidance responses to develop. It predicts that prey will be more responsive to native than introduced predators and less responsive to introduced predators that differ substantially from native predators and from those newly established. To test these predictions, we conducted a global meta-analysis of studies that measured the wariness responses of small mammals to the scent of sympatric mammalian mesopredators. We identified 26 studies that met our selection criteria. These studies comprised 134 experiments reporting on the responses of 36 small mammal species to the scent of six introduced mesopredators and 12 native mesopredators. For each introduced mesopredator, we measured their phylogenetic and functional distance to local native mesopredators and the number of years sympatric with their prey. We used predator and prey body mass as a measure of predation risk. Globally, small mammals were similarly wary of the scent of native and introduced mesopredators; phylogenetic and functional distance between introduced mesopredators and closest native mesopredators had no effect on wariness; and wariness was unrelated to the number of prey generations, or years, since first contact with introduced mesopredators. Small mammal wariness was associated with predator-prey body mass ratio, regardless of the nativity. The one thing animals do not seem to recognize is whether their predators are native.

La hipótesis de la ingenuidad de la presa plantea que ésta es vulnerable a los depredadores introducidos porque se requiere que muchas generaciones atraviesen una coevolución lenta y gradual para que se desarrollen las respuestas de evasión adecuadas. La hipótesis supone que la presa será más sensible a los depredadores introducidos que difieren notoriamente de los nativos y de aquellos recién establecidos. Realizamos un metaanálisis global de estudios que midieron las respuestas cautelosas de mamíferos pequeños ante el rastro de meso depredadores simpátricos para probar estas suposiciones. Identificamos 26 estudios que cumplieron con nuestro criterio de selección. Estos estudios estuvieron conformados por 134 experimentos que reportaban las respuestas de 36 especies de mamíferos pequeños ante el rastro de seis meso depredadores introducidos y 12 nativos. Medimos la distancia funcional y filogenética entre cada meso depredador introducido y los meso depredadores locales nativos y el número de años simpátricos con su presa. Usamos la masa corporal del depredador y la presa como medida del riesgo de depredación. A nivel mundial, los mamíferos pequeños compartieron la cautela ante el rastro de los meso depredadores nativos e introducidos; la distancia funcional y la filogenética entre los meso depredadores introducidos y el meso depredador nativo más cercano no tuvieron efecto sobre la cautela; y la cautela no estuvo relacionada con el número de generaciones de la presa, o años, desde el primer contacto con los meso depredadores introducidos. La cautela de los mamíferos pequeños estuvo asociada con las proporciones de masa corporal entre el depredador y la presa, sin importar el origen. Lo único que los animales parecen no reconocer es si el depredador es nativo o no.