We introduce a model that can be used for the description of the distribution of species when there is scarcity of data, based on our previous work (Ballesteros et al. J Math Biol 85(4):31, 2022). We address challenges in modeling species that are seldom observed in nature, for example species included in The International Union for Conservation of Nature\'s Red List of Threatened Species (IUCN 2023). We introduce a general method and test it using a case study of a near threatened species of amphibians called Plectrohyla Guatemalensis (see IUCN 2023) in a region of the UNESCO natural reserve \"Tacaná Volcano\", in the border between Mexico and Guatemala. Since threatened species are difficult to find in nature, collected data can be extremely reduced. This produces a mathematical problem in the sense that the usual modeling in terms of Markov random fields representing individuals associated to locations in a grid generates artificial clusters around the observations, which are unreasonable. We propose a different approach in which our random variables describe yearly averages of expectation values of the number of individuals instead of individuals (and they take values on a compact interval). Our approach takes advantage of intuitive insights from environmental properties: in nature individuals are attracted or repulsed by specific features (Ballesteros et al. J Math Biol 85(4):31, 2022). Drawing inspiration from quantum mechanics, we incorporate quantum Hamiltonians into classical statistical mechanics (i.e. Gibbs measures or Markov random fields). The equilibrium between spreading and attractive/repulsive forces governs the behavior of the species, expressed through a global control problem involving an energy operator.

Wild chimpanzees (Pan troglodytes) are caught in snares set for other animals and sometimes injure or lose body parts. Snaring can compromise the health, growth, survival, and behavior of chimpanzees and, thus, represents a threat for the conservation of this endangered species. During a long-term study of chimpanzees at Ngogo in Kibale National Park, Uganda, we started a project to remove snares in and around their territory. We compared the number of times chimpanzees were snared during the 12.75 years after the start of this project with the number of times individuals were snared during the previous 14 years. Only one chimpanzee was snared after we began removing snares compared with 12 individuals caught during the period before. This represents a clear reduction in the risk created by snaring at this site and suggests that removing snares can be employed to protect chimpanzees.

BACKGROUND: Reintroduction represents an effective strategy for the conservation of endangered wildlife, yet it might inadvertently impact the native ecosystems. This investigation assesses the impact of reintroducing endangered Przewalski\'s horses into the desert grassland ecosystem of the Kalamaili Nature Reserve (KNR), particularly its effect on the spatial distribution of ticks. In a 25 km2 core area of Przewalski\'s horse distribution, we set up 441 tick sampling sites across diverse habitats, including water sources, donkey trails, and grasslands, recording horse feces and characteristics to analyze the occurrence rate of ticks. Additionally, we gathered the data of 669 fresh feces of horses. To evaluate the spatial dynamics between these feces and ticks, we used methods such as Fixed Kernel Estimation (FKE), Moran\'s I spatial autocorrelation index, and Generalized Linear Models (GLM).
RESULTS: The dominant species of ticks collected in the core area were adult Hyalomma asiaticum (91.36%). Their occurrence rate was higher near donkey trails (65.99%) and water sources (55.81%), particularly in areas with the fresh feces of Przewalski\'s horses. The ticks\' three risk areas, as defined by FKE, showed significant overlap and positive correlation with the distribution of Przewalski\'s horses, with respective overlap rates being 90.25% in high risk, 33.79% in medium risk, and 23.09% in low risk areas. Moran\'s I analysis revealed a clustering trend of the fresh feces of Przewalski\'s horses in these areas. The GLM confirmed a positive correlation between the distribution of H. asiaticum and the presence of horse fresh feces, alongside a negative correlation with the proximity to water sources and donkey trails.
CONCLUSIONS: This study reveals the strong spatial correlation between Przewalski\'s horses and H. asiaticum in desert grasslands, underlining the need to consider interspecific interactions in wildlife reintroductions. The findings are crucial for shaping effective strategies of wildlife conservation and maintaining ecological balance.

Birds are excellent bioindicators of environmental pollution, and blood provides information on contaminant exposure, although its analysis is challenging because of the low volumes that can be sampled. The objective of the present study was to optimize and validate a miniaturized and functional extraction and analytical method based on gas chromatography coupled to Orbitrap mass spectrometry (GCOrbitrap-MS) for the trace analysis of contaminants in avian blood. Studied compounds included 25 organochlorine pesticides (OCPs), 6 polychlorinated biphenyls (PCBs), 8 polybrominated diphenyl ethers (PBDEs) and 15 polycyclic aromatic hydrocarbons (PAHs). Four extraction and clean-up conditions were optimized and compared in terms of efficiency, accuracy, and uncertainty assessment. Extraction with hexane:dichloromethane and miniaturized Florisil pipette clean-up was the most adequate considering precision and accuracy, time, and costs, and was thereafter used to analyse 20 blood samples of a pelagic seabird, namely the Bermuda petrel (Pterodroma cahow). This species, endemic to the Northwest Atlantic, is among the most endangered seabirds of the region that in the \'60 faced a decrease in the breeding success likely linked to a consistent exposure to dichloro-diphenyl-trichloroethane (DDT). Indeed, p,p\'-DDE, the main DDT metabolite, was detected in all samples and ranged bewteen 1.13 and 6.87 ng/g wet weight. Other ubiquitous compounds were PCBs (ranging from 0.13 to 6.76 ng/g ww), hexachlorobenzene, and mirex, while PAHs were sporadically detected at low concentrations, and PBDEs were not present. Overall, the extraction method herein proposed allowed analysing very small blood volumes (∼ 100 µL), thus respecting ethical principles prioritising the application of less-invasive sampling protocols, fundamental when studying threatened avian species.

Expanding digital data sources, including social media and online news, provide a low-cost way to examine human-nature interactions, such as wildlife exploitation. However, the extent to which using such data sources can expand or bias understanding of the distribution and intensity of threats has not been comprehensively assessed. To address this gap, we quantified the geographical and temporal distribution of online sources documenting the hunting and trapping, consumption, or trade of bats (Chiroptera) and compared these with the distribution of studies obtained from a systematic literature search and species listed as threatened by exploitation on the International Union for Conservation of Nature Red List. Online records were collected using automated searches of Facebook, Twitter, Google, and Bing and were filtered using machine classification. This yielded 953 relevant social media posts and web pages, encompassing 1099 unique records of bat exploitation from 84 countries. Although the number of records per country was significantly predicted by the number of academic studies per country, online records provided additional locations and more recent records of bat exploitation, including 22 countries not present in academic literature. This demonstrates the value of online resources in providing more complete geographical representation. However, confounding variables can bias the analysis of spatiotemporal trends. Online bat exploitation records showed peaks in 2020 and 2014, after accounting for increases in internet users through time. The second of these peaks could be attributed to the COVID-19 outbreak, and speculation about the role of bats in its epidemiology, rather than to true changes in exploitation. Overall, our results showed that data from online sources provide additional knowledge on the global extent of wildlife exploitation, which could be used to identify early warnings of emerging threats and pinpoint locations for further research.
Sondeo del potencial de las fuentes virtuales de datos para mejorar el mapeo de amenazas para las especies por medio del estudio de caso de la explotación mundial de murciélagos Resumen La expansión de las fuentes virtuales, incluidas las redes sociales y las noticias en línea, proporciona una forma asequible de analizar las interacciones entre el humano y la naturaleza, como la explotación de fauna. Sin embargo, no se ha analizado por completo el rango al que dichas fuentes pueden expandir o sesgar el conocimiento de la distribución e intensidad de las amenazas. Para abordar este vacío cuantificamos la distribución geográfica y temporal de las fuentes virtuales que documentan la caza, captura, consumo o mercado de murciélagos (Chiroptera) y las comparamos con la distribución de los estudios obtenidos de una búsqueda sistemática en la literatura y con las especies catalogadas como amenazadas por la explotación según la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza. Recolectamos los registros virtuales por medio de búsquedas automatizadas en Facebook, Twitter, Google y Bing y después las filtramos con clasificaciones automatizadas. Esto arrojó 953 publicaciones relevantes en redes sociales y sitios web que englobaban 1099 registros únicos de la explotación de murciélagos en 84 países. Aunque pronosticamos de forma significativa el número de registros por país con el número de estudios académicos por país, los registros virtuales proporcionaron localidades adicionales y registros más recientes de la explotación de murciélagos, incluyendo a 22 países que no se encuentran en la literatura académica. Lo anterior demuestra el valor que tienen los recursos en línea para proporcionar una representación geográfica más completa. Sin embargo, las variables confusas pueden sesgar el análisis de las tendencias espaciotemporales. Los registros virtuales de la explotación de murciélagos mostraron picos en 2020 y en 2014, esto después de considerar el incremento de usuarios de internet con el tiempo. El segundo pico podría atribuirse al brote de COVID‐19 y la especulación en torno al papel que tenían los murciélagos en su epidemiología y no tanto a un verdadero cambio en la explotación. En general, nuestros resultados mostraron que los datos de las fuentes virtuales proporcionan conocimiento adicional sobre el alcance mundial de la explotación de fauna, el cual podría usarse para identificar señales tempranas de amenazas emergentes y ubicar localidades para su mayor investigación.
不断扩大的数字数据源, 包括社交媒体和在线新闻, 为研究野生动物资源开发等人与自然互作提供了一种低成本的方法。然而, 目前尚未全面评估这些数据源能在多大程度上增进或误导人们对威胁分布和强度的理解。为了填补这一空白, 本研究量化了记录对蝙蝠(翼手目)的猎杀、诱捕、消费和贸易的在线资料的时空分布, 并将其与系统性文献检索所获得的研究分布以及在《世界自然保护联盟红色名录》中被列为受到人类资源开发威胁的物种进行了比较。我们通过自动搜索 Facebook 、 Twitter 、 Google 和 Bing 收集了在线记录, 并使用机器分类进行过滤, 共收集到 953 条相关的社交媒体帖子和网页, 包括来自84个国家的 1099 条关于蝙蝠资源开发利用的非重复记录。虽然每个国家的学术研究数量可以很好地预测每个国家的在线记录数量, 但在线记录提供了更多的地点和更近期的蝙蝠资源开发记录, 还包含了学术文献中没有的 22 个国家。这表明了在线资源在提供更完整的地理代表性方面的价值。然而, 混杂变量会使时空趋势分析出现偏差。在考虑了互联网用户不断增加的因素后, 关于蝙蝠资源开发利用的在线记录数量在2020年和 2014 年达到峰值。第二个峰值可能是由于COVID‐19的爆发, 以及对蝙蝠在其流行病学中的作用的猜测, 而非真正的资源开发变化。总之, 我们的研究结果表明, 在线数据提供了有关全球野生动物资源开发程度的更多知识, 可用于识别新出现威胁的早期预警, 并确定需要进一步研究的地点。【翻译: 胡怡思; 审校: 聂永刚】.

BACKGROUND: Hemangiomas are a relatively common type of tumor in humans and animals. Various subtypes of hemangiomas have been described in the literature. The classification methods for hemangiomas differ between human and veterinary medicine, and the basis for tumor classification can be found in the literature.
METHODS: This study describes a tumor in the subcutaneous tissue of the right dorsum of an artificially rescued juvenile Chinese pangolin. Computed tomography (CT) examination yielded the preliminary diagnosis of a vascular malformation, and surgery was performed to resect the tumor. Histopathological examination showed that the tumor mainly was consisted of adipose tissue, capillaries, and spindle cells in the fibrous stroma. Immunohistochemistry showed the positive expression of CD31, CD34, α-SMA, GLUT1 and WT-1 in the tumor tissue, and the tumor was eventually diagnosed as an infantile haemangioma.
CONCLUSIONS: The final diagnosis of infantile hemangioma was depended on the histopathological immunohistochemical and CT examination of the neoplastic tissue. This is the first report of infantile hemangioma in a critically endangered species Chinese pangolin.

Traditionally, researchers have assessed diet selection by comparing consumed versus available taxa. However, taxonomic assignment is probably irrelevant for predators, who likely base their selection on characteristics including prey size, habitat, or behavior. Here, we use an aquatic insectivore, the threatened Pyrenean Desman (Galemys pyrenaicus), as a model species to assess whether biological traits help unravel the criteria driving food and habitat preferences. We reanalyzed data from a previous taxonomy-based study of prey selection in two contrasting streams, one with excellent conservation status and the other affected by diversion for hydropower and forestry. Available and consumed prey were characterized according to nine biological traits, and diet selection was estimated by comparing availability-measured from Surber net samples, and consumption-analyzed by metabarcoding desman feces. Traits offered a biologically coherent image of diet and almost identical selection patterns in both streams, depicting a highly specialized rheophilic predator. Desmans positively selected prey with a preference for fast flow and boulder substrate, indicating their preferred riffle habitat. On the other hand, they positively selected prey with larger but not the largest potential size, living in the water column or the litter, and not inside sediments. They also chose agile prey, swimmers or prey attached to the substrate, prey with high body flexibility, and prey living exposed and clustered in groups. Overall, our results offer a picture of desman diet preference and point to biological traits as being better than taxonomic identity to describe the diet preference of consumers.
Tradicionalmente, los investigadores han estimado la selección de dieta comparando los taxones ingeridos con los disponibles. Sin embargo, la asignación taxonómica probablemente sea irrelevante para los depredadores, que probablemente basan su selección en características tales como el tamaño de presa, su hábitat o su comportamiento. Aquí, utilizamos como especie modelo un insectívoro acuático, el amenazado desmán ibérico (Galemys pyrenaicus), para evaluar si los rasgos biológicos ayudan a desvelar los criterios que rigen las preferencias de alimentos y de hábitat. Reanalizamos los datos de un estudio previo basado en taxonomía sobre la selección de presas de desmán en dos ríos diferentes, uno en excelente estado de conservación y el otro afectado por la derivación de agua para producción de energía hidroeléctrica y por actividades forestales. Se caracterizaron las presas disponibles y consumidas en función de nueve rasgos biológicos y se estimó la selección de dieta comparando la disponibilidad, medida a partir de muestras de redes Surber, y el consumo, determinado mediante metabarcoding de las heces del desmán. Los rasgos biológicos ofrecieron una imagen biológicamente coherente de la dieta y unos patrones de selección casi idénticos en ambos ríos, representando a un depredador reófilo altamente especializado. Los desmanes seleccionaron positivamente las presas con preferencia por corriente rápida y sustrato de bloques, indicando su preferencia de hábitat por los rápidos. Por otro lado, seleccionaron positivamente presas con tamaño potencial grande—pero no el mayor—, que vivían en la columna de agua o en la hojarasca, y no dentro de los sedimentos. También eligieron presas ágiles, presas nadadoras o adheridas al sustrato, presas con alta flexibilidad corporal y presas que viven expuestas y agrupadas. En general, nuestros resultados ofrecen una imagen de las preferencias tróficas del desmán y apuntan a que los rasgos biológicos de las presas describen las preferencias tróficas de los consumidores mejor que su identidad taxonómica.

Areas used for livestock production and dominated by native grasses represent a unique opportunity to reconcile biodiversity conservation and livestock production. However, limited knowledge of individual species\' responses to rangeland management restricts our capacity to design grazing practices that favor endangered species and other priority birds. In this work, we applied Hierarchical Modelling of Species Communities (HMSC) to study individual species responses, as well as the influence of traits on such responses, to variables related to rangeland management using birds of the Rio de la Plata Grasslands as a case study. Based on presence-absence data collected in 454 paddocks across 46 ranches we inferred the response of 69 species considering imperfect detection. This degree of detail fills a major gap in rangeland management, as species-level responses can be used to achieve targeted conservation goals other than maximizing richness or abundance. We found that artificial pastures had an overall negative impact on many bird species, whereas the presence of tussocks had a positive effect, including all threatened species. Grassland specialists were in general sensitive to grass height and tended to respond positively to tussocks but negatively to tree cover. Controlling grass height via adjustments in stocking rate can be a useful tool to favor grassland specialists. To favor a wide range of bird species in ranches, a mosaic of short and tall native grasslands with patches of tussocks and trees is desirable. We also found that species-specific responses were modulated by their traits: small-sized birds responded positively to tussocks and tree cover while large species responded negatively to increasing grass height. Ground foragers preferred short grass while birds that scarcely use this stratum were not affected by grass height. Results on the influence of traits on bird responses are an important novelty in relation to previous work in rangelands and potentially increase our predicting capacity and model transferability across grassland regions.

Dam construction in riverine ecosystems has fragmented natural aquatic habitats and has altered environmental conditions. As a result, damming has been demonstrated to threaten aquatic biodiversity by reducing species distribution ranges and hindering gene exchange, leading to the inability to adapt to environmental changes. Knowledge of the contemporary genetic diversity and genetic structure of fish populations that are separated by dams is vital to developing effective conservation strategies, particularly for endangered fish species. We chose the Lianjiang River, a tributary of the Pearl River, as a case study to assess the effects of dams on the genetic diversity and genetic structure of an endangered fish species, Hemibagrus guttatus, using whole-genome resequencing data from 63 fish samples. The results indicated low levels of genetic diversity, high levels of inbreeding and decreasing trend of effective population size in fragmented H. guttatus populations. In addition, there were significant genetic structure and genetic differentiation among populations, suggesting that the dams might have affected H. guttatus populations. Our findings may benefit management and conservation practices for this endangered species that is currently suffering from the effects of dam construction.

The world\'s largest rivers are home to diverse, endemic, and threatened fish species. However, their sheer sizes make large-scale biomonitoring challenging. While environmental DNA (eDNA) metabarcoding has become an established monitoring approach in smaller freshwater ecosystems, its suitability for large rivers may be challenged by the sheer extent of their cross sections (>1 km wide and tens of meters deep). Here, we sampled fish eDNA from multiple vertical layers and horizontal locations from two cross sections of the lower reach of the Yangtze River in China. Over half of the ASVs (amplicon sequence variants) were detected in only a single combination of the vertical layers and horizontal locations, with ∼7% across all combinations. We estimated the need to sample >100 L of water across the cross-sectional profiles to achieve ASV richness saturation, which translates to ∼60 L of water at the species level. No consistent pattern emerged for prioritizing certain depth and horizontal samples, yet we underline the importance of sampling and integrating different layers and locations simultaneously. Our study highlights the significance of spatially stratified sampling and sampling volumes when using eDNA approaches. Specifically, we developed and tested a scalable and broadly applicable strategy that advances the monitoring and conservation of large rivers.