Seasonal Diet Composition of Goitered Gazelle (Gazella subgutturosa) in an Arid and Semi-Arid Region of Western China.

Global climate change, habitat fragmentation, and human interference have resulted in a significant, ongoing decline in the population of goitered gazelles. Effective conservation strategies require an understanding of resource requirements of threatened species, such as dietary needs. Therefore, we aimed to elucidate the food composition and seasonal dietary changes of goitered gazelles through microhistological analyses of fresh feces. Fabaceae (11.5%), Gramineae (9.4%), Chenopodiaceae (20.2%), Asteraceae (10.1%), and Rosaceae (19.5%) formed the primary dietary components of goitered gazelle. Additionally, Krascheninnikovia arborescens (13.4%) and Prunus sibirica (16.3%) were identified as the key forage plants. Forbs (50.4%) were the predominant plants for grazing throughout the year, particularly in the spring (72.9%). The proportion of trees in the diet was highest in the autumn (36.7%) and comparatively lower in other seasons. Furthermore, the proportions of shrubs (22.0%) and graminoids (14.8%) both reached their peaks in the winter. Our findings indicate that goitered gazelles strategically forage seasonally to cope with resource bottlenecks, enhancing their adaptability to arid and semi-arid habitats. Our study provides essential ecological information for the conservation of goitered gazelles and emphasizes the importance of dietary studies of species of ecological significance in environmentally sensitive areas.

Seasonal Prey Abundance and Food Plasticity of the Vulnerable Snow Leopard (Panthera uncia) in the Lapchi Valley, Nepal Himalayas.

Conservation strategies for apex predators, like the snow leopard (Panthera uncia), depend on a robust understanding of their dietary preferences, prey abundance, and adaptability to changing ecological conditions. To address these critical conservation concerns, this study presents a comprehensive evidence on prey availability and preferences for snow leopards in the Lapchi Valley in the Nepal Himalayas from November 2021 to March 2023. Field data were collected through the installation of twenty-six camera traps at 16 strategically chosen locations, resulting in the recording of 1228 events of 19 mammalian species, including domesticated livestock. Simultaneously, the collection of twenty snow leopard scat samples over 3800 m above sea level allowed for a detailed dietary analysis. Photo capture rate index and biomass composition analysis were carried out and seasonal prey availability and consumption were statistically analyzed. A total of 16 potential prey species for the snow leopard were documented during the study period. Himalayan musk deer (Moschus leucogaster) was the most abundant prey species, but infrequent in the diet suggesting that are not the best bet prey for the snow leopards. Snow leopards were found to exhibit a diverse diet, consuming eleven prey species, with blue sheep (Pseudois nayaur) being their most consumed wild prey and horses as their preferred livestock. The Pianka's index of dietary niche overlap between the summer and winter seasons were 0.576, suggesting a pronounced seasonal variation in food preference corroborating with the prey availability. The scarcity of larger preys in winter is compensated by small and meso-mammals in the diet, highlighting the snow leopard's capacity for dietary plasticity in response to the variation in resource availability. This research suggests for the utilization of genetic tools to further explore snow leopard diet composition. Additionally, understanding transboundary movements and conducting population assessments will be imperative for the formulation of effective conservation strategies.

Micro-histology combined with cytology improves the diagnostic accuracy of endometrial lesions.

BACKGROUND: In the study, we aimed to evaluate the ability of micro-histology combined with cytology to improve the quality of slides and diagnose endometrial lesions. METHODS: Endometrial specimens were collected from Li Brushes. Every specimen was prepared for micro-histological and cytological slides, using cell block (CB) and liquid-based cytology (LBC) technologies. Semi-quantitative scoring system was used to evaluate the qualities of slides. CB slides were assessed by 5-category scoring system. Diagnostic accuracy was calculated in LBC, CB, and LBC + CB groups based on the histological gold standard. Endometrial atypical hyperplasia, and endometrial cancer were considered positive, whereas others were considered negative. RESULTS: A total of 167 patients were enrolled. CB slides were inferior to LBC slides only in cellularity (p < 0.001), but superior in the other six parameters (all p < 0.001). The satisfaction rate of micro-histology accounted for 92.3%. The accuracy index in the CB group was higher than in the LBC group in terms of sensitivity (85.5% vs. 82.7%) and specificity (98.9% vs. 95.7%). The sensitivity and specificity in the LBC + CB group were increased to 94.2% and 99.0%, respectively. CONCLUSIONS: The quality of micro-histological slides was higher than that of cytological slides. By combining micro-histology with cytology, higher accuracy was achieved for endometrial lesions diagnosis.

The precautionary principle and dietary DNA metabarcoding: Commonly used abundance thresholds change ecological interpretation.

Dietary DNA metabarcoding enables researchers to identify and characterize trophic interactions with a high degree of taxonomic precision. It is also sensitive to sources of bias and contamination in the field and laboratory. One of the earliest and most common strategies for dealing with such sensitivities has been to remove all low-abundance sequences and conduct ecological analyses based on the presence or absence of food taxa. Although this step is now often perceived to be necessary, evidence of its sufficiency is lacking and more attention to the risk of introducing other errors is needed. Using computer simulations, we demonstrate that common strategies to remove low-abundance sequences can erroneously eliminate true dietary sequences in ways that impact downstream inferences. Using real data from well-studied wildlife populations in Yellowstone National Park, we further show how these strategies can markedly alter the composition of dietary profiles in ways that scale-up to obscure ecological interpretations about dietary generalism, specialism, and composition. Although the practice of removing low-abundance sequences may continue to be a useful strategy to address research questions that focus on a subset of relatively abundant foods, its continued widespread use risks generating misleading perceptions about the structure of trophic networks. Researchers working with dietary DNA metabarcoding data-or similar data such as environmental DNA, microbiomes, or pathobiomes-should be aware of drawbacks and consider alternative bioinformatic, experimental, and statistical solutions.

Effects of boom and bust grazing management on vegetation and health of beef cattle used for wildfire prevention in a Mediterranean forest.

Humans and wildfires have historically driven landscape structure in the Mediterranean basin. The Iberian Peninsula is not an exception to that rule, and therefore, farmers, researchers, and governments seek alternative tools to minimize the loss of biodiversity and wildfire risks. Extensive livestock including beef cattle is currently promoted as a suitable management tool by European agro-environmental policies yet pieces of evidence exist regarding the reciprocal effects between cows and Mediterranean woody vegetation. In this work, we performed a field manipulation to evaluate whether free-ranging beef cattle without supplementary feeding, at high density (2 livestock units (LU)/ha) for a short period of time i.e. "boom and bust grazing" management, are able to adapt their grazing preferences to the Mediterranean woody vegetation without health impairment, and prevent from bush encroachment and wildfires. For our purposes, a native herd of 14 adult cows was kept captive without supplementary feeding in a 14 ha enclosure covered by Mediterranean vegetation for two months (April-June 2016). Plant and cattle fecal and blood samples were collected to assess diet composition (plant cuticle microhistological analysis), fecal nitrogen and protein contents of consumed plants, and the nutritional status (non-esterified fatty acids) of cattle. Our results showed that cattle adapted their feeding habits toward a more woody diet including potentially flammable taxa but with some detrimental effects on health status. Hence, cattle cannot control woody vegetation for long periods of time without supplementary feeding. Further research should be oriented to explore other alternative approaches to minimize the health impairment of cattle used for control flammable vegetation in Mediterranean regions.

Food and Feeding Habits of Gaur (Bos gaurus) in Highlands of Central India: A Case Study at Pench Tiger Reserve, Madhya Pradesh (India).

Indian gaur (Bos gaurus) is one of nine species of wild oxen found in the world. They are largely confined to evergreen, semi-evergreen, and moist deciduous forests, but also occur in dry deciduous forest areas at the periphery of their range. According to the IUCN Red List ( 2017 ), the estimated population of gaur in India is between 15,000 and 35,000 individuals, and probably due to this, despite the gaur's vast range of distribution, they are listed as a vulnerable species by IUCN and listed as schedule-I of the Indian Wildlife Protection Act ( 1972 ) as well as in appendix-I in CITES ( 2003 ). Gaur is not a well studied species, and baseline data are thus needed to support conservation efforts. We studied the feeding habits of gaur in Pench Tiger Reserve. Pench Tiger Reserve is the 19th tiger reserve in India, situated in the Seoni and Chhindwara districts of MP, India (21°41'35″N 79°14'54″E). Diet composition of gaur was studied by micro-histological examination of 32 dung piles collected from different sampling plots in different seasons. For this purpose, 169 sampling plots were established at an interval of 200 m. To locate gaur faecal matter, a circular plot of 10 m radius was laid within each sampling plot. Eighty-eight permanent reference slides of available plants were prepared and used for plant fragment identification from the dung piles. A total of 29 plant species were identified from dung piles of gaur. On average, 44.51% of grass-fragments were detected in the diet of gaur, suggesting that gaurs are primarily grazers in the Pench Tiger Reserve.

Diagnose of the ingestion of Asclepias mellodora St. Hil. by sheep through microhistological analysis of their digestive contents / Diagnose da ingestão de Asclepias mellodora St. Hil. por ovinos através da análise micro-histológica de seu conteúdo digestivo

Asclepias mellodora St. Hil. is a native acute toxic species frequent in the grasslands of the Buenos Aires province, Argentina, whose toxicity had not been assessed until now. This study evaluates the minimal lethal dose of this species for sheep, and the possibility of microscopically recognizing its fragments in gastrointestinal contents as a complementary diagnostic tool in necropsies. Three Frisona sheep (average LW=55±4.5 kg) were dosed via an esophageal tube with each one of the following doses of asclepias: 8.0, 5.0, 2.0 and 0.8 g DM.kg LW-1. Sheep poisoned with the three higher doses died between 10 and 85 h after intoxication, but those receiving the lower dose did not. During necropsies we: 1) determined the dry weight of the contents of rumen+reticulum, omasum+abomasum, and large intestine, 2) estimated the percentages of asclepias fragments by microanalysis correcting for digestion effects on fragment recognition, and 3) calculated the total mass of asclepias in the digestive tract of each animal. For the three higher doses, the mass of asclepias identified in the total ingesta was 12.3±3.4 percent of the amount supplied, possibly because of the strong diarrhea its ingestion produced. The percentages of asclepias in rumen+reticulum did not differ from the average quantified for the entire tract. The results of this study indicate that the minimal lethal doses of asclepias for sheep is between 2.0 and 0.8g DMÀkg LW-1, and that the microhistological analysis of the rumen+reticulum, the easiest region to sample, can be used to confirm the ingestion of this toxic species, although the estimated percentage will be not a good estimator of the ingested percentage.

Asclepias mellodora St. Hil. é uma espécie nativa de aguda toxicidade, frequente nos campos da província de Buenos Aires, Argentina. A sua toxicidade não foi avaliada até agora. Este estudo avalia a dose mínima letal desta espécie, para os ovinos, bem como a possibilidade de reconhecer microscopicamente seus fragmentos no conteúdo gastrointestinal como uma ferramenta complementar de diagnóstico em necropsias. Três ovinos Frisona (PV média = 55±4,5 kg) foram dosados através de uma sonda esofágica em cada uma das seguintes doses de Asclepias: 8,0, 5,0, 2,0 e 0,8 g DM.kg PV-1. Ovinos intoxicados com as três maiores doses morreram entre 10-85 h após a intoxicação, mas não aqueles que receberam a dose menor. Durante as necropsias se: 1) determinou o peso seco do conteúdo do rúmen + retículo, omaso + abomaso e intestino grosso, 2) estimou as porcentagens de fragmentos de Asclepias por microanálise, fazendo a correção para efeitos de digestão no reconhecimento dos fragmentos, e 3) calculou a massa total de Asclepias no trato digestivo de cada animal. Para as três doses maiores, a massa de Asclepias identificada na ingesta total foi de 12,3±3,4 por cento da quantidade fornecida, possivelmente por causa da forte diarréia produzida pela sua ingestão. As porcentagens de Asclepias no rúmen + retículo não diferiram da média quantificada para o trato completo. Os resultados deste estudo indicam que a dose letal mínima de Asclepias em ovinos é de entre 2,0 e 0,8 g kg PV ò DM-1, e que a análise micro-histológica do rúmen + retículo, a região mais fácil de amostrar, pode ser usada para confirmar a ingestão desta espécie tóxica, embora a percentagem estimada não será um bom estimador da porcentagem ingerida.