Mammalian Herbivores Research Articles

DNA barcoding as new diagnostic tool to lethal plant poisoning in herbivorous mammals

Reliable identification of plant species in the digestive tract of a deceased animal often represents the major key to diagnose a lethal intoxication with poisonous plants in veterinary pathology. In many cases, identification of the species is challenging or even impossible because the diagnostic morphological features have been degraded, and because the interpretation of such features requires a considerable expertise in plant anatomy and biodiversity. The use of DNA barcoding markers can support or even replace classical morphological assessment. While these markers have been widely used for plant taxonomy, their forensic application to clarify causes of animal poisoning is novel. In addition, we use specific single-nucleotide polymorphisms as fingerprints. This allows for a clear decision even in cases, where the conventionally used statistical e-values remain ambiguous. In the current work, we explore the feasibility of this strategy in a couple of exemplary cases, either in concert with anatomical diagnostics, or in cases where visual species identification is not possible, or where chemical toxin detection methods are not well established, complex, time consuming and expensive.

Diversity of the infusoria symbiofauna of cattle

Infusoria from the digestive tract of herbivorous mammals have been known to science for almost a century and a half. However, protozoans remain an understudied group of rumen dwellers in ruminants. In cattle, in a multi-chambered stomach, in addition to microorganisms (fungi and bacteria), there are a large number of protozoa (infusoria), which also participate in the digestive processes that support the vital activity of the body. Endobiontic infusoria take an active part in the digestion of complex carbohydrates, fiber, in the breakdown of indigestible polysaccharides, which are essential sources of energy for animals. In this regard, the study of the species and quantitative composition of the infusoria fauna of cattle bred in the Far North, as one of the factors of sustainable adaptation to extreme conditions, is of great scientific and practical interest.This article presents the results of a study of endobiontic infusoria of cattle breeds bred in Yakutia. A total of 36 species have been identified and described in 12 genera and 3 families. It was found that the genus Entodinium and the genus Isotricha were the most represented in the Yakut cattle, while the genus Entodinium and Euplodiniumin are in the crossbred and cultivated cattle. The smallest genus in all groups are Polyplastron and Metadinium.

Effects of large mammal exclusion on seedling communities depend on plant species traits and landscape protection in human‐modified Costa Rican forests

Abstract Large terrestrial herbivorous mammals (LTH‐mammals) influence plant community structure by affecting seedling establishment in mature tropical forests. Many of these LTH‐mammals frequent secondary forests, but their effects on seedling establishment in them are understudied, hindering our understanding of how LTH‐mammals influence forest regeneration in human‐modified landscapes. We tested the hypothesis that the strength of LTH‐mammals' effects on seedling establishment depends on landscape protection, forest successional stage and plant species' traits using a manipulative field experiment in six 1‐ha sites with varying successional age and landscape protection. In each site, we established 40 seedling plot‐pairs, with one plot excluding LTH‐mammals and one not, and monitored seedlings of 116 woody species for 26 months. We found significant effects of LTH‐mammal exclusion on seedling survival contingent upon the protection of forests at the landscape level and forest stage. After 26 months, survival differences between LTH‐mammal exclusion and non‐exclusion treatments were greater in protected than unprotected landscapes. Additionally, plant species' traits were related to the LTH‐mammals' differential effects, as LTH‐mammals reduced the survival of seedlings of larger‐seeded species the most. Overall, LTH‐mammals' effects translated into significant shifts in community composition as seedling communities inside and outside the exclosures diverged. Moreover, lower density and higher species diversity were found as early as 12 and 18 months outside than inside exclosures. Synthesis and applications. Insight into the interactions between LTH‐mammals and seedling communities in forest regeneration can be instrumental in planning effective restoration efforts. We highlight the importance of landscape protection in seedling survival and the role of LTH‐mammals in promoting seedling diversity in mature forests but also in secondary successional forests. The findings suggest that conservation efforts and possibly trophic rewilding can be important approaches for preserving diversity and influencing the trajectory of secondary tropical forest succession. However, we also caution that an overabundance of LTH‐mammals may adversely impact the pace of forest succession due to their preference for large‐seeded species. Therefore, a comprehensive wildlife management plan is indispensable. Additionally, longer term studies on LTH‐mammals are necessary to understand the effects of temporal fluctuations that are undetected in short‐term studies.

Classification and distribution of functional groups of birds and mammals in Mexico.

There has been a recent exponential growth in the study of functional trait ecology. Nonetheless, the study of functional traits and functional groups has been limited for terrestrial vertebrates. We conducted a classification update of functional groups (FG) of birds and mammals in Mexico, and determined the distribution patterns of FG species richness in different ecosystems nationwide. We selected six functional traits (feeding habit, locomotion, feeding substrate and technique, activity period, seasonality, and body size) obtained for 987 and 496 species of birds and mammals, respectively. A cophenetic correlation analyses resulted in values of 0.82 for the bird species dendrogram, and 0.79 for the mammal species dendrogram showing that the structures adequately reflected the similarity between observations. We obtained 52 FG for birds, assembled into 9 broader groups based on their feeding habits (16 invertivores, 6 carnivores: 5 herbivores, 9 aquatic vertivore/invertivore, 5 granivores, 1 scavenger, 3 nectarivores, 4 frugivores, and 3 omnivores). We obtained 35 FG for mammals, assembled into 9 broader groups based on their feeding habits (4 granivores, 10 herbivores, 1 nectarivore, 4 frugivores, 8 invertivores, 3 omnivores, 2 aquatic vertivore/invertivore, 1 hematophagous, and 2 carnivores). Overall, the distribution of FG species richness for birds and mammals gradually increased from the Nearctic to the Neotropical region, following a typical latitudinal species richness pattern. Few FG of migratory birds, and FG of granivore and herbivore mammals showed more species in the Nearctic and in the transitional regions. Our study provides a baseline for identifying ecological functions of species of birds and mammals in different ecosystems in Mexico, and contributes to understand the relationship between species diversity, community structure and ecosystem functioning. Identifying spatial patterns of functional trait diversity is important as biodiversity loss has a negative impact on ecosystem functioning and provision of environmental services.

Paleobiology of Pleistocene large land mammals from the Brazilian Pampa

The southern Brazilian Pleistocene fauna exhibited a rich diversity of large mammalian herbivores, which are now extinct or locally extinct. In this study, we employed stable isotope analysis to investigate the past ecology of these animals. Specifically, we examined the carbonate fraction of bones and teeth and utilized compiled carbon and oxygen isotopic ratios from previous research publications. The δ13C values indicated that most specimens inhabited grassland environments, which aligns with environmental reconstructions based on pollen records of the “Campos” region. The dominant food resource for these herbivores consisted of C3 photosynthesizers, mainly cool-season grasses. This preference can be attributed to the higher abundance and nutritional quality of cool-season grasses compared with warm-season grasses employing C4 photosynthesis. The variability in δ18O values within and between taxa may suggest a seasonal climate. Based on these findings, we conclude that the environmental changes during the Pleistocene-Holocene transition were detrimental to the survival of these large herbivores.

Diversity and Distribution of Large Herbivore Mammals in Kawal Tiger Reserve, Telangana State

The usage of habitat, rate of growth, dispersion, and the reaction of a population to management activities are all factors in estimating the richness of wild animals. However, because there are so many real-world field issues, determining the densities of herbivore animals in the forest is challenging. The current study is conducted in Kawal Tiger Reserve, northeast of Telangana, to estimate the number of big herbivore mammals and learn more about how these animals use various habitats. The direct sighting and line transect methods were applied to collect systematic data. 7 species of large herbivore viz. Bluebull, Four-horned Antelope, Indian Gaur, Spotted Deer, Sambar Deer, Indian Gazelle, Wild boar were observed during the surveys. Based on the information, the habitat preferences of different large herbivore species in the study area is assessed. Results shows the richness of the species is abundant in the study area due to availability of sufficient food resources, sufficient water resources. No adverse increase or decrease in the quantity of sightings annually. Even if there have been a few local hunting occurrences, they are not noteworthy nor do they appear to have any impact on the extinction of species. It may also lamentably state that our carnivore density is really low.

Community composition, and not species richness, of microbes influences decomposer functional diversity in soil

Diversity-function relationships in producers, and how these are influenced by consumers, are well known. However, these are not well known for microbial decomposers in soil. It is also unknown whether and how consumers such as large mammalian herbivores influence soil microbial decomposer diversity-function relationships. We used a 14-year-old herbivore-exclusion experiment in the Trans-Himalayan drylands of northern India to address whether microbial functions vary with microbial diversity (both species richness and composition), and whether herbivores alter the diversity-function relationships. We analyzed soils from n = 10 paired grazed-and-fenced plots three times during the growth season of 2019. Data were from 16S rDNA gene amplicon sequencing of 7.6 million reads covering 1937 operational taxonomic units (OTU) of bacteria across 47 phyla (of which 924 OTUs were identifiable to genus level), and 1800 catabolic profiles across 30 substrates related to carbon metabolism. We found that functional diversity was positively related to microbial community composition, but not to species richness; it was also unaffected by large mammalian herbivore-exclusion to indicate resilience and resistance. This positive relationship between community composition and functional diversity challenges the prevailing notion of functional redundancy in hyper-diverse soil microbial communities since certain combinations of species could outperform others and determine decomposition processes and services. Structural equation models suggested that the strength of this relationship is favoured by availability of soil moisture. Microbial functions varied more strongly with temporal variables (e.g., seasonality) than with spatial variables (e.g., edaphic factors such as soil texture and pH). Although interpretations can be constrained by which and how many functions are investigated, the relationship was generalizable and robust once 16 or more functions were quantified. Decomposition in drylands may be particularly susceptible to how the identity of the microbial species, and not the number of species, responds to rising precipitation variability under ongoing and projected climate change.

Paleoenvironmental inferences on the Late Miocene hominoid-bearing site of Can Llobateres (NE Iberian Peninsula): An ecometric approach based on functional dental traits

Hispanopithecus laietanus from the Late Miocene (9.8 Ma) of Can Llobateres 1 (CLL1; Vallès-Penedès Basin, NE Iberian Peninsula) represents one of the latest occurrences of fossil apes in Western mainland Europe, where they are last recorded at ∼9.5 Ma. The paleoenvironment of CLL1 is thus relevant for understanding the extinction of European hominoids. To refine paleoenvironmental inferences for CLL1, we apply ecometric models based on functional crown type (FCT) variables—a scoring scheme devised to capture macroscopic functional traits of occlusal shape and wear surfaces of herbivorous large mammal molars. Paleotemperature and paleoprecipitation estimates for CLL1 are provided based on published regional regression models linking average FCT of large herbivorous mammal communities to climatic conditions. A mapping to Whittaker's present-day biome classification is also attempted based on these estimates, as well as a case-based reasoning via canonical variate analysis of FCT variables from five relevant biomes. Estimates of mean annual temperature (25 °C) and mean annual precipitation (881 mm) classify CLL1 as a tropical seasonal forest/savanna, only in partial agreement with the canonical variate analysis results, which classify CLL1 as a tropical rainforest with a higher probability. The former biome agrees better with previous inferences derived from fossil plants and mammals, as well as preliminary isotopic data. The misclassification of CLL1 as a tropical forest is attributed to the mixture of forest-adapted taxa with others adapted to more open environments, given that faunal and plant composition indicates the presence of a dense wetland/riparian forest with more open woodlands nearby. The tested FCT ecometric approaches do not provide unambiguous biome classification for CLL1. Nevertheless, our results are consistent with those from other approaches, thus suggesting that FCT variables are potentially useful to investigate paleoenvironmental changes through time and space—including those that led to the extinction of European Miocene apes.

Temporal and spatial variations in body mass and thermogenic capacity associated with alterations in the gut microbiota and host transcriptome in mammalian herbivores

Most wild animals follow Bergmann's rule and grow in body size as cold stress increases. However, the underlying thermogenic strategies and their relationship with the gut microbiota have not been comprehensively elucidated. Herein, we used the plateau pikas as a model to investigate body mass, thermogenic capacity, host transcriptome, gut microbiota and metabolites collected from seven sites ranging from 3100 to 4700 m on the Qinghai–Tibetan Plateau (QTP) in summer and winter to test the seasonal thermogenesis strategy in small herbivorous mammals. The results showed that the increase in pika body mass with altitude followed Bergmann's rule in summer and an inverted parabolic shape was observed in winter. However, physiological parameters and transcriptome profiles indicated that the thermogenic capacity of pikas increased with altitude in summer and decreased with altitude in winter. The abundance of Firmicutes declined, whereas that of Bacteroidetes significantly increased with altitude in summer. Phenylalanine, tyrosine, and proline were enriched in summer, whereas carnitine and succinate were enriched in winter. Spearman's correlation analysis revealed significant positive correlations between Prevotella, Bacteroides, Ruminococcus, Alistipes and Akkermansia and metabolites of amino acids, pika physiological parameters, and transcriptome profiles. Moreover, metabolites of amino acids further showed significant positive correlations with pika physiological parameters and transcriptome profiles. Our study highlights that the changes in body mass and thermogenic capacity with altitude distinctly differentiate small herbivorous mammals between summer and winter on the QTP, and that the gut microbiota may regulate host thermogenesis through its metabolites.

Enhancing subtropical monsoon grassland management: Investigating mowing and nutrient input effects on initiation of grazing lawns

Subtropical monsoon grasslands in Asia are commonly in a fire-dominated state with tall grasses (> 2 m) that provide poor-quality forage for mammalian herbivores. In contrast, small patches of grazing lawns with short, nutritious grasses are sparsely distributed within these subtropical monsoon grasslands. Despite the importance of grazing lawns in providing high-quality forage for mammalian herbivores, the process of formation and maintenance of grazing lawns has not been studied in the monsoon grasslands of subtropical Asia. We conducted a large-scale multi-year experiment in subtropical monsoon grasslands within a protected area in Nepal to examine whether mowing tall grasses at different frequencies and spatial scales, along with the application of chemical fertilisers (urea or single superphosphate), could change tall grasslands into grazing lawns. We found that nitrogen and phosphorus concentrations in grasses increased to levels exceeding the minimum maintenance requirements for ruminants in 3600 m2 plots that were mown four times and fertilised. The concentrations of nitrogen and phosphorus remained below the minimum maintenance level for ruminants in unfertilised and unmown plots and in small plots that were four-time mown and fertilised. The frequently mown plots exhibited a significant increase in the proportion of ground cover of lawn grass, from 1% to 3%, and a corresponding decrease in the proportion of ground cover of tall grasses, from 24% to 1%. These results supported our hypothesis that frequent mowing at a larger spatial scale with the addition of chemical fertilisers and grazing leads to the inception of grazing lawns that are favourable for wild herbivores. However, the persistence of the grazing lawns presents challenges due to the highly productive monsoon season and the functional extinction of large bulk grazers. To our knowledge, this is the first empirical study conducted in the subtropical monsoon grasslands of Asia to experimentally demonstrate the importance of active management for the initiation of grazing lawns. Our findings have important implications for the management of subtropical monsoon grasslands.

Soil erosion under forest hampers beech growth: Impacts of understory vegetation degradation by sika deer

The overpopulation of large herbivorous mammals degrades understory vegetation and hence promotes soil erosion in some northern hemisphere forests. Topsoil removal via erosion reduces soil water and nitrogen (N) content as well as exposes tree roots. However, whether topsoil removal inhibits tree growth through water and N uptake limitations has not been examined. This study aimed to measure the vertical length from exposed roots surface to the soil surface (exposed root height; ERH) under degraded forest understory vegetation and to evaluate its influence on tree growth. Specifically, we examined the relationships between ERH and beech growth and identified the timing of growth reduction based on annual tree-ring analysis at the individual scale. Furthermore, we discussed the effects of water and N limitations on beech growth reduction. We studied 12 Japanese beech trees on Mt. Sanpo, southern Kyushu Island, Japan, where understory vegetation was degraded and lost due to herbivory by Japanese sika deer from 1980 to 2003. Lower amounts of leaf production and relative growth rates of stem basal area increment (BAI) were observed in beech trees with higher ERH. Segmented regression analysis, which detects the changing time of a temporal trend (i.e., break-point), revealed that the BAI has resulted in a decreasing trend after 1997.6 ± 9.0 (yr), which coincided with the field observations on understory degradation in the study site. After the break-point of the BAI, the BAI of each study tree was negatively related to intrinsic water use efficiency, an integrated index of water limitation. These results suggest that soil erosion after the degradation of understory vegetation reduced beech growth, possibly because of the water limitations associated with root exposure. Reduced beech growth will reduce the supply of the litter layer that prevents topsoil erosion, which may enhance further soil erosion and tree growth reduction.

The effects of landscape and yard features on mammal diversity in residential yards within Northwest Arkansas, USA

The human footprint is rapidly expanding, and wildlife habitat is continuously being converted to human residential properties. Surviving wildlife that reside in developing areas are displaced to nearby undeveloped areas. However, some animals can co-exist with humans and acquire the necessary resources (food, water, shelter) within the human environment. This ability to coexist may be particularly true when development is low intensity, as in residential suburban yards. Yards are individually managed “greenspaces” that can provide a range of food (e.g., bird feeders, compost, gardens), water (bird baths and garden ponds), and shelter (e.g., brush-piles, outbuildings) resources and are surrounded by varying landscape cover. To evaluate which residential landscape and yard features influence the richness and diversity of mammalian herbivores and mesopredators; we deployed wildlife game cameras throughout Northwestern Arkansas, USA in 46 residential yards in summer 2021 and 96 yards in summer 2022. We found that mesopredator diversity had a negative relationship with fences and was positively influenced by the number of bird feeders present in a yard. Mesopredator richness increased with the amount of forest within 400 m of the camera. Herbivore diversity and richness were positively correlated to the area of forest within 400 m surrounding yard and by garden area within yards, respectively. Our results suggest that while landscape does play a role in the presence of wildlife in a residential area, homeowners also have agency over the richness and diversity of mammals using their yards based on the features they create or maintain on their properties.

Herbivore–shrub interactions influence ecosystem respiration and biogenic volatile organic compound composition in the subarctic

Abstract. Arctic ecosystems are warming nearly 4 times faster than the global average, which is resulting in plant community shifts and subsequent changes in biogeochemical processes such as gaseous fluxes. Additionally, herbivores shape plant communities and thereby may alter the magnitude and composition of ecosystem respiration and biogenic volatile organic compound (BVOC) emissions. Here we determine the effect of large mammalian herbivores on ecosystem respiration and BVOC emissions in two southern and two northern sites in Swedish Scandes, encompassing mountain birch (LOMB) and shrub heath (LORI) communities in the south and low-herb meadow (RIGA) and shrub heath (RIRI) communities in the north. Herbivory significantly altered BVOC composition between sites and decreased ecosystem respiration at RIGA. The difference in graminoid cover was found to have a large effect on ecosystem respiration between sites as RIGA, with the highest cover, had 35 % higher emissions than the next highest-emitting site (LOMB). Additionally, LOMB had the highest emissions of terpenes, with the northern sites having significantly lower emissions. Differences between sites were primarily due to differences in exclosure effects and soil temperature and the prevalence of different shrub growth forms. Our results suggest that herbivory has a significant effect on trace gas fluxes in a productive meadow community and that differences between communities may be driven by differences in shrub composition.

Exotic herbivores and fire energy drive standing herbaceous biomass but do not alter compositional patterns in a semiarid savanna ecosystem

AbstractQuestionsFire regime alterations are pushing open ecosystems worldwide past tipping points where alternative steady states characterized by woody dominance prevail. This reduces the frequency and intensity of surface fires, further limiting their effectiveness for controlling cover of woody plants. In addition, grazing pressure (exotic or native grazers) can reinforce woody encroachment by potentially reducing fine‐fuel loads. We investigated the effects of different fire energies on the herbaceous plant community, together with mammalian wildlife herbivory (exotic and native combined) exclusion, to inform best management practices.LocationTexas semi‐arid savanna, southern Great Plains, USA.MethodsWe conducted an experiment in which we manipulated fire intensity and herbivore access to herbaceous biomass in a split‐plot design. We altered fire energy via fuel addition rather than applying fire under different environmental conditions to control for differences in standing biomass and composition attributable to differential plant physiological status and fire season.ResultsHigh‐energy fire did not reduce herbaceous biomass or alter plant community composition, although it did increase among‐plot variability in composition and forb biomass relative to low‐energy fire and non‐burned controls. Grazing pressure from native and non‐native mammalian herbivores reduced above‐ground herbaceous biomass regardless of fire treatments, but did not alter community composition.ConclusionsManagers seeking to apply high‐intensity prescribed fire to reduce woody encroachment will not negatively impact herbaceous plant productivity or alter community composition. However, they should be cognizant that repeated fires necessary for greatly reducing woody plants in heavily invaded areas might be difficult to accomplish due to fine‐fuel reduction from wild herbivores. High fencing to restrict access by wildlife herbivores or culling might be necessary to build fuels sufficient to conduct high‐intensity burns for woody‐plant reduction.

Metagenomic analysis of herbivorous mammalian viral communities in the Northwest Plateau

BackgroundMammals are potential hosts for many infectious diseases. However, studies on the viral communities of herbivorous mammals in the Northwest Plateau are limited. Here, we studied the viral communities of herbivorous mammals in the Northwest Plateau using virus metagenomic analysis to analyze and compare the viral community composition of seven animal species.ResultsBy library construction and next-generation sequencing, contigs and singlets reads with similar viral sequences were classified into 24 viral families. Analyzed from the perspective of sampling areas, the virus community composition was relatively similar in two areas of Wuwei and Jinchang, Gansu Province. Analyzed from the perspective of seven animal species, the viral reads of seven animal species were mostly ssDNA and dominated by CRESS-DNA viruses. Phylogenetic analysis based on viral marker genes indicated that CRESS-DNA viruses and microviruses have high genetic diversity. In addition to DNA viruses, nodaviruses, pepper mild mottle viruses and picornaviruses were RNA viruses that we performed by phylogenetic analysis. The CRESS-DNA viruses and nodaviruses are believed to infect plants and insects, and microviruses can infect bacteria, identifying that they were likely from the diet of herbivorous mammals. Notably, two picornaviruses were identified from red deer and wild horse, showing that the picornavirus found in red deer had the relatively high similarity with human hepatitis A virus, and the picornavirus carried by wild horse could potentially form a new species within the Picornaviridae family.ConclusionsThis study explored the herbivorous mammalian virus community in the Northwest Plateau and the genetic characteristics of viruses that potentially threaten human health. It reveals the diversity and stability of herbivorous mammalian virus communities in the Northwest Plateau and helps to expand our knowledge of various herbivorous mammalian potentially pathogenic viruses.

Plant defences as functional traits: A comparison across savannas differing in herbivore specialization

Abstract Top‐down and bottom‐up forces in tropical savannas have shaped the evolution of traits that enable plants to thrive in environments where soils are poor, dry seasons are long, fire is frequent, woody plants and grasses compete and herbivores range from cryptic caterpillars to elephants that topple entire trees. African savannas and the South American cerrado have similar climates and fire regimes, but differ in the presence of large mammal herbivores, which are mostly extinct in the cerrado. These biomes offer an instructive comparison to understand how plant defence traits evolved in response to differential herbivore pressure. Within Africa, mammalian herbivore pressure also differs across savannas, being lower in the miombo relative to more open, mixed savannas. The dominance of specialist insect herbivores in the cerrado, relative to the more generalist mammalian herbivores in Africa, suggests that defence traits will differ between savannas in accordance with herbivore identity and pressure. Wood is densest in mixed African savannas, as expected because large mammals often damage trees. Specific leaf area, related to palatability, is higher in mixed African savannas and the cerrado relative to the miombo, while leaf N is surprisingly higher in miombo species. Ant mutualists are important defences in mixed African savannas and the cerrado. Defensive chemistry has received less attention in the trait literature. Foliar phenolics, the most commonly studied chemical defences in savannas, vary in their efficacy. New analyses isolating specific compounds are informative as is the evaluation of phytochemical diversity as a defence. There are indications that phytochemical defences are more diverse in the cerrado, which may be related to greater specialization of cerrado herbivores. Synthesis. The dominance of specialist insect herbivores in the cerrado, relative to generalist mammalian herbivores in Africa, selected for different plant defence traits, contributing to the separation of species along the leaf economics spectrum and demonstrating the importance of plant defences as plant functional traits. African savanna species seem to follow a more acquisitive strategy, followed by miombo species. Cerrado species appear to follow a more conservative strategy with greater investments in tough leaves and chemical defences.

Influence of Abiotic Factors and Umbelliferone Toxicity in Snail Attractant Pellets Against the Vector Snail <i>Lymnaea acuminata</i>

Background and Objective: Fasciolosis is a zoonotic disease, which is transmitted by Lymnaea acuminata snails of the Lymnaidae family and causes the disease in human and herbivorous mammals in all over the world. One of the suitable approaches for the control of fasciolosis is the snail control. The snail control by snail attractant pellets is a new technique because there is no any side effect on other biota/human/natural environment. Material and Methods: The influence of various abiotic factors and umbelliferone toxicity in bait against the vector snail Lymnaea acuminata was checked in different months of the years 2018-2019. Result: After 24h of molluscicide exposure, it was found that LC50 values 4.37, 4.22 and 5.66 % in SAP containing starch + umbelliferone and 4.02, 4.33, and 4.76 % in SAP containing proline + umbelliferone during May, June and July, respectively, were most effective treatments in killing the snails. While SAP containing starch + umbelliferone was 9.84% and proline + umbelliferone was 8.94% were minimum effective in January in 24h toxicity. Conclusion: This study indicates that various abiotic factors significantly changed the toxicity of umbelliferone; so, the snails can be controlled by snail attractant pellets containing umbelliferone will be applied in a particular month rather than the whole month of the year.

Spatiotemporal variations in the acoustic presence of dugongs and vessel traffic around Talibong Island, Thailand: Inputs for local coastal management from passive acoustical aspects

Examining the spatiotemporal habitat use by marine megafauna and human activities at a fine scale is important to achieve harmonised management of coastal areas. Passive acoustic monitoring (PAM) can provide this information by observing animal vocalisations and the sounds generated by motorised vessels. Dugongs (Dugong dugon), which are endangered herbivorous mammals inhabiting coastal seas, communicate through social calls. Although their spatiotemporal acoustic presence on a fine scale could assist in prioritizing local marine spatial planning, such knowledge is limited. To address this gap, we examined the spatiotemporal pattern of the acoustic presence of dugongs and its correlation with environmental and anthropological factors; additionally, the overlap of these areas with vessel traffic was illustrated. Underwater recorders were deployed at 11 locations around Talibong Island, Thailand, for one month in both rainy and dry seasons. Based on the recorded sound stream, dugong calls and vessel sounds were automatically detected using custom-made software, and false detections were removed by manual examinations. In 2019 and 2020, 1933 h and 2719 h of recordings, respectively, revealed that while dugongs had a clear spatial preference for vocal communication at some locations, their temporal patterns varied among locations. Further, their acoustic presence was significantly correlated with environmental and anthropological factors at some locations, while these factors varied among other locations. However, the distribution of vessel traffic was spatially and temporally stable. These results suggested that (1) spatial management of vocalisation areas can effectively conserve dugongs by protecting their social behaviour and (2) temporal planning may reduce the potential disturbance risk to dugongs. Moreover, to achieve harmonised marine spatial planning in coastal areas, the PAM approach for social calls can be effectively employed to provide a unique layer of habitat use for vocalising species and vessel traffic on a fine scale.

Organic Silicon in Plants as a Limiting Factor of Forage Digestibility in the Nutrition of Herbivorous Mammals

The effect of organic forms of silicon contained in plant tissues on the digestibility of feed for herbivorous mammals has been studied. In the process of digestion, an extremely small part of the consumed silicon is assimilated, which makes it possible to use organic silicon naturally contained in plants as an indicator of the digestibility of plant foods. The consumed silicon reduces the digestibility of the feed, puts a limit on the fermentation of the consumed vegetable substrate and its structural components (fiber, lignin). With an increase in the part of silicon in the consumed vegetation per unit, the digestibility decreases linearly by 3–4 units. The fermentation limit is set when the silicon content in the feed is within 3–4% of the dry weight. Among the main groups of forage plants (grasses and forbs), the amount of silicon is significantly higher in grasses (1.70 and 0.91%, respectively). For this reason, the digestibility of grasses in all compared animals (camels, Przewalski’s horses, bison, saiga) is 1.2–1.4 times lower than the digestibility of forbs. With an increase in the proportion of grasses in feed per unit, the digestibility of feed in animals with different types of digestion (ruminant, monogastric) decreases linearly by an average of 0.16 units. The different digestibility of grasses and forbs causes the separation of herbivores by types of nutrition and food specialization. Consumers of various forbs (saigas) avoid the consumption of grasses and are not viable with their dominance in pasture vegetation. The specific features of the digestion of herbivores (Equidae, Bovidae) provide an increased volume of consumption, compensating for the reduced digestibility of grasses.

Trematode parasites as indicators of an animal component in the diet of the Water Vole Arvicola amphibius.

The intestinal trematode fauna of the Water Vole Arvicola amphibius, (previously A. terrestris), was investigated to determine whether it might provide evidence of an animal component in the diet of this aquatic herbivorous small mammal. Interrogation of the electronic Host-Parasite Database of the Natural History Museum London revealed the presence of fourteen species of intestinal trematode in water voles, infection with each of which would require the ingestion of tissue from an animal intermediate host. The results obtained using these parasite indicators provide convincing evidence of animal components in the diet of A. amphibius and support anecdotal reports of water voles feeding on animal material in the field.