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The declining population of otter species in Malaysia, including the Asian small‐clawed otter (Aonyx cinereus), smooth‐coated otter (Lutrogale perspicillata) and hairy‐nosed otter (Lutra sumatrana), is primarily attributed to habitat changes. Understanding the ecological aspects of otters, including their diets, is crucial for formulating effective conservation management strategies. To address this knowledge gap, we employed Next Generation Sequencing (NGS) as an alternative approach to enhance our understanding of the species' food chain. Specifically, this study investigated the diets of Asian small‐clawed otters and smooth‐coated otters by analysing an ~130 bp segment of the Cytochrome b (Cytb) gene using Illumina Miniseq platform. The analysis successfully generated 572,311 reads, identifying four families, nine genera and 11 food species consumed by both otter species. Smooth‐coated otters primarily consumed fish (96%) and frogs (4%), whereas Asian small‐clawed otters exclusively fed on fish (100%), with the genus Esomus being the predominant fish genus found in the spraints. The diversity analysis of their diets revealed significant differences between two species (p < 0.05). As a result, DNA metabarcoding provides a reliable method for verifying otter dietary information and can serve as a valuable tool in assessing fish diversity, thus contributing significantly to the management and conservation of otter populations, particularly in Malaysia. [ABSTRACT FROM AUTHOR]

The tomato potato psyllid, Bactericera cockerelli, is an invasive pest in Australia, which can cause severe economic loss in the production of Solanaceous crops. As an invasive pest, B. cockerelli may also modify biotic interactions in Australian agricultural and native ecosystems. Resident generalist predators in an area may have the ability to utilize invasive pest species as prey but this will depend on their specific predatory behavior. The extent to which generalist predators learn from their previous dietary experience (i.e., whether they have used a particular species as prey before) and how this impacts subsequent prey choice will influence predator and prey population dynamics after invasion. In this study, one nonnative resident ladybird, Hippodamia variegata, and one native ladybird, Coccinella transversalis, were investigated. Dietary experience with B. cockerelli as a prey species significantly increased preference for the psyllid in a short term (6 h) Petri dish study where a choice of prey was given. Greater suppression of B. cockerelli populations by experienced ladybirds was also observed on glasshouse grown tomato plants. This was presumably due to altered prey recognition by experience. The result of this study suggest the potential to improve the impact of biological control agents on invasive pests by providing early life experience consuming the target species. It may prove valuable for developing improved augmentative release strategies for ladybirds to manage specific insect pest species. [ABSTRACT FROM AUTHOR]

Aphids, the important global agricultural pests, harbor abundant resources of symbionts that can improve the host adaptability to environmental conditions, also control the interactions between host aphid and natural enemy, resulting in a significant decrease in efficiency of biological control. The facultative symbiont Serratia symbiotica has a strong symbiotic association with its aphid hosts, a relationship that is known to interfere with host–parasitoid interactions. We hypothesized that Serratia may also influence other trophic interactions by interfering with the physiology and behavior of major predators to provide host aphid defense. To test this hypothesis, we investigated the effects of Serratia on the host aphid Acyrthosiphon pisum and its predator, the ladybeetle Propylaea japonica. First, the prevalence of Serratia in different A. pisum colonies was confirmed by amplicon sequencing. We then showed that harboring Serratia improved host aphid growth and fecundity but reduced longevity. Finally, our research demonstrated that Serratia defends aphids against P. japonica by impeding the predator's development and predation capacity, and modulating its foraging behavior. Our findings reveal that facultative symbiont Serratia improves aphid fitness by disrupting the predation strategy of ladybeetle larvae, offering new insight into the interactions between aphids and their predators, and providing the basis of a new biological control strategy for aphid pests involving the targeting of endosymbionts. [ABSTRACT FROM AUTHOR]

Objectives Small copepods (<2 mm) compose an important constituent of the Arctic marine food web, but their trophic interactions remain largely unexplored, partly due to methodological limitations. Methods We here characterize the prey of the abundant cyclopoid Oithona similis , harpacticoid Microsetella norvegica and calanoid Microcalanus spp. from the Arctic Barents Sea and Nansen Basin during four seasons using brute force prey metabarcoding of the 18S rRNA gene. Key findings Chaetognaths were unexpectedly the most consistently identified taxa and composed 47% of all prey reads. Some taxa were seasonally important, including diatoms in April–May (43%), dinoflagellates in December (15%) and March (17%), and urochordates in August (20%). Compositional differences among species were also discernible, and the M. norvegica diet was significantly different from both O. similis and Microcalanus spp. The diets varied nevertheless more with season than species despite the inherent trophic traits that distinguish the ambush-predator O. similis , chemosensoric particle-chaser M. norvegica and current-feeding Microcalanus spp. Conclusions Our results thus indicate that dietary plasticity is common in small Arctic copepods, regardless of their behaviors or strategies for finding sustenance. We further hypothesize that such plasticity is an important adaptation in systems where prey availability is highly seasonal. [ABSTRACT FROM AUTHOR]

Compound effects of anthropogenic disturbances on wildlife emerge through a complex network of direct responses and species interactions. Land‐use changes driven by energy and forestry industries are known to disrupt predator–prey dynamics in boreal ecosystems, yet how these disturbance effects propagate across mammal communities remains uncertain. Using structural equation modeling, we tested disturbance‐mediated pathways governing the spatial structure of multipredator multiprey boreal mammal networks across a landscape‐scale disturbance gradient within Canada's Athabasca oil sands region. Linear disturbances had pervasive direct effects, increasing site use for all focal species, except black bears and threatened caribou, in at least one landscape. Conversely, block (polygonal) disturbance effects were negative but less common. Indirect disturbance effects were widespread and mediated by caribou avoidance of wolves, tracking of primary prey by subordinate predators, and intraguild dependencies among predators and large prey. Context‐dependent responses to linear disturbances were most common among prey and within the landscape with intermediate disturbance. Our research suggests that industrial disturbances directly affect a suite of boreal mammals by altering forage availability and movement, leading to indirect effects across a range of interacting predators and prey, including the keystone snowshoe hare. The complexity of network‐level direct and indirect disturbance effects reinforces calls for increased investment in addressing habitat degradation as the root cause of threatened species declines and broader ecosystem change. [ABSTRACT FROM AUTHOR]

Non‐native species can affect ecosystems by influencing native predator‐prey dynamics. Therefore, management interventions designed to remove non‐natives may inadvertently lead to increased predation on native species. Feral horses are widely distributed throughout the arid parts of western North America. A growing body of research indicates that horses can be an important prey species to mountain lions in ecosystems where they overlap. In December 2020, the Bureau of Land Management removed 455 horses from the Delamar Mountains, Nevada, USA. We leveraged this management intervention to implement a before–after–control–impact study to test hypotheses about predation on horses and native ungulates. We predicted (1) that horses would comprise an important part of the diet in this mixed‐prey community, (2) following removal, the proportion of horses in the diet would decrease and native ungulates would increase, and (3) mountain lion home ranges overlapping the treatment areas would increase in response to decreased prey availability. From 2018 to 2022, we investigated 1360 clusters from 29 GPS‐collared lions and identified 1056 prey items. To model the probability of a predation event (a kill), we fit a mixed‐effects logistic regression model for ungulate prey as a function of lion sex, treatment area (in/out), and treatment period (pre‐/post‐removal). We used a log‐linear regression model to evaluate changes in home range size. The most common prey were mule deer (55%), feral horses (32%), and coyotes (4%). Twenty‐two of 29 lions consumed horses, although the rate of horse consumption was highly variable across individuals. Horses of both sexes and all age classes were predated. In contrast to predictions, our models detected no effect of removals on diet composition (βinteraction = 0.30 ± 1.1), nor did the removal influence home range size (βinteraction = 0.02 ± 0.02). Despite a 46% reduction in horse abundance, we found no evidence for prey‐switching following the horse removal treatment. Removal magnitude, rapid horse immigration, and/or behavioral specialization of individual mountain lions may help explain these results. Our findings have important implications for mountain lion and feral horse management in arid environments characterized by high prey diversity, but low prey abundance. [ABSTRACT FROM AUTHOR]

Bats are predated regularly by mammals like cats, birds, and snakes. However, bats are rarely observed to be predated by mongooses. Herein we document and describe a Ruddy Mongoose opportunistically predating on a pipistrelle bat at its roosting site inside a tree crevice at Nagarahole Tiger Reserve, Karnataka in December 2022. Our observation may indicate that the Ruddy Mongoose Urva smithii could be an opportunistic but not a selective hunter of bats. [ABSTRACT FROM AUTHOR]

The development of diverse capture mechanisms during foraging allows predators to select their preys and succeed in their capture, with the least energy expenditure possible. In this context, we seek to understand how prey selection mechanisms exhibited by freshwater fish piscivores relate to their foraging mode. The study was carried out in the floodplain of the Upper Paraná River, where fish were captured from March 2006 to June 2013. The fish were identified and measured, their stomachs were removed, and the stomach contents were analysed. Quantile regressions were used to evaluate possible effects and relationships between the sizes of piscivores and their prey. A significant positive effect on the predator–prey size relationship was observed, indicating an increased size of consumed prey with increased size of piscivore, mainly for Acestrorhynchus lacustris, Hoplerythrinus unitaeniatus, Hoplias intermedius, Hoplias mbigua, Hoplias sp. 2, Pseudoplatystoma corruscans, Rhaphiodon vulpinus and Salminus brasiliensis. Ambush predators were more likely to consume slow‐moderate and fast prey, while pursue predators only consume fast prey. Several mechanisms can influence a piscivore's foraging behaviour, and body size is an important factor for both the piscivore and its prey. From the prey's point of view, the way they swim and the complexity of the habitat are important characteristics to ensure their survival. For piscivores, the foraging mode will influence the type of prey consumed, depending on the prey's swimming mode. [ABSTRACT FROM AUTHOR]

Intraspecific resource partitioning may play a critical role in how predators optimize prey selection. The Black-footed Ferret (Mustela nigripes ; henceforth, ferret) is a highly specialized predator of prairie dogs (Cynomys spp.; henceforth, PDs). Adult ferrets are sexually dimorphic and PDs are of similar size making them a difficult prey item. PD young are born 6 to 8 weeks prior to births of ferrets, producing a crop of smaller prey items during a period when energetic needs of female ferrets are highest. We asked whether relatively small female ferrets select small PDs as prey. We examined survival rates from early to late summer for large and small black-tailed PDs (Cynomys ludovicianus) in Montana and South Dakota as a function of their distance to adult male and female ferrets using capture–mark–recapture of PDs and simultaneous summer monitoring of ferret locations. Survival of small PDs (<600 g) was low when a female ferret was nearby, but distance to nearest female ferret did not affect survival of large PDs. Distance to the nearest male ferret did not influence survival regardless of PD size. Reduced competition from males for a critical food resource needed by females rearing young would benefit fitness of both sexes. If female ferrets depend on young PDs during their reproductive period, existing habitat models may substantially overestimate ferret carrying capacity. [ABSTRACT FROM AUTHOR]

Among stages of avian ontogeny, the act of nest departure or fledging is an abrupt transition into a new environment and a major leap toward independence for offspring. In altricial birds, the timing (i.e. time of day) of fledging is notable in that many species tend to fledge early in the morning. Past studies have proposed nest predation as a key factor driving birds to fledge earlier in the morning (the 'survival hypothesis'), whereby offspring avoid peak times of nest predation that occur later in the day. A natural extension of this hypothesis is the predation of offspring post‐fledging, whereby offspring are also timing their fledging with future survival prospects outside of the nest. However, few studies have investigated fledging behaviour in the context of both nesting and post‐fledging predation. To help fill this knowledge gap, we investigated factors driving the timing and duration of fledging across six songbird species in the context of offspring predation: daily nest mortality, post‐fledging mortality and diel patterns of nest predation risk. We found that > 60% of songbirds fledged early in the morning, whereas the peaks in nest predation risk occurred several hours post‐fledging. Furthermore, species under greater risk of nest predation fledged earlier in the day and in closer succession to their siblings. Parameters of post‐fledging mortality were poor predictors of fledging timing, but individuals from broods of species under higher risk of post‐fledging mortality fledged in closer succession to their siblings. These results provide evidence in support of the survival hypothesis, and suggest that songbirds fledge in the morning to avoid peak times of nest predation risk that occur later in the day (~ 8 h after civil dawn). Such results corroborate past research highlighting predation on dependent offspring as a key factor driving variation in life histories across animal taxa; however, estimates of post‐fledging mortality suggest that nest predation alone does not fully explain variation in fledging behaviour among species. Future research is therefore needed to investigate the contribution of other factors, such as energetics, parent–offspring conflict and diel patterns of post‐fledging survival, which may help to mediate diel patterns of fledging within and among songbird species. [ABSTRACT FROM AUTHOR]

The article discusses a study that challenges the assumption that animals adapted to underground environments are strictly bound to those environments. The researchers found evidence of olms, a species of amphibian, actively exploiting surface habitats outside of caves. This discovery expands our understanding of the interactions between subterranean and surface environments and highlights the importance of studying groundwater and its borders. The article also provides a list of references for further research on subterranean organisms, particularly the Olm. [Extracted from the article]

Trophically transmitted parasites often infect an intermediate prey host and manipulate their behaviour to make predation more likely, thus facilitating parasite transmission to the definitive host. However, it is unclear when such a manipulation strategy should be expected to evolve. We develop the first evolutionary invasion model to explore the evolution of manipulation strategies that are in a trade-off with parasite production of free-living spores. We find that the size of the susceptible prey population together with the threat of predation drives manipulation evolution. We find that it is only when the susceptible prey population is large and the threat of predation is relatively small that selection favours manipulation strategies over spore production. We also confirm that the system exhibits cyclic population dynamics, and this can influence the qualitative direction of selection. [ABSTRACT FROM AUTHOR]

With about 8000 marine benthic species, the amphipod crustaceans form one of the richest animal groups of the worldwide Ocean. They have colonized a wide range of soft- and hard-bottom natural and artificial habitats extending from the intertidal to hadal zones. Moreover, they show a broad size spectrum, with numerous giant species exceeding 20 cm in length and some species smaller than 2 mm. When biofouling artificial hard surfaces, some tube-building species can form very dense populations comprising up to 100,000 individuals per square meter. Amphipods are important prey for fish and mammals. Along with cephalopod juveniles, they are also included in the trophic diet of shorebirds that consume amphipods mostly during the low tide on tidal flats. They display diel migration, which reinforces the predation by demersal fish in the suprabenthic zone just above the sea bed, as well as by pelagic fish in the water column. Despite their importance in terms of biodiversity and trophic transfer, no general overview is available on the role of benthic amphipods in marine ecosystem food webs. Various methods, including laboratory and field experiments, as well as the analysis of stomach contents and DNA extraction, have been used to identify the prey/predator trophic links. Based on an extensive literature review, this study discusses the role of marine benthic amphipods as potential food for higher trophic levels in natural and artificial hard-bottom communities created via the construction of offshore wind farms. [ABSTRACT FROM AUTHOR]

Turfgrass is susceptible to changes in water availability, and its effects could cascade through multiple trophic levels. In some years, turfgrass is exposed to short drought spells. It is unclear if this short period of water deprivation would cascade to predator performance on herbivory on bermudagrass. Thus, the objective of this study was to determine the effects of water deprivation on predation by Orius insidiosus (Say) (Hemiptera: Anthocoridae) on Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) when mediated by drought-tolerant 'TifTuf' and drought-susceptible 'Tifway' bermudagrass. Neonates of S. frugiperda and adults of O. insidiosus were caged on bermudagrass in greenhouse conditions. Treatments were three factors: 1) water deprivation at three levels – fully, moderately, and sparsely watered; 2) predator at two levels – present or absent; and 3) bermudagrass at two levels – drought tolerant and susceptible cultivars. The survival of S. frugiperda larvae was reduced when O. insidiosus adults were present regardless of water deprivation levels and bermudagrass cultivars. Reduced larval weight, body length, and head capsule width of S. frugiperda larvae were observed with predators compared to without predators. S. frugiperda larval mortality was significantly greater with predator's absence for the sparsely-watered treatment than for the fully and moderately-watered treatments. The levels of water deprivation had a partial impact on the survival of S. frugiperda larvae, whereas bermudagrass cultivars did not affect the survival and development of S. frugiperda larvae. Thus, during at least short-term dry spells, O. insidiosus predation can potentially reduce the S. frugiperda population on bermudagrass. [ABSTRACT FROM AUTHOR]

Achieving global targets for ecosystem restoration necessitates the development of effective restoration approaches. Current restoration approaches focus primarily on mitigating abiotic stresses or supplementing propagules to restore foundation species that support associated species by 'engineering' local habitats. Although keystone predators can strongly affect foundation species in natural ecosystems via trophic cascades and are often diminished in degraded ecosystems, they are traditionally neglected in efforts to restore foundation species.Here, we investigated how a keystone predator (Scylla serrata) might affect the restoration of a foundational plant (Scirpus mariqueter) in a degraded salt marsh. In a series of restoration experiments, we examined the effects of proximity to existing Scylla burrows, as well reintroducing Scylla, on the establishment of planted Scirpus in restoration areas. Furthermore, we tested if Scylla affected Scirpus via non‐consumptive effects in experiments that controlled Scylla's consumption of grazers.We found that planted Scirpus suffered less grazing and achieved higher density in areas closer to existing Scylla burrows where Scylla predation on grazers was stronger. Consistently, reintroduction of Scylla reduced grazing on Scirpus and increased its density by 360%. These positive effects of Scylla on Scirpus were driven by consumptive effects that reduced the abundance of grazers and by non‐consumptive effects that inhibited the herbivory by grazers.Synthesis and applications. These results demonstrate that incorporation of keystone predators, including both their consumptive and non‐consumptive effects, into restoration designs can greatly enhance the restoration of foundation species. Our study thus highlights the value of co‐restoring keystone predators and foundation species. Given that predators are depleted in many ecosystems, this co‐restoration approach may be broadly applicable. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rice dwarf virus (RDV)‐induced rice plant volatiles (E)‐β‐caryophyllene and 2‐heptanol modulate the olfactory behavior of RDV insect vectors that promote viral acquisition and transmission. However, it remains elusive whether these two volatiles could influence the behaviors of the natural enemies of RDV insect vectors. Herein, we determined the effects of these two volatiles on the olfactory and predatory behaviors of Cyrtorhinus lividipennis (Hemiptera: Miridae), an important predator of RDV insect vectors in rice paddies. RESULTS: The results showed that C. lividipennis preferred RDV‐infected rice plant odors over RDV‐free rice plant odors. C. lividipennis was attracted by (E)‐β‐caryophyllene, but showed no behavioral responses to 2‐heptanol. The attraction of (E)‐β‐caryophyllene towards C. lividipennis was further confirmed using oscas1 rice plants, which do not release (E)‐β‐caryophyllene in response to RDV infection, through a series of complementary assays. The oviposition preference of the RDV vector insect Nephotettix cincticeps (Hemiptera: Cicadellidae) showed no significant difference between RDV‐infected and RDV‐free wild‐type plants, nor between oscas1‐RDV and oscas1 plants. However, the predation rate of C. lividipennis for N. cincticeps eggs on RDV‐infected plants was higher than that on RDV‐free plants, whereas there was no significant difference between oscas1‐RDV and oscas1 plants. CONCLUSION: (E)‐β‐caryophyllene induced by RDV attracted more C. lividipennis to prey on N. cincticeps eggs and played a crucial role in plant–virus–vector–enemy interactions. These novel findings will promote the design of new strategies for disease control by controlling the populations of insect vectors, for example recruiting more natural enemies by virus‐induced plant volatiles. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Species assemblages are influenced by trophic and intraguild interactions, which may be competitive, facilitative, or neutral. These interactions vary in relative importance depending on resource availability. We assessed the nature of interactions among six carnivore species (Ursus arctos, Panthera uncia, Vulpes vulpes, Mustela altaica, and Martes foina) and their prey (Capra sibirica, Pseudois nayaur, Hemitragus jemlahicus, Moschus leucogaster, Ochotona sp., and Rodentia sp.) by examining their spatial–temporal overlaps using camera‐trap data gathered between 2016 and 2019 from the resource‐limited landscapes of the high Himalayas. We examined fine scale pairwise spatial interaction using multi‐species occupancy method and temporal overlap using time activity kernel densities function. Carnivore species showed relatively high spatio‐temporal overlap. We found spatial avoidance between two pairs and temporal avoidance between four out of 15 pairs. Contrary to our expectation that carnivore species would segregate due to competition in a resource‐poor environment, our results showed that they generally showed significant co‐occurrence and appeared to track their prey's activity. Our findings highlight the potentially overriding role of prey availability in influencing carnivore species occurrence in resource‐poor landscapes. [ABSTRACT FROM AUTHOR]

In Yakutia, 31 cases of sable preying on musk deer were registered in the years 1990–2021. Hunting success is higher during snowy winters. Large adult sable males primarily specialize in predation of musk deer. There are more females than males in the sex and age composition of the predator's killed preys (1 : 4.5) with the proportion of yearlings being minimal. The majority of sable attacks on musk deer is recorded in the second half of winter (83.3%) and peaks in February. Sable switches to large-sized prey when the availability of common food items (mouse-like rodents, berries, nuts, etc.) is reduced with snow depth accrual. [ABSTRACT FROM AUTHOR]

We study the spreading dynamics for a three-species predator-prey system with two weak competing predators and one prey in a shifting habitat. First, we derive some extinction results for each species. Then we provide some persistence theorems for each species with moving speeds exceed the shifting speed, but less than some certain quantities. Finally, the convergence to a certain constant state is proven in each persistent regime. [ABSTRACT FROM AUTHOR]

This study aims to explore the composition of natural enemy species in the fall webworm, Hyphantria cunea (Drury) population and the dynamics of its natural enemy community in Dandong, Liaoning Province, China, where it was first reported. We collected the natural enemy of eggs, larvae, and pupae of H. cunea on host trees at 12 survey sites from June 2019 to October 2020. The results showed that the community consists of 34 species: 20 predatory species, including 15 spiders and 5 insects, and 14 parasitic species, including 10 parasitic wasps and 4 parasitic flies. The top 3 dominant species based on the importance value index for both parasitic and predatory species were Pediobius pupariae  >  Chouioia cunea  >  Cotesia gregalis in the natural enemy community of H. cunea. Analysis of all 3 principal components by principal component analysis showed that Clubionidae sp. 1, Parena cavipennis , or other predators were the main factors affecting the natural enemy community. Analysis of the community structure parameters of the H. cunea natural enemy community in different developmental stages across generations revealed the following: (i) Compared with the degree of complexity of the egg and pupal stages, the larval stage was the highest. (ii) The complexity was determined by means of comprehensive evaluation: first-generation larvae in 2020 > first-generation larvae in 2019 > second-generation larvae in 2020 > second-generation larvae in 2019. These results clarify the dynamics of natural enemy species, coevolution with the host in the invaded habitat of H. cunea and development of biological control technologies. [ABSTRACT FROM AUTHOR]

Foraging is a universal behaviour that has co‐evolved with predation pressure. We investigated the role of the bed nucleus of the stria terminalis (BNST) GABA neurons in robotic and live predator threat processing and their consequences in post‐threat encounter foraging. Both robotic and live predator interactions increased BNST GABA neuron activity. Mice were trained to procure food in a laboratory‐based foraging apparatus in which food pellets were placed at incrementally greater distances from a nest zone. After mice learned to forage, they were exposed to a robotic or live predator threat, while BNST GABA neurons were chemogenetically inhibited. Post‐robotic threat encounter, mice spent more time in the nest zone, but other foraging parameters were unchanged compared with pre‐encounter behaviour. Inhibition of BNST GABA neurons had no effect on foraging behaviour post‐robotic threat encounter. Following live predator exposure, control mice spent significantly more time in the nest zone, increased their latency to successfully forage, and significantly altered their overall foraging performance. Inhibition of BNST GABA neurons during live predator exposure prevented changes in foraging behaviour from developing after a live predator threat. BNST GABA neuron inhibition did not alter foraging behaviour during robotic or live predator threats. We conclude that these results demonstrate that while both robotic and live predator encounters effectively intrude on foraging behaviour, the perceived risk and behavioural consequences of the threat are distinguishable. Additionally, BNST GABA neurons may play a role in the integration of prior innate predator threat experience that results in hypervigilance during post‐encounter foraging behaviour. [ABSTRACT FROM AUTHOR]

Springs are environments that can provide general insights into factors favouring diversity in ecotones, but they are often neglected in freshwater studies. One of the challenging processes acting in ecotones is the landscape of fear (LOF), the space–time variation of perceived predation risk. Spring exploitation often involves species that are mesopredators in surface fresh water and that can become apex predators in ground water, as in the case of the fire salamander larvae (Salamandra salamandra). Here, we aim to determine whether the activity and foraging patterns of the fire salamander in springs are affected by LOF.We surveyed the night‐ and daytime abundance of fire salamander larvae in 15 springs to assess predator occurrence. We also reared 48 salamander larvae with and without non‐lethal exposure to predators within tanks simulating groundwater or surface freshwater light features. Before and after a month of rearing, we tested larva efficiency in catching prey when exposed to predator chemical cues, both in light and dark conditions.In the field, the number of active fire salamander larvae was significantly higher during the night. At night, the number of active larvae across the transition area between ground water and surface water was higher in plots closer to the surface.Testing and rearing conditions significantly affected larva behaviour, and prey capture was significantly more effective in light conditions. It was less successful in larvae reared with predator chemical cues and in the presence of predators. Moreover, larvae reared with predators under light conditions were slower than those raised with predators in dark conditions.Our results show that LOF can interact with extant environmental features and constitute a significant behavioural pressure for mesopredator species living in freshwater ecotones. [ABSTRACT FROM AUTHOR]

Studying the effects of predation in cryptic herbivorous insects is difficult because many spend all or most of their life cycle inside their host plant. Here, we designed and 3D‐printed artificial coffee berries to study predation of coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae, Scolytinae), by the flat bark beetle, Cathartus quadricollis (Guerin‐Meneville) (Coleoptera: Silvanidae). The 3D‐printed berries were tested under laboratory and field conditions and the results confirmed the usefulness of 3D‐printed materials to create life‐like models for studying predation. [ABSTRACT FROM AUTHOR]

This paper proposes and investigates a nonselective harvesting Lotka-Volterra predator-prey system that incorporates population closure and the fear effect of the prey. The boundary equilibrium and positive equilibrium are studied in terms of their local and global stability characteristics. Our research indicates that the proportion of commodities designated for harvesting has a significant impact on the dynamic behavior of the system. Meanwhile, dynamic behavior of the system is not affected by the fear effect of the prey species. To demonstrate the viability of the key findings, numerical simulations are performed. [ABSTRACT FROM AUTHOR]

Simple Summary: The foraging behavior of European cave salamanders (genus Speleomantes) is discussed through more detailed considerations starting from published datasets gathering prey recognized from their gut contents. Flying insects were consumed the most, with a minor quantity of elongated prey. The scarce occurrence of strictly-cave prey allows us to hypothesize that Speleomantes mainly forage in surface environments, while the presence of aquatic invertebrates in the diet suggests the hypothesis of direct predatory activity in shallow water bodies. The morphology of the prey (e.g., size or presence of long appendages) seem to be a feature influencing Speleomantes prey choice, while chemical or mechanical defenses of some invertebrates do not appear to be a real limit for these salamanders. We here provide the first comprehensive analysis and discussion on prey consumed by the European cave salamanders of the genus Speleomantes. Our study stems from the need to shed light on the still unknown foraging behavior adopted by Speleomantes cave salamanders. Starting from the published datasets on gut contents from all Speleomantes species (including hybrids), we here discuss additional information (i.e., species ecology, lower taxonomic level), which were systematically omitted from those data sets. We analyzed a data set consisting of 17,630 records from 49 categories of consumed prey recognized from gut contents of 2060 adults and juveniles Speleomantes. Flying prey accounted for more than 58% of the prey items, while elongated crawling prey accounted for no more than 16% of the diet within a single population. Among the total recognized prey items, only three can be surely ascribed to the group of strictly-cave species (i.e., troglobites), meaning that European cave salamanders mostly forage in surface environment, and therefore represent one of the major drivers of allochthonous organic matter in subterranean environments. Some of the consumed prey seemed to be aquatic, allowing us to hypothesize whether Speleomantes are able to catch prey from a shallow body water. Furthermore, European cave salamanders possess the ability to prey upon taxa characterized by particular anti-predator defenses, while morphological constraints seem to be the most important limit to prey consumption. For each specific case, we provide insights and propose hypotheses concerning the foraging behavior that need to be tested to properly understand the foraging behavior of this cryptic salamanders. [ABSTRACT FROM AUTHOR]

An organism’s habitat preference may shift to one of greater structural complexity to maximize protection from predatory attack. In south-eastern Australian coastal seascape, seagrass beds, sandy substratum and/or rocky algal reef border each other forming a matrix of varying habitat configurations with varying protection potential. We investigated the change in habitat selection in four Australian seagrass fish species, Stigmatopora argus, Acanthaluteres spilomelanurus, Pelates sexlineatus and Atherinosoma microstomata with the inclusion of predatory threat using tank experiments. The 250L, 90 cm internal diameter experimental tank contained three habitats – seagrass, sand and rock arranged in an unbroken circular path creating three distinct edge combinations and resulting in six sections of varying levels of complexity and heterogeneity. A transparent inner wall separated the habitat matrix from the central test chamber, which contained and demarcated “zone of decision”. Each test fish (n=123) was placed in the tank centre for 2–3 minutes in an isolation tube to acclimatize before being released to make its selection. This was repeated for each test fish first without predatory threat then with threat. S. argus spent significantly more time in the rock section (paired t-test: p= 0.038) and less time in the seagrass-sand section (paired t-test: p=0.05) when under threat. A. spilomelanurus spent significantly less time in homogeneous seagrass when threatened (paired t-test: p = 0.016) and displayed a non-significant increased selection of sections containing rock when threatened. Shifts to the complex rocky substratum preference with predatory threat was demonstrated along with the importance of a suite of different habitats for a species’ survival. [ABSTRACT FROM AUTHOR]

Combining explicit modelling of predator movements with the Kostitzin demo-genetic equations, we study conditions promoting natural selection of consumer motility. The model is a system of partial differential equations describing spatial movements of predators pursuing the diffusing prey. Local predator–prey interactions are described by the classical Rosenzweig–MacArthur model, which additionally accounts for the Allee effect affecting reproduction of predators. Spatial activity of predators is determined by the coefficients of diffusion and indirect prey-taxis. The latter characterizes the predator ability to move directionally up the gradient of taxis stimulus (odor, pheromone, exometabolite) continuously emitted by prey. Assuming that the consumer movement ability is governed by a single diallelic locus with recessive 'mobile' and dominant 'settled' alleles, the predator population in the model consists of three competing genotypes differing by diffusion and taxis coefficients; other parameters characterizing the genotypes are assumed to be equal. Numerical simulations with different spatial patterns imitating habitat deterioration demonstrate that the direction of selection among the consumer genotypes alternates, depending on the degree of habitat deterioration affecting the overall production of the prey population. Theoretical implications of the results are discussed in relation with problems of biological control, predator interference, and evolution of animal motility. [ABSTRACT FROM AUTHOR]

The common vampire bat (Desmodus rotundus) maintains a diverse, sanguivorous diet, utilizing a broad range of prey taxa. As anthropogenic change alters the distribution of this species, shifts in predator–prey interactions are expected. Understanding prey richness and patterns of prey selection is, thus, increasingly informative from ecological, epidemiological, and economic perspectives. We reviewed D. rotundus diet and assessed the geographical, taxonomical, and behavioral features to find 63 vertebrate species within 21 orders and 45 families constitute prey, including suitable host species in regions of invasion outside D. rotundus' range. Rodentia contained the largest number of species utilized by D. rotundus, though cattle were the most commonly reported prey source, likely linked to the high availability of livestock and visibility of bite wounds compared to wildlife. Additionally, there was tendency to predate upon species with diurnal activity and social behavior, potentially facilitating convenient and nocturnal predation. Our review highlights the dietary heterogeneity of D. rotundus across its distribution. We define D. rotundus as a generalist predator, or parasite, depending on the ecological definition of its symbiont roles in an ecosystem (i.e., lethal vs. non-lethal blood consumption). In view of the eminent role of D. rotundus in rabies virus transmission and its range expansion, an understanding of its ecology would benefit public health, wildlife management, and agriculture. [ABSTRACT FROM AUTHOR]

Perceived predation risks by terrestrial predators are major ecological forces in aquatic systems, particularly for aggregating fish. Riverscape thermal refuges are discrete, localized cold‐water patches where fish temporarily aggregate to buffer against heat events. Predation pressures by terrestrial predators at thermal refuges may decrease the thermoregulatory benefits of refuge use, but quantifying such effects can be challenging and controversial when sampling can impose additional stress on fish. We passively monitored terrestrial predator visitation patterns and predation at four thermal refuges in the Housatonic River, Connecticut, USA, between May 18th and September 29th, 2022, with camera traps, a common wildlife monitoring method. Specifically, we (1) assessed diel visitation patterns by different categories of terrestrial predators at thermal refuges and determined if patterns varied among predator categories or with prevailing environmental conditions, and (2) estimated the probability of predation by hour of the day combined across all predator categories, quantifying general predation pressures at refuges. We detected at least one terrestrial predator at a thermal refuge each day, and mean hourly visitation rates (count/h) were highly variable across predator categories and sampling dates. The most supported generalized additive mixed model indicated that terrestrial predator visitation rates (count/h/day) varied with mean daily river discharge and water temperature differential, and relationships differed across categories of terrestrial predators. We observed 22 separate predation attempts on thermoregulating salmonids and predicted that the probability of predation by any terrestrial predator increased from 0.002 to 0.017 throughout a 24 h day (p =.004). Camera traps provided novel evidence that terrestrial predators are pervasive at riverine thermal refuges, which is relevant for refuge conservation and management globally. We recommend the implementation of a coordinated monitoring network across riverine thermal refuges using camera traps, further enriching our ecological understanding of cumulative predator effects in refuges across complex riverscapes. [ABSTRACT FROM AUTHOR]

Fear of predation can affect important ecosystem processes by altering the prey traits expression that, in turn, regulates the quantity and quality of nutritional inputs to soil. Here, we aimed to assist in bridging a knowledge gap in this cascading chain of events by exploring how risk of spider predation may affect grasshopper prey performances, and the activity of various microbial extracellular enzymes in the soil. Using a mesocosms field‐experiment, we found that grasshoppers threatened by spider predation ate less, grew slower, and had a higher body carbon to nitrogen ratio. Herbivory increased activity of all microbial extracellular enzymes examined, likely due to higher availability of root exudates. Predation risk had no effect on C‐acquiring enzymes but decreased activity of P‐acquiring enzymes. We found contrasting results regarding the effect of predation on the activity of N‐acetyl‐glucosaminidase and leucine arylamidase N‐acquiring enzymes, suggesting that predation risk may alter the composition of N‐inputs to soil. Our work highlighted the importance of soil microbial enzymatic activity as a way to predict how changes in the aboveground food‐web dynamics may alter key ecosystem processes like nutritional‐cycling. [ABSTRACT FROM AUTHOR]

Invasive carnivores are threatening the indigenous fauna of Aotearoa, but impacts vary with time, space and species. Conservation strategies require knowledge of predator-prey dynamics specific to different ecosystems and allowing for long-term guild shifts. To build this knowledge, we model the survivorship of the kea, a long-lived, ground-nesting parrot with an expansive species-range, using a dataset spanning two decades (1998–2021) and spanning several forest-dominated South Island montane ecosystems. Kea survivorship was lower in eastern ecosystems compared to western ones, depressed during carnivore irruptions, and elevated after predator control. Kea of all ages and both sexes fell prey to stoats and feral cats whilst foraging and roosting, not whilst nesting. Stoat depredation happened in all ecosystems, whereas feral cats featured more in eastern ones. Annual survivorship was high in most contexts (adults > 90%, juveniles > 70%), but a peak in stoat and feral cat predation in eastern ecosystems during 2020–2021 reduced adult survival to <60%. This predation peak followed a rodent population crash, the primary prey of carnivores in eastern beech forests. We conclude that predator impacts on kea are concentrated into post-mast years. Recommendations for management are provided. [ABSTRACT FROM AUTHOR]

Copyright of Acta Zoologica Lilloana is the property of Fundacion Miguel Lillo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to human-caused deforestation, global warming, and other environmental factors, habitat fragmentation became widespread. This fragmentation has a variety of detrimental repercussions for many species as well as humans, especially in the agricultural economy. It causes insect outbreaks, the expansion of alien species, and disrupts biological management by rendering the habitat unsuitable for natural enemies in agriculture. Providing natural enemies with additional food is one method to improve the ecosystem and support them. In this study, we assumed that the ecosystem is separated into two patches and that predators can easily migrate from one patch to the next, while prey stays inside its patch's territory. We looked at the impact of offering more food to predators in a patchy environment using dynamical systems theory. The permanence, stability, and various bifurcations that occur in the system are studied using a rigorous mathematical analysis. The study looks at how predator's access to other food sources affects pest management. By adjusting the provided food's characteristic qualities, such as (nutritional) quality and quantity, one can limit and manage the pest in one or both patches, as well as eliminate predators from the ecosystem. This research reveals that providing predators with additional food (of specified quality and quantity) can help in controlling chaotic behavior in the system. The findings of the study are supported by numerical simulations. [ABSTRACT FROM AUTHOR]

Large carnivores are recovering in many landscapes where the human footprint is simultaneously growing. When carnivores encounter humans, the way they behave often changes, which may subsequently influence how they affect their prey. However, little research investigates the behavioural mechanisms underpinning carnivore response to humans. As a result, it is not clear how predator–prey interactions and their associated ecosystem processes will play out in the human‐dominated areas into which carnivore populations are increasingly expanding.We hypothesized that humans would reduce predation risk for prey by disturbing carnivores or threatening their survival. Alternatively, or additionally, we hypothesized that humans would increase predation risk by providing forage resources that congregate herbivorous prey in predictable places and times.Using grey wolves Canis lupus in Jackson Hole, Wyoming, USA as a study species, we investigated 170 kill sites across a spectrum of human influences ranging from heavily restricted human activities on protected federal lands to largely unregulated activities on private lands. Then, we used conditional logistic regression to quantify how the probability of predation changed across varied types and amounts of human influences, while controlling for environmental characteristics and prey availability.Wolves primarily made kills in environmental terrain traps and where prey availability was high, but predation risk was significantly better explained with the inclusion of human influences than by environmental characteristics alone. Different human influences had different, and even converse, effects on the risk of wolf predation. For example, where prey were readily available, wolves preferentially killed animals far from motorized roads but close to unpaved trails. However, wolves responded less strongly to humans, if at all, where prey were scarce, suggesting they prioritized acquiring prey over avoiding human interactions.Overall, our work reveals that the effects of large carnivores on prey populations can vary considerably among different types of human influences, yet carnivores may not appreciably alter predatory behaviour in response to humans if prey are difficult to obtain. These results shed new light on the drivers of large carnivore behaviour in anthropogenic areas while improving understanding of predator–prey dynamics in and around the wildland–urban interface. [ABSTRACT FROM AUTHOR]

Insect exposure to their predators can affect individuals and community processes, through direct consumption or nonlethal effects. However, the links between behavioral and physiological responses and stimuli needed for the development of predator avoidance are not clear. We subjected desert locusts (Schistocerca gregaria) to three nonlethal treatments, using great tits (Parus major) as a predator. The treatments included: (1) bird—presence of a great tit and its calls, (2) call—great tit calls only, (3) control—absence of a great tit and its calls. In the first behavioral laboratory experiment, locusts were offered food and shelter in an open space. The duration of hiding versus feeding indicated predator responses. In the second laboratory experiment, locusts were subjected to the same three treatments, and adipokinetic hormone (AKH) levels were measured in the central nervous system (CNS) and hemolymph. In the third experiment in an outdoor aviary, birds were allowed to fly freely over locusts before we measured physiological response. During the first experiment, locusts hid for a significantly longer amount of time and fed for a significantly shorter amount of time when the bird was present and calls were played, compared to when only calls were played or compared to the control treatment. The proximity of birds to locusts in the laboratory experiment elicited a significant increase in AKH levels in the CNS and hemolymph compared to the call/control treatment. The physical proximity of the great tits affected both the behavioral and physiological responses of the locusts. [ABSTRACT FROM AUTHOR]

Context: The behaviours used by mammalian predators to track, kill, and consume prey are some of the most dynamic interspecific interactions in nature. However, they are often challenging to follow through the landscape and observe directly without disturbing the animals being watched. Aims: We describe the behaviours used by wild dingoes while hunting macropods in Namadgi National Park, Australian Capital Territory, Australia. Methods: Footage was initially captured by wildlife cinematographers on behalf of documentary programs and was made available for viewing after production. Hunting events were filmed from an altitude of >50 m by using a 'long lens' fitted to either a drone or helicopter. Results: We recorded a suite of hunting behaviours that would have been extremely challenging to observe from the ground via traditional methods. This includes some of the first video records published in the scientific literature of the behaviours used by dingoes to hunt and kill macropod prey, as well as some rare observations of mother and pup hunting dynamics. We did not observe any signs of disturbance as a result of filming for either predator or prey. Conclusions: The varied repertoire of predatory behaviours displayed by dingoes is similar to that documented in wolves and asserts them as a behaviourally complex top predator in the Australian landscape. In addition, we highlight the use of drones as a valuable approach for directly observing wild behaviours. They offer a minimally invasive and relatively inexpensive and accessible alternative to helicopters. This project is also a case study exemplifying the value of collaborations between filmmakers and researchers that enable the sharing of archival documentary footage for the study of wild animal behaviour. Implications: Future studies of wild animal behaviour should consider employing drones (at a safe distance and in accordance with published best practices and guidelines) as an additional tool to collect types of data that would be challenging using other methods. The behaviours that dingoes use to capture and kill their prey are highly dynamic and can be challenging to observe directly without disturbance. This study reports a series of direct observations of wild hunting behaviour filmed using cameras attached to either a helicopter or drone. This project contributes to our knowledge of dingo ecology and also acts as a case study highlighting the utility of drones for directly observing dynamic behaviours in the wild. Images by Daniel Hunter and Edward Saltau. [ABSTRACT FROM AUTHOR]

Sentinel plasticine prey has been increasingly used to estimate predation pressure. The use of plasticine prey may, however, bias the results, as this method was originally designed to account for predation by organisms that can visually recognize the shapes and colors of their prey. To evaluate the limitations of using sentinel plasticine prey, we compared predator attack rates between real prey – dead and live mealworms, Tenebrio molitor L. (Coleoptera: Tenebrionidae) – and plasticine models in a monsoonal tropical rainforest of southeastern China. The attack rates by invertebrates were highest on dead prey followed by live prey and plasticine models, whereas the attack rates by vertebrates were lowest on dead prey, and did not differ between live prey and plasticine models. These results confirm that bias imposed by using the plasticine models is affected by the type of predators. In addition, we tested the validity and generality of the premise that predators can distinguish the shapes of plasticine model prey and preferentially attack a caterpillar‐like shape over other shapes. To test this hypothesis, we conducted three independent experiments in China, Papua New Guinea, and Finland. In the two latter localities, predation rates on plasticine caterpillars were higher than on models of other shapes, whereas in China, these differences were not significant. Taken together, our study suggests that plasticine models may underestimate the predation by invertebrates to a greater extent than predation by vertebrates, and the preference of model shape by predators may be locality‐specific, presumably due to differences in the composition of the predator community. We propose that predation be estimated on both live and plasticine prey in future studies to measure the potential bias imposed by using plasticine models and its variation among various habitats and predator groups. [ABSTRACT FROM AUTHOR]

The water–air interface is a globally widespread habitat for interactions between prey and predators. We experimentally manipulated water surface conditions (flat, smooth waves, three levels of current-induced turbulence) and digitally quantified the visual integrity of above-surface models from a subsurface perspective. Progressive fragmentation was present in each of the models (upright heron, crouched heron, vertical block, horizontal block) with increased departure from flat surface conditions. Smooth directional waves produced multiple horizontal bands (shadows) that moved across the models while surface currents distorted the profile, including progressive disintegration of the models appearance into multiple fragments of different sizes. This fragmentation is caused by scattered surface irregularities interacting with waves and is accentuated at the broken periphery of the optical window, reducing recognition of the models. Unexpectedly, we found that bands and fragments emerging from different surface conditions resemble common frontal plumage patterns on some Ardeidae and shorebirds (Charadriiformes). While these natural plumages are widely recognized to reflect a diversity of adaptations, including camouflage in terrestrial habitats, we suggest that their resemblance to water surface-induced fragmentation might also reflect foraging adaptations of predators though the water–air interface. [ABSTRACT FROM AUTHOR]

Predation risk has a great influence on animal behaviour. Juveniles are often more susceptible to predation than adults owing to their small body size and limited locomotive ability. Ezohelix gainesi (Camaenidae) is a ground-dwelling land snail that swings its shell as a strategy to avoid predation by beetles. This strategy, however, does not seem to work in juveniles, probably because of their small shell size. Instead, small individuals climb plants as an alternative strategy that is likely to avoid predation; to examine this, we initially made an experimental comparison of the rates of predation by beetles on land snails of different sizes. In these conditions, smaller snails were preyed upon more frequently than larger ones. Next, we compared the size distribution of snails on plants with those on the forest floor. Small snails occurred more frequently on plants than on the ground, and the shell diameter of land snails at 50% probability of occurring on plants was similar to that at 50% probability of predation. Climbing behaviour by small snails was also confirmed in the laboratory in the absence of predators. Therefore, plant-climbing by juvenile E. gainesi is probably an adaptive strategy to avoid predation by ground-dwelling beetles. [ABSTRACT FROM AUTHOR]

Vampires are portrayed opposite to humans, depicted as the dichotomy between predator and prey. Being ever so near to their prey, vampires develop a proclivity for imbibing or emulating characteristics that are considered to be in the sole charge of humans. This text employed is The Vampire Tapestry by Suzy McKee Charnas. The article will analyse Edward Weyland as a post-human symbol, positing himself as an ever-evolving entity that is both human as well as a threshold to gauge humanity of the other characters involved. The article underlines the ways in which Giorgio Agamben's concept of Anthropological Machine and Katherine Hayles's concept of Technogenesis will be used to examine Weyland and other characters as being participants in mutual evolution, tacitly affecting each other through performative actions. The article will inspect the term 'human' as more than just a reified concept, as a term that is constantly in flux and how bio-politics is immanent to the very concept of human. [ABSTRACT FROM AUTHOR]

Apex predators ideally require vast intact spaces that support sufficient prey abundances to sustain them. In a developing world, however, it is becoming extremely difficult to maintain large enough areas to facilitate apex predators outside of protected regions. Free-roaming leopards (Panthera pardus) are the last remaining apex predator in the Greater Cape Floristic Region, South Africa, and face a multitude of threats attributable to competition for space and resources with humans. Using camera-trap data, we investigated the influence of anthropogenic land modification on leopards and the availability of their natural prey species in two contrasting communities--primarily protected (Cederberg) and agriculturally transformed (Piketberg). Potential prey species composition and diversity were determined, to indicate prey availability in each region. Factors influencing spatial utilisation by leopards and their main prey species were also assessed. Estimated potential prey species richness (Cederberg = 27, Piketberg = 26) and diversity indices (Cederberg--H' = 2.64, Ds = 0.90; Piketberg--H' = 2.46, Ds = 0.89), supported by both the Jaccard's Index (J = 0.73) and Sørensen's Coefficient (CC = 0.85), suggested high levels of similarity across the two regions. Main leopard prey species were present in both regions, but their relative abundances differed. Grey rhebok, klipspringer, and rock hyrax were more abundant in the Cederberg, while Cape grysbok, Cape porcupine, chacma baboon, and common duiker were more abundant in Piketberg. Leopards persisted across the agriculturally transformed landscape despite these differences. Occupancy modelling revealed that the spatial dynamics of leopards differed between the two regions, except for both populations preferring areas further away from human habitation. Overall, anthropogenic factors played a greater role in affecting spatial utilisation by leopards and their main prey species in the transformed region, whereas environmental factors had a stronger influence in the protected region. We argue that greater utilisation of alternative main prey species to those preferred in the protected region, including livestock, likely facilitates the persistence of leopards in the transformed region, and believe that this has further implications for human-wildlife conflict. Our study provides a baseline understanding of the potential direct and indirect impacts of agricultural landscape transformation on the behaviour of leopards and shows that heavily modified lands have the potential to facilitate mammalian diversity, including apex predators. We iterate that conservation measures for apex predators should be prioritised where they are present on working lands, and encourage the collaborative development of customised, cost-effective, multi-species conflict management approaches that facilitate coexistence. [ABSTRACT FROM AUTHOR]

Growth in the free-range and pastured egg industries has increased globally, necessitating improvements in predator control. Some egg producers are turning to the use of livestock guardian dogs (LGD; Canis familiaris) to protect hens from predation. We worked on a property where pastured layer hens were protected by two Maremma LGDs that were released from their chicken enclosure for 2–3 nights a week. GPS tracking showed that the dogs were more strongly bonded to people than the chickens, spending most of their time at night (96.1% of location data) close to the farmhouse and only 0.09% near their chicken paddock. Despite this lack of attendance, we found no change in the paddock space use by chickens with or without the dogs present (P = 0.999). Furthermore, camera trapping revealed 40 red fox (Vulpes vulpes) events over the 46-d monitoring period, with less fox activity on nights when the LGDs were allowed to roam the property and motion-activated spotlights were also deployed (P = 0.048). An online survey of 59 poultry producers found strong belief in the effectiveness of LGDs, although half the respondents (52%) indicated that they were still experiencing predation issues. There was no association with the reported degree of human bonding of their LGDs, but respondents were more likely to report current issues with predators if they owned 100 or more chickens (P = 0.031). The present case study as well as the farmer survey have identified that LGDs can be strongly bonded to people. Although there was no evidence of subsequently increased risk of predation, bonding with people could draw LGDs away from the animals they should be defending, with predation risk for poultry likely to depend on how far away LGDs move from their livestock. [ABSTRACT FROM AUTHOR]

This study aims to investigate whether the assassin snail Anentome helena may serve as a biological control agent of Bithynia siamensis goniomphalos, the 1st intermediate host of Opisthorchis viverrini. Experiments were carried out in the laboratory, and the results found that A. helena showed the variation and selection of mollusc prey. A. helena can consume B. siamensis goniomphalos, which is remarkable because this snail can compete with other snails and could be used as a biological control. The consumption rate of the predator was compared, and it was found that A. helena prefers to consume Indoplanorbis exustus, followed by Pomacea canaliculata, Melanoides tuberculata, Filopaludina sumatrensis speciosa, Lymnaea sp., and B. siamensis goniomphalos. This is the first report of an experimental study controlling B. siamensis goniomphalos using A. helena. Our data imply that A. helena can control the B. siamensis goniomphalos population with good results, especially in the absence of other snail species. [ABSTRACT FROM AUTHOR]

Freshwater gastropods play key roles in shallow aquatic ecosystems, with a central position in the periphyton–gastropod–fish trophic pathway, as they feed on periphyton and are preyed on by animals of higher trophic levels. Thus, it is of great interest to explore how climate change impacts the gastropod community and the trophic cascading effects on periphyton. Here, we constructed a simplified, shallow lake food web in 24 large mesocosm tanks to simulate warming (+4.5 °C) on the population responses of two common snails (Bellamya aeruginosa and Radix swinhoei) in two different systems (without/with common carp Cyprinus carpio) over 200 days. We found that warming lowered the biomass and density of R. swinhoei by 16.8% and 41.6%, respectively, and accelerated the average time of density peak of R. swinhoei by 21.5 days in the common carp-absent system. The density of B. aeruginosa in the warming with common carp group was lowered by 79.8% more than in the warming group without common carp. The averaged biomass and density of R. swinhoei in the fish-present system significantly lowered by 64.4% and 92.5%, respectively, compared to the fish-absent system. Cascading effects were also observed, as the snail communities declined under warming, that is, the grazing pressure on periphyton was less, resulting in its higher biomass. In conclusion, in the fish-absent system, warming decreased the biomass and density of the R. swinhoei, and in both snail populations, the biomass and density were much higher than those in the fish-present system. Due to the different phenology of snail species and species-specific predation, future stronger predation in a continuous warming condition might undermine the diversity of the gastropods, thereby changing food web structures in shallow freshwater ecosystems. [ABSTRACT FROM AUTHOR]

• Male guppies (Poecilia reticulata) were exposed to fluoxetine for 8 months • Behaviour, physiology, and morphology were assessed • Fluoxetine did not alter boldness in a maze or in the presence of a predator • Fluoxetine did not impact metabolic rate, mass, or standard length • Body condition was higher in fluoxetine-exposed guppies than in controls Contamination of aquatic ecosystems by pharmaceuticals is a growing threat worldwide. The antidepressant fluoxetine is one such pharmaceutical that is frequently detected in aquatic ecosystems, and has been found to alter the behaviour and physiology of exposed wildlife. Few studies, however, have investigated potential combined effects on behaviour and metabolic rate. In addition, exposures are often short in duration and rarely conducted under ecologically relevant conditions. Here, we examined the impacts of long-term fluoxetine exposure on boldness (exploration, activity, and antipredator behaviour), metabolic rate, and morphology in male guppies (Poecilia reticulata). Specifically, fish were exposed for 8 months (corresponding to approximately two overlapping generations) in semi-natural mesocosms to one of three treatments: an unexposed control (0 ng L−1), or low or high fluoxetine (mean measured concentrations: 30 ng L−1 and 292 ng L−1, respectively). Following exposure, we quantified male exploratory behaviour and activity in a novel environment (maze arena) and antipredator behaviour in the presence or absence of a live predator (spangled perch, Leiopotherapon unicolor), as well as metabolic rate and morphology (mass, standard length, and scaled mass index). Fluoxetine exposure did not significantly alter boldness, metabolic rate, mass, or standard length. However, fluoxetine exposure did alter body condition, whereby fish in the high treatment had a higher scaled mass index than control fish. Our results, considered alongside previous work, underscore the importance of exposure duration in mediating the effects of fluoxetine on fitness-related traits. Continued research under extended exposure periods (i.e., spanning multiple generations) is essential if we are to accurately predict the ecological impacts of fluoxetine on exposed wildlife, and their underlying mechanism(s). [ABSTRACT FROM AUTHOR]

• Sublethal concentrations of β-endosulfan reduced tadpoles weight, neutrophil and lymphocyte count, while CORT levels increased. • Tadpoles exposed to chlorothalonil show an increase in counts of monocytes and lymphocytes; and accelerated the larval development. • A combination of stress factors increases the number of lymphocytes in the blood due to synergistic cytotoxicity. • Chlorothalonil has non-monotonic effects on various immune cells at low concentrations. • Predators produce variation in weight and length of the tadpoles. Pesticide exposure and its interaction with other natural stressors can play a role in amphibian population declines because disruptions in stress hormone regulatory mechanisms may inhibit immune responses during metamorphosis. Here, we determined the interactive effects of predation risk and sublethal concentration of two pesticides on immunological and physiological responses in tadpoles of the tropical frog Lithobates taylori. Using mesocosms, we used chronic exposure to three levels of chlorothalonil and β-endosulfan in the presence or absence of Odonate larvae. Our results show that β-endosulfan in high concentrations reduced the weight of the tadpoles and increased the neutrophil count and corticosterone (CORT) levels. Larval development was accelerated by high concentrations of chlorothalonil. Also, this pesticide in low and high concentrations increases the absolute values of lymphocytes. Tadpoles exposed to chlorothalonil increased the numbers of monocytes (in low concentrations), and lymphocytes (in high and low concentrations). The interactions of the low concentrations of both pesticides with and without the predator's presence also increased the number of lymphocytes. A combination of pesticides increases the number of lymphocytes in the blood due to synergistic cytotoxicity. This study proves that β- endosulfan elevates circulating CORT and thus generates physiological stress in tadpoles. Given that both pesticides are widely used within the distribution of L. taylori in Costa Rica, it is likely that tadpoles' development and immune function are altered by pesticide use. In combination with stressors such as emerging diseases and altered precipitation regimes, widespread agrochemical uses likely caused this species enigmatic decline in recent decades. [ABSTRACT FROM AUTHOR]

Nonconsumptive effects (NCE) from natural enemy presence are known to change the behavior, morphology, and development of potential victims. However, the overwhelming majority of these studies focus on predation, documenting changes in prey behavior; far less is understood about parasitism risk and impacts on host physiology. We used the caterpillar Manduca sexta (Lepidoptera: Sphingidae) and two of its main natural enemies—a specialist parasitoid (wasp), Cotesia congregata (Hymenoptera: Braconidae), and a generalist predator (soldier bug), Podisus maculiventris (Hemiptera: Pentatomidae)—to determine how the threat of parasitism and predation during larval development alter prey growth and immunity. Caterpillars developing near female predators and parasitoids were ~ 85% larger compared to individuals without enemy exposure. Development time was not affected by natural enemies when compared to controls, but male P. maculiventris slowed M. sexta development compared to the other natural enemies. For immune functionality, phenoloxidase (PO) activity only responded to parasitoids, with wasp‐exposed caterpillars exhibiting 35% lower PO activity than all other treatments, while lysozyme activity was unaffected by any enemy treatment. This work emphasizes that parasites can induce changes to host immunity that potentially affect wasp development. More broadly, NCEs on victim immunity are likely given immunity's contribution to host defense but have been under‐appreciated compared to more easily observed phenotypes like behavior and morphology. [ABSTRACT FROM AUTHOR]

Carnivore conservation translocations are assumed to provide numerous ecological benefits, including conservation of the translocated carnivores, regulation of prey species and restoration of ecosystems. Reviews of mammalian carnivore conservation translocations and resultant ecosystem effects have focussed on large carnivores. We reviewed global terrestrial carnivore conservation translocations across all taxa, including taxonomic bias, problems influencing their population establishment and their ecosystem effects.We obtained data from 536 conservation translocations of 54 species of terrestrial mammalian carnivore (order Carnivora and family Dasyuridae, 30 g–196 kg), comprising mostly Mustelidae, Canidae, and Felidae species. A third of all projects translocated carnivores into South Africa and a third into fenced reserves.Significant bias occurred relative to threat status, with over‐representation of Mustelidae and Canidae conservation translocations relative to the number of threatened species in each family. Additionally, conservation translocations of small carnivores were generally under‐represented compared to those of large carnivores.Seventeen percent of small carnivore conservation translocations failed, compared with 25% of large carnivore conservation translocations; failure was primarily due to reported anthropogenic mortality.Effects on resident prey species or ecosystems of carnivore conservation translocations were rarely investigated. We found no significant relationship between the carnivore family or size and effects on prey or ecosystems; however, prey impacts were frequently attributed to Felidae, and ecosystem effects were frequently attributed to Canidae and Felidae.Challenges to translocations of mammalian carnivores include threats to resident threatened prey species and difficulties in monitoring the ecological effects of carnivore conservation translocations. Poor postrelease monitoring and a lack of empirical studies remain persistent problems, contributing to the poor understanding of ecosystem effects following carnivore conservation translocations. [ABSTRACT FROM AUTHOR]

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Rice‐fish co‐culture system has a history of more than 2,000 years in Asia and has been recognized as one of FAO's Globally Important Agricultural Heritage Systems (GIAHS). To date, few studies have explored rice‐fish co‐culture effects on the relationship between predator–prey aggregations and associated tri‐trophic cascades of predatory spiders, insect herbivores and rice. Indeed, predators have been shown to increase prey spatial aggregation but it is still not clear how fish (tertiary consumers) affect aggregations and interactions of their prey on multiple trophic levels (i.e. predatory spiders and rice insect herbivores).Here, we conducted a 2‐year experiment to measure the abundance and distribution of herbivores (leafrollers, stemborers and planthoppers) and their predators (spiders) along with rice yield in rice‐fish co‐culture versus monoculture‐rice (fish free) systems in eastern China. We analysed spatial aggregations of herbivores and predators using geostatistics and used correlations to examine tri‐trophic interactions.Results showed that co‐culture enhanced predatory spider and herbivore spatial aggregations, which in turn increased biocontrol of herbivores by predators, decreased herbivore damage and increased rice productivity.Synthesis and applications. Fish presence increased spatial aggregation of two different trophic levels, which enhanced a tri‐trophic cascade of predatory spiders, insect herbivores and rice in co‐culture systems. Our approach linking spatial aggregations of herbivores and predators with trophic cascades can be applied to study trophic interactions in other ecosystems. Incorporating fish into monoculture paddy fields can increase both natural pest control by predatory spiders and crop productivity via aggregation, and thus increase multiple ecosystem services. [ABSTRACT FROM AUTHOR]