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Poaching of large predators is a big threat to their survival in Norway. These illegal killings take many forms, some meticulously planned, others spontaneous, such as in situations mistakenly experienced as potential predator attacks. While the first type of offense has been studied from various perspectives, the second type is discussed here. I analyze court verdicts from unplanned, spontaneous attempted and completed illegal wolf and bear killings in Norway through the lens of Wikström's "Situational Action Theory," exploring why offenders convicted by the court shot the predators. Hoeben and Thomas' and McGloin and Thomas' notion of "situational peer influence" seems to be an important factor and is included in the analysis. The findings imply that legal hunts increase the risk of spontaneous poaching of large predators – a type of killing often overlooked in discussions of the preventative or criminogenic influence of legal hunting on illegal hunting. [ABSTRACT FROM AUTHOR]

Although artificial intelligence (AI) is currently a prominent technology that has received increasing attention, the factors affecting users' AI device adoption for healthcare were less discussed. Drawing on affordance-actualization theory and literature on AI, uniqueness theory, and healthcare, we developed a research model to explain users' adoption intention of AI devices in the healthcare context. Data collected from 307 potential users in China were used to test the proposed model. Our findings indicated that data capture, classification, and social affordances impacted self-monitoring significantly, while data capture and social affordances were the predators of uniqueness enhancement. The self-monitoring, on the other hand, had a positive influence on uniqueness enhancement. Finally, our results revealed that self-monitoring and uniqueness enhancement have significant effects on AI adoption. From the findings, theoretical and practical implications are discussed. [ABSTRACT FROM AUTHOR]

Imagine the vast Palaeozoic oceans: graptolites (Pterobranchia, Graptolithina) appear as small and inconspicuous benthic faunal elements in the early Cambrian, later becoming one of the dominating planktic groups of macrofauna in Ordovician and Silurian marine environments. Their unusual organic housing secretions (tubaria) in the fossil record makes them one of the most important biostratigraphic markers for the Ordovician to early Devonian time intervals. The occurrence, especially of the planktic graptolites, in black shales led to the common notion of a life style that related them to anoxic or dysaerobic environments, but is merely a preservational aspect. Their demise in the early Devonian may be related to the origination and diversification of large plankton feeding organisms in the marine realm as the graptolites were unable to complete with the much faster growth and reproduction of smaller, non-colonial organisms that did not need to waste time producing a housing construction. Thus, from the later Devonian onwards, the graptolites were largely gone and the oceans were teeming with fast reproducing and growing micro-and macroplankton. Larger predatory animals evolved as plankton feeders, that may have preyed on the graptolites. Only a few cryptic benthic species survived into the modern world. [ABSTRACT FROM AUTHOR]

We investigate the dynamics of a prey--predator model with cooperative hunting among specialist predators and maturation delay in predator growth. First, we consider a model without delay and explore the effect of hunting time on the coexistence of predator and their prey. When the hunting time is long enough and the cooperation rate among predators is weak, prey and predator species tend to coexist. Furthermore, we observe the occurrences of a series of bifurcations that depend on the cooperation rate and the hunting time. Second, we introduce a maturation delay for predator growth and analyse its impact on the system's dynamics.Wefind that as the delay becomes larger, predator species become more likely to go extinct, as the long maturation delay hinders the growth of the predator population. Our numerical exploration reveals that the delay causes shifts in both the bifurcation curves and bifurcation thresholds of the non-delayed system. [ABSTRACT FROM AUTHOR]

In this paper, we consider a stochastic two-species predator--prey system with modified Leslie--Gower. Meanwhile, we assume that hunting cooperation occurs in the predators. By using Itô formula and constructing a proper Lyapunov function, we first show that there is a unique global positive solution for any given positive initial value. Furthermore, based on Chebyshev inequality, the stochastic ultimate boundedness and stochastic permanence are discussed. Then, under some conditions, we prove the persistence in mean and extinction of system. Finally, we verify our results by numerical simulations. [ABSTRACT FROM AUTHOR]

Studying the interactions between prey and predators is crucial for understanding the intricacies of predator-prey dynamics and for formulating effective conservation strategies. Yet there is almost no systematic analysis of pancake tortoise predation, and its consequences on the tortoise populations. Using camera trapping and visual encounter surveys, we recorded the animals visiting the crevices inhabited by pancake tortoises, as well as their surroundings. From our data, we propose which visitors were potential predators, and consider predator impacts on the species. We suggest ten species (21.3%) as potential predators, among the 47 visiting the tortoise crevices between July 2020 and November 2022. We encountered six adult pancake tortoises killed and eaten by unknown predators. Four of six eggs laid by pancake tortoises in May−June 2022 were also depredated. The white-tailed mongoose (Ichneumia albicauda) and the honey badger (Mellivora capensis) were recorded probing rock crevices inhabited by pancake tortoises, with their behaviour suggesting potential predation upon tortoises. We recorded the rock monitor lizard (Varanus albigularis) and common dwarf mongoose (Helogale parvula) digging pancake tortoise nest sites. This study significantly advances our understanding of the predation risk to the critically endangered pancake tortoise. [ABSTRACT FROM AUTHOR]

Mimicry is widespread in the animal kingdom, with sound/or acoustic mimicry remaining less studied than visual mimicry. Some incubating female birds in cavity nests emit a hissing call when encountering nest predators, which sounds like a snake hiss and serves to scare off predators; this is considered a form of acoustic Batesian mimicry. Similarly, for nearly defenseless bird nestlings, using a hissing call to scare off predators can improve their survival; however, few studies have reported nestlings making hissing calls. In this study, we report on the hissing calls of nestlings of the open-nesting zitting cisticola (Cisticola juncidis) and compare their hissing calls with those of other animals, such as birds and snakes. The results showed that the hissing calls of C. juncidis nestlings closely approximate the sounds of snakes. This study is the first report of sounds that mimic snakes made by the nestlings of any open-nesting passerine bird species. [ABSTRACT FROM AUTHOR]

This article reviews the international literature on the natural enemies of Dreissena spp.—bivalves which internationally have strong impacts on aquatic ecosystems, industries, fisheries, and aquaculture. It represents a revised edition of the initial treatment on this topic published over two decades ago, and as in the previous publication, it reviews the biology and ecology of organisms known to be involved in the predation (143 species), parasitism and commensalism (86 species and higher taxa), and competitive exclusion (14 species) of species in the genus Dreissena. Predators can at times have major impacts on dreissenid populations, but these reductions are typically only temporal and in restricted (e.g., shallow) areas within large waterbodies. A cumulative effect of a growing suite of enemies may have a constant, but overall limited, role in suppressing Dreissena densities—one far from any likelihood of population eradication. A diverse and abundant community of natural enemies, however, is beneficial because of its positive impact on energy flow. The introduction of dreissenids has redirected energy from the planktonic to the benthic community and predators, in particular molluscivorous fish and waterfowl, have served to redistribute this energy flow back into the pelagic environment. [ABSTRACT FROM AUTHOR]

Dengue fever creates more than 390 million cases worldwide yearly. The most effective way to deal with this mosquito-borne disease is to control the vectors. In this work we consider two weapons, the endosymbiotic bacteria Wolbachia and predators of mosquito larvae, for combating the disease. As Wolbachia-infected mosquitoes are less able to transmit dengue virus, releasing infected mosquitoes to invade wild mosquito populations helps to reduce dengue transmission. Besides this measure, the introduction of predators of mosquito larvae can control mosquito population. To evaluate the impact of the predators on Wolbachia spreading dynamics, we develop a stage-structured five-dimensional model, which links the predator-prey dynamics with the Wolbachia spreading. By comparatively analysing the dynamics of the models without and with predators, we observe that the introduction of the predators augments the number of coexistence equilibria and impedes Wolbachia spreading. Some numerical simulations are presented to support and expand our theoretical results. [ABSTRACT FROM AUTHOR]

In this work, we first modify a Lotka–Volterra predator–prey system to incorporate an opportunistic predator and weak Allee effect in prey. The prey will be extinct if the combined effect of hunting and other food resources of predator is large. Otherwise, the dynamic behaviour of the system is extremely rich. A series of bifurcations such as saddle-node bifurcation, Hopf bifurcation, and Bogdanov–Takens bifurcation can happen. The validity of the theoretical results are supported with numerical simulations. [ABSTRACT FROM AUTHOR]

In this paper, we consider a predator–prey model with nonuniform predator dispersal, called predation-induced dispersal (PID), which represents predator motility depending on the maximal predation rate and the predator death rate in a spatially heterogeneous region. We study the local stability of the semitrivial steady state when predators are absent for models with PID and linear dispersal. We then investigate the local/global bifurcation from the semitrivial steady state of these models. Finally, we compare the results of the model with PID to the results of the model with linear dispersal. We conclude that the nonuniform dispersal of predators obeying PID increases fitness for predator invasion when rare; thus, predators with PID can invade a region with an increased probability even in cases wherein predators dispersed linearly cannot invade a certain region. Based on the results, we provide an ecological interpretation with the simulations. [ABSTRACT FROM AUTHOR]

Brain abnormality is one of the dominant health issues in recent years, and electroencephalogram (EEG) is a mostly employed method for identifying abnormalities in the brain. Brain abnormalities can be cured only when it is detected early stage. Even though there are various techniques for the detection of brain abnormalities, the health sector concentrates more on the advanced modern method to diagnose the abnormality very precisely. Advanced DL methods have attracted physicians very much due to the fascination with developing detection methods with minimal errors. Hence, this paper deeply concentrated on developing a well-structured technique to predict brain abnormalities using the hybrid coyote predator optimisation-dependent DCNN (hybrid coyote predator-DCNN). The results of this study demonstrate the value of hybrid coyote predator optimisation, which inherits qualities like a long jump and an intelligence ability to adapt to its surroundings and aids in fine-tuning the modal parameters of the DCNN. Additionally, to improve the detection model's precision, the frequency bands from which the features are taken are separated to identify brain changes. Utilising the CAP dataset and the performance metrics, the analysis is carried out. Regarding the TP and k-fold, the hybrid coyote predator-DCNN model attained accuracy of 98.446% and 97.384%, respectively. [ABSTRACT FROM AUTHOR]

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is the most destructive pest of tomato worldwide. Biological control has always been considered as a promising management approach of this pest in tomatoes. In this context, we evaluated the effectiveness of releasing Trichogramma cacoeciae Marchal parasitoids or Macrolophus pygmaeus (Rambur) predators in controlling T. absoluta in greenhouse tomatoes of northeastern Tunisia. Two weekly releases of either M. pygmaeus at 1 adult/m2 or T. cacoeciae at 20 adults/plant were assessed. Our results indicated that parasitism rates were significantly higher on the apical tomato leaves compared to the middle leaves. We found that the number of T. absoluta eggs and larvae was significantly reduced after releasing T. cacoeciae, while releases of M. pygmaeus did not significantly reduce T. absoluta densities. The present study demonstrated the great potential of releasing T. cacoeciae in controlling T. absoluta in greenhouse tomatoes of northeastern Tunisia. However, further studies are needed to evaluate other release rates of M. pygmaeus that could show promising effectiveness against T. absoluta in northeastern Tunisian greenhouses. [ABSTRACT FROM AUTHOR]

In this paper, we study a three-species predator-prey model with modified LG-Holling type II with Lévy jumps, and we take the competition among predators into consideration. First, We use an Ornstein-Uhlenbeck process to describe the environmental stochasticity and prove that there is a unique positive solution to the system by mathematical analysis skills such as comparison theorem. Futhermore, the extinction or persistence in the mean of each species under different conditions is obtained. Finally, some numerical simulations are carried out to support our main results. [ABSTRACT FROM AUTHOR]

Invasive species pose a threat to biodiversity, and as such feature in some conservation education programs. However, there is debate about how to teach this difficult subject. We explored perspectives using a case study of education about introduced mammalian predators in Aotearoa New Zealand (NZ). We conducted semi-structured interviews with 18 NZ educators and animal welfare advocates and supplemented these data with material from a broader project on predator control in NZ. Our data indicated agreement that education should: 1) encourage respect for all animals, i.e., introduced predators should not be demonized and must be killed humanely; 2) enable children to develop their own opinions, e.g., whether to participate in trapping; and 3) designing programs to suit specific contexts, e.g., rural versus urban. However, there were disagreements, for example at what age children might begin trapping, and whether guiding students toward a particular conclusion is compatible with enabling their agency. [ABSTRACT FROM AUTHOR]

This article examines a discrete-time predator-prey model where prey teams cooperate. Positivity and boundedness of the model solution are investigated. Positive fixed points are examined. Using an iteration scheme and the comparison principle of difference equations, we determined the sufficient condition for global stability of the positive fixed point. It is shown that the sufficient criterion for Neimark-Sacker bifurcation and flip bifurcation can be established. It is observed that the system behaves in a chaotic manner when a specific set of system parameters is selected, which are controlled by a hybrid control method. Examples are provided to illustrate our conclusions. [ABSTRACT FROM AUTHOR]

Cats are known predators of bats, but there are few published accounts of predation attempts. In this paper we report on two recent examples of bats being attacked by cats (Felis catus) in New Zealand. We found a Central lesser short-tailed bat (Mystacina tuberculata rhyacobia) in the gastrointestinal tract of a feral cat that was trapped in indigenous forest. We also report on a case where seven long-tailed bats (Chalinolobus tuberculatus) were killed or injured over two years by a companion cat living in a rural landscape. We confirmed cat attack/predation using diet analyses, and pathological assessment and identification of the predator using DNA. We consider that depredation of bats by feral, stray, and companion cats is likely to be substantial and occur within all habitats where bats and cats overlap. LSID: urn:lsid:zoobank.org:pub:8933333F-D145-41CF-BA20-3AE73D3B86B4 [ABSTRACT FROM AUTHOR]

Electroreception is an intriguing sense in the animal kingdom, that confers an advantage, when other senses cannot be used. Many shark and ray species spend a prolonged embryonic life stage enclosed in an egg case, where the avoidance of predators is difficult. In this study, we found that late stages of small-spotted catshark (Scyliorhinus canicula) exhibit a freeze response that stops ventilation when exposed to electric stimuli. The embryos also showed a short-term tolerance buildup, when exposed to several electrical stimuli over a 40-min period. Surprisingly, the embryos also reacted with a freeze response when the electrical field was turned off, indicating that the embryos reacted to a change in electrical field, rather than the presence of one. Younger embryos showed a significantly longer freeze response than older embryos. This study documents the use of electroreception in small-spotted catshark embryos as a possible predator avoidance response. [ABSTRACT FROM AUTHOR]

Lizards are commonly preyed by a great variety of predators, including vertebrates and invertebrates. Therefore, it is expected that lizards have developed a wide range of antipredator traits, increasing their chances of successful survival during agonistic events. Defence against predation involves two levels of behavioural strategies, commonly named primary and secondary defence traits. Primary defences relate to predator detection or interest and include as responses immobility, mimicry, aposematism, and cryptic colouration. Secondary defences occur after predator detection and attack, including traits that aim to prevent or interrupt predators. These defences encompass traits such as frightening (e.g., scratching or biting the predator), tail lashing, flouncing vigorously the body, cloacal discharge, agony vocalisations, and tail autotomy. In this review, we gathered information from 206 scientific publications, including peer-reviewed journals, short communications, scientific notes, and books. This compilation resulted in 22 defence traits, 23% passive and 77% active defences. Lizard species deal with a wide diversity of predators, but the number of field records, experiments, and antipredator studies remain scarce. We reviewed the defence traits presented by Neotropical lizards, using a phylogenetic approach in order to track evolutionary process behind these traits. Thanatosis, crypsis, and tail autotomy are symplesiomorphic for lizards, whereas venom and emetic substances are autapomorphic, and aposematism seems to be rare. We also present a novel case of defence trait where the dark colour helps lizards to be camouflaged in the burned vegetation. Our character mapping provides valuable information about the evolution of defensive traits in Neotropical lizards, combining natural history and phylogenetics. Trivial observations about any animal behaviour, including those provided by social networks and citizen science pages, might be important, and we strongly recommend that ethological observations describe the event in all possible details. [ABSTRACT FROM AUTHOR]

This study explored the communication of Predator Free 2050 (PF2050), a biodiversity conservation programme promoted by the New Zealand government. Drawing on semi-structured interviews and an online survey, the study found that the information about PF2050 was made available by diverse contributing agencies but ineffectively disseminated to the public who believed PF2050 provided insufficient or unclear communication. These were experienced as barriers to public engagement with PF2050. A coordinated approach is judged vital to communicate PF2050 to the public. A key to this coordination is effective engagement with Māori as Treaty partners to ensure the success of PF2050. This study provides valuable insights into the features provoking and sustaining public engagement with biodiversity preservation in Aotearoa New Zealand and highlights the need for environmental movements worldwide to improve communication publicity and visibility. It contributes to our understanding of prioritising both inclusiveness and cultural sensitivity if communication strategies are to inspire collaborative actions of the public. [ABSTRACT FROM AUTHOR]

The cost–benefit approach to nest defence behaviour is based on an assumption that parents are able to distract potential predators away from their nest. However, this assumption has received little support from direct observations as predator-prey encounters near nests are rarely recorded, especially in small passerines. Here, we describe two observations of little bitterns appearing near nests of Eurasian reed warblers containing nestlings and eggs, respectively. In both cases parental birds showed anti-predatory behaviour, which was much more vigorous at the nestling stage than at the egg stage. During both observations, the heron finally flew away and did not attack the nest content, indicating that nest defence behaviour of small passerines may be effective. [ABSTRACT FROM AUTHOR]

Predators affect prey by killing them or inducing changes in their physiology and behaviour through a fear effect associated with predation risk. In birds, perceived predation risk influences reproductive decisions, such as the reduction of parental investment in offspring during both egg production and nestling rearing. Visual and vocal cues of predator presence have been widely used to test the direct effects of predation risk. However, few studies have examined the indirect cues of predator activity such as dead avian prey or their remains. In this study, for the first time, we experimentally studied whether piles of feathers, simulating the remains of avian prey, induce changes in the reproductive decisions of adult birds. Before and during egg laying, great tit, Parus major, pairs were exposed to piles of bright down and cover feathers from domestic goose (treatment), woodchips (procedural control), or were not exposed (control). Our experiment affected maternal investment in individual eggs, but did not influence other reproductive parameters. Females from the treatment group laid larger and more asymmetrical (pointed) eggs than control females. Moreover, females from the procedural control group laid larger eggs than those from the control group, but without differences in egg shape. However, the eggs from the treatment and procedural control groups did not differ. This indicates that great tit females can perceive feathers and woodchips as informative cues, such as potential predation risk or habitat suitability, or as novel items in the environment. Importantly, females respond to such cues by changing their maternal investment in eggs, which may result from an adaptive mechanism aimed at increasing offspring fitness in the face of specific environmental conditions experienced by a female. Our study contributes to the understanding of how female songbirds adjust their maternal reproductive investment in response to publicly available social and environmental cues. [ABSTRACT FROM AUTHOR]

In this paper, some complicate dynamical behaviors are formulated for a discrete predator–prey model with group defense and nonlinear harvesting in prey. After considering the existence and stability for all of its nonnegative fixed points, our main work is to present those conditions for the occurrences of transcritical bifurcation, saddle-node bifurcation and Neimark–Sacker bifurcation, respectively. Numerical simulations not only verify the theoretical results for saddle-node bifurcation and Neimark–Sacker bifurcation but also display more interesting dynamical properties of the model. [ABSTRACT FROM AUTHOR]

Early detection of predators is fundamental for the survival of the prey. Predator detection can occur by perception of the chemical substances released by predators or injured conspecifics, granting prey the opportunity to avoid the attack. However, overreacting to cues can generate false alarm reactions that result in fruitless energetic costs. Given that chemical cues in natural habitats rarely occur singly, individuals can benefit from obtaining information from multiple sources, such as the combined chemical cues from predators and conspecifics. We experimentally tested the movement reaction of cane toad (Rhinella marina) tadpoles when in contact with isolated chemical cues from a conspecific, a predator (dragonfly larvae), and the combination of these two substances. We quantified duration of swimming activity before and after the exposure to the chemical cues and compared it to a control group. A significant reduction in swimming activity was only observed when the tadpoles were exposed to the combination of both cue types. Our results suggest that the tadpoles can recognise the chemical cues from conspecifics and predators, but a behavioural response is only elicited when both stimuli are detected simultaneously. We suggest that behavioural change in response to predation threat in R. marina is a compromise between early detection of predators and avoidance of unnecessary energetic expenditures. [ABSTRACT FROM AUTHOR]

Copyright of Ecoscience (Ecoscience) is the property of Taylor & Francis Ltd 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.)

The evolutionary significance of color expression in animals is often framed within either an interspecific (e.g., antipredator display) or intraspecific (e.g., mate choice) context. In part, this dichotomy stems from assumptions that the expression of conspicuous sexually selected traits likely hinders survival in the wild. Here we address the potential for natural and sexual selection to reinforce expression of a conspicuous tail bar pattern in zebra-tailed lizards (Callisaurus draconoides). In C. draconoides, display of this tail bar pattern has historically been considered an interspecific signal to deter predator pursuit. However, a putative honest link between the tail bar pattern and escape likelihood (e.g., sprint speed) is unknown. Further, studies on related taxa also support the potential for this trait to be informative as a signal of individual quality during mating interactions as well. We assessed variation in the morphology of male and female C. draconoides, and then evaluated how variation in morphology (emphasizing the tail bar pattern) contributed to variation in performance (sprint capacity) and, for males, variation in female preference. Males were larger than females, but size was unrelated to variation in tail bar number. Males sprinted faster than females overall, but tail bar number only mattered for males: specifically, males with more tail bars sprinted faster. Females also preferred males with more tail bars. Overall, our findings suggest that natural (mediated via an honest link between bar number and sprint speed) and sexual (mediated via a preference for males with more tail bars) selection may mutually reinforce expression of a color signal. Thus, the potential adaptive benefits of a color signal may span intra- and interspecific contexts. For males at least, the tail bar pattern is useful for both deterring the pursuit of predators as well as attracting the attention of potential mates. [ABSTRACT FROM AUTHOR]

Multiple factors influence predation risk, ranging from habitat conditions to the composition and behaviour of predators. Although these factors are well documented for forest ecosystems, there is little evidence for wetlands, especially within Patagonia. Using artificial nests and camera traps, we documented the nest predation rates and predator assemblage of birds nesting in wetlands of the Patagonian steppe. We also determined the effect of vegetation cover on nest survival and studied the variation in predator groups according to nest placement: nests located in an open wetland, peripheral grassland to the wetland, and nests located in shrubs at different heights. We found 84% of nests failed, counting birds, mice, and armadillos as the main predators. Vegetation cover affected predation events of birds and small mammals, but not those of larger mammals. In turn, small mammals preyed on nests exclusively located in peripheral grassland, medium mammals preferred nests placed in open wetlands, and predation by birds was irrespective of open wetlands and grassland. We also found differences in nest predator assemblage between nests placed on the ground and in shrubs, with birds being the main predators of nests located above ground. These results can be attributed to differential habitat use and movement patterns specific to each predator group. Therefore, the identity, density, and behaviour of predators should be taken into account when planning conservation strategies for birds breeding in wetlands. [ABSTRACT FROM AUTHOR]

Some porcellanid crabs (Decapoda Anomura) are known to escape predator crabs through a hair-trigger autotomy response when they are held by the cheliped only. The porcellanid crab Petrolisthes japonicus autotomizes chelipeds, and the post-autotomy cheliped movement functions like a lizard tail, which may increase predator distraction time, affording the prey more time to escape. However, the predatory encounters between prey and the relevant predators have not been observed to understand the benefits of autotomy in P. japonicus. The present study conducted 140 predation trials to evaluate the effectiveness of cheliped autotomy by P. japonicus in avoiding predation from its potential predator crab Gaetice depressus that commonly co-occurs with P. japonicus under cobble and boulders in intertidal zones. The predator attacked the prey in many trials (84%) and successfully grasped the prey in most attack cases (94%). The prey held by the body was able to escape the predator in a few cases (7%). When the prey was held by the cheliped only, the prey autotomized the cheliped and was able to escape the predator in many cases (75 and 83%, respectively), while the predator was eating the autotomized cheliped. The predator appeared to take a long time to handle the autotomized cheliped with its claws. Thus, our laboratory experiments demonstrated that P. japonicus exhibited high incidences of cheliped autotomy when it was held by the cheliped only, enabling it to escape the predator crab at high probabilities. Furthermore, post-autotomy movements may improve the efficacy of the antipredator defence mechanism of autotomized chelipeds in P. japonicus. [ABSTRACT FROM AUTHOR]

In-vitro chemical characterization and mosquitocidal screening of essential oil derived from Mikania scandens (L.) Willd. (Asteraceae) (CVO-MS) against the malarial vector Anopheles gambiae was investigated. GC-MS analysis evidenced a total of 12 bio-active compounds, and maximum at α-bisabolol (39.34%) followed by stigmasterol (13.45%) respectively. The larvicidal activity of CVO-MS against the malarial vector An. gambiae evidenced that the mortality rate was prominent at the maximum dosage of 1000 ppm. The Median Lethal Concentration (LC50) of CVO-MS was established at 488±2.45 ppm, respectively. Enzyme inhibition assay showed that the CVO-MS delivers a significant upsurge in the level of CYP450, GST, and a decline in the level of α-β carboxylesterase activity in both the third and fourth instar (p ≤ 0.0001). The gut-histological examination of CVO-MS showed that there is severe damage in the mid-gut tissues, especially epithelial layer (EL), gut-lumen (GL), and peritrophic membrane (pM). The non-target screening against the mosquito predators (A. bouvieri, D. indicus, and third instar larvae of Tx. splendens) suggests that CVO-MS showed less toxicity as compared to Pestanal® (1 ppm) respectively. The present study has paved a new insight in understanding the bioactivity of CVO-MS as a potential larvicidal agent of malarial vector and non-toxic against mosquito predators. [ABSTRACT FROM AUTHOR]

Overabundant species can alter a fish community and negatively influence recreationally important species. Introducing new or more predators into a system to control such nuisance fish has been met with limited success and may involve some risk. Understanding to what degree consumption of nuisance species occurs by existing predators and whether an existing predator community is physically capable of consuming the nuisance species can help to determine whether biological control may be possible without new introductions of predators. The objectives of this study were to: (1) document consumption of black bullheads Ameiurus melas by three predators; and (2) determine the relative vulnerability and potential ingestion of bullheads by these predators. We used gastric lavage monthly from May through September to collect stomach contents of channel catfish Ictalurus punctatus, largemouth bass Micropterus salmoides, and walleye Sander vitreus in four reservoirs to calculate the percent occurrence of black bullheads in predator stomachs. We also collected various sizes of juvenile black bullheads to measure body width and depth, with and without the pectoral and dorsal spines extended, respectively. This information was coupled with measured gape widths from the predators to calculate relative vulnerability curves and probabilities of ingestion based on predator size. Black bullheads were rarely consumed by the three predators, and stomach contents generally contained a single black bullhead when consumption did occur. Relative vulnerability based on body depth was similar for all three predators. Potential ingestion was similar among all three predators but was higher for channel catfish compared to the other two predators when black bullhead depths were measured with the dorsal spines extended. This study provides new information about the potential for biological control of black bullheads by an existing predator community. [ABSTRACT FROM AUTHOR]

Biological control is an alternative strategy to control Cacopsylla bidens. The aim of this study was to untanglethe trophic network involving C. bidens as prey. Molecular techniques along with predator activity surveys were employed to evaluate predation on psylla. Feeding on C. bidens was detected for five predators: Chrysoperla externa, Chrysopidae sp., Hemerobiidae sp., Harmonia axyridis and Cycloneda sanguinea. All these predators begin to feed earlier in the season, apart from C. externawhich fedds from the third psylla generation. These results will allow the development of strategies to increase the presence of these predators in the orchards. [ABSTRACT FROM AUTHOR]

Copyright of Ecoscience (Ecoscience) is the property of Taylor & Francis Ltd 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.)

Prey animals use various signals to detect their predators and respond accordingly to enhance their survival. Since responding to a predator is costly, prey species may cut cost by using other strategies such as behavioural tactics, morphological changes, seeking natural refuge or unique habitat acquisition. Tadpoles of Microhyla nilphamariensis have a transparent body and live in a neustonic environment, which provides them protection against benthic predators. As a result, we investigated the predator detection mechanism in M. nilphamariensis tadpoles using different cues from an insect predator, dragonfly larvae, to determine if the presence of natural shelter and unique habitat acquisition influences the chemo-ecology of predator recognition in this species. We also exposed these tadpoles to active caged predators and a stress hormone, corticosterone (CORT) to study physiological mechanism underlying their behavioural anti-predator responses toward alarm cues. In the predator avoidance assay, M. nilphamariensis tadpoles did not respond to the predator using visual or chemical signals. The tadpoles did not change their activity in response to alarm, heterospecific, kairomones, and dietary cues released from the predator. Pre-conditioning of M. nilphamariensis tadpoles with caged predator and different concentrations of CORT also did not alter their activity in response to alarm cues. These results clearly demonstrated that neustonic tadpoles of M. nilphamariensis do not detect and respond to co-existing insect predator. We discuss these results in the context of unique habitat occupied by these prey tadpoles, the presence of alternate prey, and inherent factors such as transparent body. [ABSTRACT FROM AUTHOR]

The larva of the limnephilid caddisfly Limnephilus sackeni Banks, 1930 is associated, described, diagnosed, and illustrated for the first time. The larvae of this species can be readily separated from other described Nearctic Limnephilus larvae according to head pigmentation and patterning. A brief discussion on possibly cryptic colouration and predator avoidance is provided. [ABSTRACT FROM AUTHOR]

Almost sixty years ago, Bdellovibrio and like organisms (BALOs) were discovered as the first obligate bacterial predators of other bacteria known to science. Since then, they were shown to be diverse and ubiquitous in the environment, and to bear astonishing ecological, physiological, and metabolic capabilities. The last decade has seen important strides made in understanding the mechanistic basis of their life cycle, the dynamics of their interactions with prey, along with significant developments towards their use in medicine, agriculture, and industry. This review details these achievements, identify current understanding and knowledge gaps to encourage and guide future BALO research. [ABSTRACT FROM AUTHOR]

Anti-predator mechanisms play a key role in the survival of any animal in nature. Anurans exhibit a great diversity of defensive behaviours and interact with the widest range of predators of any vertebrates. However, there are few systematic and experimental studies of anuran defensive behaviours, which are generally opportunistic. Here, we deploy a range of methods to investigate various facets of anuran defensive behaviour using the cane toad Rhinella marina as a model organism. This originally Amazonian anuran is now widely distributed across the globe and has caused several predators to decline at introduction sites where this species is not native, a direct result of its anti-predation defenses. First, we compiled previously published data on anuran predation events to assess the relationship between predator/anuran size and predator size and type. We then performed a systematic experiment to test the hypothesis that there is an ontogenetic variation in cane toad behavioural defense displays, as well as a variation in these displays between males and females. In total, we tested 173 individuals including juveniles, adult males and adult females. We show that the size and type of the predator is related to the size of the anuran as prey and that this, in turn, has led to the adoption of different predation-avoiding behavioural defensive strategies during ontogeny. Our results also indicate that both the sex and the size of anurans influence the adoption of defensive strategies. [ABSTRACT FROM AUTHOR]

Live trapping (e.g. pitfall trapping or funnel trapping) is an important sampling tool for a wide range of small terrestrial animals and is one of the predominant methods for survey and monitoring of terrestrial lizards in New Zealand. As it results in the confinement of animals, methods using live trapping must mitigate risks to animal welfare. Foraging predators can kill or injure animals confined in pitfall traps (e.g. lizards); however, visitation rates of various predatory mammals are poorly understood and reported occurrences are largely anecdotal. Following an observation of a rat depredating a skink in a pitfall trap during a lizard salvage operation, we recorded the removal of bait (pear) from traps over a 24-h period and installed motion-detecting cameras to record trap visitation. Bait loss occurred rapidly over the observed period, with 77% removed after 24 h. Three rodent species were detected visiting a trap, with one ship rat (Rattus rattus) entering it and removing the bait. We suggest that operations involving live trapping of lizards should consider predator densities and carefully monitor and report trap disturbance. Further research should examine how different trapping methods (e.g. predator-exclusive trap design, baiting, and timing of trap checks) might reduce the risk of predation to trapped animals. [ABSTRACT FROM AUTHOR]

A modified marine predators optimizer (MMPO) is proposed for simultaneous distribution network reconfiguration (DNR) associated with the allocation of distributed generators (DGs). In the MMPO, the predator's strategies are merged to consider the possibilities for variation in the environmental and climatic circumstances. The suggested MMPO is contrasted with the standard marine predators optimizer (MPO) and genetic, harmony search, fireworks, firefly and improved sine–cosine optimizers. The proposed MMPO is validated on single and multiple objectives using 33- and 69-bus distribution systems at light, nominal and heavy loading levels. The results obtained by the proposed MMPO are compared with those obtained by the original MPO and other optimizers. The achieved simulation outputs reveal a great improvement over the standard MPO and demonstrate the superiority of the proposed MMPO for simultaneous DNR and DG allocation. [ABSTRACT FROM AUTHOR]

In this study, we provide detailed ethological notes on the predation behaviour of Chvalaea yolkamini Jaume-Schinkel, Soares & Barros, 2020, a neotropical sit-and-wait dance fly from Mexico, with description and video evidence of hunting and feeding behaviours. Furthermore, we analysed in situ predation success in relation to biotic and abiotic factors (prey size, prey taxonomic group, temperature, humidity and perch height). We observed 94 individuals for a total of ~15.68 hours. Chvalaea yolkamini uses its hind legs armed with spikes to strike and handle prey, while its short proboscis pierces and sucks on intersegmental areas as they are less sclerotised. Feeding time ranged from 1.27 to 15.24 minutes. In addition, C. yolkamini was more successful when attacking large-sized prey, but apparently the limit for prey size is the predator's own size. The individuals were more successful when ambushing large Brachycera than relatively small nematocerous Diptera and Hemiptera. No influence of temperature and humidity was detected, but higher perches favoured predation success. Our study supplies the first detailed information on the perching and hunting behaviour of a sit-and-wait hybotid fly. We advance hypotheses that may be investigated by including covariables, such as wind and prey colouration, with a view to further our comprehension of the sit-and-wait behaviour in predatory animals. [ABSTRACT FROM AUTHOR]

Snakes are common predators of birds. However, reported cases of snake predation on Troglodytes musculus are scarce. Here, we report a predation attempt of a Troglodytes musculus nestling by the dipsadid snake Philodryas olfersii. We also present a list with bird species recorded as prey of this snake species. We found 25 predation events of P. olfersii on adult, juvenile, and nestling birds. A total of 19 bird species from 14 families have been reported as prey of P. olfersii. Most predation events occurred on the vegetation, while some others were observed on the ground, cage, and artificial nest. [ABSTRACT FROM AUTHOR]

We describe the interaction between harpoon fishing activity and sharks, which opportunistically depredated harpoon catches in the Strait of Messina. Shark bite marks were observed on harpooned swordfish during the period 2014–2020, with different damages to the catches. Most of the depredation events have focused on large swordfish, generally weighing more than 60 kg. Data on direct observations were implemented by interviews and questionnaires to fishermen aimed to recover the information on their local fishing and ecological knowledge. Fishermen provided additional data on shark-harpoon fishing interactions also supplying information on by-catch species (i.e., bluefin tuna). Therefore, these results suggest that sharks migrating through the Strait of Messina are occasionally attracted by injured prey, due to their ability to detect chemical cues, fish distress stimuli and body fluids (i.e. blood) in the water. In addition, our investigations showed an increase in shark attacks on harpooned fish over time, likely due to an increase in harpoon swordfish catches. This may be related to the effects of the driftnets' ban enforced by European Regulations in the last decades. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the combined effects of fear, prey refuge and additional food for predator in a predator–prey system with Beddington type functional response. We observe oscillatory behaviour of the system in the absence of fear, refuge and additional food whereas the system shows stable dynamics if anyone of these three factors is introduced. After analysing the behaviour of system with fear, refuge and additional food, we find that the system destabilizes due to fear factor whereas refuge and additional food stabilize the system by killing persistent oscillations. We extend our model by considering the fact that after sensing the chemical/vocal cue, prey takes some time for assessing the predation risk. The delayed system shows chaotic dynamics through multiple stability switches for increasing values of time delay. Moreover, we see the impact of seasonal change in the level of fear on the delayed as well as non-delayed system. [ABSTRACT FROM AUTHOR]

This paper is concerned with a stochastic predator–prey model with Holling II increasing function in the predator. By applying the Lyapunov analysis method, we demonstrate the existence and uniqueness of the global positive solution. Then we show there is a stationary distribution which implies the stochastic persistence of the predator and prey in the model. Moreover, we obtain respectively sufficient conditions for weak persistence in the mean and extinction of the prey and extinction of the predator. Finally, some numerical simulations are given to illustrate our main results and the discussion and conclusion are presented. [ABSTRACT FROM AUTHOR]

Lethal effects of thiacloprid were determined on Schizaphis graminum (Rondani) and Hippodamia variegata (Goeze) at 27 ± 1 °C, 65 ± 10% RH, and 16:8 (L:D) h. The effect of sublethal concentrations (LC10 and LC30) was estimated by the International Organization for Biological Integrated Control (IOBC). The LC50 values of thiacloprid for H. variegata and S. graminum were 730.3 and 212.7 mg a.i.L−1, respectively. Both tested sublethal concentrations negatively affected the demography of H. variegata and S. graminum. The LC30 treatments had a higher negative effect on demographic parameters of both tested insects compared to the LC10 one. Based on the IOBC classification, the LC10 and LC30 treatments were found to be harmless for H. variegata and slightly harmful for S. graminum. Therefore, thiacloprid can be suggested to be used in cereal fields where S. graminum and its predators are active. [ABSTRACT FROM AUTHOR]

Diet is a fundamental aspect of the ecological niche of amphibians and usually varies intra-specifically in response to extrinsic environmental and intrinsic individual factors. Phenotypic variations among individuals can generate intrapopulation differences in trophic resource use, which could have important ecological and evolutionary implications in amphibian populations. Here, we studied the intrapopulation dietary variation of the frog Pseudopaludicola pusilla in an anthropic savanna of the Colombian Caribbean region, considering the effects of seasonality and sex on the size, amount, prey composition and dietary individual specialization. We collected 44 adult frogs during the dry season and 46 during the rainy season and analyzed their stomach contents to determine their dietary composition. Our results indicate that P. pusilla is a generalist and opportunist predator, feeding mainly on insects of the orders Orthoptera, Coleoptera and Hymenoptera, which were the most important prey categories due to their numeric, volumetric and frequency contributions. We observed seasonal variations regarding volumetric prey composition and the importance value of each prey category in the populational diet. Individuals of P. pusilla consume more prey items during the rainy season and bigger prey during the dry season, but the volume of stomach contents did not vary seasonally. Males and females of P. pusilla consumed a similar number of prey items, but females ingested more voluminous prey and had greater volumes of stomach contents than males. Additionally, we observed a pattern of dietary individual specialization, which was not related to morphological trade-offs and did not differ among seasons. These findings contribute to the understanding of the seasonal dynamics of the use of trophic resources by anurans and the effect of sex on dietary characteristics of P. pusilla, in environments strongly influenced by climatic seasonality. [ABSTRACT FROM AUTHOR]

Habitat complexity plays an important role in structuring species diversity, behaviour and distribution. Furthermore, habitat complexity can mediate the strength of predator-prey interactions through the provision of prey refugia or through enhancing ambush predation. In this study, we use functional responses (FRs) to compare the effect of habitat complexity on resource utilisation between Largemouth Bass Micropterus salmoides and Florida Bass Micropterus floridanus predating upon Mozambique Tilapia Oreochromis mossambicus fry. Treatments for this study were zero and high habitat complexities, with the latter being artificially constructed using plastic strips. Both predator species exhibited a Type II FR in both habitat complexities, with Florida Bass exhibiting significantly higher FR magnitudes, compared with Largemouth Bass under both habitat complexities. Both species experienced dampening of FR magnitudes under high habitat complexity. Florida Bass had persistently lower handling parameters than Largemouth Bass regardless of habitat complexity. While higher habitat complexity may offer prey refugia from Florida Bass, changes in complexity had a negligible effect upon Largemouth Bass predatory efficiency. Measures to enhance natural complexity through system restoration may be a useful conservation measure for endemic fish in rivers invaded by Florida Bass, however, the same mitigation measures may not be as effective for Largemouth Bass. [ABSTRACT FROM AUTHOR]

From September 2015, the deaths of hundreds of pet cats in Croydon, London and the UK have been attributed to the actions of one or more killers. In September 2018, the police operation to catch the 'Croydon cat killer' was called off, with the deaths attributed to the actions of cars and foxes. This paper considers what the case says about our relations with other animals in the city, why we accept some animal deaths as normal, and others unnatural forms of violence. We focus on the concept of 'predation' in media representations, and how predation may mean different things to different audiences. The paper looks at the logic, optics, and politics of predation in turn, meaning the analytical premises, the framing devices that make these narratives visible, and the broader political positions taken by protagonists. The role of the media in promulgating these narratives of predation is central to what we term 'fabulous ecologies', speculating that nonhuman animals inhabit a cultural as well as a physical environment. Narratives of animal killers and animal victims have the potential to make the metropolis more, or less, viable to our nonhuman animal neighbours. [ABSTRACT FROM AUTHOR]

Ball-roller dung beetles of the subfamily Scarabaeinae exhibit two nesting patterns ranging from simple nests (nesting pattern IV) to highly complex nests with parental care (nesting pattern V). Most species of the genus Canthon build a simple nest formed by a single brood ball that is abandoned after oviposition. We studied the nesting behaviour and brood ball architecture of two dung beetle species from South America. Canthon unicolor (Blanchard, 1846) and C. histrio (Le Peletier de Saint-Fargeau & Audinet-and Serville, 1828) construct a shallow nest containing a single brood ball. This brood ball is unique in that it is covered with a thick shield layer made of soil. The shield layer provides to the final brood ball an amorphous external aspect, never described in roller dung beetles. It is less dense than the brood ball layer, and provides, an additional post-ovipositional care. Our results suggest that the nesting behaviour observed in C. unicolor and C. histrio can be considered a new variation of the nesting pattern IV in dung beetles, in which post-ovipositional care through the outer shield layer could increase survival chance of the offspring by protecting them from potential predators, desiccation and a variety of other environmental hazards. [ABSTRACT FROM AUTHOR]

Many animals produce antipredator calls in response to the presence of a predator, which, in some species, can provide information about the distance to predator. Although previous research has shown that several bird species are able to encode information about predator distance in their calls, such information is still lacking for a range of species. Moreover, most previous research has categorised the distance between the caller and the predator in two classes (close and far), but subtle acoustic variation can occur within each distance class. We investigate whether calls given by the Western Australian magpie varied according to predator distance. By presenting a taxidermied predator to a population of magpies at different distances, we found that calls varied according to predator distance from the caller, with more calls being produced when the predator was closer. In addition, we found that calls given in response to a predator nearby are acoustically different from those given in response to the same predator further away. This way of encoding information may allow prey to more efficiently moderate antipredator behaviours according to the level of threat. [ABSTRACT FROM AUTHOR]

This article sets out to investigate the image of China in South Africa's mainstream English-language newspapers in the context of changing dynamics of Sino-SA bilateral relations, and their respective growing ambitions. To do so, this research adopts a corpus-based method to examine discursive mechanism through which China is represented in South African media. Corpus findings transcend the traditional and often oversimplified dichotomy of partner or predator, and recognise the complexities, contradictions, and changing dynamics of Sino-SA relation. Despite increasingly converging visions on matters of continental and global import, chief challenges faced by these two countries are contested interests over issues of BRICS versus African Agenda, weak bilateral political and public trust, and responsible versus irresponsible China. The findings are discussed in relation to China's pursuit of soft power and SA's geopolitical ambitions. [ABSTRACT FROM AUTHOR]