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1.  The replacement of native habitats by monocultures has led to the loss of insect biodiversity, including beetles.2.  In an attempt to minimize this loss, Brazilian legislation requires farmers to conserve a proportion of farmland as a Legal Reserve.3.  In this study, we investigated the decay of similarity in beetle communities of soybean monocultures compared to Legal Reserves.4.  To do this, we studied 77 sample points distributed across the transition zone between the Amazon and Cerrado biomes, with a maximum distance of 625 km between the farthest points.5.  Our results show that the transformation of forest areas into monocultures causes a drastic decrease in beta diversity for both herbivores and predators.6.  This pattern is not observed in Legal Reserves, where the communities are, for the most part, different in a short geographic space.7.  We noted an increase in beta diversity between sites at a shorter distance (200 km) compared with soybean monoculture areas (350 km).8.  In these environments, many species are generalist pests that benefit from the simplified landscape.9.  To verify the relationship between species dissimilarity and geographic distances, we used the Chord‐Normalized Expected Species Shared dissimilarity index, replacing Bray–Curtis due to its robustness in dealing with small samples or subsampling.10. We reinforce the importance of Legal Reserves in conserving beetle biodiversity, emphasizing the need for preserved areas distributed throughout the landscape as they play a crucial role in maintaining beta diversity and preserving ecosystem services in anthropized landscapes. [ABSTRACT FROM AUTHOR]

The presence of predators can induce non‐consumptive effects on prey that result in subsequent changes to prey behaviour and defence. We investigate the interaction between top‐down non‐consumptive effects of various stages of the predator Coccinella septempunctata L.(Coleoptera: Coccinellidae) (larvae and adult) and bottom‐up effects of host nutrition on Plutella xylostella (L.) (Lepidoptera: Plutellidae) oviposition and larval host choice. We also compare the effect of presence of intact predators, predators without mandibles, confined predators and a no predator control treatment on P. xylostella larval growth, survival and herbivory. Host plant nutrition influenced the host choice of adult female P. xylostella; no interaction was observed between bottom‐up host plant nutrition and the presence of C. septempunctata adults or larvae on oviposition or larval host choice by P. xylostella. Predator presence impacted larval feeding and weight gain. The presence of free‐moving C. septempunctata adults without mandibles that could not predate P. xylostella reduced mean leaf consumption by P. xylostella larvae to 1.88 ± 0.21 cm2 and reduced weight gain to 2.12 ± 0.16 mg. Despite differences in leaf damage and larval weight gain, survival remained consistent across the non‐consumptive treatments. Intact C. septempunctata larvae reduced leaf damage and subsequent P. xylostella larval weight gain. The presence of larval predators across the non‐consumptive treatments, however, had no effect on feeding damage or weight gain. Results of our investigation indicate that C. septempunctata causes some non‐consumptive effects on P. xylostella that depend on predator life stage, level of confinement and prey life stage. It is likely that P. xylostella responds to multi‐modal cues in predator detection. [ABSTRACT FROM AUTHOR]

Although large carnivores usually prefer large prey, in some situations, they may shift their predation patterns towards smaller but abundant prey. The jaguar (Panthera onca) is a large carnivore capable of changing its diet according to prey and habitat availability. Here, we assessed the temporal and spatiotemporal interactions between jaguars and their prey in the Maracá‐Jipioca Islands (Northeastern Amazon, Brazil) through camera traps. We assessed overlapping activity patterns and tested for spatiotemporal segregation/avoidance between jaguars and nine potential prey species. We used a time‐to‐encounter approach, which consists in calculating the minimum time between prey and jaguar's detections, and vice versa, for each record of preys' species at a specific camera trap station, which translates into aggregation or avoidance behaviors. We found that these insular jaguars are more active in daylight periods when most of their prey are active and in locations used by species that cannot become nocturnal to avoid predators due to morphology constraints. Four prey species (great egret, white‐tailed deer, muscovy duck, and black‐and‐white tegu) presented moderate activity overlapping with jaguars. Agoutis and white‐tailed deer seek to spatiotemporally segregate from jaguars, although jaguars did not show spatiotemporal aggregation with any of the evaluated prey. Understanding the spatiotemporal dynamics is essential to establish the islands' trophic network composition and structure. This is fundamental information to efficiently allocate efforts for reducing costs and maximizing benefits in managing this population aiming to protect and conserve it, and consequently, the related ecosystems. [ABSTRACT FROM AUTHOR]

Pop-off satellite archival tags (PSATs) have been increasingly deployed on marine megafauna to remotely monitor their movements, behavior, and environmental preferences. These tags have also allowed the occasional novel documentation of ecological interactions, such as predation on tagged animals. A PSAT deployed on a pregnant porbeagle Lamna nasus in the Northwest Atlantic suggests the shark was predated upon in mesopelagic waters near Bermuda. Predation was evident approximately 5 months after tagging based on depth and temperature data transmitted by the PSAT. Four days prior to PSAT pop-off, depth data indicated that the tag continued to descend and ascend in the water column while the temperature remained approximately 5°C above ambient levels, even at several hundred meters in depth, indicating ingestion. Given the location of predation and elevated temperature at depth recorded by the pregnant porbeagle's tag, potential predators include endothermic shark species such as the white shark Carcharodon carcharias and shortfin mako Isurus oxyrhinchus. This is the first evidence of predation on a porbeagle globally and provides novel insight into inter-specific interactions for this large, threatened shark species. [ABSTRACT FROM AUTHOR]

We explore a diffusive predator–prey system that incorporates the fear effect in advective environments. First, we analyze the eigenvalue problem and the adjoint operator, considering Constant-Flux and Dirichlet boundary conditions, as well as Free-Flow boundary conditions. Next, we use the principle of comparison to prove the non-negativity of the solution. Our investigation focuses on determining the direction and stability of spatial Hopf bifurcation, with the generation delay serving as the bifurcation parameter. Additionally, we examine the influence of both linear and Holling-II functional responses on the dynamics of the model. Through these analyses, we gain better understanding of the intricate relationship among advection, predation, and prey response in this system. [ABSTRACT FROM AUTHOR]

Dietary decisions by predators can affect prey abundance and overall food web dynamics. Many predators do not forage on the same prey at the same frequency throughout their lives. Ontogenetic shifts in prey preference are not, however, often accounted for when modeling food web relationships, despite growing literature that suggests that stage specific dietary relationships may be an important consideration when modeling trophic interactions. We investigated the importance of considering size-structure of a predator population with ontogenetic diet shifts in evaluating relationships with prey response using a manipulative experiment with the brown treesnake (Boiga irregularis) in Guam. After removing ~ 40% of the snake population via toxic mammal carrion, we measured the strength of the relationship between snake density and the response of two types of prey (lizards and mammals). We evaluated these relationships based on total population size or division of the population into stage specific size categories based on diet preference predictions. We hypothesized that the density of juvenile snakes would correlate more strongly with lizard detections, while adult snakes would better correlate to rodent detections. We also measured reproductive output following changes in rates of prey detection. As expected by known ontogenetic shifts in dietary preference, explicit stage-based models better predicted shifts in rates of observed prey items than did total predator density for both lizards and mammals. Additionally, rodent detections were predictive of one reproductive pulse from snakes, while lizard detections were not predictive or correlated. Our findings support that consideration of predatory species stage-based dietary preference can be meaningful for understanding food web dynamics, particularly when a predator has a broad diet or one that changes through time. [ABSTRACT FROM AUTHOR]

Recently, certain biological field experiments and research findings have revealed that predators not only reduce prey populations through direct predation (lethal effect) but also indirectly affect the growth rate of prey by inducing fear; these nonlethal effects can be carried over seasons or generations. In this paper, we proposed an autonomous and a nonautonomous Leslie–Gower model incorporating some biological factors such as fear and its carry‐over effects, prey refuge, and nonlinear predator harvesting. In the autonomous model, first, we examined the well‐posedness, positivity solutions, and their boundedness. Also, it is shown that new equilibrium points emerge and disappear with the change in intrinsic growth rate of predator. Further, we compute and analyzed the local and global stability at the interior equilibrium points. Furthermore, Hopf bifurcation and direction and stability of limit cycle at interior equilibrium points are established. Moreover, the sensitivity analysis of the biological parameters is carried out numerically with two statistical methods via Latin hypercube sampling and partial rank correlation coefficients. It was found that at the small values of fear factor, carry‐over effect, and refuge behavior of prey parameters, the autonomous system exhibits oscillatory behavior, whereas for small values of prey birth rate and harvesting effort, the system remains stable. However, when intrinsic growth rate of predator increases from a low value to a higher value, the system shows transition from stability to instability and back to stability. We also explore the effects of seasonal variations in biological parameters in the nonautonomous model. Additionally, we investigate the theoretical existence of positive periodic solutions using the continuation theorem. The influences of seasonal variations in some parameters such as prey's birth rate, fear, and its carry‐over effects; refuge behavior of prey; intrinsic growth rate of predator; and harvesting effort are then numerically investigated. The results reveal the emergence of positive periodic solutions and bursting patterns in the seasonally forced model. [ABSTRACT FROM AUTHOR]

Daphnia (Crustacea: Cladocera) has been frequently used as a model taxon for studying prey antipredator defences. Among numerous representatives of this genus, there are several taxa within the subgenus Daphnia (Ctenodaphnia) with a morphological innovation unique for these cladocerans, a head plate. In some populations, the margin of this anterior projection of carapace into the head shield is adorned with a remarkable ‘crown of thorns’, which has been shown to be an antipredator adaptation against tadpole shrimps (Notostraca). This structure is phenotypically plastic, dependent on the presence of these omnivorous crustaceans in the respective water bodies. We aimed to evaluate the monophyly of Eurasian ‘crowned’ Daphnia species (i.e., those forming the ‘crown of thorns’ under some circumstance) based on genomic phylogenies and morphology. For this study, we have individually sequenced the genomes of five daphniids, four representing taxa able to form ‘crowns’ (two specimens of different clades of the D. (C.) atkinsoni complex and two specimens of D. (C.) triquetra from distant populations), and D. (C.) mediterranea distantly related to D. (C.) atkinsoni that lacks the head plate. We analysed them along with genomes obtained from GenBank, focusing on either full mitochondrial or partial nuclear datasets (BUSCO). Our main hypothesis on a monophyly of all ‘crowned’ daphnids was rejected. Genomic analyses confirmed existence of two independent lineages able to express this phenotypic trait in the Palaearctic: (1) a monophyletic D. (C.) atkinsoni s. lat. and (2) D. (C.) triquetra, formally redescribed here. These lineages form a well‐supported clade together with several other species lacking a head plate (including D. (C.) mediterranea). Genomic analyses indicate that D. (C.) atkinsoni s. lat. is closely related to D. (C.) tibetana; mitochondrial markers also suggest a close relationship of D. (D.) triquetra with D. (C.) studeri, both D. (C.) tibetana and D. (C.) studeri, are lacking this morphological feature. Molecular clock estimated the time of the differentiation of the major clade containing both ‘crowned Daphnia’ to the Late Mesozoic, confirming an antiquity of the head plate as antipredator defence. [ABSTRACT FROM AUTHOR]

This study explored how increased water turbidity in open-aquaculture ponds as a result of enhanced fertilization influences piscivorous bird assemblages and predation pressure on fish. Fertilization treatments were applied to 24 earth-bottom ponds, and bird assemblages, visitation frequencies, diversities and predation rate responses were compared at species richness and across four functional group scales during six months. Bird visitation frequency, species richness and functional diversity increased around unfertilized ponds, especially for large wading birds. Fertilization and bird species richness were each negatively related to bird predation rate, whereas functional diversity was positively associated with predation rate regardless of pond fertilization. Furthermore, predation rate reduced in response to pairwise interactive effects of fertilization and functional group identity, but increased with fertilization's respective interaction with functional diversity and visitation frequency. Contrastingly, species richness showed no interactive effect with fertilization or visitation rate. Thus, in applying enhanced pond water fertilization as a mitigation measure for controlling and tracking damage impact caused by piscivorous birds, it is potentially more beneficial to adopt a bird functional rather than species-based approach, given the observed higher sensitivity of functional diversity in predicting predation rates. The findings present novel, farmer-centered and affordable strategies for piscivorous problem-bird control toward sustainable aquaculture. [ABSTRACT FROM AUTHOR]

Mosquitoes transmit viruses that affect public health in tropical regions. Identifying factors that influence their fitness can help control mosquito-borne diseases. We investigated the impacts of predation risk effects, from a fish predator, and food availability on the oviposition behavior of Aedes aegypti. We hypothesize that predation risk and food availability interactively affect Ae. aegypti oviposition. Gravid Ae. aegypti females were offered oviposition sites with all possible combinations of predation risk (with vs. without predator cues) and food availability (low vs. high). We found a significant interaction between predation risk and food availability. The magnitude of oviposition and the probability of egg laying in high food availability treatments exceeded the values of low food availability treatments, but only in treatments without predation risk. Predation risk critically modulated the effects of food availability on the oviposition of Ae. aegypti. This study demonstrates the interplay between predation risk and food availability in controlling mosquito-borne diseases. [ABSTRACT FROM AUTHOR]

ABSTRACT Through killing and instilling fear in their prey, large terrestrial carnivores shape the structure and function of ecosystems globally. Most large carnivore species have experienced severe range and population declines due to human activities, and many are now threatened with extinction. Consequently, the impacts of these predators on food webs have been diminished or lost completely from many ecosystems. Kill rates provide a fundamental metric for understanding large carnivore ecology and assessing and comparing predation within and across ecological communities. Our systematic review of large terrestrial mammalian carnivore kill rates reveals significant positive geographic (North America, Europe, and Africa) and taxonomic (grey wolf Canis lupus, puma Puma concolor, lion Panthera leo, and Eurasian lynx Lynx lynx) bias, with most studies apparently motivated by human–carnivore conflict over access to ungulate prey and wildlife management objectives. Our current understanding of the behaviour and functional roles of many large carnivore species and populations thus remains limited. By synthesising and comparing kill rates, we show that solitary carnivores (e.g. brown bears Ursus arctos and most felids) exhibit higher per capita kill rates than social carnivores. However, ungulate predation by bears is typically limited to predation of neonates during a short period. Lower per capita kill rates by social carnivores suggests group living significantly reduces energetic demands, or, alternatively, that group‐living carnivores defend and consume a greater proportion of large prey carcasses, or may acquire more food through other means (e.g. scavenging, kleptoparasitism) than solitary hunters. Kill and consumption rates for Canidae – measured as kilograms of prey per kilogram of carnivore per day – are positively correlated with body mass, consistent with increasing energy costs associated with a cursorial hunting strategy. By contrast, ambush predators such as felids show an opposite trend, and thus the potential energetic advantage of an ambush hunting strategy for carnivores as body mass increases. Additionally, ungulate kill rates remain relatively constant across solitary felid body sizes, indicative of energetic constraints and optimal foraging. Kill rate estimates also reveal potential insights into trophic structuring within carnivore guilds, with subordinate carnivores often killing more than their larger counterparts, which may be indicative of having to cope with food losses to scavengers and dominant competitors. Subordinate carnivores may thus serve an important role in provisioning food to other trophic levels within their respective ecosystems. Importantly, kill rates also clarify misconceptions around the predatory behaviour of carnivores (e.g. spotted hyaenas Crocuta crocuta and wolverines Gulo gulo are often considered scavengers rather than the capable hunters that they are) and thus the potential impacts of various carnivore species on their ecological communities. Despite the importance of kill rates in understanding predator–prey interactions, their utility is not widely recognised, and insufficient research limits our ability to fully appreciate and predict the consequences of modified predation regimes, justify current management actions affecting carnivores, or inform effective conservation measures. Together with other important research on predator–prey interactions, robust kill rate studies that address the research deficiencies we highlight will provide a deeper understanding of the foraging behaviours and potential ecosystem impacts of many of the world's carnivores, thus aiding effective conservation and management actions. [ABSTRACT FROM AUTHOR]

In migratory insects performing multigenerational migration, such as the painted lady butterfly Vanessa cardui, successive generations face a wide variety of predator communities and may be subject to different predation risks. Here, we analyze the pattern of wing damage of over 2000 butterflies to investigate, for the first time, the risk of predation of adult painted ladies across a latitudinal range of ca 3500 km extending from the northern Mediterranean through the Maghreb to sub‐Saharan West Africa. Large number of butterflies showed substantial wing damage attributable to failed attacks, with birds, mantids and lizards being the most likely predators. The risk of attack increased towards the equator, even after controlling for wing wear. In addition, there was a strong effect of butterfly size on predation risk, with larger butterflies facing a higher risk compared to their smaller counterparts, and clear evidence that females suffered more attacks than males. Although size is a major factor, latitude was a stronger predictor of predation risk across the migratory system, as evidenced by greater wing damage in butterflies at lower latitudes, even though their size notably decreased. These results raise an interesting evolutionary conflict, with a tradeoff between size and predation risk, as larger butterflies are likely to be more fecund and efficient in migratory flight but, at the same time, more vulnerable to predation. [ABSTRACT FROM AUTHOR]

Comparative studies suggest remarkable similarities among food webs across habitats, including systematic changes in their structure with diversity and complexity (scale-dependence). However, historic aboveground terrestrial food webs (ATFWs) have coarsely grouped plants and insects such that these webs are generally small, and herbivory is disproportionately under-represented compared to vertebrate predator–prey interactions. Furthermore, terrestrial herbivory is thought to be structured by unique processes compared to size-structured feeding in other systems. Here, we present the richest ATFW to date, including approximately 580 000 feeding links among approximately 3800 taxonomic species, sourced from approximately 27 000 expert-vetted interaction records annotated as feeding upon one of six different resource types: leaves, flowers, seeds, wood, prey and carrion. By comparison to historical ATFWs and null ecological hypotheses, we show that our temperate forest web displays a potentially unique structure characterized by two properties: (i) a large fraction of carnivory interactions dominated by a small number of hyper-generalist, opportunistic bird and bat predators; and (ii) a smaller fraction of herbivory interactions dominated by a hyper-rich community of insects with variably sized but highly specific diets. We attribute our findings to the large-scale, even resolution of vertebrate, insect and plant guilds in our food web. This article is part of the theme issue 'Connected interactions: enriching food web research by spatial and social interactions'. [ABSTRACT FROM AUTHOR]

Alarm calls produced by basal prey have a well-known informative value. In multi-predator communities, mesopredators, when faced with top predators, may emit alarm calls that could inform basal prey about their lowered predation risk. To test this unexplored possibility, we conducted one field and one mesocosm experiment in which we simulated alarm and non-alarm calls from little owls (Athene noctua) as mesopredators and measured their effects on grasshoppers as prey of little owls but not of top predators. In the field experiment, we found that grasshopper species were significantly more abundant in patches where we simulated either the presence of scared little owls (alarm treatment) or no owls (control treatment) compared to patches where the presence of non-scared little owls (non-alarm treatment) was simulated. In the mesocosm experiment, locusts (Locusta migratoria) moved significantly more to exposed areas when we simulated the presence of scared little owls (alarm treatment) or of a granivorous bird (control treatment), while they moved to sheltered areas when we simulated the presence of non-scared owls (non-alarm treatment). These results show that prey could cue on predators' calls to assess their predation risk and make decisions, revealing unprecedented potential ecological consequences of alarm calls in invertebrate communities. [ABSTRACT FROM AUTHOR]

The bigmouth buffalo Ictiobus cyprinellus (Catostomidae) is a freshwater fish native to North America that is known for its longevity. During the 1970s, the bigmouth buffalo was recorded as declining in Canada, Minnesota, and North Dakota and became a protected species in Canada. In the USA, population declines are exacerbated by wasteful recreational bowfishing, lack of fisheries management, and overall lack of knowledge. However, recent studies have revealed the exceptional lifespan of bigmouth buffalo, their negligible senescence, slow growth, delayed maturity, and episodic recruitment. Yet little is known about the spawning phenology of bigmouth buffalo, nor their age demographics in east central Minnesota. In this 2021–2023 study of bigmouth buffalo from Rice Lake National Wildlife Refuge we found that 99.7% (389 of 390) of the extant population hatched prior to 1972 despite annual spawning in Rice Lake. Moreover, recruitment success declined significantly since water control measures were established (1953). We found males arrive to spawning grounds with females but depart later, that both the midpoint and duration of spawn significantly vary across years, and that more massive females of the same age range invest disproportionately more in ovaries. Extensive post-spawn seining revealed bigmouth buffalo young-of-the-year in low numbers, but by mid-to-late summer they were no longer evident having likely succumbed to predation. Overall, these findings thoroughly reveal one of the oldest populations of vertebrate currently known (median age of 79 years as of 2024) and expose the stark vulnerability of a bigmouth buffalo population for which substantial recruitment has not occurred for more than six decades. Multiple lines of evidence indicate that the long-lived bigmouth buffalo is vulnerable, that a precautionary approach is immediately needed, and that the unlimited and unregulated kill-fishery be closed. [ABSTRACT FROM AUTHOR]

Group living has well-known costs and benefits. Large groups may experience greater competition for resources, while simultaneously benefit from reduced risk through predator dilution. When there is a tradeoff between forage acquisition and predation risk, the ability to congregate into large groups may unlock access to previously unavailable habitat with high risk of predation, thereby increasing forage available to the population. We evaluated whether forage availability increased with population size and how it was mediated through changes in group size. There was a tradeoff between forage availability and predation risk. Larger groups used areas with more forage biomass and greater predation risk than smaller groups. Group size also increased with population abundance, meaning bighorn sheep used gentler terrain and areas with more forage biomass at greater population abundance. Group size functionally increased carrying capacity by yielding access to more resources for growing populations of gregarious ungulates. [ABSTRACT FROM AUTHOR]

Marine ecosystems are experiencing growing pressure from multiple threats caused by human activities, with far‐reaching consequences for marine food webs. Determining the effects of multiple stressors is complex, in part, as they can affect different aspects of biological organisation (behaviour, individual traits and demographic rates). Determining the combined effects of stressors, through different biological pathways, is key to predict the consequences for the viability of populations threatened by global change.Due to their position in the food chain, top predators such as seabirds are considered more sensitive to environmental changes. Climate change is affecting the prey resources available for seabirds, through bottom‐up effects, while organic pollutants can bioaccumulate in food chains with the greatest impacts on top predators. However, knowledge of their combined effects on population dynamics is scarce.Using a path analysis, we quantify the effects of climate change and pollution on the survival of adult great black‐backed gulls, both directly and through effects of individuals' body mass.Warmer ocean temperatures in gulls' winter foraging areas in the North Sea were correlated with higher survival, potentially explained by shifts in prey availability associated with global climate change. We also found support for indirect negative effects of organochlorines, highly toxic pollutants to seabirds, on survival, which acted, in part, through a negative effect on body mass.The results from this path analysis highlight how, even for such long‐lived species where variance in survival tends to be limited, two stressors still have had a marked influence on adult survival and illustrate the potential of path models to improve predictions of population variability under multiple stressors. [ABSTRACT FROM AUTHOR]

Research Highlight: Bourbour et al., 2024. Feeding en route: Prey availability and traits influence prey selection by an avian predator on migration. Journal of Animal Ecology. Diet selection plays a key role in the eco‐evolutionary dynamics of animals, exhibiting substantial variability across species, environments and seasons. The complex interplay between movement capability, hunting strategies, habitat use, prey traits and availability shapes the foraging patterns of avian predators. However, detailed information on how these birds exploit their extensive territories remains limited. In this study, Bourbour et al. utilised a novel integration of eDNA metabarcoding and citizen science to explore predator–prey interactions between migrating sharp‐shinned hawks (Accipiter striatus) and an ephemeral avian prey community along North America's Pacific flyway. The research identified 1396 detections from the diet (65 species) of 588 migrating sharp‐shinned hawks. Hawks' diet composition correlated with prey abundance indices sourced from the eBird database throughout the migration season, highlighting the significant impact of prey availability—shaped by migration tendency, flocking behaviour, and habitat—on raptor‐songbird interactions. Notably, the study also found significant differences in prey size between male and female hawks, indicating that sexual dimorphism has led to diverse foraging strategies during migration. These findings underscore the potential of combining eDNA metabarcoding with citizen science to deepen our understanding of the foraging ecology of highly mobile and wide‐ranging birds, as well as to monitor complex and vast ecosystems. [ABSTRACT FROM AUTHOR]

Parents routinely encounter stress in the ecological environment that can affect offspring development (transgenerational plasticity: TGP); however, parents' interactions with conspecifics may alter how parents respond to ecological stressors.During social buffering, the presence of conspecifics can reduce the response to or increase the speed of recovery from a stressor. This may have cascading effects on offspring if conspecifics can mitigate parental responses to ecological stress in ways that blunt the transmission of stress‐induced transgenerational effects.Here, we simultaneously manipulated both paternal social isolation and experience with predation risk prior to fertilisation in threespined stickleback (Gasterosteus aculeatus). We generated offspring via in‐vitro fertilisation to allow us to isolate paternal effects mediated via sperm alone (i.e. in the absence of paternal care). If social buffering mitigates TGP induced by paternal exposure to predation risk, then we expect the transgenerational effects of predation exposure to be weaker when a conspecific is present compared to when the father is isolated.Offspring of predator‐exposed fathers showed reduced anxiety‐like behaviour and tended to be captured faster by the predator. Fathers who were socially isolated also had offspring that were captured faster by a live predator, suggesting that paternal social isolation may have maladaptive effects on how offspring respond to ecological stressors. Despite additive effects of paternal social isolation and paternal predation risk, we found no evidence of an interaction between these paternal treatments, suggesting that the presence of a conspecific did not buffer fathers and/or offspring from the effects of predation risk.Our results suggest that socially induced stress is an important, yet underappreciated, mediator of TGP and can elicit transgenerational effects even in species that do not form permanent social groups. Future studies should therefore consider how the parental social environment can affect both within and trans‐generational responses to ecological stressors. [ABSTRACT FROM AUTHOR]

During animal migration, ephemeral communities of taxa at all trophic levels co‐occur over space and time. The interactions between predators and prey along migration corridors are ecologically and evolutionarily significant. However, these interactions remain understudied in terrestrial systems and warrant further investigations using novel approaches.We investigated the predator–prey interactions between a migrating avivorous predator and ephemeral avian prey community in the fall migration season. We tested for associations between avian traits and prey selection and hypothesized that prey traits (i.e. relative size, flocking behaviour, habitat, migration tendency and availability) would influence prey selection by a sexually dimorphic raptor on migration.To document prey consumption, we sampled trace prey DNA from beaks and talons of migrating sharp‐shinned hawks Accipiter striatus (n = 588). We determined prey availability in the ephemeral avian community by extracting weekly abundance indices from eBird Status and Trends data. We used discrete choice models to assess prey selection and visualized the frequency of prey in diet and availability on the landscape over the fall migration season.Using eDNA metabarcoding, we detected prey species on 94.1% of the hawks sampled (n = 525/588) comprising 1396 prey species detections from 65 prey species. Prey frequency in diet and eBird relative abundance of prey species were correlated over the migration season for top‐selected prey species, suggesting prey availability is an important component of raptor‐songbird interactions during fall. Prey size, flocking behaviour and non‐breeding habitat association were prey traits that significantly influenced predator choice. We found differences between female and male hawk prey selection, suggesting that sexual size dimorphism has led to distinct foraging strategies on migration.This research integrated field data collected by a volunteer‐powered raptor migration monitoring station and public‐generated data from eBird to reveal elusive predator–prey dynamics occurring in an ephemeral raptor‐songbird community during fall migration. Understanding dynamic raptor‐songbird interactions along migration routes remains a relatively unexplored frontier in animal ecology and is necessary for the conservation and management efforts of migratory and resident communities. [ABSTRACT FROM AUTHOR]

The transport of plankton by highly dynamic (sub)mesoscale currents—often associated with fronts and eddies—shapes the structure of plankton communities on the same time scales as biotic processes, such as growth and predation (days–weeks). The resulting biophysical couplings generate heterogeneities in their finescale distributions (1–10 km), or "patchiness." Here, we test the hypothesis that cross‐frontal plankton patchiness at a front found 200–250 km offshore in the California Current System was influenced by wind‐driven upwelling conditions upstream of the front. We show that in situ Eulerian measurements (cross‐frontal transects) can be interpreted in a Lagrangian framework by using satellite‐derived current velocities to trace water parcels backward in time to their coastal origins. We find that the majority of the water parcels sampled at this front originated along the central California coast during different episodic wind‐driven upwelling pulses and followed various trajectories before converging temporarily at the front. In response to nutrient injections at the coast, plankton communities transformed during their journeys from the coast to the sampling zone, with a succession of phytoplankton and zooplankton blooms. The cross‐frontal sampling captured the convergence of these distinct water parcels at different points in their biological histories, which resulted in the observed spatial patchiness. Our results suggest that identifying the processes controlling frontal plankton communities requires understanding them in the context of their spatial and temporal histories. In particular, Lagrangian approaches should be more widely applied to understand critical ecological patterns in highly dynamic systems. [ABSTRACT FROM AUTHOR]

A species' expansion beyond the native range is often assumed to be associated with an increased dietary niche breadth. However, empirical evidence remains limited due to a scarcity of studies comparing both the parental and invaded ranges. Here, we test the trophic niche expansion hypothesis by examining stable isotopes and functional morphology across native (NW Black Sea) and invaded (SE Baltic Sea) ranges of two amphipods, Dikerogammarus villosus and Pontogammarus robustoides, originating from the Ponto‐Caspian region—a major source of species invading Holarctic inland waters. Stable isotopes revealed that both species underwent a marked dietary niche contraction by becoming less carnivorous in the invaded range. This dietary shift was morphologically mirrored by an overall reduction of functional traits related to predation. The magnitude of dietary and morphological change was greater in D. villosus. Our findings indicate that previous experimental reports of aggressive predation in D. villosus reflect opportunistic foraging and align with local stable isotope studies which generally indicate a low trophic position. We conclude that Ponto‐Caspian species can undergo rapid dietary changes outside the native range, and that dietary niche expansion is not a prerequisite for successful non‐native establishment. [ABSTRACT FROM AUTHOR]

Cleaning symbiosis of the bluestreak cleaner wrasse, Labroides dimidiatus (Labridae), is a well-known example of mutualism in coral reefs. The cleaner wrasse is characterized by its bluish body colour with black stripes, and the false cleanerfish, Aspidontus taeniatus (Blenniidae), mimics those characteristics precisely. Cleaner fish mimicry is believed to evolve as an aggressive mimicry to bite the fins of deceived fishes; however, protective mimicry to reduce predation risk has not been examined sufficiently. Here, we tested the effect of protective mimicry through field observations and aquarium experiments. Field observations revealed that false cleanerfish were occasionally attacked by piscivorous lizardfishes (Synodontidae). In the aquarium experiments, ambushing predators, the honeycomb grouper, Epinephelus merra (Serranidae), which did not show predatory behaviour to false cleanerfish in the field, attacked the cleaner wrasse (model), the false cleanerfish (mimic), and the lance blenny, Aspidontus dussumieri (non-mimic). When a shelter was provided in the tank, the false cleanerfish and the lance blenny immediately hid inside the shelter for a considerable duration to escape from the predator. These results suggest that cleaner fish coloration does not always decrease predation risks, and our conclusions support the possibility that this mimicry evolved primarily as aggressive mimicry. [ABSTRACT FROM AUTHOR]

The sugarcane caterpiliar (Diatraea Saccharalis) is one of the most important pests of sugarcane plantations. Studies suggest that the Cotesia wasp Flavipes can control the population of the Diatraea Caterpillar Saccharalis, thus avoiding economic damage. This paper considers the application of optimal control in a ratio-dependent predator-prey system, where the caterpillar Diatraea saccharalis is the prey and the Cotesia wasp Flavipes. The linearization of the ratio-dependent model made it possible to reduce the problem of obtaining optimal control to the problem of control synthesis for linear systems with a quadratic functional. Numerical simulations showed that the proposed control is efficient in stabilizing the system at a desired point below the critical concentration, thus allowing it to minimize the level of economic damage. [ABSTRACT FROM AUTHOR]

This paper presents the observations of predation by the grouper Epinephelus quoyanus on sea turtle hatchlings in Chagar Hutang bay, Redang Island, Malaysia. Two of the eight collected specimens had hatchlings in their guts, whereas the remaining specimens had empty stomachs. This field report provides an in‐depth understanding of the E. quoyanus diet and new insights into its feeding behavior. [ABSTRACT FROM AUTHOR]

Free ranging-dogs are being recognized as a potential threat for native wildlife around the globe. They interact with native wildlife at multiple levels, ranging from predation, competition, acting as a reservoir for diseases and hybridization with the native carnivores. We have recorded cases that focus on interactions of dogs with wildlife in and around Ranthambhore Tiger Reserve (RTR). Between 2017–2020, we collected data on free-ranging dogs interacting with native wildlife of RTR. We classified the interactions into two categories: resource acquisition and predation. Based on our results we propose that dogs in rural settings around wildlife reserves can cause more resource competition for the existing carnivore scavenging guild resulting in reduced biomass consumption for the native scavengers. When present in large numbers, they can have a negative interaction with native wildlife through predation and harassment. To understand how dogs can pose threats to the native wildlife, there is a need for an extensive study on the ecology of dogs around wildlife reserves, pertaining to their feeding ecology and their raging behaviour. [ABSTRACT FROM AUTHOR]

Information transmission among species is a fundamental aspect of natural ecosystems that faces significant disruption from rapidly growing anthropogenic sensory pollution. Understanding the constraints of information flow on species' trophic interactions is often overlooked due to a limited comprehension of the mechanisms of information transmission and the absence of adequate analytical tools. To fill this gap, we developed a sensory information‐constrained functional response (IFR) framework, which accounts for the information transmission between predator and prey. Through empirical evaluation, the IFR provided a biologically grounded explanation for the systematic variation of functional responses. Specifically, it posits that the variation of different functional‐response shapes, associated with community stability, is attributable to limitations in sensory information transmission among species. This not only deepens our mechanistic understanding of species interactions but also elucidates how anthropogenic activities are reshaping species interactions and community dynamics by disrupting information exchange through sensory pollution. [ABSTRACT FROM AUTHOR]

Fear prompts prey to adopt risk-averse behaviors, such as reduced foraging activity, increased vigilance, and avoidance of areas with high predator presence, which affects its reproduction. In a real scenario, a population requires a minimum density to avoid extinction, known as an Allee threshold. In light of these biological factors, we propose a predator–prey model with (i) a fear effect in a prey population, (ii) an Allee effect in a predator population, and (iii) a non-constant attack rate that modifies the functional response. We ensured the non-negativity and boundedness of the solutions and examined the local and global stability status for each existing steady state solutions. We investigated some deep dynamical properties of the system by varying different parameters, such as cost of fear in prey and strength of the Allee effect in predators and their mortality rate. In codimension one bifurcations, we observed saddle node, Hopf, homoclinic, and coalescence of two limit cycles. Additionally, codimension two bifurcations were observed, including Bautin and Bogdanov Takens bifurcations. To provide a clearer understanding of these bifurcations, we conducted biparametric analysis involving the fear and Allee parameters, as well as the fear parameter and predator mortality rate. Our investigation shows that cost of fear and strength of Allee strongly influences the survival status of the predator. Furthermore, bistability and tristability reveal that the survival and extinction of predator are dependent on the initial population level. Numerical simulations and graphical illustrations are provided to support and validate our theoretical findings. [ABSTRACT FROM AUTHOR]

Incorporating a weak Allee effect in a two-dimensional biological model in ℜ 2 , the study delves into the application of bifurcation theory, including center manifold and Ljapunov–Schmidt reduction, normal form theory, and universal unfolding, to analyze nonlinear stability issues across various engineering domains. The focus lies on the qualitative dynamics of a discrete-time system describing the interaction between prey and predator. Unlike its continuous counterpart, the discrete-time model exhibits heightened chaotic behavior. By exploring a biological Mmdel with linear functional prey response, the research elucidates the local asymptotic properties of equilibria. Additionally, employing bifurcation theory and the center manifold theorem, the analysis reveals that, for all α 1 (i.e., intrinsic growth rate of prey), ð 1 ˙ (i.e., parameter that scales the terms y n), and m (i.e., Allee effect constant), the model exhibits boundary fixed points A 1 and A 2 , along with the unique positive fixed point A ∗ , given that the all parameters are positive. Additionally, stability theory is employed to explore the local dynamic characteristics, along with topological classifications, for the fixed points A 1 , A 2 , and A ∗ , considering the impact of the weak Allee effect on prey dynamics. A flip bifurcation is identified for the boundary fixed point A 2 , and a Neimark–Sacker bifurcation is observed in a small parameter neighborhood around the unique positive fixed point A ∗ = (m ð 1 ˙ − 1 , α 1 − 1 − α 1 m ð 1 ˙ − 1). Furthermore, it implements two chaos control strategies, namely, state feedback and a hybrid approach. The effectiveness of these methods is demonstrated through numerical simulations, providing concrete illustrations of the theoretical findings. The model incorporates essential elements of population dynamics, considering interactions such as predation, competition, and environmental factors, along with a weak Allee effect influencing the prey population. [ABSTRACT FROM AUTHOR]

In this paper, a mathematical analysis of fractional order fishery model with stage structure for predator is carried out under the background of prey refuge and protected area. First, it is demonstrated that the solution exists and is unique. The paper aims to analyze predator-prey dynamics in a fishery model through the application of fractional derivatives. It is worth emphasizing that we explicitly examine how fractional derivatives affect the dynamics of the model. The existence of each equilibrium point and the stability of the system at the equilibrium point are proved. The theoretical results are proved by numerical simulation. Alternatively, allocate harvesting efforts within an improved model aimed at maximizing economic benefits and ecologically sustainable development. The ideal solution is obtained by applying Pontryagin's optimal control principle. A large number of numerical simulations show that the optimal control scheme can realize the sustainable development of the ecosystem. [ABSTRACT FROM AUTHOR]

The article "Reframing African ecology: Challenging bias and celebrating contribution" discusses the bias and marginalization faced by African ecological studies in Western discourse and scientific research. It highlights the rich scientific heritage of African ecosystems and the contributions of both native and foreign scientists. The article emphasizes the need for collaborative efforts and inclusive scholarship to challenge biases and elevate African ecological research on a global scale. It also explores the significant role of African ecology in shaping our understanding of ecological processes, conservation biology, and other scientific disciplines. The article provides examples of groundbreaking research in Africa, such as Dr. Christiaan N. Barnard's heart transplant and Louis Leakey's work in paleoanthropology. It also discusses the contributions of African ecosystems to evolutionary biology, genetics, and conservation science. The article concludes by calling for a more transparent and open discussion in journals like the African Journal of Ecology to promote and recognize African talent in the international scientific community. The article discusses the importance of African ecological research in understanding various topics such as predation, population dynamics, optimal foraging theory, resource stoichiometry, and the composition of food webs. It also highlights the significance of studying bushmeat and its impact on conservation, public health, and local communities. The emergence of zoonotic diseases like Ebola and COVID-19 has further emphasized the need for interdisciplinary research in wildlife ecology, epidemiology, and socio-cultural studies. The article acknowledges the challenges faced in conducting ecological research in Africa, including logistical [Extracted from the article]

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]

Simple Summary: Macaw and parrot populations are declining because of a combination of habitat loss and capture for the illegal trade. As a result, IUCN Red List data suggest many are candidates for captive-based conservation efforts. Unfortunately, when captive-raised parrots are released, many fly off and get lost in the landscape or get killed by predators, making it difficult to establish new populations. Previous research suggests that pet parrots trained using free flight methods can form good flocks in flight, avoid predators, and navigate well, all skills that should help them survive in the wild. Here, we conduct a small-scale, proof-of-concept study using free flight methods and three already trained adults in the release of six captive-bred Blue-and-yellow Macaws in southeastern Brazil. All six released birds stayed together and remained near the release site, avoided predators, learned to feed themselves, and survived without supplemental feeding for over one year. One bird was captured and briefly held by local people but was recovered and rereleased and is doing well. This work suggests that free flight training can help captive-raised parrots survive release into the wild and make it easier to establish new populations of parrots and macaws in areas where they have gone extinct. As habitat loss and other threats accelerate, ecological restoration and reintroduction science are becoming progressively more important. The psittacines are among the most endangered bird groups and are prime candidates for restoration through reintroduction. Unfortunately, post-release survival of captive-raised animals is often quite low because, in part, of high predation rates, low site fidelity, poor flight ability, and low flock cohesion. Current best practices in parrot release hold the birds in captivity for a year or more and include distinct methods to address each of these challenges. Here, we conduct a small-scale, proof-of-concept study using free flight methods and human-socialized trained adult birds to hand raise and release a group of six fledgling Blue-and-yellow Macaws in their historical range in southeastern Brazil. All six released birds showed strong flock cohesion and fidelity to the release site, avoided predation, and survived without supplemental feeding for over one year. One bird was captured by local people but was recovered and rereleased and it has reintegrated into the group and is still alive and doing well. The human-socialized trained adult birds modeled both desirable behaviors (flocking, foraging, reacting to predators) and undesirable behaviors and they were returned to captivity before the conclusion of this study. Our study suggests that free flight training has great potential to help captive-raised young attain a broad array of vital skills needed for survival post-release. [ABSTRACT FROM AUTHOR]

Livestock farming has been a practice of great importance for the evolution of civilization, not only influencing social, economic, and cultural aspects at a global level, but also food, the economy, and sustainability, especially in developing countries, where it generates significant pressure on natural resources and biodiversity. In this context, conflict arises between wildlife, mainly top predators, and livestock farmers. Despite the efforts of different communities to implement measures against predation, the conflict continues to increase. In Latin America, the livestock sector is growing at a much higher rate than in the rest of the world, particularly in Chile, where around a third of agricultural production units use livestock as their main source of livelihood. To understand the factors influencing the behavior of goat farmers when adopting measures, we applied a hurdle model with social, spatial, economic, and productive information to assess the decision to adopt measures and the intensity of the adoption of such practices. To perform this, we used data from a survey, administered in 2014 to 476 farmers located in the three provinces of the Coquimbo Region. Our dependent variable was defined by six measures: a protection dog, night confinement of the herd, supervised grazing, anti-carnivore corral, the death or capture of the predator, and repelling the predator. The adoption decision, as well as the intensity of adoption, were influenced by the location, household size, the type of livestock, the income generated by the livestock, health management, and access to technical advice. The decision to adopt measures was influenced by the production system and whether it was self-sustaining, while the intensity of adoption was influenced by herd size and the number of losses due to predation. The results showed the importance of developing and adjusting livestock support initiatives in the study area, including those that could be created, based on differentiated measures according to the profiles of farmers in the territory. [ABSTRACT FROM AUTHOR]

The impact of global changes on populations may not be necessarily uniform across a species' range. Here, we aim at comparing the phenotypic and transcriptomic response to warming and an invasive predator cue in populations across different geographic scales in the damselfly Ischnura elegans. We collected adult females in two ponds in southern Poland (central latitude) and two ponds in southern Sweden (high latitude). We raised their larvae in growth chambers and exposed them to combination of temperature and a predator cue released by the crayfish Orconectes limosus. When larvae reached the prefinal larval stage, they were phenotyped for traits related to growth and size and collected for a gene expression analysis. High‐latitude populations exhibited greater phenotypic and transcriptomic variation than central‐latitude populations. Across latitudes and ponds, temperature generally increased growth rate and the predator cue decreased mass, but the effects of temperature were also pond‐specific. Comparison of the transcriptomic profiles revealed a greater overlap in the response to temperature across latitudes and ponds, especially for pathway‐related oxidative stress and sugar and lipid metabolism. The transcriptomic response to a predator cue and to the interaction temperature × predator cue was more pond‐specific and overlapped only for few genes and pathways related to cuticle, development and signal transduction. We demonstrated that central‐ and high‐latitude populations may partially respond through similar mechanisms to warming and, to a lower extent to a predator cue and to the interaction temperature × predator cue. For the predator cue and the interaction, the large fraction of ponds‐specific genes suggests local adaptation. We show that high‐latitude populations were generally more plastic at the phenotypic and transcriptomic level and may be more capable to cope with environmental changes than their central‐latitude counterparts. [ABSTRACT FROM AUTHOR]

Transparency is an intuitive form of concealment and, in certain butterflies, transparent patches on the wings can contribute to several distinct forms of camouflage. However, perhaps paradoxically, the largely transparent wings of many clearwing butterflies (Ithomiini, Nymphalidae) also feature opaque, and often colorful, elements which may reduce crypsis. In many instances, these elements may facilitate aposematic signaling, but little is known of how transparency and aposematism may interact. Here, we used field predation trials to ask two main questions regarding camouflage and signaling in Ithomiini clearwings. In Experiment 1, we focused on camouflage to ask where being transparent may have an advantage over being opaque. We predicted that, as a single opaque pattern can only match a limited range of backgrounds, transparent wings would offer more effective concealment, and experience lower predation risk, over a wider range of backgrounds colors (i.e., green vs. brown substrates) and behaviors (i.e., perched vs. flying) than opaque wings. In Experiment 2, we focused on the effect conspicuous opaque colors may have on clearwing survival. We predicted that although salient signals may increase detectability, those commonly associated with toxic Ithomiini clearwings would not increase predation risk. Both experiments were conducted among educated predators within the natural range of Ithomiini clearwings and we found predation rates to be very low. In Experiment 1, we found some marginal evidence to suggest that opaque, but not transparent, butterflies may suffer increased predation during flight, whereas in Experiment 2, we found equal survival across all model prey types regardless of coloration. Taken together we suggest that any loss of camouflage due to conspicuous coloration may be compensated by aversive signaling, and that educated predators may broadly generalize across a wide range of known and novel clearwing phenotypes. [ABSTRACT FROM AUTHOR]

Carnivore guilds are charismatic and have vital and irreplaceable roles in their native ecosystems, yet many of these species are threatened and remain understudied. Borneo is a biodiversity hotspot that hosts a rich diversity of endemic wildlife but is threatened by deforestation and habitat loss. Using cameras placed by the Smithsonian Institution in Sabah, Borneo, we assessed the detection rates and diel activity patterns of the native felid species. Across 51 camera trap sites between 2016 and 2019, felids were detected 55 times across a combined 9958 trap nights, including 20 independent detection events for Sunda leopard cats, 15 for Sunda clouded leopards, 12 for Borneo bay cats, and 5 for marbled cats, with no detections of flat‐headed cats. Collectively, this demonstrates the challenge of sampling cryptic species that have declined due to habitat loss and conflict with humans. Despite this, we show that Borneo bay cats and marbled cats exhibited different diel activity patterns than Sunda cloud leopards, suggesting the smaller species use temporal displacement to avoid competition and predation. Sunda leopard cats exhibited broadly similar activity patterns to Sunda clouded leopard, potentially because the two species typically occupy different dietary and habitat niches. These results demonstrate the importance of devoting future research towards monitoring these species and understanding the mechanisms by which they co‐exist. [ABSTRACT FROM AUTHOR]

Omnivores obtain resources from more than one trophic level, choosing food based on quantity and quality. They usually engage in intraguild predation (IGP) when prey is scarce. Orius laevigatus is an example of omnivore that becomes superior predator of the predatory mite Amblyseius swirskii when released in a combined system under low levels of the preferred prey, the thrips Frankliniella occidentalis. Here, we test two genetically enhanced O. laevigatus strains for bigger size and better fitness feeding on pollen (BIG30 and 2POL-11, respectively), hence with a wider dietary diversification, to elucidate the potential effects on prey preference and IGP on the predatory mite, in comparison with a commercial population of O. laevigatus. To do that, predation rates were registered on adult phytoseiids solely or in a choice situation at different availability ratios of adult thrips under laboratory conditions. The effect of pollen as supplemental food on IGP and prey preference was examined, too. We found that our two enhanced lines killed up to 9% less predatory mites and fed preferably on adult thrips, compared to the commercial population. While BIG30 showed a significantly higher total predation rate, killing up to 150% more adult thrips, 2POL-11 is defined as an efficient user of resources, switching between different prey and pollen showing low IGP. Pollen supplementation had a significant effect on reducing IGP, but only for 2POL-11 the influence on prey preference was significant. The theory of intraguild predation and the impact of prey switching on food webs and biological control strategies are also discussed. [ABSTRACT FROM AUTHOR]

This study presents a novel predator-prey model that incorporates Susceptible-Infected (SI) disease dynamics within the predator population. In this model, infected predators face a higher risk of death due to hunger compared to disease-induced death. We introduce two control variables aimed at reducing disease transmission and mitigating the impact of hunger on infected predators. The optimal control problem is formulated using a smoothed prey penalty cost function to ensure the prey population remains above a critical threshold, thereby reducing predator mortality. Existence results for the optimal control are established, and numerical simulations illustrate the effectiveness of the proposed strategies. [ABSTRACT FROM AUTHOR]

Very little is known about the range, diet and eco-ethology of the African striped hyena, compared to its sympatric hyena species; the spotted hyena. Here we present the results of bone assemblages collected in eight striped hyena dens located in a pastoralists' area in and near the Shompole conservancy, southern Kenya. We present the dens taxonomical representation; comparing domestic and wildlife prey and their prey age structure. This is to aid in making inferences on the striped hyena's prey acquisition, selection and mode of transportation. Ultimately, this is to highlight the species' interaction with pastoralists and some eco-ethological features of this little known near threatened species. Total wildlife proportions were higher than livestock. However, both wild and domestic ungulates are the major prey of the striped hyena and carnivores constitute a greater proportion of its non-ungulate prey. Striped hyena appears to predate on younger livestock when their dens are located closer to human settlements than those away from human occupied areas. Juveniles and old adults of wild ungulates dominated the striped hyena dens than the prime adults and this was reversed in the case of livestock ungulates. [ABSTRACT FROM AUTHOR]

This article discusses a case of nest predation involving a Japanese Sparrowhawk and a Siberian Weasel in China. The researchers observed the weasel attacking the sparrowhawk and taking all of the nestlings and the remaining unhatched egg. The study highlights the vulnerability of small raptors to nest predation and its potential impact on their reproductive success. The document is a list of literature cited in a research article on various topics related to raptors, including breeding biology, nesting habits, and behavior, with studies conducted in different regions. The topics explored in the cited literature range from nesting failure to population decline and include aspects such as fearfulness, competitive interactions, migration routes, and parental investment theory. [Extracted from the article]

The river lapwings are inhabitant of river banks with sand or gravel bars and river islands. In this study, we investigated vital threats (natural and anthropogenic) and the conservation status of river lapwing in the riverine ecosystem of Northern India. In this regard, we frequently visited selected study sites along the banks of the river Ganges in the district of Raebareli (Uttar Pradesh), India, from January 2016 to December 2019. To estimate perceived threats for river lapwing, we developed a questionnaire and collected threat scores. The line transect method was used to estimate the density of river lapwing. Predation and farming activities were the most potent threats influencing the survival and abundance of river lapwing. River lapwings were primarily observed at open unvegetated river banks and open unvegetated islands. They were seen in significant density near the water in the breeding season. We concluded that the population of river lapwing is relatively stable in the Gangetic plains of Northern India. However, it is declining in other parts of the world, for example, in Southern Laos. Though it is a relatively common species, robust scientific information about its population and habitat relation is mainly absent. Therefore, accurate counts from other parts of the world are needed to place the estimate for river lapwing into a comprehensible, inclusive perspective. Furthermore, detailed information on habitat relationships is also necessary to develop conservation strategies. [ABSTRACT FROM AUTHOR]

The distribution of New Zealand sea lions is typically localised to New Zealand and its remote subantarctic islands. However, non-resident male sea lions were seen on Macquarie Island, 650 km from their nearest natal islands, in all months of all years from 1965 to 1980. The majority of the apparently opportunistic sightings were at the northern end of the island. Sightings increased from May to a September-October peak that was coincident with the cessation of breeding activities in the sea lions' natal range and the period when resident gentoo and royal penguins, and fur and elephant seals aggregated for breeding, all of which are now confirmed prey for New Zealand sea lions on Macquarie Island. The long-term effect of predation pressure from New Zealand sea lions on resident species remains unmeasured. After sleeping, interacting with southern elephant seals was a core sea lion activity. Predation on seabirds and interactions with elephant seals increase the risk of cross-species disease transmission. [ABSTRACT FROM AUTHOR]

Predation's consequences can manifest through either consumptive or nonconsumptive effects, but the prey response may also vary depending on the predator hunting strategy. Considerable attention has been paid to coursing predators, whereas less information is available regarding responses to ambush predators. To remedy this paucity, we utilized a three‐dimensional tracking platform to record groups of Daphnia magna under predation risk from the ambush invertebrate predator red‐eyed damselfly, Erythromma najas. This design allowed us to test individual antipredator responses in multiple metrics of swimming behaviors. We demonstrate that predation risk was greatest for those that swam at 85% of the available depth and averaged 8.1 mm/s. Examining the swimming behavior of each individual separately showed that predation risk did not affect any of the prey response metrics. Interestingly, however, Daphnia did conform to one of two strategies while under predation risk: either swim fast high up in the water column or swim slowly close to the bottom. Hence, this dichotomous behavior is driven by strategies combining speed and depth in different constellations. In a broader context, our findings highlight the importance of considering both the spatial and temporal dimensions of predation events in order to correctly detect antipredator responses. [ABSTRACT FROM AUTHOR]

Alarm signals have evolved to communicate imminent threats to conspecifics but animals may also perceive other species' alarm displays to obtain adaptive information. In birds, mixed‐species foraging flocks are often structured around a focal sentinel species, which produces reliable alarm calls that inform eavesdropping non‐sentinel heterospecifics about predation risk. Ongoing work has revealed that several species can recognize the alarm calls of certain sentinel species even without prior encounters, including when these are from distant biogeographic regions. Similar work has yet to examine whether naive subjects' responses to unfamiliar sentinel alarm calls differ from responses to non‐sentinel alarm calls. Here we played the alarm calls of three subtropical Asian bird species that participate in mixed species flocks, to temperate North American birds. Birds responded most to the alarm call of an allopatric core sentinel and a local sympatric sentinel control species, less so to an allopatric non‐core sentinel, and least so to an allopatric non‐sentinel and a negative control stimulus. These patterns provide evidence that broad phylogenetic and geographic recognition is a pertinent aspect of sentinel alarm calls in general. [ABSTRACT FROM AUTHOR]

As climate change transforms marine environments globally, species distributions correspondingly shift to locations where conditions have become or remain favourable. The ability to model these distributional shifts has been facilitated by species distribution models (SDMs). However, current SDM approaches have largely ignored climate‐driven changes in species interactions, which ultimately can have an important influence on species distributions. In this study, we utilize a long‐term, large‐scale dataset spanning 48 years and approximately 30 degrees latitude across the Canadian Atlantic shelf. We examine how climate influences the distribution and predation patterns of two invertebrates, northern shrimp Pandalus borealis and snow crab Chionoecetes opilio, aiming to evaluate the impacts of climate change on prey distributions. We found that both invertebrate species have a pronounced predicted response to climate change, with a northern shift in the distribution of northern shrimp and an overall reduction in abundance of both snow crab and shrimp associated with warming temperatures. Including predatory interactions as predictors in the SDMs (either directly via predator densities or via estimated predation rates) improved prediction accuracy for northern shrimp but not for snow crab. This is consistent with the ecology of these two species, as northern shrimp is more vulnerable to predation than snow crab. We found that the projections of future northern shrimp distributions are sensitive to the predicted spatial distribution and abundance of predators, highlighting the inherent complexity of predicting species response to climate change. Collectively, these results contribute to a broader literature that seeks to improve the capabilities of models to predict the effects of species interactions on species distributions under changing ecological conditions. [ABSTRACT FROM AUTHOR]

Reproduction of the pancake tortoise in the wild has remained poorly known over the decades. This study fills the knowledge gap by investigating the reproductive ecology of the species in its natural habitats in Kenya. Data were collected using the time‐constrained search‐and‐seize method, group‐level scan sampling, radio tracking, and camera‐trapping. Our observations revealed a total of 19 mating events that occurred between December and April, predominantly during the rainy seasons. Mating duration averaged 15.2 ± 2.4 min. Male–male aggression was observed during the mating season, with the dominant male keeping off all other males and mating with the resident females. Nest preparation events occurred between April and June. Nine nesting events were recorded, but in only five of them was an egg deposited. The nests were dug in loose soil, appeared almost circular, and measured 8.4 ± 0.9 cm wide and 7.0 ± 0.1 cm deep (n = 7). The average clutch size was one egg. The eggs were white, hard‐shelled, oval, and elongated measuring 4.4 ± 0.4 cm long, 2.7 ± 0.04 cm wide and weighed 17 ± 0.6 g (n = 3). Incubation period lasted 177 ± 5.7 days (n = 2), and hatching coincided with the onset of the short rainy season in November, aligned with the availability of abundant food for the tortoises. The hatchlings were minimally wider than long, having an average straight carapace length of 4.5 ± 0.6 cm, an average width of 4.5 ± 0.4 cm, and on average weighed 14.7 ± 3.7g, (n = 9). They remained near the nest site for 4–5 days before relocating to tiny rock crevices away from the adult tortoise crevices. Egg and hatchling predation was high, with four of the total of six eggs, observed after they were laid, being destroyed. Three juveniles, out of nine, were also eaten by predators. These findings contribute useful information for the formulation of effective conservation and management strategies for this critically endangered species. [ABSTRACT FROM AUTHOR]

Energy flow through consumer-resource interactions is largely determined by body size. Allometric relationships govern the dynamics of populations by impacting rates of reproduction as well as alternative sources of mortality, which have differential impacts on smaller to larger organisms. Here we derive and investigate the timescales associated with four alternative sources of mortality for terrestrial mammals: mortality from starvation, mortality associated with aging, mortality from consumption by predators, and mortality introduced by anthropogenic subsidized harvest. The incorporation of these allometric relationships into a minimal consumer-resource model illuminates central constraints that may contribute to the structure of mammalian communities. Our framework reveals that while starvation largely impacts smaller-bodied species, the allometry of senescence is expected to be more difficult to observe. In contrast, external predation and subsidized harvest have greater impacts on the populations of larger-bodied species. Moreover, the inclusion of predation mortality reveals mass thresholds for mammalian herbivores, where dynamic instabilities may limit the feasibility of megafaunal populations. We show how these thresholds vary with alternative predator-prey mass relationships, which are not well understood within terrestrial systems. Finally, we use our framework to predict the harvest pressure required to induce mass-specific extinctions, which closely align with previous estimates of anthropogenic megafaunal exploitation in both paleontological and historical contexts. Together our results underscore the tenuous nature of megafaunal populations and how different sources of mortality may contribute to their ephemeral nature over evolutionary time. [ABSTRACT FROM AUTHOR]

Inhabitants of rocky intertidal shores, including gastropods, require specific adaptations to cope with numerous challenges that vary across the intertidal levels. We collected Stramonita biserialis snails from upper (wave-protected and intense predation) and lower (wave-exposed and low predation) intertidal sites to compare the following traits: shell skeleton (ventral and abaxial lateral views of shell shape, thickness, and mass), foot size, energy metabolism, and attachment strength to determine whether the trait values of snails from each zone fit the environmental challenges they face. We used a Principal Component Analysis to reduce the dimensionality of the data. Multivariate Analysis of Covariance (MANCOVA) for comparing characteristics between the two intertidal zones, and Partial Least Squares (PLS) analyses for testing the integration of overall snail characteristics. The traits of the snails of the two intertidal sites matched with the adaptations expected to allow them to cope with their contrasting challenges. The snails from the lower intertidal had more streamlined shells (which reduces drag forces) and a larger aperture and foot extension (which increase the strength of their attachment to the substrate) compared to snails from the upper sites. Snails from the lower intertidal also had a high mass-specific metabolism and soft body proportion, indicating that these snails from the wave-exposed sites have an energetically active musculature that matches their strong substrate attachment. The thin shell walls of the snails of the lower intertidal match the relatively low predatory pressure there. [ABSTRACT FROM AUTHOR]