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People with disabilities are often targets for exploitation. Persons with disabilities subject to guardianship require additional planning protections to safeguard them from financial predation. This article reviews the literature on this topic and identifies key areas of concern that financial advisors should address to protect this vulnerable population. [ABSTRACT FROM AUTHOR]

The costs of foraging can be high while also carrying significant risks, especially for consumers feeding at the top of the food chain. To mitigate these risks, many predators supplement active hunting with scavenging and kleptoparasitic behaviours, in some cases specializing in these alternative modes of predation. The factors that drive differential utilization of these tactics from species to species are not well understood. Here, we use an energetics approach to investigate the survival advantages of hunting, scavenging and kleptoparasitism as a function of predator, prey and potential competitor body sizes for terrestrial mammalian carnivores. The results of our framework reveal that predator tactics become more diverse closer to starvation, while the deployment of scavenging and kleptoparasitism is strongly constrained by the ratio of predator to prey body size. Our model accurately predicts a behavioural transition away from hunting towards alternative modes of predation with increasing prey size for predators spanning an order of magnitude in body size, closely matching observational data across a range of species. We then show that this behavioural boundary follows an allometric power-law scaling relationship where the predator size scales with an exponent nearing 3/4 with prey size, meaning that this behavioural switch occurs at relatively larger threshold prey body size for larger carnivores. We suggest that our approach may provide a holistic framework for guiding future observational efforts exploring the diverse array of predator foraging behaviours.

This poster was presented at the UCSB EEMB research symposium in 2024.Seed predation by granivores limits plant survival and recruitment of new germinates, especially of rare species limited by small populations and increasing pressure from nonnative invasives. The relationship between granivores and native flora at the Dune Protected Area in Callandar, CA is currently shifting away from historic patterns; Nipomo  mesa lupine (L. nipomensis) and other dune stabilizing plant species have been impacted by the habitat-wide colonization by the invasive perennial veldt grass (Ehrharta calycina). Current veldt management practices prevent the use of herbicide to control the grass within a 15-foot buffer of extant lupine populations. Understanding how dense stands of veldt grass may support increased populations of L. nipomensis seed predators can inform the management of veldt grass and the recovery of the endangered lupine. This study assessed seed predation through low profile boxes baited with L. nipomensis seeds and camera traps capturing both video and still images to compare seed predation rates relative to dense stands of veldt grass. Conservation implications were further assessed by considering the role of cages (fencing) in reducing seed predation.  We found that increased proximity to veldt grass modestly increased seed predation, and that uncaged bait stations lost the most seeds (~70% loss rates compared to ~15% in caged plots). The most common seed predators captured on camera were Heermann’s kangaroo rats, Dipodomys heermanni (found outside of cages and away from veldt grass), Deer mice, Peromyscus maniculatus (found outside of cages and adjacent to veldt grass), and California towhees (found within cages and away from veldt grass). Our results establish patterns of seed predation consistent with predicted results and emphasize potential vulnerability to seed predation in areas near veldt or areas unprotected by caging.

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]

Community composition in aquatic environments can be shaped by a broad array of factors, encompassing habitat conditions in addition to abiotic conditions and biotic interactions. This paper pertains to reaction–diffusion–advection predator–prey model featuring a variable predator habitat in advective environments, governed by a unidirectional flow. First, we establish the near‐complete global dynamics of the system. In instances where the functional response to predation conforms to Holling‐type I or II, we explore the uniqueness and stability of positive steady‐state solutions via the application of particular auxiliary techniques, the comparison principle for parabolic equations, and perturbation analysis. Furthermore, we obtain the critical positions at the upper and lower boundaries of the predator's habitat, which determine the survival of the prey irrespective of the predator's growth rate. Finally, we show how the location and length of the predator's habitat affect the persistence and extinction of predators and prey in the event of a small population loss rate at the downstream end. From the biological point of view, these results contribute to our deeper understanding of the effects of habitat on aquatic populations and may have applications in aquaculture and the establishment of protection zones for aquatic species. [ABSTRACT FROM AUTHOR]

The die‐off of the long‐spined sea urchin Diadema antillarum in the 1980s highlighted its crucial role as a primary grazer in tropical western Atlantic coral reefs. However, natural recovery has been slow, exacerbated by a new die‐off in 2022. Interest in actively restoring D. antillarum populations has grown with the emergence of culture and rearing techniques. Restocking reefs with laboratory‐reared urchins shows potential for enhancing coral reef resilience by reducing algal cover and promoting coral settlement, but success rates vary. Predation and migration contribute to low retention rates, with distinguishing between them is challenging. In this study near Saba, Caribbean Netherlands, we released 200 laboratory‐reared D. antillarum on a reef and monitored for D. antillarum retention and potential D. antillarum predator presence and interaction for 35 days. Only 40% of the urchins were still present on the reef after day one. The Spanish hogfish Bodianus rufus was identified as the primary daytime predator, responsible for nine direct predation events. No nighttime predation was observed, but interaction with a batwing coral crab Carpilius corallinus was noted. These insights can help optimize future restocking attempts and emphasize  the importance of assessing predator presence beforehand. Reefs with high abundances of predators such as Spanish hogfish should be avoided for D antillarum restocking. In addition, before being released, lab‐reared animals should be given time to acclimate to conditions in the wild by being placed in protected in situ cages. Here, they could also grow to larger sizes that are less vulnerable to predation. [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]

Nestmate recognition is a widespread phenomenon and evolutionary important trait in the social insects. Yet evidence accumulates that the responses to non‐nestmates varies more than previously thought. We present a simple frequency‐dependent cost‐benefit model of nestmate recognition to understand conditions that might or might not favor the evolution of nestmate recognition that is based on cuticular hydrocarbon (CHC) profiles. Costs accounted for are costs for 1) maintaining a functional recognition system and 2) keeping a CHC profile that may be sub‐optimal regarding other functionalities like desiccation control, whereas the benefit of recognition is the prevention of nest raiding by other colonies. Unsurprisingly, the model indicates that recognition systems only evolve if costs are sufficiently low and benefits sufficiently high. In addition, the model suggests that nestmate recognition is more likely to evolve if colony turnover is fast (colony life‐expectancy is low). Our model creates evolutionary cycles that are typically longest under parameter combinations that just allow the evolution of recognition systems at all; the system expresses attributes of a rock‐paper‐scissors game. The model shows that a breakdown of nestmate recognition may occur under changing ecological situations, e.g. as a result of reduced intraspecific competition or increased abiotic stress. We speculate that such effects may be involved in the formation of supercolonies during invasions. Nestmate recognition may have evolved more to prevent interspecific predation or parasitism by antagonists that managed to mimic their host's CHC profile than as a mechanism to prevent exploitation by conspecific colonies. [ABSTRACT FROM AUTHOR]

Water diversions that support agricultural and municipal use result in fish mortality through entrainment and impingement. Additionally, this infrastructure may attract both predators and prey fishes, thereby increasing predation rates and prey mortality near these anthropogenic contact points. The Sacramento–San Joaquin Delta (the Delta) in California's Central Valley is a tidal freshwater ecosystem that exports large volumes of water for municipal and agricultural use while at the same time providing valuable migratory and rearing habitat for imperilled fishes. Emigrating juvenile salmonids experience high mortality in the Delta, with predation by non‐native fishes contributing substantially. Therefore, this study had three main objectives. First, we determined if small water diversions aggregated piscivorous fishes like other similar structures in freshwater ecosystems. Second, we determined how small diversions may influence juvenile salmon predation risk in conjunction with other known predation risk factors (e.g. predator abundance, temperature and depth). Third, we assessed the predator assemblage, abundance and distribution to determine the likely predator composition in objectives one and two. Throughout the spring of 2021, we used ARIS (adaptive resolution imaging sonar; Sound Metrics) sonars to compare piscivore abundance at 30 water diversions in the north Delta to shorelines adjacent to diversions that did not contain these structures. We used predation event recorders (PERs) to assess the predation risk juvenile salmonids were exposed to, with linear distance (m) from diversions, and other predation risk factors in the north Delta. Finally, we used a boat electrofishing survey to determine the piscivore assemblage and compare spatial trends in black bass (Micropterus spp.) CPUE and relative abundance throughout these waterways. Piscivore abundance was greater near small water diversions than at adjacent shorelines and the predation risk of juvenile salmonids increased with diversion proximity. Additionally, predation risk increased with increasing piscivore abundance and decreasing water depth. The north Delta predator assemblage was dominated by black basses (Micropterus spp.), which likely drove the negative relationship of predation risk with water depth, given habitat requirements of these species. Furthermore, increasing smallmouth (Micropterus dolomieu) and spotted bass (Micropterus punctulatus) abundance in our northern study sites may have weakened temperature effects on predation, given metabolic requirements of these species. Our work demonstrated that small water diversions are likely to increase mortality of endangered salmonids, and that the north Delta predator assemblage was different than recorded by previous work in this system, changing predation risk factors. Although more work is needed to determine the population level impacts of diversions, the ubiquitous distribution of these structures warrants management solutions to reduce mortality from this source. These results indicate that in addition to entrainment and impingement, water diversions may increase mortality of small‐bodied fishes by attracting predators and elevating predation risk. Given the continual human demand for freshwater, predator–prey interactions should be considered along with entrainment and impingement when assessing intake infrastructure mitigation, especially when diversions co‐occur along migratory routes and essential habitat of imperilled fishes. [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]

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]

Cases of anomalous coloration are regularly reported in Neotropical mammals, including the rodent family Dasyproctidae (agoutis and acouchis) where leucistic and albino individuals have been observed. Here, we document the first case of leucism in the Brown Agouti (Dasyprocta variegata) in Bolivia. During a camera trap survey of the Barba Azul Nature Reserve, we obtained footage of a Brown Agouti with a completely white body. Additional pictures of this individual revealed that it has black eyes, indicating leucism instead of albinism. Previous observations (since 2017) of a white agouti in the area suggest that these anomalously colored individuals can survive in the wild. Rare observations of top predators suggest a relatively low predation pressure in the area. We had only one record of a South-American Puma (Puma concolor) during our camera trap survey. Hence, leucistic individuals of a common prey species might also be indicative of the dwindling population densities of top predators in the region. [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]

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]

Moose (Alces alces) and woodland caribou (Ranger tarandus caribou) are the 2 large prey species for wolves (Canis lupus) in the Nearctic boreal forest in North America. Caribou have declined, with widespread anthropogenic disturbance as the ultimate cause and wolf predation as the proximal cause. To conserve caribou the government of Alberta, Canada initiated a wolf control program to reduce predation rates on caribou populations and contribute to caribou population recovery. Predators play an important role in shaping the structure and function of ecosystems through top‐down forces. We hypothesized that the strongest factors influencing moose occurrences would reflect changes in predation risk before and after the onset of wolf control. We weighed evidence for competing hypothesis by deploying cameras across a highly industrialized landscape in Alberta for 3 years after wolf control (2017–2020), capitalizing on 3 years of existing data before the onset of wolf control (2011–2014). We created generalized linear models representing competing hypotheses about moose response to natural and anthropogenic landscape features before and after wolf control, examining support for each in an information‐theoretic framework. Prior to wolf control, the model containing landscape features providing security cover was best‐supported, but this was scale‐dependent. After wolf control, the model containing landscape features that offer increased forage opportunities was best‐supported. Unexpectedly, the direction of effect was often opposite to predictions, with moose avoiding some features thought to provide security and forage. We demonstrate that lethal predator control affects the spatial distribution of its primary prey species but in ways we do not fully comprehend, highlighting the need for a better understanding of community dynamics following wolf control. [ABSTRACT FROM AUTHOR]

The dynamics of consumers can be affected by both nutrient-deficient food (low phosphorus (P) to carbon (C) ratio) and nutrient-excessive (high P:C) food, which is known as the stoichiometric knife-edge phenomenon. In this study, aiming to illustrate the responses of herbivores and omnivores to food with excessive P content, we present and analyze a tri-trophic level stoichiometric knife-edge model incorporating the intraguild predation structure. The model dynamics are theoretically examined, including the boundedness and positivity of solutions, the existence and stability of boundary equilibria, and the existence of positive equilibria. Numerical simulations show that the model has complex dynamics, encompassing chaotic-like oscillations, multiple types of bifurcations, long transients, and regime shifts. Moderate P levels facilitate the coexistence of the three species, whereas both lower and higher P levels result in the extinction of herbivores and omnivores. Specifically, the energy enrichment paradox occurs at low P levels. In contrast, the nutrient enrichment paradox occurs at high P levels, both of which are detrimental to the survival of herbivores and omnivores. Furthermore, the high-intensity predation of producers by omnivores helps to restrain the occurrence of chaotic dynamics. These findings contribute to a deeper understanding of the mechanisms of multi-species coexistence. [ABSTRACT FROM AUTHOR]

When, where, and what predators prey upon salmon is fundamental to understanding their mortality in a given region. We reviewed the available information about predators of three Japanese Pacific salmon species throughout their life history: chum salmon Oncorhynchus keta, pink salmon O. gorbuscha, and masu salmon O. masou. Thirteen fish species, including seven salmonid species, and three avian species, such as great cormorant Phalacrocorax carbo, have been described as predators of fry/juvenile salmon in rivers. Predators of fry/juveniles in estuarine–coastal areas have been relatively well investigated and include 15 fish species, including young masu salmon, and five avian species, such as rhinoceros auklet Cerorhinca monocerata. Four large fish species, such as salmon shark Lamna ditropis, one baleen whale species, and pinnipeds are reported predators of subadults in the open sea. In the sea around Japan, including the Pacific, the Sea of Okhotsk, and the Japan Sea, we found evidence of predation on subadults, adults, unknown life-stage salmon by four pinniped species and three species of baleen and toothed whales. Adults returning to rivers were preyed upon by two mammal species including brown bear Ursus arctos and two raptor species. We also identified information gaps for specific predators by region and life stage. Collaborating with non-researchers to obtain observation records of predation on salmon is one method that could efficiently expand our knowledge of local predators. We further suggest using the information from our review to incorporate predation effects as well as environmental factors in models examining salmon stock fluctuation mechanisms. [ABSTRACT FROM AUTHOR]

Predator–prey dynamics have led to a strong selection of prey's ability to detect and respond to information about the risk environment. Further, intrinsic factors, such as sex, may cause prey to perceive and respond to information differently. Chemical alarm cues from injured conspecifics are a classic example of how prey have evolved to use publicly available information to shape their behavior and enhance fitness, yet sex‐specific alarm reactions are rarely considered. The purpose of our study was to compare how males and females respond to conspecific chemical alarm cues in the livebearing fish species, Brachyrhaphis rhabdophora. Furthermore, we tested males and females from populations with a high‐ or low‐predation environment. Brachyrhaphis rhabdophora showed strong alarm reactions, but contrary to our predictions, showed limited variation due to sex or predation environment. We found that males and females from both populations displayed lower activity levels and increased their swimming depth when exposed to an alarm cue, despite variable and consistent baseline behaviors among individuals. These data further contribute to our understanding of what factors shape the evolution of behavioral responses to chemical alarm cues in fishes. [ABSTRACT FROM AUTHOR]

Death feigning is hypothesized to be an anti-predator behavior in which prey is temporarily immobilized in response to external stimuli. While death feigning may be an effective predator-defense strategy, there may be trade-offs in terms of energy and time for finding food and/or mating. The duration of death feigning is regulated by the balance of various selection pressures, and its duration is influenced by many internal and environmental factors. However, little is known about the factors that influence arousal from death-feigning behavior. Sex pheromones are important semiochemicals that affect reproductive success and may influence the duration of death-feigning behavior. In this study, we aimed to investigate the effects of sex pheromones on the death-feigning behavior of the sweet potato weevil (Cylas formicarius) by conducting laboratory experiments. The results showed that males had a significantly shorter death-feigning duration in the presence of sex pheromones because it aroused them from their death-feigning behavior, but females were unaffected. This is the first study to show that sex pheromones alter death-feigning behavior. The results of this study elucidate the factors influencing predator-avoidance behavior and reveal the impact of death-feigning behavior on prey reproduction under predation pressure. [ABSTRACT FROM AUTHOR]

Division of roles was observed during group hunting by the false cleanerfish, Aspidontus taeniatus (Blenniidae), when they raid the nests of the damselfish (Pomacentridae) and eat their guarded eggs. In this paper, we provide the first description of the collaborative group egg-eating behavior by the false cleanerfish. When raiding the nests of the three-spot dascyllus, Dascyllus trimaculatus, whose eggs are guarded by parents, the false cleanerfish divided roles as follows: "decoy" or "watcher" to draw attention and attract attacks from the parents, and "hider" or "intruder" to avoid detection by the parents and invade the nest. The potential differential costs associated with each role are unique among examples of group hunting strategies in fishes. However, once any individual in the group successfully invaded the nest, all individuals quickly achieved successful predation of the eggs and gained immediate shared benefit. We propose that the group egg-eating behavior of the false cleanerfish not only reinforces the evidence that fish can collaborate with other individuals but also suggests the hypothesis that collaborative hunting can evolve through mutualism even in fishes. Digital video images related to the article are available at http://www.momo-p.com/showdetail-e.php?movieid=momo240411at01a, and http://www.momo-p.com/showdetail-e.php?movieid=momo240411at02a. [ABSTRACT FROM AUTHOR]

This paper takes a reaction-diffusion predator-prey system with ratio-dependent Holling III functional response function and Leslie-Gower term into consideration. First of all, the system model is proposed on the basis of basic biological assumptions and previous work, and the existence conditions of the equilibrium point of the system are discussed. Secondly, under the assumption of the existence of equilibrium point, the Turing instability necessary conditions induced by diffusion are investigated. Thirdly, optimal control theory is derived, and the adjoint system and the first-order optimization condition are established. Fourthly, parameter identification based on optimal control is studied, and the technique is extended to network structure. Finally, extensive numerical simulations, including Turing pattern, Normalized Population High Distribution Area (NPHDA) diagram and parameter identification, are carried out to illustrate and validate the analytical results. For the system dynamics phenomena, the results from different perspectives effectively demonstrate that the theoretical findings, numerical simulations and natural reality are identical. In terms of the parameter identification of continuous model and network model, the efficiency and accuracy of various algorithms are fully tested. • This paper proposes and investigates index normalized population height distribution area. • The optimal control problem of reaction-diffusion predator-prey system is formally derived. • The parameter identification research is extended to population network structure space. [ABSTRACT FROM AUTHOR]

Non-native species can react to changes to their thermal environment by altering their feeding behaviour, thereby potentially causing shifts in predator–prey dynamics and competitive dominance over native species. In this study, we measured intraspecific variation in the functional response (i.e., predation rate as a function of prey density) of the rusty crayfish Faxonius rusticus (Girard, 1852) at two temperatures (18 °C and 26 °C) in the laboratory. We compared six invasive populations spanning a 2° latitudinal gradient in eastern North America to test the prediction that under warmer conditions individuals from more southerly populations exhibit a higher functional response than those from northern populations. Temperature, latitude, and the interaction between these two variables had significant effects on attack rates and handling times of individual crayfish from the tested populations. Contrary to our prediction, the attack rates of individuals from northern populations were consistently higher than those from southern populations at both temperatures. We propose that these interpopulation differences in functional response could arise, at least in part, from countergradient selection. Our results suggest that climate warming promotes spatiotemporal variation in per capita effects across latitudinally distributed populations of aquatic invasive species. [ABSTRACT FROM AUTHOR]

Understanding inter-annual variation in the density of young-of-the-year fish is an important tool for assessing stock status and guiding management decisions. We analyzed data spanning from 2003 to 2022 collected at Lipno Reservoir in Czechia. The study aimed to identify factors influencing the density of pikeperch (Sander lucioperca), a valuable predatory fish species in European waters. A bimodality test for the size class distribution has revealed the existence of two distinct YOY cohorts: extremely small (ES) and ordinary fingerlings. Using the Bayesian horseshoe prior method with 37 potential predictors, followed by linear regression, we observed that certain environmental factors similarly influenced both cohorts. Higher temperatures during spring and summer, coupled with increased densities of large and medium-sized cladocerans, positively affected the density of both cohorts. However, distinct influences were observed: for ordinary fingerlings, increased summer precipitation and a lower abundance of predators were beneficial, whereas, for ES fingerlings, summer copepod density emerged as an additional positive factor. This study emphasizes the importance of a detailed investigation of factors influencing pikeperch recruitment. Examining these drivers provides a clearer insight into the causes of variations in the early life stage, which is crucial for monitoring and managing populations in temperate reservoirs. [ABSTRACT FROM AUTHOR]

Salamanders serve as bioindicators of mercury (Hg) in both terrestrial and aquatic habitats and are an important link in the food web between low‐trophic prey and higher‐trophic predators. We investigated the drivers of methylmercury (MeHg) exposure in three common plethodontid salamander species in New York State, USA, including comparisons among regions, habitat types (terrestrial and semiaquatic), and color morphs of Plethodon cinereus (striped and unstriped). Nonlethal tail samples were collected from one terrestrial species (P. cinereus) and two semiaquatic species (Eurycea bislineata and Desmognathus spp.) in the Adirondack Mountains (ADK) and the Finger Lakes National Forest (FLNF) regions. Samples were analyzed for MeHg and stable isotopes, including δ15N and δ13C which are proxies of trophic position and diet, respectively. Despite elevated biota Hg concentrations typically found in the ADK, salamander MeHg concentrations did not differ by region in the terrestrial species and one of the semiaquatic species. In addition, diet and trophic level did not explain MeHg exposure in salamanders. Semiaquatic salamanders exhibited higher MeHg concentrations than terrestrial salamanders in the FLNF only. Within species, only snout–vent length predicted MeHg concentrations in E. bislineata with few other variables significant as predictors of MeHg concentrations in path models. Among P. cinereus individuals in the FLNF, the striped morph had greater MeHg concentrations than the unstriped morph, and food web tracers were not different between morphs. Overall, New York State salamander Hg concentrations were elevated compared to other locations where these species are present. The present study establishes baseline Hg data in salamanders for future assessments of changes in Hg bioavailability to forests of New York State. Environ Toxicol Chem 2024;43:2045–2057. © 2024 SETAC [ABSTRACT FROM AUTHOR]

This paper concerns a discrete diffusive predator–prey system involving two competing predators and one prey in a shifting habitat induced by the climate change. By assuming that both predators can increase when the prey is at the maximal capacity and the prey can still survive under optimal climatic conditions when these two predators have their maximal densities, we investigate the existence and non-existence for different types of forced traveling waves which describe the conversion from the state of a saturated aboriginal prey with two invading alien predators, an aboriginal co-existent predator–prey with an invading alien predator, and the coexistence of three species to the extinction state, respectively. The existence of supercritical and critical forced waves is showed by applying Schauder's fixed point theorem on various invariant cones via constructing different types of generalized super- and sub-solutions while the non-existence of subcritical forced waves is obtained by contradiction. [ABSTRACT FROM AUTHOR]

Predation is a powerful driving force leading to the evolution of antipredator defences in prey. The effectiveness of the antipredator defences can depend on various ecological contexts such as predator density and the development stages of the prey species. Males and females often exhibit remarkably different morphologies, behaviours and life histories, and the sexual differences are expected to generate different ecological contexts for males and females, potentially driving the evolution of sex-specific antipredator defences. In the horned beetle Gnatocerus cornutus , males have enlarged mandibles, but females lack this exaggeration. As potential defences against predators, these beetles either become immobile or run away. In this study, we established populations subjected to sex-specific predation. We found that male locomotion was increased in populations subjected to male-specific predation and that female immobility was increased in populations subjected to female-specific predation. We also found that males appeared on the surface of food resources more frequently than females. Given such differences in microhabitat preferences, the males are more likely to be detected by predators than the females. The sexual differences in morphology and microhabitat preferences may generate different predatory environments for males and females, resulting in males using locomotion to escape from predators and females using immobility to hide from them. In this laboratory selection experiment, we did not observe the evolution of the opposite sex's antipredator traits in response to sex-specific predation. We detected no intersexual genetic correlation of immobility and locomotion. The genetic decoupling and different predatory contexts for the two sexes may promote sexually different antipredator defences in G. cornutus. • Males and females are predicted to evolve different defences against natural enemies. • Male Gnatocerus cornutus evolved to flee when confronted by natural enemies. • Females evolved to hide when confronted by natural enemies. [ABSTRACT FROM AUTHOR]

Abandoning a brood to maximize lifetime reproductive success may result from the current costs affecting future reproductive opportunities. In certain contexts, clutch abandonment can be an evolved breeding strategy rather than a generalized response to stressors such as inclement weather and predation. Obligate brood parasitism, a reproductive strategy in which a parasitic species relies solely on other species to raise its young, imposes fitness costs to hosts and could serve as a trigger for clutch abandonment. This cost, and the resulting clutch abandonment strategy, may vary according to contact with the parasite, sensitivity to parasitism and the value of the current reproductive effort (i.e. brood value). We conducted a phylogenetically controlled meta-analysis covering 85 host species of the three generalist cowbird species (Molothrus sp.) in which we examined the following effects on the abandonment (nest desertion and egg burial) of parasitized versus unparasitized clutches: habitat at a small scale (higher host–parasite encounter frequency in open versus forested habitats) and at a large scale (longer interaction between parasites and hosts in prairie versus nonprairie regions), brood value (relative value of a clutch) and host species sensitivity to brood parasitism (relative body mass). Parasitism increased clutch abandonment overall. This increase was strongest in open nonforested habitats, with smaller, more sensitive hosts being more likely to abandon their clutch. Brood value and occurrence in prairie regions did not affect clutch abandonment, indicating that recent, more fine-scale host–parasite interactions were more important than coevolutionary history. Therefore, the abandonment of a brood can be used in diverse parental care strategies, including antiparasitic defences of brood-parasitic hosts. • We examined responses of hosts to parasitism by cowbirds (Molothrus sp.). • Parasitism increased clutch abandonment overall. • Abandonment strongly affected host sensitivity and current exposure to parasitism. • We found no effect of brood value or coevolutionary history. • Host behavioural plasticity may modulate host defences more than previously thought. [ABSTRACT FROM AUTHOR]

This paper aims to establish the existence of traveling wave solutions connecting different equilibria for a spatial eco-epidemiological predator–prey system in advective environments. After applying the traveling wave coordinates, these solutions correspond to heteroclinic orbits in phase space. We investigate the existence of the traveling wave solution connecting from a boundary equilibrium to a co-existence equilibrium by using a shooting method. Different from the techniques introduced by Huang, we directly prove the convergence of the solution to a co-existence equilibrium by constructing a special bounded set. Furthermore, the Lyapunov-type function we constructed does not need the condition of bounded below. Our approach provides a different way to study the existence of traveling wave solutions about the co-existence equilibrium. The existence of traveling wave solutions between co-existence equilibria are proved by utilizing the qualitative theory and the geometric singular perturbation theory. Some other open questions of interest are also discussed in the paper. [ABSTRACT FROM AUTHOR]

Evaluating human–wildlife conflict is necessary to reach positive long-term management solutions and aid the conservation of biodiversity. We used indirect approaches to evaluate the Human–Neotropical otter conflict in three river basins with high fishing activity in western Mexico and provided recommendations to mitigate the conflict by identifying the variables that increase the risk of predation of ponds by otters. Human–Otter conflict was moderate, and the opinions of community members toward otters were mostly negative, particularly those of the fishing sector. However, after offering environmental education workshops, the number of people recognizing the importance of protecting the species increased, which could result in the acceptance and tolerance toward otters. Avoiding building ponds at ground level and covering ponds with metal mesh, especially in fish-farms located in the middle and upper areas of rivers, as explored with fish-farmers, merits more experimentation, since it could be a good means for reducing the conflict. [ABSTRACT FROM AUTHOR]

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

Winter is a critical period for the survival of local bird species in temperate regions. Some wintering birds may rely on transient food, such as that provided at birdfeeders, but bird communities around birdfeeders may also attract predators. However, these effects of birdfeeders on interspecific interactions between birds and their predators remain largely unexplored and have so far not been tested experimentally. We hypothesized that birdfeeders indirectly attract predators in winter because of the attraction of small birds, and tested this hypothesis using experimental feeders at 52 different urban and rural sites across western Poland. We found that the number of small birds increased around birdfeeders, particularly those with provided food. We found that birdfeeders that attracted more small birds (regardless of whether they provided food) attracted also more predators, such as sparrowhawks Accipiter nisus and feral cats Felis domesticus. Moreover, birdfeeders in urban habitats attracted relatively fewer small birds but not fewer predators compared to those in rural areas. Altogether, birdfeeders with food provided attracted small prey birds but they attracted also more predators, whose presence may hinder small birds from fully utilizing available resources, potentially impacting their winter survival through direct (mortality) and indirect (increased monitoring and vigilance) effects. [ABSTRACT FROM AUTHOR]

• Spider community composition changed during the rice growing season. • The rice field development generally decreased the number of horizontal web-building spiders and captured detritivorous prey. • Species identity and species traits of spider as well as environmental factors affect prey capture by web-building spiders. Understanding the effects of microhabitat changes on arthropod predator communities and their prey in agroecosystems is essential for field management and biocontrol. Few studies have investigated the trait composition of web-building spider communities in rice ecosystems. Here, we examined how temporal changes during the rice field development affect the abundance and traits of orb-web spiders, and how these effects consequently influence captured prey number and prey composition in irrigated rice ecosystems in southern Thailand. We used structural equation models to evaluate direct and indirect, spider-mediated effects of rice field development on captured prey numbers in each different guild. We found that the number of horizontal web-building spiders decreased during the rice field development, whereas there was no significant change in number of vertical web-building spiders. The number of captured detritivorous insects was positively related to the numbers of horizontal and vertical web-building spiders, while phytophagous insects and others were positively related only to the numbers of vertical web-building spiders. Moreover, the prey number captured by vertical web-building spiders seems to be indirectly increased through the decreasing number of horizontal web-building spiders in the late rice season. A fourth-corner analysis showed that spider species identity, spider traits (web type, web height and web diameter), vegetation height, and water level generally influenced the prey captured by web-building spiders. Horizontal web-building spider species with lower web placement during the flooding phase captured high numbers of detritus-feeding insects, while vertical web-building spider species with higher web placement captured high numbers of rice pests, predators and others. Our results suggest that the field development acted as an environmental factor that determined the species identity and traits of web-building spider communities. The findings of this study can help to predict the ecosystem services provided by the web-building spider community in rice ecosystems. [ABSTRACT FROM AUTHOR]

The article explores the issue of overtrading of generalist amphibians and its impact on biodiversity. It challenges the belief that poaching and trading of these species are less harmful than that of rare or charismatic species. The negative consequences of amphibian trade, such as the spread of diseases and biological invasions, are highlighted. The authors stress the importance of stricter monitoring and legislation, as well as community-driven programs and collaboration with local researchers and development authorities. Amaël Borzée, a professor at Nanjing Forestry University, is a respected expert in amphibian conservation and his work is valuable for research in this field. [Extracted from the article]

In this paper, we study the dynamics and pattern formation of a reaction-diffusion system with Ivlev-type functional response and homogeneous Neumann boundary conditions. We first consider the global existence and boundedness of nonnegative solutions and then discuss the global stability of nonnegative steady states. By using the energy estimates and Leray-Schauder degree theory, we prove the nonexistence and existence of nonconstant positive steady states respectively. Finally, we show some interesting spatiotemporal dynamical behaviors in numerical simulations. Our result is consistent with the 'activation-inhibition' mechanism, where the prey is treated as an activator and the predator is treated as an inhibitor. When the diffusion rate of the prey is much lower than that of the predator, patterns may be generated. [ABSTRACT FROM AUTHOR]

In this paper, a diffusive prey-predator model with hunting cooperation and prey-taxis is proposed and investigated. First, we prove the uniform boundedness and global existence of time-varying solutions to the model. Then the stability and prey-taxis-driven instability of positive equilibrium are discussed through linearization analysis. It is found that negative prey-taxis may change the spatial stability of the positive equilibrium, implying formation of Turing pattern. Next, we discuss the existence and stability of the spatial pattern by choose the prey-tactic sensitivity coefficient as bifurcation parameter. Finally, some numerical simulations are performed to visualize the impact of prey-taxis on the complex spatial pattern formation. [ABSTRACT FROM AUTHOR]