Search Results (126)

Understanding how emotions and psychological states influence both individual and collective actions is critical for expressing the real complexity of biosocial and ecological systems. Recent breakthroughs in mathematical modeling have created new opportunities for systematically integrating these emotion-specific elements into dynamic frameworks ranging from human health to animal ecology and socio-technical systems. This review builds on mathematical modeling approaches by bringing together insights from neuroscience, psychology, epidemiology, ecology, and artificial intelligence to investigate how psychological effects such as fear, stress, and perception, as well as memory, motivation, and adaptation, can be integrated into modeling efforts. This article begins by examining the influence of psychological factors on brain networks, mental illness, and chronic physical diseases (CPDs), followed by a comparative discussion of model structures in human and animal psychology. It then turns to ecological systems, focusing on predator–prey interactions, and investigates how behavioral responses such as prey refuge, inducible defense, cooperative hunting, group behavior, etc., modulate population dynamics. Further sections investigate psychological impacts in epidemiological models, in which risk perception and fear-driven behavior greatly affect disease spread. This review article also covers newly developing uses in artificial intelligence, economics, and decision-making, where psychological realism improves model accuracy. Through combining these several strands, this paper argues for a more subtle, emotionally conscious way to replicate intricate adaptive systems. In fact, this study emphasizes the need to include emotion and cognition in quantitative models to improve their descriptive and predictive ability in many biosocial and environmental contexts. Full article

Trace metals and metalloids pose persistent threats to freshwater ecosystems, yet their trophic transfer and sublethal effects across food webs remain poorly understood. We investigated bioaccumulation patterns and biomarker responses in a predator–prey system comprising Prussian carp (Carassius gibelio) and Great Cormorant (Phalacrocorax carbo) nestlings from the Danube floodplain wetland Kopački rit Nature Park (Croatia) during 2023–2024. Concentrations of arsenic (As), selenium (Se), cadmium (Cd), mercury (Hg) and lead (Pb) were determined in Prussian carp liver and in Great Cormorant whole blood. The activities of acetylcholinesterase (AChE), carboxylesterase (CES), glutathione S-transferase (GST) and the levels of reactive oxygen species (ROS) and reduced glutathione (GSH) were measured in brain, muscle and gill tissues of Prussian carp, as well as in plasma and S9 blood fractions of Great Cormorants. In addition, tissue-specific metal concentration ratios (TSMCR) were calculated to assess the relative magnitude of recent dietary exposure in the predator compared to the prey. Biomarker activity showed strong tissue- and fraction-specific variation, with temporal differences. Exposure–response modelling revealed significant associations between As, Cd, and Hg and specific biomarkers, particularly in gill and plasma. Cross-species comparisons indicated elevated TSMCR as a proxy for recent trophic exposure only for Hg in 2023, whereas As and Se exhibited lower TSMCR. These findings demonstrate that metal exposure in floodplain systems induces physiological responses and Hg poses the greatest prey-to-predator exposure risk, highlighting the value of integrating pollutant measurements with mechanistic biomarker endpoints to evaluate ecosystem-level impacts. Full article

Microplastics (<5 mm) have become a pervasive pollutant because of their persistence, bioavailability, and risk of trophic transfer. The present work provides new evidence on microplastic contamination in three economically important species from the Romanian Black Sea coast: Mytilus galloprovincialis, Rapana venosa, and Sprattus sprattus. Microplastics were extracted using 10% potassium hydroxide (KOH) chemical digestion and examined under a stereomicroscope. Microplastics frequency of occurrence (FO%) ranged from 66.7% to 93.3%, with mean abundances per individual being 3.06 ± 3.71 in mussels, 3.26 ± 2.08 in rapa whelks, and 3.13 ± 2.44 in sprats. Fibers were the dominant type, followed by fragments, with blue, black, and transparent colours most common. Most particles were within the 1–5 mm and 330 µm⁻¹ mm size classes, with smaller fractions between 100 and 330 µm, indicating ingestion of particles large enough to accumulate rather than be rapidly egested. The microplastic contamination found in predatory R. venosa suggests trophic transfer of microplastics from bivalve prey. As all three species are consumed by humans, they represent potential pathways for microplastic exposure. These results emphasize the urgent necessity for additional research on sources, environmental pathways, and possible health risks of microplastics in the Black Sea. Full article

Despite growing evidence of the widespread impacts of human activities on carnivores and their prey, it remains unclear how different types and intensities of human disturbance reshape predator–prey interactions. In this study, we conducted a systematic camera-trapping survey on a threatened carnivore, the small Indian civet (Viverricula indica). This species forages on prey with contrasting diel patterns, including nocturnal rats and diurnal species such as Pallas’s squirrel (Callosciurus erythraeus) and Chinese bamboo partridge (Bambusicola thoracica) in the southern Wuyi Mountains of southeastern China. Based on data from an extensive sampling effort (60,901 trap days at 180 camera stations), we used kernel density estimation and Pianka’s index to examine whether and how different types and intensities of human activity (human presence, roads, and settlements), as well as diverse altitudes and different seasons, affect the spatiotemporal interactions between small Indian civets and their potential prey. We found that all studied species adjusted their activity patterns, either advancing or delaying their peaks, to achieve temporal segregation under varying types and intensities of human disturbance and different altitudes and seasons. At the temporal scale, interactions between small Indian civets and their potential prey supported the human shield hypothesis, suggesting that increased human disturbance provides diurnal prey with refuge from predation pressure. Conversely, at both spatial and spatiotemporal scales, higher levels of human disturbance increased the overlap between small Indian civets and their prey species. These findings highlight that human impacts on wildlife interactions are scale-dependent: temporal refuge for prey does not necessarily reduce spatial or spatiotemporal overlap, which may still increase encounter rates and predation risk. Because our sampling relied on ground-level cameras, our inferences are limited to terrestrial interactions; arboreal interactions remain unquantified and require combined ground–canopy sampling in future work. Effective conservation management thus requires considering these scale-dependent effects of human activities on wildlife interactions. Full article

We adapt previous conceptual and numerical models of ciguateric food chains for the bioaccumulation of Pacific-ciguatoxin-1 (P-CTX-1) to a general model for bioaccumulation of P-CTX3C by parrotfish (Scarus frenatus, S. niger, and S. psittacus) that feed by scraping turf algae, and surgeonfish (Naso unicornis) that mostly feed on macroalgae. We also include the Indian Ocean parrotfish Chlorurus sordidus as a model for an excavator feeding parrotfish and include comparisons with the detritivorous surgeonfish Ctenochaetus striatus that brush-feeds on turf algae. Our food chain model suggests that, of the Gambierdiscus and Fukuyoa species so far analysed for ciguatoxin (CTX) production from the Pacific, only G. polynesiensis produces sufficient P-CTX3C to consistently produce parrotfish or N. unicornis with poisonous flesh. Our model suggests that insufficient CTX would accumulate into the flesh of parrotfish or N. unicornis to become poisonous from ingesting benthic dinoflagellates producing ≤0.03 pg P-CTX3C eq./cell, except from extended feeding times on high-density blooms and in the absence of significant depuration of CTX. Apart from G. polynesiensis, only G. belizeanus and possibly G. silvae and G. australes are thought to produce >0.03 pg P-CTX3C eq./cell in the Pacific. However, with relatively low maximum concentrations of ≤0.1 pg P-CTX3C eq./cell it is likely that their contribution is minimal. Our model also suggests that the differences between the area of turf algae grazed by parrotfish and similar sized C. striatus results in greater accumulation of CTX by this surgeonfish. This makes C. striatus a higher ciguatera risk than similar sized parrotfish, either directly for human consumption or as prey for higher trophic level fishes, consistent with poisoning data from Polynesia. It also suggests the possibility that C. striatus could bioaccumulate sufficient CTX to become mildly poisonous from feeding on lower toxicity Gambierdiscus or Fukuyoa species known to produce ≥0.02 P-CTX3C eq./cell. This indicates the potential for at least two food chain pathways to produce ciguateric herbivorous fishes, depending on the CTX concentrations produced by resident Gambierdiscus or Fukuyoa on a reef and the grazing capacity of herbivorous fish. However, only G. polynesiensis appears to produce sufficient P-CTX3C to consistently accumulate in food chains to produce higher trophic level fishes that cause ciguatera in the Pacific. We incorporate CTX depuration into our model to explore scenarios where mildly poisonous parrotfish or N. unicornis ingest CTX at a rate that is balanced by depuration to estimate the Gambierdiscus/Fukuyoa densities and CTX concentrations required for these fish to remain poisonous on a reef. Full article

The increased presence of harmful algal blooms (HABs) is a concern for many aquatic environments, especially with the increasing effects of climate change. Members of the dinoflagellate genus Dinophysis have been shown to produce toxins that can cause Diarrheic Shellfish Poisoning (DSP) in humans who consume infected shellfish. The advancing oyster aquaculture industry in Delaware will require the development of management practices and monitoring HAB species to protect environmental and human health. Temperature, nutrients, and prey abundance can be drivers of Dinophysis blooms. D. acuminata has been historically identified at high concentrations (>200,000 cells L⁻¹) in water samples from Rehoboth Bay, DE, USA. However, the reach of spring blooms and how far they extend to aquaculture sites have not been determined. This study monitored an emergent HABs threat of a toxin-producing dinoflagellate, Dinophysis acuminata, by assessing a transect during the first recorded winter bloom in Torquay Canal and analyzing concentrations of chemical nutrients of combined nitrate and nitrite, and orthophosphate. Pearson correlation coefficient analysis between cell density (cells L⁻¹) and environmental variables across all sites was conducted to determine significant relationships between water temperature, Chl-a concentration, conductivity, dissolved oxygen (DO), combined nitrate and nitrite concentrations (NO_x), and orthophosphate concentrations (PO₄³⁻). Genetic techniques and PCR were utilized to determine the presence of Dinophysis using genus-specific primers to monitor cell density or abundance within the sediments during winter months. There were no significant correlations between environmental variables, and nutrient concentrations did not exceed EPA regulations. Molecular analyses of benthic sediments detected Dinophysis spp., offering insight into potential bloom origins. Overall, there is limited ecological data on Dinophysis acuminata in Rehoboth Bay, DE, USA. The results of this study will help strengthen resources for monitoring HAB species and understanding potential risks to oyster aquaculture in Delaware. Full article

Due to their zoonotic potential and close interaction with humans, feline parasitic infections are an important public health concern. This study investigated 2758 domiciled and feral cats sampled across Mexico to assess the occurrence of parasites, coinfections, and associated risk factors. Twelve genera of parasites were identified, with Ancylostoma and Ctenocephalides being the most frequent. Coinfections were common, often involving both intestinal and ectoparasites. Multivariable logistic regression revealed that feral lifestyle, absence of recent antiparasitic treatment, female sex, and climatic conditions were significant predictors of infection. Cats with unrestricted outdoor access and direct contact with other cats, where hunting behavior and the ingestion of prey cannot be ruled out (ESCCAP risk group B), were more than five times as likely to be infected as those cats that live indoors (ESCCAP risk group A). Although antiparasitic use was reported in some cats, inappropriate drug choice and long treatment intervals reduced effectiveness, while nearly seven out of ten cats had never received treatment. These findings highlight major gaps between current practices in Mexico and international guidelines. Strengthening surveillance, promoting owner education, and implementing risk-based strategies are critical to reducing feline parasitism and associated zoonotic risks within a One Health framework. Full article

Anti-predator behaviour in birds is required by day and night but has barely been studied at night. For prey which detect predators visually, low light levels may diminish detection or monitoring of approaching threats. We conducted standardised approaches to Silver Gulls (Chroicocephalus novaehollandiae) by day and night along an urban foreshore in Melbourne, Australia, measuring light levels (Lux) experienced by the gull, Flight-initiation Distance (FID; the distance at which escape is initiated), and Starting Distance (the initial distance between the observer and the bird). We fitted models reflecting different conceptual possibilities for the relationship between Lux and FID. Support existed for a model with a stepwise effect of light on FID. Longer FIDs (i.e., earlier escape) in darker conditions suggest that gulls can detect an approaching threat in darkness at least as well as by day, but the tolerance of closer approaches may be diminished in dull and dark conditions, perhaps due to difficulty in monitoring an approaching threat and/or because nighttime represents a time of greater predator risk. Starting Distance was positively related to FID, a result commonly reported for many taxa by day. Full article

Predation plays a key organizational role in structuring plankton communities. However, predator diversity can lead to emergent effects in which the outcomes of predator–prey interactions are modified. The response of the plankton community to three different predator regimes at natural densities was investigated over a 10-day mesocosm experiment in a temperate, temporarily open/closed estuary in South Africa. The regimes included: (1) predation by the mysid, Mesopodopsis wooldridgei; (2) predation by larval Rhabdosargus holubi and (3) a combination of the two predators. M. wooldridgei are primarily copepod feeders, and juvenile R. holubi consume a broader diet including zooplankton, algae and invertebrate fauna. In the absence of predators, zooplankton grazing contributed to a significant decline in the phytoplankton size structure and total chlorophyll-a (Chl-a) concentration. The presence of the predators contributed to a decline in the total zooplankton abundances and biomass which dampened the grazing impact of the zooplankton on the total Chl-a, consistent with the expectations of a trophic cascade. There were no significant differences in the size structure of the phytoplankton community, total Chl-a concentration and the total zooplankton abundances and biomass between the different predator treatments, suggesting that the increase in predator diversity did not contribute to increased prey risk. These findings highlight both the direct and indirect ecological impacts of predators on plankton dynamics. Full article

Although the ultimate drivers of bat fatalities at wind turbines are still not well understood, the foraging behavior of insectivorous bats puts them at increased risk of collision with rotating blades. Wind energy facilities are commonly located in agriculture fields where bats can exploit periodic superabundant insect emergence events in the late summer and early autumn. Thermal imaging, acoustic monitoring, and bat carcass stomach content analyses show that bats prey upon insects on and near wind turbine towers. Studies have shown a positive association between insect abundance and bat activity, including in agricultural systems. We conducted a systematic review of bat diets for four common bat species in the Midwest and northern Great Plains to synthesize existing knowledge across species, assess the extent to which these bat focal species consume crop pests, and evaluate the potential for crop pest emergence models to predict temporal and spatial patterns of bat fatalities in this region. Big brown bats and eastern red bats consumed a variety of crop pests, including some for which emergence models may be available. In contrast, there were few studies for hoary bats or silver-haired bats, and the dietary evidence available has insufficient taxonomic resolution to conclude that crop pests were consumed. To augment existing data and illuminate relationships, we recommend that genetic diet analyses for bats, specifically hoary and silver-haired, be conducted in the late summer and autumn in this region. The results of these studies may provide additional candidate insect models to evaluate for predicting bat fatalities at wind turbines and clarify if the superabundant insect emergence hypothesis warrants further investigation. Full article

Understanding how prey and predator species partition activity patterns across time and space is essential for elucidating behavioral adaptation and ecological coexistence. In this study, we examined the diel and seasonal activity rhythms of two sympatric rodent species—Rhombomys opimus (Great gerbil) and Meriones meridianus (Midday gerbil)—and their primary predators, Otocolobus manul (Pallas’s cat) and Vulpes vulpes (Red fox), in a desert-steppe ecosystem on the northern slopes of the Qilian Mountains, China. Using over 8000 camera trap days and kernel density estimation, we quantified their activity intensity and spatiotemporal overlap. The two rodent species showed clear temporal niche differentiation but differed in their synchrony with predators. R. opimus exhibited a unimodal diurnal rhythm with spring activity peaks, while M. meridianus showed stable nocturnal activity with a distinct autumn peak. Notably, O. manul adjusted its activity pattern to partially align with that of R. opimus, whereas V. vulpes maintained a crepuscular–nocturnal rhythm overlapping more closely with that of M. meridianus. Despite distinct temporal rhythms, both rodent species shared high spatial overlap with their predators (overlap index OI = 0.64–0.83). These findings suggest that temporal partitioning may reduce predation risk for R. opimus, while M. meridianus co-occurs more extensively with its predators. Our results highlight the ecological role of native carnivores in rodent population dynamics and support their potential use in biodiversity-friendly rodent management strategies under arid grassland conditions. Full article

Savanna systems are characterised by a community of large mammal herbivores with up to 30 species; coexistence is based on resource partitioning. In this paper we analyse the features of the landscape and plant structure which lead herbivores to use particular locations, a key to resource partitioning. The processes involved, top-down versus bottom-up, are well known for large species and small ones but not for medium-sized ones. We use two resident, medium-sized species, topi (Damaliscus lunatus jimela) and kongoni, (Alcelaphus buselaphus cokei) in the central woodlands of the Serengeti; selection of habitat by the residents is important for predator-prey interactions and for interactions among the grazers. Using Principal Component Analysis and Multiple Regression we develop highly predictive models which show that resource availability is the critical determinant of habitat selection in the dry season; and reduction in predation risk appears to be important in the wet season. These results show for the first time that habitat selection by the medium-sized herbivores is driven by different strategies in the two seasons. This contributes to understanding the processes involved in the dynamics of this globally important savanna system, a necessary foundation for management. Full article

The non-traditional companion animal (NTCA) sector, particularly involving avian species, has significantly expanded in Italy, raising concerns over the spread of infectious diseases. These animals can harbor various pathogens and act as reservoirs, posing risks to native wildlife through legal or illegal trade, escapes, or intentional releases. However, the epidemiology of avian pathogens in NTCAs remains poorly understood and is typically investigated only in symptomatic individuals. In the present study, cloacal and choanal cleft swabs were collected from 319 ornamental and raptor birds across 19 families, pooled and tested for beak and feather disease virus (BFDV), avian polyomavirus (APV-1), psittacid herpesvirus 1 (PsHV-1), and avian metapneumovirus (aMPV). BFDV and APV-1 were detected in 13.79% and 2.19% of birds, respectively, with five co-infections. No cases of PsHV-1 or aMPV were found. Both viruses showed a higher prevalence than in previous Italian and most of international studies, with several non-psittacine species, including birds of prey, testing positive—some for the first time. Mixed-species settings and participation in public exhibitions were proven as significant infection risk factors. The study highlights the growing relevance of BFDV and APV-1 in non-commercial birds and recommends improved biosecurity and preventive screening to reduce disease spread and safeguard animal health. Full article

Background/Objectives: Increasing levels of antimicrobial resistance (AMR) have recently been observed at the human–domestic animal–wildlife interface. Wild birds have been identified as carriers of antimicrobial-resistant bacteria and serve as excellent biomarkers for epidemiological studies. This study assessed the current AMR presence in Eastern Spain’s commensal Escherichia coli isolated from free-ranging Bonelli’s eagles (Aquila fasciata). Methods: Nestlings and their nests were intensively sampled between 2022 and 2024 to determine their AMR profile and characterize E. coli. AMR testing was conducted using the broth microdilution method, following the European Committee on Antimicrobial Susceptibility Testing guidelines. Additionally, the presence of eaeA (intimin gene) and stx-1 and stx-2 (shiga toxins) was analyzed by real-time PCR to classify E. coli strains into enteropathogenic (EPEC) and Shiga-toxigenic (STEC) pathotypes. Results: Of all E. coli isolates, 41.7% were resistant to at least one antimicrobial, and 30% were multidrug-resistant. Only two strains were classified as EPEC and none as STEC. The highest resistance rates were observed for amoxicillin and tetracycline (19.6% each). Alarmingly, resistance to colistin and meropenem, last-resort antibiotics in human medicine, was also detected. Conclusions: Although the mechanisms of resistance acquisition remain unclear, transmission is likely to occur through the food chain, with synanthropic prey acting as intermediary vectors. These results highlight the role of Bonelli’s eagles as essential sentinels of environmental AMR dissemination, even in remote ecosystems. Strengthening One Health-based surveillance is necessary to address AMR’s ecological and public health risks in wildlife. Full article

Background/Objectives: Australian terrestrial mammals that fall within the critical weight range (35 g–5.5 kg) have experienced large population declines due to a combination of habitat loss and modification, and the introduction of non-native cats, dogs, and foxes. Because running speed typically increases with body size, predators are usually faster but less agile than their prey due to the biomechanical trade-offs between speed and agility. Quantifying the maximum locomotor capacities of Australian mammals in the critical weight range, and the magnitude of the trade-off between speed and agility, can aid in estimating species’ vulnerability to predation. Methods: To do this, we quantified the trade-off between speed and agility in both males and females (n = 36) of a critical weight range species, the northern brown bandicoot (Isoodon macrourus), and determined if there was an influence of morphology on locomotor performance. Results: When turning, individuals who had higher turn approach speeds, and higher within-turn speeds, had greater turning radii and lower angular velocities, meaning a decrease in overall maneuverability. Females were more agile and exhibited greater turning speeds at similar turning radii than males. For both sexes, individuals with longer relative hind digits had relatively faster sprint speeds, while those with longer forearms had relatively smaller turning radii and higher agility. Conclusions: Due to the constrained limb morphology of the bandicoot species, these findings could translate across this group to provide a better understanding of their escape performance and risk of predation. Full article