Prey Interactions Research Articles

Prey and Predator Behavioral Interactions with a Primary Burrowing Crayfish (Lacunicambarus thomai)

Burrowing crayfish represent a small, specialized group of crayfish that inhabit self-made terrestrial burrows. Primary burrowing crayfish depend upon their burrows for protection, respiration, rearing of young, food storage, and thermoregulation. Burrowing crayfish tend to stay in proximity to or around their burrows causing them to be elusive lifestyle and consequently poorly documented. All crayfish are opportunistic generalists regarding food and have been recorded eating detritus, periphyton, and small invertebrates. Due to their stygobitic lifestyle, food resources are also limited to what is near their burrow, which commonly includes vegetation as well as smaller invertebrates. The predatory behaviors of burrowing crayfish has been studied and observed in abundance in epigean crayfish, however, it has been rare and few studies have been conducted on this behavior in burrowing species. This study utilized 24-h surveillance of a burrowing crayfish species, the Little Brown Mud Bug (Lacunicambarus thomai). A total of 633 H of videos were recorded of 6 different crayfish at varying times for each individual. Predatory behaviors were observed on several organisms including ants, worms, spiders, and dragonfly naiads. Gut analysis was performed on 23 L. thomai from 4 separate populations confirming the findings of the video footage that, in all populations, both animal and vegetation were being consumed. This study suggested that a sit-and-wait predation behavior may be a far more common foraging behavior in burrowing crayfish than previously observed.

Quantifying predator functional responses under field conditions reveals interactive effects of temperature and interference with sex and stage.

Predator functional responses describe predator feeding rates and are central to predator–prey theory. Originally defined as the relationship between predator feeding rates and prey densities, it is now well known that functional responses are shaped by a multitude of factors. However, much of our knowledge about how these factors influence functional responses is based on laboratory studies that are generally logistically constrained to examining only a few factors simultaneously and that have unclear links to the conditions organisms experience in the field.We apply an observational approach for measuring functional responses to understand how sex/stage differences, temperature and predator densities interact to influence the functional response of zebra jumping spiders on midges under natural conditions.We used field surveys of jumping spiders to infer their feeding rates and examine the relationships between feeding rates, sex/stage, midge density, predator density and temperature using generalized additive models. We then used the relationships supported by the models to fit parametric functional responses to the data.We find that feeding rates of zebra jumping spiders follow some expectations from previous laboratory studies such as increasing feeding rates with body size and decreasing feeding rates with predator densities. However, in contrast to previous results, our results also show a lack of temperature response in spider feeding rates and differential decreases in the feeding rates of females and juveniles with densities of different spider sexes/stages.Our results illustrate the multidimensional nature of functional responses in natural settings and reveal how factors influencing functional responses can interact with one another through behaviour and morphology. Further studies investigating the influence of multiple mechanisms on predator functional responses under field conditions will increase our understanding of the drivers of predator–prey interaction strengths and their consequences for communities and ecosystems.

Safe Passage or Hunting Ground? A Test of the Prey-Trap Hypothesis at Wildlife Crossing Structures on NH 44, Pench Tiger Reserve, Maharashtra, India

Crossing structures are widely accepted mitigation measures used to offset the impacts of roads in ecologically sensitive areas that serve as important animal corridors. However, altered interspecies interactions at crossing structures may reduce the potency of these structures for some species and groups. Anecdotes of predation events at crossing structures have necessitated the assessment of predator–prey interactions at crossing structures. We investigated the ‘prey-trap’ hypothesis at nine crossing structures on a highway in central India adjacent to a tiger reserve by comparing the geometric mean latencies between successive prey, predator and free-ranging dog camera trap capture events at the crossing structures. Among all interactions, prey–predator latencies were the shortest, and significantly lower than prey–dog and predator–prey latencies. Prey–predator sequences involving wild dogs had the shortest average latencies (65.6 ± 9.7 min). Prey–predator latencies decreased with increasing crossing structure width; however, these crossing structures are also the sites that are most frequently used by wildlife. Results indicate that the crossing structures presently do not act as ‘prey-traps’ from wild predators or free-ranging dogs. However, measures used to alleviate such prospects, such as heterogeneity in structure design and increase in vegetation cover near crossing structures, are recommended.

Spatiotemporal dynamics of Leslie–Gower predator–prey model with Allee effect on both populations

In the present paper, we consider a reaction–diffusion system, based on the Leslie–Gower predator–prey model with Allee effect in both the predator and prey populations. The model is a generalization of the case where the individual population is subject to the Allee effect and it is flexible such that one can easily obtain the scenario with the Allee effect only on the prey population or, predator population. The non-spatial model was analyzed by using the positivity of solutions, uniformly boundedness and local stability of the interior equilibrium. The sufficient conditions for the instability with zero-flux boundary conditions are obtained for the spatial model. We have derived the analytical conditions for Hopf and Turing bifurcation on the spatial domain. We also observe that the system exhibits complex dynamics like Bogdanov–Takens (BT) bifurcation and generalized Hopf (GH) bifurcation. Our numerical simulations reveal that depending on the strength of Allee effects, the model dynamics exhibit stripes, spots, cold–hot spots–stripes coexistence and cold–hot spots patterns. We obtain very interesting characteristics of the reaction–diffusion model which reflects the fact that the system can develop patterns both inside and outside of the Turing parameter domain. Our study may enrich the field of the Allee effect and will help us to acquire a better understanding of the predator–prey interaction in a real environment.

Monogenean body size, but not reproduction, increases with infracommunity density

Body size reveals a plethora of life-history, ecological, and evolutionary information about a species. It plays a critical role in success or failure during competitive, reproductive, or predator–prey interactions. Typically, there is a negative relationship between body size and population density in natural populations and communities. I analysed this relationship within and among multiple populations of two prominent monogenean parasites (>90% prevalence) on Lepomis macrochirus in three lakes in New Jersey (USA), using multiple regression models. To elucidate the causes and benefits of this relationship, I also measured host body condition via a regression index, and reproductive output of the parasite community by measuring parasite eggs shed from the host. The relationship between body size and density of infrapopulations (parasites of a single species on a single host) was positive, and the strength of this relationship for both species depended on which lake they occupied, indicating the potential for Allee effects. This relationship persists at the infracommunity level, where there was a similar positive relationship between a community weighted mean body size and density. However, this relationship did not result in greater reproductive success as measured by infracommunity egg production per individual per 24 h or egg size. The cause of this relationship also remains elusive; it was not explained by host condition or age. The results suggest that there is either no reproductive advantage to this increase in body size or the advantage conferred was not related to these measured fitness components. These findings indicate that researchers should be cautious using body size as a proxy for fitness or reproduction, while also raising further questions about the nature of the relationship between parasites on a host and that between those parasites and the host.

Lack of evidence for indirect effects from stonefly predators on primary production under future climate warming scenarios

ABSTRACT Consumptive and non-consumptive interactions of predators and prey can have strong direct and indirect effects on primary producers, such as stream algae. Increasing water temperatures may alter these interactions and thus influence productivity in streams. For each of 3 temperature treatments (‘ambient’, +2°C and +4°C), we measured the amount of algal biomass removed by grazing mayflies from 91 mesocosms after a 24-hour test period under 3 grazing treatments: lethal predators, non-lethal predators, and no predators. At all temperatures, grazers reduced algal biomass (p < 0.01), and the presence of lethal predators effectively dampened mayfly consumption of algae (p < 0.01). However, differences in algal biomass between lethal and non-lethal predator treatments were not significant, indicating that predators had no indirect behaviorally mediated effects on grazer consumption. Grazer removal of algal biomass marginally increased with increasing temperature (p = 0.051). We analyzed video data for changes in grazer foraging and drift behavior. Mayflies increased drift in the presence of lethal predators (p < 0.01) but not non-lethal predators, and no behavioral changes were seen with temperature increases. Mesocosms can help elucidate possible future shifts in trophic interactions due to climate warming. Yet, we found no evidence of indirect stonefly predator effects on grazing mayflies under these warming scenarios.

Controls and characteristics of biomass quantization in size-structured planktonic ecosystem models

Strong relationships between size and other traits have long motivated studies of the size structure and dynamics of planktonic food webs. Size structured ecosystem models (SSEMs) are often used to represent the behavior of these ecosystems, with organism size as a first order approximation of the axis of biological diversity. Previous studies using SSEMs have reported the emergence of localized “peaks” in the size spectrum, a phenomenon that will be referred to in this study as “quantization”. However, SSEMs that are used routinely in Earth System Models (ESMs), they tend to be too coarsely discretized to resolve quantization. Observational studies of plankton biomass have also shown qualitatively similar patterns, with localized peaks along the size spectrum. The conditions under which quantization occurs and the ecosystem parameters that control the locations of the biomass “peaks” along the size spectrum have not been systematically explored. This study serves to simultaneously advance our understanding of the constraints on quantization in size-structured ecosystems, and to suggest an approach to discretizing SSEMs that leverages quantization to select a greatly reduced number of size classes. A size-structured model of the pelagic food web, similar to those implemented in global models, is used to investigate the sensitivity of biomass peaks to predator–prey interactions, and nutrient forcing. This study shows that the location of biomass peaks along the size spectrum is strongly controlled by the size selectivity of predation, and the location of biomass peaks along the size spectrum is less sensitive to variations in nutrient supply, external ecosystem forcing, and vertical heterogeneity. Taking advantage of a robust localization of biomass peaks, the dynamics of a continuous planktonic size spectrum to be represented using a few selected size classes, corresponding to locations of the peaks along the size spectrum. These findings offer an insight on how to approach discretization of size structured ecosystem model in Earth system models.

Fear at the top: killer whale predation drives white shark absence at South Africa’s largest aggregation site

Risk-induced fear effects exerted by top predators are pervasive in terrestrial and marine systems, with lasting impacts on ecosystem structure and function. The loss of top predators can disrupt ecosystems and trigger trophic cascades, but the introduction of novel apex predators into ecosystems is not well understood. We documented the emigration of white sharks Carcharodon carcharias in response to the presence of a pair of killer whales, Orcinus orca, at a large white shark aggregation site in South Africa. Between February and June in 2017, five white shark carcasses washed up on beaches in Gansbaai, Western Cape Province, four of which had their livers removed. Sightings per unit effort (sea days) and telemetry data demonstrated that white sharks emigrated from Gansbaai following these predation events, and in response to further sightings of this pair and other killer whale pods in the vicinity. Tagging data demonstrated the immediate departure of white sharks from Gansbaai, and some sharks were subsequently moving east. Contrary to expected and well-documented patterns of white shark occurrence at this site, their sightings dropped throughout the following 2.5 years; change-point analysis on both datasets confirmed these departures coincided with killer whale presence and shark carcasses washing out. These findings suggest that white sharks respond rapidly to risk from a novel predator, and that their absence triggered the emergence of another predator, the bronze whaler Carcharhinus brachyurus. Predator–prey interactions between white sharks, other coastal sharks, and killer whales are increasing in South Africa and are expected to have pronounced impacts on the ecosystem.

Supporting marine spatial planning with an ecosystem model of Algoa Bay, South Africa

The Ecopath with Ecosim (EwE) modelling framework was used to develop a model of Algoa Bay and test the ecosystem impacts of the implementation of the Addo Elephant National Park Marine Protected Area (MPA). The Ecopath model included 37 functional groups ranging from phytoplankton to top predators and was fitted to 12 and 14 time-series of biomass and landings, respectively, from 2010 to 2019 (calibration period), using Ecosim. Two scenarios representing different degrees of fisheries closures in the MPA were explored through a 30% and a 100% reduction in fishing effort. Temporal simulations were run until 2059. The fitting procedure identified the best-fit model as the one including the effects of fishing, the six most-sensitive predator–prey interactions, and environmental forcing (primary production anomaly on small phytoplankton). Overall, the predicted biomass and catch time-series reasonably reproduced the observed time-series for 2010–2019, with the biomass of sardine Sardinops sagax, round herring Etrumeus whiteheadi, and African penguins Spheniscus demersus showing the best fits to data. Both MPA scenarios resulted in higher total biomass compared with the baseline by the end of the simulation and decreased catches due to less fishing effort. The most profound biomass increases under the MPA scenarios were observed in apex and pelagic elasmobranchs, yellowtail Seriola lalandi and African penguins. Future research is needed to improve the more-uncertain model parameters and include other key sectors in Algoa Bay, such as shipping. However, this model provides a good foundation for future work including the application of spatially explicit modelling of the bay using Ecospace.

Predator–prey interactions: Strategic biting

The nematode Pristionchus pacificus occasionally encounters other nematode species that compete for similar resources. A new study shows that P. pacificus perform an aggressive patrolling and biting behavior to expel adult Caenorhabditis elegans nematodes from food patches.

Stochastic pursuit-evasion curves for foraging dynamics

Many predator species attempt to locate prey by following seemingly random paths. Although the underlying physical mechanism of the search remains largely unknown, such search paths are usually modeled by some type of random walk. Here, we introduce the stochastic pursuit-evasion equations that consider the bidirectional interaction between predators and prey. This assumption results in a modulated persistent random walk that is characterized by three interesting properties: power-law or tempered power-law distributed running times, superdiffusive or transient superdiffusive dynamics, and strong directional persistence. Furthermore, the proposed model exhibits a transition from Brownian to Lévy-like motion with intensifying predator–prey interaction. Interestingly, persistent random walks with pure-power law distributed running times emerge at the limit of highest predator–prey interaction. We hypothesize that the system ultimately self-organizes into a critical interaction to avoid extinction.

The broken-wing display across birds and the conditions for its evolution.

The broken-wing display is a well-known and conspicuous deceptive signal used to protect birds' broods against diurnal terrestrial predators. Although commonly associated with shorebirds, it remains unknown how common the behaviour is across birds and what forces are associated with the evolution of the display. Here, we use the broken-wing display as a paradigmatic example to study the evolution of a behaviour across Aves. We show that the display is widespread: it has been described in 52 families spread throughout the phylogeny, suggesting that it independently evolved multiple times. Further, we evaluated the association with 16 ecological and life-history variables hypothesized to be related to the evolution of the broken-wing display. Eight variables were associated with the display. We found that species breeding farther from the equator, in more dense environments, with shorter incubation periods, and relatively little nest cover were more likely to perform the display, as were those in which only one parent incubates eggs, species that mob nest predators and species that are altricial or multi-brooded. Collectively, our comprehensive approach identified forces associated with the repeated evolution of this conspicuous display, thereby providing new insights into how deceptive behaviours evolve in the context of predator–prey interactions.

Scale dependence of drilling predation in the Holocene of the northern Adriatic Sea across benthic habitats and nutrient regimes

AbstractPredation has strongly shaped past and modern marine ecosystems, but the scale dependency of patterns in drilling predation, the most widely used proxy for predator–prey interactions in the fossil record, is a matter of debate. To assess the effects of spatial and taxonomic scale on temporal trends in the drilling frequencies (DFs), we analyzed Holocene molluscan assemblages of different benthic habitats and nutrient regimes from the northern Adriatic shelf in a sequence-stratigraphic context. Although it has been postulated that low predation pressures facilitated the development of high-biomass epifaunal communities in the eastern, relatively oligotrophic portion of the northern Adriatic shelf, DFs reaching up to 30%–40% in the studied assemblage show that drilling predation levels are comparable to those typical of late Cenozoic ecosystems. DFs tend to increase from the transgressive systems tract (TST) into the highstand systems tract (HST) at the local scale, reflecting an increase in water depth by 20–40 m and a shift from infralittoral to circalittoral habitats over the past 10,000 years. As transgressive deposits are thicker at shallower locations and highstand deposits are thicker at deeper locations, a regional increase in DFs from TST to HST is evident only when these differences are accounted for. The increase in DF toward the HST can be recognized at the level of total assemblages, classes, and few abundant and widespread families, but it disappears at the level of genera and species because of their specific environmental requirements, leading to uneven or patchy distribution in space and time.

Fear of parasitism affects the functional role of ecosystem engineers

Fear is an integral part of predator–prey interactions with cascading effects on the structure and function of ecosystems. Fear of parasitism holds a similar ecological potential but our understanding of the underlying mechanisms in host–parasite interactions is limited by lack of empirical examples. Here, we experimentally test if blue musselsMytilus edulisrespond behaviourally to the mere presence of infective transmission stages of the trematodeHimasthla elongataby ceasing filtration activity, thereby avoiding infection. Our results show that blue mussels reduced clearance rates by more than 30% in presence of parasites. The reduced filtration activity resulted in lower infection rates in experimental mussels. The identified parasite‐specific avoidance behaviour can be expected to play a significant role in regulating the ecosystem engineering function of blue mussels in coastal habitats.

Predator cues target signaling pathways in toxic algal metabolome

AbstractEarly detection of predators is critical to the survival of all living organisms. For phytoplankton, recognition and response to chemical cues from predators, as evidence of predation risk, are particularly crucial. The phytoplankton Alexandrium minutum upregulates its toxicity when exposed to copepodamides, a suite of compounds released by copepod predators. However, how A. minutum perceives these predatory cues and what metabolic pathways are involved in initiating toxin induction remains unknown. In this study, liquid chromatography‐mass spectrometry and NMR‐based metabolomics uncovered subtle physiological responses of A. minutum to copepodamides, including altered regulation of branched‐chain amino acid biosynthesis and potential enhancement of butanoate metabolism and arginine biosynthesis. While we have yet to identify a chemoreceptor directly activated by copepod cues, based on the results of inhibition experiments, detection of copepodamides appears to disrupt the activity of serine/threonine phosphatases leading to increased jasmonic acid biosynthesis and signaling, which leads to amplified gonyautoxin biosynthesis in A. minutum. This study is an important step toward a better understanding of chemosensory ecology of predator–prey interactions in phytoplankton.

Body mass ratios determine dietary patterns and help predicting predator–prey interactions of Neotropical Carnivora

Body mass ratios determine dietary patterns and help predicting predator–prey interactions of Neotropical Carnivora

Adaptive Vertical Positioning as Anti-Predator Behavior: The Case of a Prey Fish Cohabiting with Multiple Predatory Fish within Temperate Marine Algal Forests.

Simple SummaryFish cohabiting within structurally complex habitats (e.g., coral reefs, seagrass meadows, algal forests) include abundant small-bodied prey fish and specialized piscivorous fish. Habitat structural complexity mediating fish predator–prey interactions has been shown to be an important mechanism sustaining this coexistence. However, the effect of the vertical stratification of habitat structure on predator–prey interactions remains poorly known, especially within a forest-like marine habitat, i.e., a habitat containing three vertical strata (understory, canopy and open-water). We set up tank experiments to test how such habitat vertical stratification affects predator–prey lethal and behavioral interactions, using one prey and two predator model species cohabiting in Mediterranean algal forest. We found that prey anti-predator behavior was predator-specific. When exposed to a sit-and-wait predator, the prey increased its vertical distance from the predator, regardless of the habitat structure. Conversely, when exposed to a stalk-and-attack predator, the prey sought refuge within forest structures. Prey hide motionless within the canopy, the most complex strata, while they avoid and escape from predators within the understory, which is a less complex stratum allowing for fast prey movements but still protected from predators by the canopy above. Our results suggest the crucial role of habitat vertical stratification in influencing predator–prey interactions, which should be studied in three dimensions.Prey fish cohabit with specialized predator fish within structurally complex habitats. How the vertical stratification of the habitat affects lethal and behavioral predator–prey interactions and contributes to explaining these patterns has never been investigated within a forest-like marine habitat, i.e., a habitat containing three vertical strata (understory, canopy, open-water above). We studied this in tank experiments, with a model prey (the wrasse Symphodus ocellatus) and two model predators (the stalk-and-attack comber Serranus cabrilla and the sit-and-wait scorpionfish Scorpaena porcus), which are among the most abundant prey and predators cohabiting in Mediterranean Cystoseira forests. Wrasse anti-predator behavior was predator-specific. When exposed to the scorpionfish, the wrasse increased its vertical distance from the predator, regardless of the habitat structure. Conversely, when exposed to the comber, the wrasse sought refuge within forest structures: (1) the canopy provides more hiding opportunities due to its high complexity, and (2) the understory provides more escape/avoidance opportunities due to (a) its low complexity that allows for fast prey movements, and (b) the presence of the canopy above that limits the comber’s access to the understory. Our results suggest that habitat vertical stratification mediates predator–prey interactions and potentially promotes the co-existence of prey and multiple predators within marine forests.

Fire as a driver and mediator of predator-prey interactions.

ABSTRACTBoth fire and predators have strong influences on the population dynamics and behaviour of animals, and the effects of predators may either be strengthened or weakened by fire. However, knowledge of how fire drives or mediates predator–prey interactions is fragmented and has not been synthesised. Here, we review and synthesise knowledge of how fire influences predator and prey behaviour and interactions. We develop a conceptual model based on predator–prey theory and empirical examples to address four key questions: (i) how and why do predators respond to fire; (ii) how and why does prey vulnerability change post‐fire; (iii) what mechanisms do prey use to reduce predation risk post‐fire; and (iv) what are the outcomes of predator–fire interactions for prey populations? We then discuss these findings in the context of wildlife conservation and ecosystem management before outlining priorities for future research. Fire‐induced changes in vegetation structure, resource availability, and animal behaviour influence predator–prey encounter rates, the amount of time prey are vulnerable during an encounter, and the conditional probability of prey death given an encounter. How a predator responds to fire depends on fire characteristics (e.g. season, severity), their hunting behaviour (ambush or pursuit predator), movement behaviour, territoriality, and intra‐guild dynamics. Prey species that rely on habitat structure for avoiding predation often experience increased predation rates and lower survival in recently burnt areas. By contrast, some prey species benefit from the opening up of habitat after fire because it makes it easier to detect predators and to modify their behaviour appropriately. Reduced prey body condition after fire can increase predation risk either through impaired ability to escape predators, or increased need to forage in risky areas due to being energetically stressed. To reduce risk of predation in the post‐fire environment, prey may change their habitat use, increase sheltering behaviour, change their movement behaviour, or use camouflage through cryptic colouring and background matching. Field experiments and population viability modelling show instances where fire either amplifies or does not amplify the impacts of predators on prey populations, and vice versa. In some instances, intense and sustained post‐fire predation may lead to local extinctions of prey populations. Human disruption of fire regimes is impacting faunal communities, with consequences for predator and prey behaviour and population dynamics. Key areas for future research include: capturing data continuously before, during and after fires; teasing out the relative importance of changes in visibility and shelter availability in different contexts; documenting changes in acoustic and olfactory cues for both predators and prey; addressing taxonomic and geographic biases in the literature; and predicting and testing how changes in fire‐regime characteristics reshape predator–prey interactions. Understanding and managing the consequences for predator–prey communities will be critical for effective ecosystem management and species conservation in this era of global change.

Predation risk can modify the foraging behaviour of frugivorous carnivores: Implications of rewilding apex predators for plant-animal mutualisms.

Apex predators play key roles in food webs and their recovery can trigger trophic cascades in some ecosystems. Intra‐guild competition can reduce the abundances of smaller predators and perceived predation risk can alter their foraging behaviour thereby limiting seed dispersal by frugivorous carnivores. However, little is known about how plant–frugivore mutualisms could be disturbed in the presence of larger predators.We evaluated the top‐down effect of the regional superpredator, the Iberian lynx Lynx pardinus, on the number of visits and fruits consumed by medium‐sized frugivorous carnivores, as well as the foraging behaviour of identified individuals, by examining the consumption likelihood and the foraging time.We carried out a field experiment in which we placed Iberian pear Pyrus bourgaeana fruits beneath fruiting trees and monitored pear removal by frugivorous carnivores, both inside and outside lynx ranges. Using camera traps, we recorded the presence of the red fox Vulpes vulpes, the Eurasian badger Meles meles and the stone marten Martes foina, as well as the number of fruits they consumed and their time spent foraging.Red fox was the most frequent fruit consumer carnivore. We found there were fewer visits and less fruit consumed by foxes inside lynx ranges, but lynx presence did not seem to affect badgers. We did not observe any stone marten visits inside lynx territories. The foraging behaviour of red foxes was also altered inside lynx ranges whereby foxes were less efficient, consuming less fruit per unit of time and having shorter visits. Local availability of fruit resources, forest coverage and individual personality also were important variables to understand visitation and foraging in a landscape of fear.Our results show a potential trophic cascade from apex predators to primary producers. The presence of lynx can reduce frugivorous carnivore numbers and induce shifts in their feeding behaviour that may modify the seed dispersal patterns with likely consequences for the demography of many fleshy‐fruited plant species. We conclude that knowledge of the ecological interactions making up trophic webs is an asset to design effective conservation strategies, particularly in rewilding programs.

Predator-prey interactions of terrestrial invertebrates are determined by predator body size and species identity.

Predator-prey interactions shape ecosystems and can help maintain biodiversity. However, for many of the earth's most biodiverse and abundant organisms, including terrestrial arthropods, these interactions are difficult or impossible to observe directly with traditional approaches. Based on previous theory, it is likely that predator-prey interactions for these organisms are shaped by a combination of predator traits, including body size and species-specific hunting strategies. In this study, we combined diet DNA metabarcoding data of 173 individual invertebrate predators from nine species (a total of 305 individual predator-prey interactions) with an extensive community body size data set of a well-described invertebrate community to explore how predator traits and identity shape interactions. We found that (1) mean size of prey families in the field usually scaled with predator size, with species-specific variation to a general size-scaling relationship (exceptions likely indicating scavenging or feeding on smaller life stages). We also found that (2) although predator hunting traits, including web and venom use, are thought to shape predator-prey interaction outcomes, predator identity more strongly influenced our indirect measure of the relative size of predators and prey (predator:prey size ratios) than either of these hunting traits. Our findings indicate that predator body size and species identity are important in shaping trophic interactions in invertebrate food webs and could help predict how anthropogenic biodiversity change will influence terrestrial invertebrates, the earth's most diverse animal taxonomic group.