Predator-prey Interactions Research Articles

Intraguild processes drive space-use patterns in a large-bodied marine predator community.

Interspecific interactions, including predator-prey, intraguild predation (IGP) and competition, may drive distribution and habitat use of predator communities. However, elucidating the relative importance of these interactions in shaping predator distributions is challenging, especially in marine communities comprising highly mobile species. We used individual-based models (IBMs) to predict the habitat distributions of apex predators, intraguild (IG) prey and prey. We then used passive acoustic telemetry to test these predictions in a subtropical marine predator community consisting of eight elasmobranch (i.e. shark and ray) species in Bimini, The Bahamas. IBMs predicted that prey and IG prey will preferentially select habitats based on safety over resources (food), with stronger selection for safe habitat by smaller prey. Elasmobranch space-use patterns matched these predictions. Species with predator-prey and asymmetrical IGP (between apex and small mesopredators) interactions showed the clearest spatial separation, followed by asymmetrical IGP among apex and large mesopredators. Competitors showed greater spatial overlap although with finer-scale differences in microhabitat use. Our study suggests space-use patterns in elasmobranchs are at least partially driven by interspecific interactions, with stronger spatial separation occurring where interactions include predator-prey relationships or IGP.

The behavioral and neurobiological response to sound stress in salmon.

Noise associated with human activities in aquatic environments can affect the physiology and behavior of aquatic species which may have consequences at the population and ecosystem levels. Low frequency sound is particularly stressful for fish, since it is an important factor in predator-prey interactions. Even though behavioral and physiological studies have been conducted to assess the effects of sound on fish species, neurobiological studies are still lacking. In this study we exposed farmed salmon to low frequency sound for 5 minutes a day for 30 trials and conducted behavioral observations and tissue sampling before sound exposure (timepoint zero; T0) and after 1 (T1), 10 (T2), 20 (T3) and 30 (T4) exposures, to assess markers of stress. These included plasma cortisol, neuronal activity, monoaminergic signaling, and gene expression in 4 areas of the forebrain. We found that sound exposure induced an activation of the stress response by eliciting an initial startle behavioral response, together with increased plasma cortisol levels and a decrease in neuronal activity in the hypothalamic tubercular nuclei (TN). At T3 and T4 salmon showed a degree of habituation in their behavioral and cortisol response. However, at T4, salmon showed signs of chronic stress with increased serotonergic activity levels in the dorsolateral and dorsomedial pallium, the preoptic area, and the TN, as well as an inhibition of growth and reproduction transcripts in the TN. Together, our results suggest that prolonged exposure to sound results in chronic stress that leads to neurological changes which suggest a reduction of life fitness traits.

Effects of Seed Size and Frequency on Seed Dispersal and Predation by Small Mammals.

Frequency-dependent predation is common in predator-prey interactions. Size is an important characteristic of seeds and is crucial in the regeneration stage of plant seeds. However, the frequency dependence of animal predation on seed size has not been reported. In this study, we conducted a field experiment and used different sizes of Liaodong oak (Quercus wutaishanica) seeds to test the frequency dependence of intraspecific seed size selection in rodents. We used the number ratio of large to small seeds as the frequency. The results show that the rate of small seeds being eaten in situ was significantly higher than that of large seeds (p < 0.05). The rates of different-sized seeds being eaten after removal decreased with increasing frequencies, and there was no significant difference between frequencies except for 1:9 and 9:1. The rates of large seeds being scatter-hoarded were significantly higher than those of small seeds at different frequencies (p < 0.05). The eating distances after removal of large seeds were significantly longer than those of small seeds at the same frequencies (p < 0.05). Furthermore, the scatter-hoarding distances of large seeds were significantly longer than those of small seeds at three frequencies (1:9, 3:7, and 9:1) (p < 0.05). That is, rodents consumed more small seeds in situ, dispersed and scatter-hoarded more large seeds, and dispersed large seeds over longer distances. Rodents exhibited a negative frequency dependence for small seeds and a positive frequency dependence for large seeds on being eaten in situ. Moreover, rodents exhibited a negative frequency dependence for large seeds and a positive frequency dependence for small seeds on being eaten after removal and scatter-hoarding. These results reveal the frequency dependence of rodent selection on seed size and provide new insights into animal-mediated seed dispersal and the regeneration of plant populations.

Automated escape system: identifying prey's kinematic and behavioral features critical for predator evasion.

Identifying the kinematic and behavioral variables of prey that influence the evasion from predator attacks remains challenging. To address this challenge, we have developed an automated escape system that responds quickly to an approaching predator and pulls the prey away from the predator rapidly, as real prey. Reaction distance, response latency, escape speed, and other variables can be adjusted in the system. By repeatedly measuring the response latency and escape speed of the system, we demonstrated the system's ability to exhibit fast and rapid responses while maintaining consistency across successive trials. Using the live predatory fish species, Coreoperca kawamebari, we show that escape speed and reaction distance significantly affect the outcome of predator-prey interactions. These findings indicate that the developed escape system is useful for identifying kinematic and behavioral features of prey that are critical for predator evasion, as well as for measuring the performance of predators.

Seasonal variation in the activity pattern of red squirrels and their mammalian predators

Camera traps are a powerful tool to monitor the activity pattern of species over long time periods. Camera data can be used to analyze activity patterns of or temporal niche partitioning among species. Temporal niche partitioning plays an important role for species coexistence and is under constant evolutionary pressure from predator-prey relationships. Our study aimed to investigate temporal shifts in activity patterns of red squirrels and two mammalian predators, red fox and marten (Martes spec.). Previous studies yielded different activity patterns for these species depending on location, season, predator-prey interactions, and food- availability. We used camera traps to monitor the activity of squirrels, red fox and martens throughout a whole year in a mountainous forest in southwestern Germany. We also investigated a possible difference in activity among different color morphs as coloration in mammals is often associated with concealment, for squirrels, however, such an effect could not be demonstrated so far. We found a diurnal activity for squirrels in all seasons with a bimodal activity pattern during spring, trimodal in summer and unimodal in fall and winter. Activity patterns did not differ between black and red color morphs. The activity of the squirrels showed only low to moderate overlaps with fox and marten, but there was still slight variation among seasons. Activity overlaps were higher in spring and summer, which coincides with breeding season. Our results suggest that predators might adjust their activity during squirrel breeding season to increase the chance of preying on their offspring. Squirrels in turn could benefit by minimizing the activity overlap during wintertime when they are highly visible to predators as trees are leaf-free or even snow might enhance the contrast between them and their background. Lastly, our results indicate that temporal niche portioning among red squirrel, red fox and martens might be rather fine scaled.

Species-specific predation determines the feeding impacts of six soil protist species on bacterial and eukaryotic prey

Predatory protists play a central role in nutrient cycling and are involved in other ecosystem functions by predating the microbiome. While most soil predatory protist species arguably are bacterivorous, some protist species can prey on eukaryotes. However, studies about soil protist feeding mainly focused on bacteria as prey and rarely tested both bacteria and eukaryotes as potential prey. In this study, we aimed to decipher soil predator–prey interactions of three amoebozoan and three heterolobosean soil protists and potential bacterial (Escherichia coli; 0.5–1.5 µm), fungal (Saccharomyces cerevisiae; 5–7 µm) and protist (Plasmodiophora brassicae; 3–5 µm) prey, either as individual prey or in all their combinations. We related protist performance (relative abundance) and prey consumption (qPCR) to the protist phylogenetic group and volume. We showed that for the six soil protist predators, the most suitable prey was E. coli, but some species also grew on P. brassicae or S. cerevisiae. While protist relative abundances and growth rates depended on prey type in a protist species-specific manner, phylogenetic groups and volume affected prey consumption. Yet we conclude that protist feeding patterns are mainly species-specific and that some known bacterivores might be more generalist than expected, even preying on eukaryotic plant pathogens such as P. brassicae.

Temperature alters the predator-prey size relationships and size-selectivity of Southern Ocean fish

A primary response of many marine ectotherms to warming is a reduction in body size, to lower the metabolic costs associated with higher temperatures. The impact of such changes on ecosystem dynamics and stability will depend on the resulting changes to community size-structure, but few studies have investigated how temperature affects the relative size of predators and their prey in natural systems. We utilise >3700 prey size measurements from ten Southern Ocean lanternfish species sampled across >10° of latitude to investigate how temperature influences predator-prey size relationships and size-selective feeding. As temperature increased, we show that predators became closer in size to their prey, which was primarily associated with a decline in predator size and an increase in the relative abundance of intermediate-sized prey. The potential implications of these changes include reduced top-down control of prey populations and a reduction in the diversity of predator-prey interactions. Both of these factors could reduce the stability of community dynamics and ecosystem resistance to perturbations under ocean warming.

Moving towards an ecological management of overabundant ungulates: insights from wildlife-vehicle collisions and hunting bag data

Increasing abundance of large ungulates is raising human-wildlife impacts and the effectiveness of recreational hunting to reduce their population growth is increasingly questioned. We report on long-term trends (> 15 years) in wildlife-vehicle collisions (WVC) and hunting bags, and on associations between the annual growth rate of WVC and that of hunting bags for three ungulates – the wild boar, the red deer, and the roe deer – and the grey wolf in northwest Spain to evaluate the regulating capacity of recreational hunting at large spatial scale. Wildlife-vehicle collisions increased by 332% in 16 years and 91% of all traffic accidents were caused by collisions with these three ungulates. All ungulate species showed significant positive trends in WVC and hunting bags, but we did not observe a negative association between annual growth rate of hunting bags and that of WVC except for the wild boar. Results suggest that recreational hunting was unable to reduce ungulate population growth at the regional scale. There was no upward trend of vehicle collisions with wolves over the study period, possibly reflecting stable wolf populations. Natural mortality due to predation could be promoted through the protection of apex predators, but the lethal management of apex predators, often based on sociopolitical pressures rather than damage levels, can conflict with the strategy for mitigating ungulate impacts. Ungulate management needs to be reconsidered from an ecological perspective that integrates human management measures, including recreational hunting, based on the population dynamics and the recovery of predator–prey interactions by favoring the expansion of apex predators.

Social interactions generate complex selection patterns in virtual worlds.

Understanding the influence of social interactions on individual fitness is key to improving our predictions of phenotypic evolution. However, we often overlook the different components of selection regimes arising from interactions among organisms, including social, correlational, and indirect selection. This is due to the challenging sampling efforts required in natural populations to measure phenotypes expressed during interactions and individual fitness. Furthermore, behaviours are crucial in mediating social interactions, yet few studies have explicitly quantified these selection components on behavioural traits. In this study, we capitalize on an online multiplayer video game as a source of extensive data recording direct social interactions among prey, where prey collaborate to escape a predator in realistic ecological settings. We estimate natural and social selection and their contribution to total selection on behavioural traits mediating competition, cooperation, and predator-prey interactions. Behaviours of other prey in a group impact an individual's survival, and thus are under social selection. Depending on whether selection pressures on behaviours are synergistic or conflicting, social interactions enhance or mitigate the strength of natural selection, although natural selection remains the main driving force. Indirect selection through correlations among traits also contributed to the total selection. Thus, failing to account for the effects of social interactions and indirect selection would lead to a misestimation of the total selection acting on traits. Dissecting the contribution of each component to the total selection differential allowed us to investigate the causal mechanisms relating behaviour to fitness and quantify the importance of the behaviours of conspecifics as agents of selection. Our study emphasizes that social interactions generate complex selective regimes even in a relatively simple ecological environment.

Interaction of sound-audition traits between eared insects and arthropodophagous bats: using a DNA approach to assess diet

Abstract Arthropod–bat interactions are often considered as a base model for studying factors underlying predator–prey coevolutionary processes. Bats developed ultrasonic echolocation to hunt, and in response some arthropods developed defense mechanisms such as ultrasonic hearing, allowing them to elude bat predators. The present study analyzes the feeding patterns of bats, focusing on sonic-auditory sensory mechanisms in predator–prey interactions. Next-generation DNA sequence data from fecal samples were used to analyze the diet of 17 bat species from Mexico. Arthropod prey taxa were classified according to their auditory traits, and echolocation data were recompiled from literature review. We: (i) classified arthropod families according to their hearing ability; (ii) estimated arthropod taxon richness and proportion in the diet of each bat species; and (iii) used multidimensional scaling, principal component analysis, and regression to analyze prey consumption patterns in relation to their auditory traits and in relation to echolocation characteristics of bats. Finally, we analyzed the relationship between foraging time and auditory characteristics of prey. Families with hearing organs correspond to the orders Lepidoptera and Orthoptera. We registered 20 families of Lepidoptera and 5 of Orthoptera—7 and 3 with hearing organs, respectively. Of these orders, families lacking ears were recorded in the diet of a few bat species. Our results support the allotonic frequency hypothesis predicting a difference in emission frequency intervals between predator and prey. However, we found that the consumption of earless moths is less frequent and is related to diurnal and twilight activity—hence, their consumption is limited to bat species foraging early. Results indicate bats feed on arthropod prey successfully despite the ultrasonic hearing ability of the prey. These results may be due to counteradaptations that allow maintenance of an asymmetric “arms race” between bats and eared insects that favors the predator.

Predator-prey interactions across hunting mode, spatial domain size, and habitat complexities.

Predator-prey interactions are a fundamental part of community ecology, yet the relative importance of consumptive and nonconsumptive effects (NCEs) (defined as a risk-induced response that alters prey fitness) has not been resolved. Theory suggests that the emergence and subsequent predominance of consumptive or NCEs depend on the given habitat's complexity as well as predator hunting mode and spatial domain sizes of both predator and prey, but their relative influence on the outcome of predator-prey interactions is unknown. We built agent-based models in NetLogo to simulate predator-prey interactions for three hunting modes-sit-and-wait, sit-and-pursue, and active-while concurrently simulating large versus small spatial domain sizes for both predators and prey. We studied (1) how hunting mode and spatial domain size interact to influence the emergence of consumptive or NCEs and (2) how, when NCEs do dominate, hunting mode and spatial domain separately or additively determine prey shifts in time, space, and habitat use. Our results indicate consumptive effects only dominate for active predators when prey habitat domains overlap completely with the predator's spatial domain and when sit-and-wait and sit-and-pursue predators and their prey both have large spatial domains. Prey are most likely to survive when they shift their time but most frequently shift their habitat. Our paper helps to better understand the underlying mechanisms that drive consumptive or NCEs to be most dominant.

Three sympatric host nestlings eavesdrop on cuckoo nestling distress calls.

In predator-prey interactions, the prey faces extreme challenges from predation, which drives the evolution of defense or anti-predator mechanisms. Compared with adult birds, nestlings are more vulnerable but not helpless. However, data on whether nestlings eavesdrop on the danger signals transmitted by other prey nestlings and the mechanisms of eavesdropping remain limited. In brood parasitism, common cuckoo (Cuculus canorus) nestlings, raised by host adults who are not closely related, offer an instructive system for studying the transmission and recognition of danger signals among nestlings of different species that share special relationships. We played back the distress calls of common cuckoo nestlings to nestlings of three sympatric host species (the oriental reed warbler Acrocephalus orientalis, which is a primary host of the common cuckoo, the reed parrotbill Paradoxornis heudei, an occasional host, and the vinous-throated parrotbill Sinosuthora webbiana, which is not parasitized in the study area) to investigate whether the host nestlings reduced their begging behavior. We also quantified the degree of inhibition toward begging behavior for these nestlings. The results revealed that, in response to the distress calls, the three sympatric host species markedly suppressed their begging behavior. This response can likely be attributed to the innate response of host nestlings caused by the general characteristics of distress calls, rather than the acoustic similarity and phylogenetic relationship between host nestlings and cuckoo nestlings. Furthermore, we observed that upon hearing the distress calls of cuckoo nestlings, the oriental reed warbler nestlings exhibited the greatest reduction in the total number of calls compared to the other two host species, potentially owing to stronger predation and parasitic pressures. This study suggests that host nestlings can detect danger signals emitted by parasitic nestlings; however, further investigation is needed to determine whether they can respond to distress calls from unfamiliar nestlings in different regions.

Relative predation intensity of an intertidal gastropod on artificial coastal defense structures.

Despite seawalls becoming ubiquitous coastal features, and having some physical similarities to natural rocky shores, it remains unclear how these urban habitats influence predator-prey interactions. Predators can affect intertidal mobile prey densities through two pathways: (1) successful predation directly influences prey mortality rates, and (2) direct and indirect effects of predation can scare and induce motile prey to seek safer areas. In this study, we investigated whether intertidal predators affect the density of the marine gastropod, Nerita undata, at four seawall sites in Singapore. Using a tethering method that we developed, we monitored the mortality and other evidence of predation (shell state) of tethered N. undata. Field experiments revealed high (22.5%-82.5%) predation potential of N. undata across the four sites, with significantly higher predation risk at lower shore heights and for snails with mixed shell coloration. Observations and analysis of the shell state after 3 days showed that predation on seawalls was primarily by crushing predators such as fish. Other predators of N. undata include predatory snails, with various feeding methods that left behind different predator signatures. Our results add substantially to the limited knowledge on predator-prey interactions on seawalls, particularly for Nerita undata, and suggest that seawall systems are more dynamic than previously thought. This further highlights the role of these artificial structures as important habitats and feeding grounds in urban coastal ecosystems.

When aposematism is not enough: Exotic Rattus rattus shows no mercy for carcasses of Salamandra salamandra in insular populations.

Predator-prey interaction is a major force driving natural selection. Yet, the identification of species preying on, or consuming, aposematic species is largely unknown. Here, I conduct a study evaluating the role of the exotic Rattus rattus as a consumer and possible predator of the aposematic and toxic Salamandra salamandra. I used camera traps to investigate the response of R. rattus towards S. salamandra carcasses in two insular populations, Ons and San Martiño (NW Spain), which show remarkable contrasting behaviour (nocturnal vs. diurnal activity) and demographic and phenotypic differences. This study unveils R. rattus consumes S. salamandra despite its aposematic colour pattern and toxicity. The high number of salamander carcasses consumed or taken by rats throughout each island (90%-100%) and the lack of other possible predator-prey interactions points to R. rattus as an efficient consumer of S. salamandra in these insular environments, which might exert a high predation pressure on both islands. Yet, the drivers underlying the behavioural and phenotypic differences in these insular populations should be further investigated.

Zoophytophagous predator sex pheromone and visual cues of opposing reflectance spectra lure predator and invasive prey.

In sub-Saharan Africa, the invasive South American leafminer Phthorimaea absoluta is the most damaging tomato pest. Females of the pest can reproduce both sexually and through parthenogenesis and lay their eggs on all tomato plant parts. The mirid predator Nesidiocoris tenuis, a biological control agent for the pest, is also a tomato pest when prey population is low. To date, however, no study has developed an eco-friendly solution that targets both the predator and its host in a tomato farming system. To develop a bio-based management system for both pest and predator based on the combined use of sexual communication in the predator and visual cues. We collected volatiles from both sexes of the Kenyan population of the predator N. tenuis and identified candidate sex pheromone components by coupled gas chromatography-mass spectrometry (GC-MS). We used electrophysiological assays to identify antennally-active odorants in the volatiles, followed by field trials with different pheromone-baited colored traps to validate the responses of both predator and prey. Thereafter, we compared the reflectance spectra of the colored traps with those of different tomato plant tissues. Our results reveal an interplay between different sensory cues which in the predator-prey interaction may favor the predator. Antennae of both sexes of predator and prey detect the predator sex pheromone identified as 1-octanol and hexyl hexanoate. Unexpectedly, our field experiments led to the discovery of a lure for P. absoluta females, which were lured distinctly into a pheromone-baited trap whose reflectance spectrum mimicked that of ripe tomato fruit (long wavelength), an egg-laying site for females. Contrastingly, N. tenuis males were lured into baited white trap (short wavelength) when the predator is actively searching for prey. Our results demonstrate the novel use of a predator sex pheromone and different visual cues to assess complex trophic interactions on tomatoes.

Synergistic effects of musking and autohaemorrhaging on the duration of death feigning in dice snakes (Natrix tessellata).

Predation exerts a significant selection pressure on prey, shaping a multitude of traits that serve as antipredator defences. In turn, natural selection could favour combinations of antipredator defences with synergistic effects that enhance prey survival. An especially interesting antipredator defence is death feigning (DF), present in a wide variety of taxa and usually characterized by the prey lying motionless often along with defaecation, musking and autohaemorrhaging (AH). All these aspects of the DF display should work in conjunction with one another, intensifying the overall effect of the display and in turn facilitating quicker escape. To confirm this hypothesis, we tested 263 dice snakes (Natrix tessellata) directly in the field. We noted the occurrence of smearing faeces, musk and AH, and we measured the duration of DF, expecting to see a negative association between the occurrence of these behaviours and the duration of DF. Our results affirm our hypothesis: dice snakes that smeared themselves in musk and faeces prior to DF and had AH during DF spent significantly less time in DF. Our results highlight the functional integration of antipredator behaviours across different phases of predator-prey interactions, emphasizing the need for future research to prioritize studying the sequential display of behaviours.

A robotic falcon induces similar collective escape responses in different bird species.

Patterns of collective escape of a bird flock from a predator are fascinating, but difficult to study under natural conditions because neither prey nor predator is under experimental control. We resolved this problem by using an artificial predator (RobotFalcon) resembling a peregrine falcon in morphology and behaviour. We imitated hunts by chasing flocks of corvids, gulls, starlings and lapwings with the RobotFalcon, and compared their patterns of collective escape to those when chased by a conventional drone and, in case of starlings, hunted by wild peregrine falcons. Active pursuit of flocks, rather than only flying nearby by either the RobotFalcon or the drone, made flocks collectively escape more often. The RobotFalcon elicited patterns of collective escape in flocks of all species more often than the drone. Attack altitude did not affect the frequency of collective escape. Starlings escaped collectively equally often when chased by the RobotFalcon or a wild peregrine falcon. Flocks of all species reacted most often by collective turns, second most often by compacting and third by splitting into subflocks. This study demonstrates the potential of an artificial aerial predator for studying the collective escape behaviour of free-living birds, opening exciting avenues in the empirical study of prey-predator interactions.

Behavioral responses to predator and heterospecific alarm calls are habitat-specific in Eurasian tree sparrows

Acoustic communication plays a vital role in predator-prey interactions. Although habitat structure has been shown to affect anti-predator tactics, little is known about how animals vary their behaviors in response to predator calls or heterospecific alarm calls in different environments. Here we used sound playbacks to test the responses of Eurasian tree sparrows (Passer montanus) foraging in harvested/unharvested rice paddy and open residential area. In the first experiment, we tested their behavioral responses to dove calls, male common cuckoo (Cuculus canorus) calls, hawk-like calls mimicked by female common cuckoo, sparrowhawk (Accipiter nisus) calls, and human yell calls produced to scare birds (predator signal playbacks). In the second experiment, we tested their behavioral responses to the Japanese tit’s (Parus minor) territorial songs and alarm calls (heterospecific alarm signal playbacks). Results showed that the tree sparrows had less fleeing in unharvested ripe rice paddy than in harvested rice paddy and open residential area. In predator signal playbacks, call type affected the escape behavior of sparrows in unharvested rice paddy and open residential area but not harvested rice paddy. In alarm signal playbacks, tit alarm calls evoked more fleeing than territorial songs in harvested rice paddy and open residential area but not unharvested rice paddy. These results suggest that anthropogenic habitat changes may influence avian anti-predator tactics.

A probabilistic foundation for the study of larval fish feeding, growth, and mortality rates

Survival through the larval phase is predicated on the probabilities of successful feeding, which dictates growth rates, and the probabilities of encountering predators. Here I perform a synthesis of feeding, growth, and mortality rates estimated during several studies from coastal Newfoundland, Canada, to provide a description of the probability distribution that can serve as a foundation of the expected distribution of vital rates. The standardized observations clearly follow that of skewed distributions, appropriately fit to a probability gamma distribution, with feeding demonstrating a stronger degree of skewness than either mortality or growth, possibly because each vital rate integrates prey–predator interactions over different time scales. Commonality in the underlying form of the distribution of vital rates in larval fish, along with clear functional relationships between gamma parameters, represents a probabilistic basis of expectations against which observations from prior or new studies can be contrasted. An example of the use of such expectations demonstrates that they can provide useful contextual information about the contrast among observations and our ability to identify their relationship with environmental drivers.

Effects of predation risk on parasite-host interactions and wildlife diseases.

Landscapes of fear can determine the dynamics of entire ecosystems. In response to perceived predation risk, prey can show physiological, behavioral, or morphological trait changes to avoid predation. This in turn can indirectly affect other species by modifying species interactions (e.g., altered feeding), with knock-on effects, such as trophic cascades, on the wider ecosystem. While such indirect effects stemming from the fear of predation have received extensive attention for herbivore-plant and predator-prey interactions, much less is known about how they alter parasite-host interactions and wildlife diseases. In this synthesis, we present a conceptual framework for how predation risk-as perceived by organisms that serve as hosts-can affect parasite-host interactions, with implications for infectious disease dynamics. By basing our approach on recent conceptual advances with respect to predation risk effects, we aim to expand this general framework to include parasite-host interactions and diseases. We further identify pathways through which parasite-host interactions can be affected, for example, through altered parasite avoidance behavior or tolerance of hosts to infections, and discuss the wider relevance of predation risk for parasite and host populations, including heuristic projections to population-level dynamics. Finally, we highlight the current unknowns, specifically the quantitative links from individual-level processes to population dynamics and community structure, and emphasize approaches to address these knowledge gaps.