Sedentary Prey Research Articles

Diet of Crossodactylus timbuhy (Anura: Hylodidae) in the Reserva Biológica Augusto Ruschi, state of Espírito Santo, Brazil

Abstract: Anurans are predator and prey, playing an important role in ecosystem functioning. The diet composition is closely related to feeding strategy, and the information about prey items is useful to understand intra and interspecific interactions in trophic webs. Here we determined diet composition, feeding strategy, and relation between prey ingestion and body measures of Crossodactylus timbuhy, a recently described anuran species. We found 466 prey items from 20 prey categories in the stomach of 66 specimens (15 males and 51 females) of C. timbuhy. The diet consists mostly of Formicidae and Coleoptera, the items with the highest number, frequency of occurrence and prey importance. The diet composition was relatively similar to other species of Crossodactylus. Prey volume was positively related to frog size and weight, suggesting frogs may feed upon any prey they can swallow. Diet showed some variation between sexes. Despite females were larger and heavier than males, females had higher consumption of smaller prey, and ingested a larger number of prey categories. We suggest C. timbuhy has an invertebrate-opportunistic feeding habit. It is likely C. timbuhy uses a combination of ‘sit-and-wait’ and ‘active search’ strategies due to high consumption of both highly mobile and sedentary prey.

Analysis of diet composition and morphological characters of the Peruvian lizard Microlophus stolzmanni (Squamata: Tropiduridae)

Analysis of diet composition and morphological characters of the Peruvian lizard Microlophus stolzmanni (Squamata: Tropiduridae). Microlophus stolzmanni is a diurnal lizard that is endemic to the dry forest of northern Peru. Little is known about the ecology of the species and the composition of its diet never has been studied. The stomach contents and morphological features related to feeding behavior are analyzed herein. Microlophus stolzmanni is a semi-herbivorous food generalist that also consumes animal items. All age groups prefer sedentary prey for which M. stolzmanni forages actively. As the lizard matures, plant material becomes a more important part of the diet.

Complexity in a prey-predator model with prey refuge and diffusion

Prey-predator interaction is one of the most commonly observed relationships in ecosystem. In the study of prey-predator models, it is frequently assumed that the changes in population densities are only time-dependent and the dynamics is generally represented by coupled nonlinear ordinary differential equations. In natural system, however, either prey or predator or both move from one place to another for various reasons. In such a case, their dynamic interaction depends both on time and space and requires coupled nonlinear partial differential equations for its dynamic representation. It is also well documented that prey refuges affect the interaction between prey and predator significantly. In this paper, we studied the dynamics of a diffusive prey-predator interaction with prey refuge and type III response function. We have considered both one and two dimensional diffusivity in the model system and presented different stability results under the assumptions that one or both species may be mobile or sedentary. Our results showed that the system may exhibit different spatiotemporal (non-Turing) patterns, like spiral waves, patchy structures, spot pattern, or even spatiotemporal chaos depending on the refuge availability and diffusion rate of species. Another interesting finding was that the dynamic complexity in a prey-predator model increases in case of mobile predator and sedentary prey compare to mobile prey and sedentary predator while refuge availability is varied.

First Observation of a Disturbance Foraging Association between Obligate Ant-following Birds and a Tamandua Anteater in Central Panama

ABSTRACT.— Disturbance foraging – the use of disturbances created by other animals to locate cryptic or sedentary prey – is a widespread phenomenon, particularly in birds. In the Neotropics, a prominent example of disturbance foraging in birds is their relationship with army ants (Eciton burchellii). Numerous bird species attend army ant swarms and forage on the prey that the ants flush from the leaf litter. Here, I document a previously undescribed disturbance foraging association between two species of obligate ant-following birds and a small anteater, the northern tamandua (Tamandua mexicana). I observed both bird species approach and forage on fallen termites underneath the anteater, which was excavating a termite nest. The foraging association appeared to be a commensal relationship – the antbirds obtained a foraging benefit from the anteater, which was in turn unaffected by the birds. My observation suggests that ant-following birds may respond to other disturbances in addition to army ant swarms to...

Habitat complexity dampens selection on prey activity level

AbstractConspecific prey individuals often exhibit persistent differences in behavior (i.e., animal personality) and consequently vary in their susceptibility to predation. How this form of selection varies across environmental contexts is essential to predicting ecological and evolutionary dynamics, yet remains currently unresolved. Here, we use three separate predator–prey systems (sea star–snail, wolf spider–cricket, and jumping spider–cricket) to independently examine how habitat structural complexity influences the selection that predators impose on prey behavioral types. Prior to conducting staged predator–prey interaction encounters, we ran prey individuals through multiple behavioral assays to determine their average activity level. We then allowed individual predators to interact with groups of prey in either open or structurally complex habitats and recorded the number and individual identity of prey that were eaten. Habitat complexity had no effect on overall predation rates in any of the three predator–prey systems. Despite this, we detected a pervasive interaction between habitat structure and individual prey activity level in determining individual prey survival. In open habitats, all predators imposed strong selection on prey behavioral types: sea stars preferentially consumed sedentary snails, while spiders preferentially consumed active crickets. Habitat complexity dampened selection within all three systems, equalizing the predation risk that active and sedentary prey faced. These findings suggest a general effect of habitat complexity that reduces the importance of prey activity level in determining individual predation risk. We reason this occurs because activity level (i.e., movement) is paramount in determining risk within open environments, whereas in complex habitats, other behavioral traits (e.g., escape ability to a refuge) may take precedence.

Sedentary prey facing an acute predation risk: testing the hypothesis of inducible metabolite emission suppression in zebra mussels, Dreissena polymorpha

It takes time before a defensive phenotype can be effectively developed, which handicaps sessile bivalves exposed to acute predation risks. In a laboratory experiment, we examined whether predation threats induce zebra mussels to limit metabolic rates, serving as a fast-response defence that reduces the chances of chemical detection by predators. We measured the respiration rate of mussels exposed to predation treatments (fish fed zebra mussels, fish fed chironomids, crushed zebra mussels) and to predation-free conditions, and we tested the effect of these treatments on attachment strength and aggregation. Compared with the predation-free controls, all mussels in the predation treatments tended to initially have suppressed metabolic rates. The rate of metabolism increased over time in all treatments, but only in the presence of fish fed chironomids was the increase significantly greater than in the control. Attachment strengths and aggregation rates were similar for all treatments after 7 days. Our results provide the first evidence of predation-induced changes in zebra mussel metabolic rates. We suggest that mussels respond differently to different types of predation threats. Immediately after receiving predation cues, they react promptly by lowering their production of metabolites, but over time, they re-adjust their response to the actual predation threat present.

Aegean wall lizards switch foraging modes, diet, and morphology in a human‐built environment

Foraging mode is a functional trait with cascading impacts on ecological communities. The foraging syndrome hypothesis posits a suite of concurrent traits that vary with foraging mode; however, comparative studies testing this hypothesis are typically interspecific. While foraging modes are often considered typological for a species when predicting foraging‐related traits or mode‐specific cascading impacts, intraspecific mode switching has been documented in some lizards. Mode‐switching lizards provide an opportunity to test foraging syndromes and explore how intraspecific variability in foraging mode might affect local ecological communities.Because lizard natural history is intimately tied to habitat use and structure, I tested for mode switching between populations of the Aegean wall lizard, Podarcis erhardii, inhabiting undisturbed habitat and human‐built rock walls on the Greek island of Naxos. I observed foraging behavior among 10 populations and tested lizard morphological and performance predictions at each site. Furthermore, I investigated the diet of lizards at each site relative to the available invertebrate community.I found that lizards living on rock walls were significantly more sedentary—sit and wait—than lizards at nonwall sites. I also found that head width increased in females and the ratio of hindlimbs to forelimbs in both sexes increased as predicted. Diet also changed, with nonwall lizards consuming a higher proportion of sedentary prey. Lizard bite force also varied significantly between sites; however, the pattern observed was opposite to that predicted, suggesting that bite force in these lizards may more closely relate to intraspecific competition than to diet.This study demonstrates microgeographic variability in lizard foraging mode as a result of human land use. In addition, these results demonstrate that foraging mode syndromes can shift intraspecifically with potential cascading effects on local ecological communities.

Nestling diet optimization and condition in relation to prey attributes and breeding patch size in a patch-resident insectivorous passerine: an optimal continuum and habitat constraints

Direct observational studies are needed to address dietary adjustment in species breeding in isolated non-forest habitat islands with respect to the energy demands of growing nestlings and breeding patch size. Using new dietary records determined for nestlings of Whinchat Saxicola rubetra, a dramatically declining insectivorous passerine and an indicator species of the cessation of agricultural activity, we investigated the relationships between changes in the main dietary characteristics, numerical and biomass contributions of major taxonomic and functional prey groups (expressing chitin content, vertical distribution, habitat preference and vagility within the landscape) and brood age, nestling condition and size of abandoned fields (i.e. breeding patches). Broods from larger abandoned fields received more sedentary and heavier prey like Orthoptera and soil-dwelling invertebrates, whereas the proportion of caterpillars, aerial insects and prey from vegetation decreased with increasing patch size. Nestling condition was positively correlated with the proportion of caterpillars and Orthoptera or sedentary prey taxa, but negatively with the proportion of Coleoptera or vagile prey taxa in the diet, though not with patch area. This suggests that parent Whinchats can overcome the habitat constraints resulting from the small area of an abandoned field by interchangeably incorporating the two major prey groups (Orthoptera or Lepidoptera) into the diet they feed to their nestlings. This implies a continuum in dietary optimization that is a trade-off between a brood’s nutritional demands and the parents’ ability to deliver top-ranked invertebrates present mostly within the breeding patch.

Strike mechanics of an ambush predator: the spearing mantis shrimp

Ambush predation is characterized by an animal scanning the environment from a concealed position and then rapidly executing a surprise attack. Mantis shrimp (Stomatopoda) consist of both ambush predators ('spearers') and foragers ('smashers'). Spearers hide in sandy burrows and capture evasive prey, whereas smashers search for prey away from their burrows and typically hammer hard-shelled, sedentary prey. Here, we examined the kinematics, morphology and field behavior of spearing mantis shrimp and compared them with previously studied smashers. Using two species with dramatically different adult sizes, we found that strikes produced by the diminutive species, Alachosquilla vicina, were faster (mean peak speed 5.72±0.91 m s(-1); mean duration 3.26±0.41 ms) than the strikes produced by the large species, Lysiosquillina maculata (mean peak speed 2.30±0.85 m s(-1); mean duration 24.98±9.68 ms). Micro-computed tomography and dissections showed that both species have the spring and latch structures that are used in other species for producing a spring-loaded strike; however, kinematic analyses indicated that only A. vicina consistently engages the elastic mechanism. In the field, L. maculata ambushed evasive prey primarily at night while hidden in burrows, striking with both long and short durations compared with laboratory videos. We expected ambush predators to strike with very high speeds, yet instead we found that these spearing mantis shrimp struck more slowly and with longer durations than smashers. Nonetheless, the strikes of spearers occurred at similar speeds and durations to those of other aquatic predators of evasive prey. Although counterintuitive, these findings suggest that ambush predators do not actually need to produce extremely high speeds, and that the very fastest predators are using speed to achieve other mechanical feats, such as producing large impact forces.

A Two-Patch Predator-Prey Metapopulation Model

AbstractA minimal model for predator-prey interaction in a composite environment is presented and analysed. We first consider free migrations between two patches for both interacting populations, and then the particular cases where only one-directional migration is allowed and where only one of the two populations can migrate. Our findings indicate that in all cases the ecosystem can never disappear entirely, under the model assumptions. The predator-free equilibrium and the coexistence of all populations are found to be the only feasible stable equilibria. When there are only one-directional migrations, the abandoned patch cannot be repopulated. Other equilibria then arise, with only prey in the second patch, coexistence in the second patch, or prey in both patches but predators only in the second one. For the case of sedentary prey, with predator migration, the prey cannot thrive alone in either of the two environments. However, predators can survive in a prey-free patch due to their ability to migrate into the other patch, provided prey is present there. If only the prey can migrate, the predators may be eliminated from one patch or from both. In the first case, the patch where there are no predators acts as a refuge for the survival of the prey.

A Two-Patch Predator-Prey Metapopulation Model

A minimal model for predator-prey interaction in a composite environment is presented and analysed. We first consider free migrations between two patches for both interacting populations, and then the particular cases where only one-directional migration is allowed and where only one of the two populations can migrate. Our findings indicate that in all cases the ecosystem can never disappear entirely, under the model assumptions. The predator-free equilibrium and the coexistence of all populations are found to be the only feasible stable equilibria. When there are only one-directional migrations, the abandoned patch cannot be repopulated. Other equilibria then arise, with only prey in the second patch, coexistence in the second patch, or prey in both patches but predators only in the second one. For the case of sedentary prey, with predator migration, the prey cannot thrive alone in either of the two environments. However, predators can survive in a prey-free patch due to their ability to migrate into the other patch, provided prey is present there. If only the prey can migrate, the predators may be eliminated from one patch or from both. In the first case, the patch where there are no predators acts as a refuge for the survival of the prey.

Diet, morphology and performance in two chameleon morphs: do harder bites equate with harder prey?

AbstractEcologically induced morphological variation has been identified as a mainstay in evolutionary theory. Species that inhabit different habitats are likely to display morphological and functional differences related to the exploitation of different dietary resources available in each habitat within limits imposed by trade‐offs. Here, we examine two populations of the Cape Dwarf Chameleon, Bradypodion pumilum, from fynbos (heathland) and woodland to investigate whether head morphology and bite performance are related to diet within and between populations. Stomach contents are compared with prey availability to test whether chameleons are selective with respect to prey size, hardness and evasiveness. Our data show that for adult chameleons from the fynbos (Kogelberg; n = 44), mean and maximum prey size are tightly correlated with head morphology and performance. In woodland habitat (Stellenbosch; n = 52), only maximum prey size is correlated with head morphology and performance. Fynbos chameleons showed no preference with respect to prey hardness, while those from woodland ate less hard and/or sedentary prey than available, thus preferring items that were soft and/or evasive. Finally, fynbos chameleons have a diet of sedentary and/or evasive prey similar in proportions to that available. Our results suggest that diet is not directly related to selection on the head morphology and biting performance of B. pumilum in woodland habitat, but that it may be important for selection in fynbos due to a reduction in overall prey availability.

Tracking large carnivore dispersal using isotopic clues in claws: an application to cougars across the Great Plains

Summary1. Cougar (Puma concolor) populations, like other large carnivores, have increased during recent decades and may be recolonizing their former ranges in Midwestern North America. The dispersal routes taken by these animals from established populations are unknown and insight into these movements would facilitate their conservation and management.2. We inferred the origin and migration route of four dispersing cougars using stable hydrogen (δD) and carbon (δ13C) isotope values along one of their claws. We compared isotopic variations within claws to regional and large‐scale isoscapes of δD and δ13C values in prey species. Using a likelihood‐based assignment approach, we predicted the most likely dispersal route of each cougar (among several least‐cost dispersal paths to potential source populations) in a chronological sequence dating back from its final location.3. Our model predicted the origin of a radio‐collared short‐distance disperser and inferences about the most likely dispersal corridors for two long‐distance dispersers matched reported information from re‐sighting events and genetic investigations.4. Insights about the most likely migration corridors may help identify critical areas and guide future conservation efforts of cougars and other large carnivores. We encourage managers to extend regional isoscapes based on sedentary prey species as they prove to be valuable tools in isotopic tracking of long‐distance migration.5. Our isotopic approach may be extended to other metabolically inert tissues that grow continuously, to investigate dispersal paths of species of interest, providing that individuals disperse across known isotopically structured landscapes.

Foraging mode of Australolacerta rupicola (FitzSimons, 1933) (Sauria: Lacertidae): evidence of seasonal variation in an extremely active predator?

Foraging mode of the endemic Soutpansberg rock lizard (Australolacerta rupicola) was determined by (1) measuring the number of movements per minute (MPM) and the percentage time spent moving (PTM); and (2) analysing faecal samples. Furthermore, these criteria were related to diet composition, proportion of attacks initiated while moving and foraging substrate. The results are discussed in comparison to the foraging modes of 20 other lacertid species. Values for MPM and PTM as well as faecal analysis indicate an active foraging strategy for A. rupicola. Although rock living, this species mostly forages in leaf litter where it is well camouflaged while actively searching for sedentary prey. Even in comparison to other active foragers of the family Lacertidae, A. rupicola displays the prototypic behaviour of a widely foraging lizard with very high PTM and very low MPM.

Predator identity and the nature and strength of food web interactions

1. Most trophic interaction theory assumes that all predators are an abstract form of risk to which prey respond in a quantitatively similar manner. This conceptualization can be problematic because recent empirical work demonstrates that variation in the responses of prey to different predators can play a key role in structuring communities and regulating ecosystem function. 2. Predator identity - the species specific response of prey to a predator - has been proposed as an ultimate mechanism driving the relative contribution of indirect effects in food webs; however few studies have explicitly tested this hypothesis. 3. This study explores the impact of predator identity on direct consumptive (CE) and non-consumptive effects (NCEs), and on the relative contribution of indirect, density and trait-mediated effects in trophic cascades within host-parasitoid communities. 4. We systematically compared the individual, host-parasitoid-plant interactions of two actively foraging parasitoid species with disparate foraging styles, one aggressive and one furtive, a common aphid host and plant. Our results demonstrate that the degree of risk aversion by prey to each particular predator species (i.e. predator identity) is a key factor driving the nature and strength of direct and indirect transmission pathways. 5. Both parasitoid species, in general, had a negative impact on plants. The magnitude of the aphid anti-predator dispersal response was positively correlated with plant infestation and plant damage. The qualitative effect of predator-induced infestation of new plants superseded the quantitative effects of predator-mediated reductions in aphid numbers. 6. The greatest indirect impact on plants was generated by the aggressively foraging parasitoid, and the strength of the aphids anti-predator response (a NCE) antagonistically traded-off with CEs due to an increased investment in attempting to capture risk-sensitized prey. In contrast, the furtive parasitoid did not elicit a strong anti-predator response, had little indirect impact on plants, but generated very high CEs due to the advantage of ovipositing into a sedentary prey population. 7. Our data suggest the responses of prey to different predatory cues may be an important mechanism driving the relative contribution of transmission pathways in trophic cascades. We conclude that predator identity is a key factor influencing the nature and strength of food web interactions.

Habitat structure mediates predation risk for sedentary prey: experimental tests of alternative hypotheses

1. Predation is an important and ubiquitous selective force that can shape habitat preferences of prey species, but tests of alternative mechanistic hypotheses of habitat influences on predation risk are lacking. 2. We studied predation risk at nest sites of a passerine bird and tested two hypotheses based on theories of predator foraging behaviour. The total-foliage hypothesis predicts that predation will decline in areas of greater overall vegetation density by impeding cues for detection by predators. The potential-prey-site hypothesis predicts that predation decreases where predators must search more unoccupied potential nest sites. 3. Both observational data and results from a habitat manipulation provided clear support for the potential-prey-site hypothesis and rejection of the total-foliage hypothesis. Birds chose nest patches containing both greater total foliage and potential nest site density (which were correlated in their abundance) than at random sites, yet only potential nest site density significantly influenced nest predation risk. 4. Our results therefore provided a clear and rare example of adaptive nest site selection that would have been missed had structural complexity or total vegetation density been considered alone. 5. Our results also demonstrated that interactions between predator foraging success and habitat structure can be more complex than simple impedance or occlusion by vegetation.

When cormorants go fishing: the differing costs of hunting for sedentary and motile prey

Cormorants hunt both benthic (sedentary) and pelagic (motile) prey but it is not known if the energy costs of foraging on these prey differ. We used respirometry to measure the costs of diving in double-crested cormorants (Phalacrocorax auritus) foraging either for sedentary (fish pieces) or motile (juvenile salmon) prey in a deep dive tank. Short dives for sedentary prey were more expensive than dives of similar duration for motile prey (e.g. 20% higher for a 10s dive) whereas the reverse was true for long dives (i.e. long dives for motile prey were more expensive than for sedentary prey). Across dives of all durations, the foraging phase of the dive was more expensive when the birds hunted motile prey, presumably due to pursuit costs. The period of descent in all the dives undertaken appears to have been more expensive when the birds foraged on sedentary prey, probably due to a higher swimming speed during this period.

Diet and foraging of the endemic lizard Cnemidophorus littoralis (Squamata, Teiidae) in the restinga de Jurubatiba, Macaé, RJ

We investigated the diet and foraging of the endemic teiid lizard Cnemidophorus littoralis in a restinga habitat in Jurubatiba, Macaé - RJ. The stomach contents were removed, analyzed and identified to the Order level. There was no relationship between C. littoralis morphological variables and number, length or volume of preys. Termites (48.7%) and larvae (35.5%) were the most important prey items which occurred in the examined lizards' stomachs. The diet did not differ between males and females. Cnemidophorus littoralis is an active forager and predominantly consumes relatively sedentary prey or prey that is aggregated in the environment. We also found an intact and undigested hatchling of the crepuscular/nocturnal gekkonid lizard Hemidactylus mabouia in the stomach of an adult male of C. littoralis, which indicates that C. littoralis is a potential source of mortality for individuals of H. mabouia in the restinga de Jurubatiba.

Contrasting diel activity and feeding patterns of four instars of Rhyacophila dorsalis (Trichoptera)

Summary1. Ontogenetic shifts in prey choice and predator behaviour can affect food‐web structure. Therefore, it is important to establish if the diet and feeding activity differ between life‐stages of the same species. This hypothesis was tested for second, third, fourth and fifth larval instars of Rhyacophila dorsalis by comparing their diel activity and feeding patterns. Second to fifth instars collected from two streams were used either for gut analyses or for observations of their activity and feeding patterns in three stream tanks. Food was provided in excess; being organisms living in bryophytes on top of a large stone in each tank, augmented by different‐sized larvae of Ephemeroptera, Simuliidae and Chironomidae. As few first instars for gut analyses were found in the field, the diet of first instars reared in the laboratory was also studied.2. Larvae for gut analyses were taken 1 h before dusk or dawn (n = 50 larvae per instar for each day or night sample). First and second instars fed on the smaller food items with no significant day‐night differences in diet. Gut contents indicated a progressive trend from feeding chiefly at night in third instars to almost exclusively at night in fifth instars. Fourth and fifth instars fed on the larger food items, whilst the diet of the third instar larvae overlapped with that of both the earlier and later instars.3. Diel activity patterns of single larvae differed between instars but not within each instar (n = 20 larvae per instar). Second instars were active throughout the 24 h, with peaks at dusk, around midnight, dawn and around midday. A similar pattern was shown by third instars but the peak of activity at midday was less than the other three peaks. Prey were captured only during these peaks for both instars. Fourth and fifth instars were most active, and fed only, at night. They used an ambush strategy to capture more active prey at dusk and dawn (e.g. Baetis, Gammarus), and a searching strategy to capture more sedentary prey during the night (e.g. chironomids, simuliids). These experiments provided support for the hypothesis under test. If competition and/or interference occur between instars, then it could be reduced between earlier and later instars because of differences in their diet and diel pattern of feeding activity.

Multiple predator effects on microdistributions, survival, and drift of stream hydropsychid caddisflies

We studied microdistributions, survival, and drift of larval hydropsychid caddisflies in the physical and/or chemical presence of 2 types of benthic predators with different foraging modes. Sculpins (Cottus bairdi, C. cognatus) are ambush predators, whereas perlid stoneflies (Acroneuria, Paragnetina) are stalkers, and stoneflies are an intermediate predator consumed by sculpins. Hydropsychid larvae in a northern Michigan stream were significantly more abundant in crevices than on flat surfaces on real cobbles in riffles with both predators. Larval colonization on experimental substrates (bricks) in 7 riffles was greater in crevices (grooves) than on flat surfaces, and the greatest differences in larval densities between these microhabitats occurred where predator densities were highest. Mean size (head capsule width) of larvae in both microhabitats was negatively related to densities of sculpins, but not stoneflies. A multifactorial experiment done in artificial stream channels revealed that caddisflies selected crevices over flat surfaces even in predator-free conditions. Sculpin and stonefly effects on hydropsychid survival were additive, suggesting a lack of multiple predator effects. Crevices provided a refuge from predators; however, stoneflies were more effective than large sculpins (>65 mm total length) at consuming hydropsychids in crevices. Like caddisflies, stoneflies predominantly occupied crevices, but stonefly crevice use and activity were not affected by sculpins, and no stoneflies were consumed by sculpins. Caddisfly drift was ∼3 to 4× greater in the physical presence of each predator than in predator-free channels. However, drift by caddisflies in the physical presence of both predators was lower than expected (i.e., nonadditive), suggesting it is less risky to remain in retreats (i.e., immovable cases) than to drift when both predators are present. Elevated chemical cues of either predator did not trigger drift responses by these sedentary prey. Crevice use and drift appear to be key mechanisms enabling larval hydropsychid caddisflies to coexist with a multispecies complex of predators.