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1
Mogali, Santosh M., Srinivas K. Saidapur, and Bhagyashri A. Shanbhag. "Behavioral responses of tadpoles of Duttaphrynus melanostictus (Anura: Bufonidae) to cues of starved and fed dragonfly larvae." Phyllomedusa: Journal of Herpetology 19, no. 1 (June 29, 2020): 93–98. http://dx.doi.org/10.11606/issn.2316-9079.v19i1p93-98.
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Behavioral responses of tadpoles of Duttaphrynus melanostictus (Anura: Bufonidae) to cues of starved and fed dragonfly larvae. Tadpoles of Duttaphrynus melanostictus use chemoreception to detect kairomonal cues and excretory metabolites from predatory anuran tadpoles (Hoplobatrachus tigerinus) that consume them. We describe here the behavioral responses of tadpoles of D. melanostictus to predatory dragonfly larvae (Pantala flavescens). The predator’s kairomones (water conditioned by the starved predator) or its diet-derived metabolites released in excreta of predator after consumption of conspecific prey tadpoles were used to simulate predation risk. The tadpoles of D. melanostictus had no behavioral response to predator kairomones. However, the larvae reduced swimming movements and overall time spent in swimming, and had a higher burst speed/swimming velocity in response to water borne cues released from the excreta of predators fed conspecific prey. Thus, just the presence of dragonfly larvae does not elicit defense behaviors in tadpoles of D. melanostictus, but when predation risk is recognized as real (i.e., when tadpoles are exposed to excretory metabolites of predators fed conspecific tadpoles), defense behaviors are activated.
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Mirza, Reehan S., and Douglas P. Chivers. "Predator diet cues and the assessment of predation risk by juvenile brook charr: do diet cues enhance survival?" Canadian Journal of Zoology 81, no. 1 (January 1, 2003): 126–32. http://dx.doi.org/10.1139/z02-225.
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Recent studies have shown that predator diet cues provide important information that prey animals can use to assess predation risk. Predator-naïve prey animals may even learn to recognize unknown predators when they detect conspecific cues in the predator's diet. We examined the importance of predator diet cues in the responses of juvenile brook charr (Salvelinus fontinalis) to chemical cues of predators. In our first experiment, we showed that charr respond to chemical cues of adult yellow perch (Perca flavescens) that were fed a diet of either brook charr or rainbow trout (Oncorhynchus mykiss), but not to perch fed a diet of brook stickleback (Culaea inconstans). Responses to diet cues from perch fed both charr and trout may indicate that charr are responding to evolutionarily conserved salmonid alarm cues in the predator's diet. In a second experiment, we exposed charr to chemical cues from predatory northern pike (Esox lucius) that were fed charr, trout, or stickleback. Live-predation trials revealed that charr exposed to diet cues from pike fed salmonids exhibited higher survival than charr exposed to diet cues from pike fed a non-salmonid. These results are the first to document a survival benefit for prey exhibiting behavioural responses to predator diet cues.
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Buitenhuis, R., L. Shipp, and C. Scott-Dupree. "Intra-guild vs extra-guild prey: effect on predator fitness and preference of Amblyseius swirskii (Athias-Henriot) and Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae)." Bulletin of Entomological Research 100, no. 2 (May 7, 2009): 167–73. http://dx.doi.org/10.1017/s0007485309006944.
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AbstractThe relationships between the predatory mites, Amblyseius swirskii (Athias-Henriot) and Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae), and their prey, western flower thrips (Frankliniella occidentalis Pergande) (Thysanoptera: Thripidae), were investigated to determine the effects of predation on intra-guild or extra-guild prey and predator preference. Life history characteristics of both predatory mites were measured when fed eggs and larvae of the other predator species and compared to data obtained when the predators were fed thrips larvae. In addition, choice tests were conducted to determine if the predators had a preference for different prey or if they were indiscriminate predators. Amblyseius swirskii appears to be an important intra-guild predator of N. cucumeris juveniles because of a high predation rate and a preference for N. cucumeris juveniles over thrips. Neoseiulus cucumeris is also an intra-guild predator of A. swirskii juveniles; however, it has a lower predation rate than A. swirskii. Contrary to intra-guild predation theory, intra-guild prey was an equally good or better food source than thrips (extra-guild prey) for both predators, based on high oviposition rates and fast development times. The results of this study indicate a high potential for negative interactions between A. swirskii and N. cucumeris when used together in biological control of thrips.
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Puu, Yustina Maria Silvia Wonga. "KERAGAMAN JENIS DAN PERILAKU PEMANGSA PREDATOR YANG BERASOSIASI DENGAN HAMA KEPIK PENGISAP BUAH KAKAOHelopeltis spp. PADA TANAMAN KAKAO." AGRICA 10, no. 1 (July 20, 2020): 1–7. http://dx.doi.org/10.37478/agr.v10i1.75.
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Helopeltis spp. is one of the pests that attack cocoa fruit and can lead to decreased quality and quantity of fruit. Efforts to control that can be done is the utilization of natural enemy one of them is a predator. The large predator populations in the cocoa ecosystem will decrease the pest population of Helopeltisspp. the aim of this study was to know the predator species of pests associated with Helopeltisspp pests and predatory behavior. This research was conducted in Ende Sub-district in 6 villages and Laboratory of Agricultural Faculty of Flores University from March to May 2017. The method used was observation in the field by taking predator samples and observed their morphology and testing of predatory behavior. The variables observed were predators and behavioral diversity and predator predation time. The results obtained 3 species of predators namely Oecophyllasmaragdina, Gasteracanthacancriformis, and Leucaugevenusta. The diversity of predator types associated with Helopeltis spp. all of which are low in Randorama village of 0.29; Randotonda village 0.31; village Ndetundora I 0.26; village Ndetundora II 0.16; village Ndetundora III 0.18; and Embutheru village 0.23. Predator behavior of each predator differs from the predation time of Oecophyllasmaragdina 47 min/ tail, Gasteracanthacancriformis 1 hour 51 min/tail and Leucaugevenusta 1 hour 29 min/ head.
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Palmer, Meredith S., and Craig Packer. "Reactive anti-predator behavioral strategy shaped by predator characteristics." PLOS ONE 16, no. 8 (August 18, 2021): e0256147. http://dx.doi.org/10.1371/journal.pone.0256147.
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Large mammalian herbivores use a diverse array of strategies to survive predator encounters including flight, grouping, vigilance, warning signals, and fitness indicators. While anti-predator strategies appear to be driven by specific predator traits, no prior studies have rigorously evaluated whether predator hunting characteristics predict reactive anti-predator responses. We experimentally investigated behavioral decisions made by free-ranging impala, wildebeest, and zebra during encounters with model predators with different functional traits. We hypothesized that the choice of response would be driven by a predator’s hunting style (i.e., ambush vs. coursing) while the intensity at which the behavior was performed would correlate with predator traits that contribute to the prey’s relative risk (i.e., each predator’s prey preference, prey-specific capture success, and local predator density). We found that the choice and intensity of anti-predator behaviors were both shaped by hunting style and relative risk factors. All prey species directed longer periods of vigilance towards predators with higher capture success. The decision to flee was the only behavior choice driven by predator characteristics (capture success and hunting style) while intensity of vigilance, frequency of alarm-calling, and flight latency were modulated based on predator hunting strategy and relative risk level. Impala regulated only the intensity of their behaviors, while zebra and wildebeest changed both type and intensity of response based on predator traits. Zebra and impala reacted to multiple components of predation threat, while wildebeest responded solely to capture success. Overall, our findings suggest that certain behaviors potentially facilitate survival under specific contexts and that prey responses may reflect the perceived level of predation risk, suggesting that adaptive functions to reactive anti-predator behaviors may reflect potential trade-offs to their use. The strong influence of prey species identity and social and environmental context suggest that these factors may interact with predator traits to determine the optimal response to immediate predation threat.
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Albecker, Molly, and Heather D. Vance-Chalcraft. "Mismatched anti-predator behavioral responses in predator-naïve larval anurans." PeerJ 3 (December 7, 2015): e1472. http://dx.doi.org/10.7717/peerj.1472.
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Organisms are adept at altering behaviors to balance the tradeoff between foraging and predation risk in spatially and temporally shifting predator environments. In order to optimize this tradeoff, prey need to be able to display an appropriate response based on degree of predation risk. To be most beneficial in the earliest life stages in which many prey are vulnerable to predation, innate anti-predator responses should scale to match the risk imposed by predators until learned anti-predator responses can occur. We conducted an experiment that examined whether tadpoles with no previous exposure to predators (i.e., predator-naive) exhibit innate antipredator behavioral responses (e.g., via refuge use and spatial avoidance) that match the actual risk posed by each predator. Using 7 treatments (6 free-roaming, lethal predators plus no-predator control), we determined the predation rates of each predator onLithobates sphenocephalustadpoles. We recorded behavioral observations on an additional 7 nonlethal treatments (6 caged predators plus no-predator control). Tadpoles exhibited innate responses to fish predators, but not non-fish predators, even though two non-fish predators (newt and crayfish) consumed the most tadpoles. Due to a mismatch between innate response and predator consumption, tadpoles may be vulnerable to greater rates of predation at the earliest life stages before learning can occur. Thus, naïve tadpoles in nature may be at a high risk to predation in the presence of a novel predator until learned anti-predator responses provide additional defenses to the surviving tadpoles.
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El Balaa, Rayan, and Gabriel Blouin-Demers. "Does exposure to cues of fish predators fed different diets affect morphology and performance of Northern Leopard Frog (Lithobates pipiens) larvae?" Canadian Journal of Zoology 91, no. 4 (April 2013): 203–11. http://dx.doi.org/10.1139/cjz-2012-0232.
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Phenotypic plasticity allows animals to change their morphological and life-history traits when exposed to predator cues, which modifies performance and can enhance survival but engender costs. Thus, the extent of plastic changes should vary in relation to the perceived risk of predation. We tested the hypothesis that plastic changes in morphology (and their effect on performance) and life history of developing Northern Leopard Frog (Lithobates pipiens (Schreber, 1782)) larvae vary when exposed to cues of fish predators fed different diets. During development, we exposed tadpoles to control cues, cues from brown bullhead (Ameiurus nebulosus (Lesueur, 1819)) fed trout pellets, or cues from A. nebulosus fed L. pipiens tadpoles. Tadpoles exposed to predatory fish cues had smaller bodies, deeper tail fins, slower growth and development rates, and better turning performance than tadpoles that were not exposed to predatory fish cues, but we found limited evidence that the predator’s diet had an effect on phenotypic plasticity. Predator diet affected tail morphology and activity, but the latter effect was only marginally significant. Lithobates pipiens tadpoles clearly respond to predatory fish cues, but it remains unclear whether their response is modulated by the predator’s diet.
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Wikenros, Camilla, Dries P. J. Kuijper, Robert Behnke, and Krzysztof Schmidt. "Behavioural responses of ungulates to indirect cues of an ambush predator." Behaviour 152, no. 7-8 (2015): 1019–40. http://dx.doi.org/10.1163/1568539x-00003266.
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Ambush predators provide more persistent cues of predation risk compared to coursing predators and are predicted to exert stronger effects on behaviour of their prey. We studied anti-predator responses of ungulates by means of camera traps to an olfactory cue (fresh scat) of an ambush predator, the Eurasian lynx (Lynx lynx). Roe deer (Capreolus capreolus) and red deer (Cervus elaphus) both important prey species for lynx were not more vigilant when exposed to lynx scent, but reduced their visitation duration. Our results contrast with previously reported responses of red deer to scent from a coursing predator, the wolf (Canis lupus), where only vigilance and foraging behaviour but not visitation duration changed in response to wolf scat. This indicates that ungulates are able to recognize the risk of predation from predators with differing hunting modes based on olfactory cues and adjust their anti-predatory behaviour.
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Griffin, John N., and Brian R. Silliman. "Predator diversity stabilizes and strengthens trophic control of a keystone grazer." Biology Letters 7, no. 1 (August 25, 2010): 79–82. http://dx.doi.org/10.1098/rsbl.2010.0626.
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Despite the global vulnerability of predators to extinction, and the critical functional role they play in many ecosystems, there have been few realistic tests of the consequences of predator species deletion (conversely, predator diversity) in natural ecosystems. We performed a four-month field experiment in a southeastern United States salt marsh to test the role of predatory crab diversity in regulating populations of a keystone grazer that can decimate marsh vegetation at high densities. Our results revealed that a combination of this system's two resident predator species, in comparison to individual species, both stabilize and strengthen predation rates on the potent grazer. Monthly monitoring of predation rates from intense, hot summer months into the cooler autumn indicate this diversity benefit arises from predators responding differentially to changing environmental conditions across seasons. This study provides some of the first experimental field support for the insurance hypothesis from marine ecosystems, suggests that predator temporal complementarity may be more common than currently perceived, and argues for conservation of predator diversity to ensure reliable and effective control of potentially habitat-destroying grazers.
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Wasserman, R. J., T. J. F. Vink, R. Kramer, and P. W. Froneman. "Hyperbenthic and pelagic predators regulate alternate key planktonic copepods in shallow temperate estuaries." Marine and Freshwater Research 65, no. 9 (2014): 791. http://dx.doi.org/10.1071/mf13233.
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Although predation has been identified as an important community driver, the role of predator diversity in structuring estuarine zooplankton has not been assessed. As such, we investigated the effects of two different zooplanktivorous fish species on the estuarine zooplankton community during a 12-day mesocosm study. Three experimental treatments were established, whereby natural zooplankton communities were subject to either (1) no predatory pressure, (2) predation by a pelagic predator (Monodactylus falciformis) or (3) predation by a hyper-benthic predator (Glossogobius callidus). The pelagic feeding M. falciformis fed largely on the numerically dominant mid-water copepod species, Paracartia longipatella. In contrast, the hyper-benthic fish had a greater predatory impact on the less numerically dominant copepod, Pseudodiaptomus hessei, which demonstrates strong diel vertical migration. Variations in prey-population regulation are ascribed to the distinct behavioural differences of the predators, and mediated by the differences in behaviour of the copepod species.
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Morgan, Andrew D., R. Craig MacLean, Kristina L. Hillesland, and Gregory J. Velicer. "Comparative Analysis of Myxococcus Predation on Soil Bacteria." Applied and Environmental Microbiology 76, no. 20 (August 27, 2010): 6920–27. http://dx.doi.org/10.1128/aem.00414-10.
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ABSTRACT Predator-prey relationships among prokaryotes have received little attention but are likely to be important determinants of the composition, structure, and dynamics of microbial communities. Many species of the soil-dwelling myxobacteria are predators of other microbes, but their predation range is poorly characterized. To better understand the predatory capabilities of myxobacteria in nature, we analyzed the predation performance of numerous Myxococcus isolates across 12 diverse species of bacteria. All predator isolates could utilize most potential prey species to effectively fuel colony expansion, although one species hindered predator swarming relative to a control treatment with no growth substrate. Predator strains varied significantly in their relative performance across prey types, but most variation in predatory performance was determined by prey type, with Gram-negative prey species supporting more Myxococcus growth than Gram-positive species. There was evidence for specialized predator performance in some predator-prey combinations. Such specialization may reduce resource competition among sympatric strains in natural habitats. The broad prey range of the Myxococcus genus coupled with its ubiquity in the soil suggests that myxobacteria are likely to have very important ecological and evolutionary effects on many species of soil prokaryotes.
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Daniell, Tara L., Mark N. Hutchinson, Phil Ainsley, and Michael G. Gardner. "Recognition of reptile predator scent is innate in an endangered lizard species." Australian Journal of Zoology 68, no. 2 (2020): 76. http://dx.doi.org/10.1071/zo20064.
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Chemical cues can alert prey to the presence of predators before the predator is within visual proximity. Recognition of a predator’s scent is therefore an important component of predator awareness. We presented predator and control scents to wild, wild-born captive, and predator-naive captive-born pygmy bluetongue lizards to determine (1) whether lizards respond to reptile chemical cues differently from controls, (2) whether captive lizards respond more strongly to a known predator than to other predatory reptiles, (3) whether captive-born lizards recognise predators innately, whether captive-born lizards have reduced predator recognition compared with wild lizards and whether time spent in captivity reduces responses to predators, and (4) whether the avoidance response to predator detection differs between naive and experienced lizards. There was no significant difference in the number of tongue flicks to predator scent among wild, wild-born and captive-born lizards, suggesting that predator detection is innate in the pygmy bluetongue lizard and time in captivity did not reduce predator recognition. The number of tongue flicks directed towards brown snake scent was significantly higher than that to the novel and water controls for all lizard origins. Lizards of all origins continued to bask in the presence of predator scents, suggesting that chemical cues alone may be insufficient to instigate an avoidance response and other cues may be required.
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Brown, Joel S., Keren Embar, Eric Hancock, and Burt P. Kotler. "Predators risk injury too: the evolution of derring-do in a predator–prey foraging game." Israel Journal of Ecology and Evolution 62, no. 3-4 (May 18, 2016): 196–204. http://dx.doi.org/10.1080/15659801.2016.1207298.
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Derring-do is how aggressive a predator is in stalking and capturing prey. We model predator–prey interactions in which prey adjust vigilance behavior to mitigate risk of predation and predators their derring-do to manage risk of injury from capturing prey. High derring-do increases a predator's likelihood of capturing prey, but at higher risk of injury to itself. For fixed predator derring-do, prey increase vigilance in response to predator abundance, predator lethality, and predator encounter probability with prey and decrease vigilance with their own feeding rate; there is a humped-shaped relationship between prey vigilance and effectiveness of vigilance. For fixed prey vigilance, predators increase derring-do with the abundance of prey and predator lethality and decrease it with benefit of vigilance to prey and level of prey vigilance. When both prey and predator are behaviorally flexible, a predator–prey foraging game ensues whose solution represents an evolutionarily stable strategy (ESS). At the ESS, prey provide themselves with a public good as their vigilance causes predators to decrease derring-do. Conversely, predators have negative indirect effects on themselves as their derring-do causes prey to be more vigilant. These behavioral feedbacks create negative intra-specific interaction coefficients. Increasing the population size of prey (or predators) now has a direct negative effect on the prey (or predators). Both effects help stabilize predator–prey dynamics. Besides highlighting a common way by which predators may experience a food-safety tradeoff via dangerous prey, the model suggests why natural selection favors even small defensive measures by prey and hulky predators.
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Gu, Xin-yao, Guang-yun Li, and Zhi-qiang Zhang. "Indirect effects in predator-prey interaction: development and predation rates by immature Neoseiulus cucumeris increased by odour from its prey (Tyrophagus putrescentiae) ." Systematic and Applied Acarology 25, no. 7 (July 14, 2020): 1247–56. http://dx.doi.org/10.11158/saa.25.7.7.
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Predator-prey interactions have long been of great interest to ecologists. Although the direct consumptive effects have received extensive research, indirect influences of odour derived from their conspecifics and prey on predators have largely been underestimated and overlooked. In this study, the indirect effects of predator-prey interactions were determined with predatory mites Neoseiulus cucumeris and its factitious prey Tyrophagus putrescentiae. The responses of immature N. cucumeris to mixed odour with their conspecifics and prey were determined in a laboratory experiment. Our results showed that the mixed odour with their conspecifics did not demonstrate any obvious influences on the survival rates, developmental periods, predation rates and activities of the predatory mites. Intriguingly, the predators prolonged their protonymphal stage and consumed more prey eggs when exposed to mixed odour with their prey. Our results indicated that the mixed odour with their conspecifics was weak and its influence was insignificant for this species, but the prey odour showed a signifcant influence on the growth and consumption rates of immature predators, which highlighted that the indirect influences of predator-prey interactions on the predator were substantial and cannot be neglected.
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Stewart, Heather C., and Sandra J. Walde. "THE DYNAMICS OF APHIS POMI DE GEER (HOMOPTERA: APHIDIDAE) AND ITS PREDATOR, APHIDOLETES APHIDIMYZA (RONDANI) (DIPTERA: CECIDOMYIIDAE), ON APPLE IN NOVA SCOTIA." Canadian Entomologist 129, no. 4 (August 1997): 627–36. http://dx.doi.org/10.4039/ent129627-4.
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AbstractThe dynamics of Aphis pomi De Geer (Homoptera: Aphididae) and its predator, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae), were studied over two seasons in a commercial apple orchard in Nova Scotia. Aphid and predator population dynamics were very different in the two seasons. The most numerous predator in both years was A. aphidimyza. This predator was found in the earliest colonies sampled each season and was present throughout the growing season. In the year with relatively high aphid densities a single peak in aphid and predator density was seen in mid-July, just prior to maximum predation rate. The predator’s numerical response resulted in delayed density dependence in predation rate. In the year of low aphid densities, predator and prey dynamics appeared uncoupled, and a higher rate of colony turnover may have been caused by other predators such as mirids. Aphidoletes aphidimyza tended to aggregate oviposition in high-density aphid colonies, but this aggregation resulted in predation that was only very weakly spatially density dependent.
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Demšar, Jure, and Iztok Lebar Bajec. "Simulated Predator Attacks on Flocks: A Comparison of Tactics." Artificial Life 20, no. 3 (July 2014): 343–59. http://dx.doi.org/10.1162/artl_a_00135.
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It is not exactly known why birds aggregate in coordinated flocks. The most common hypothesis proposes that the reason is protection from predators. Most of the currently developed examples of individual-based predator-prey models assume predators are attracted to the center of a highly coordinated flock. This proposed attraction of a predator to a flock would appear to be contradictory to an alternate hypothesis that flocks evolved as a protection against predation. In an attempt to resolve this apparent conflict, in this article we use a fuzzy individual-based model to study three attack tactics (attack center, attack nearest, attack isolated) and analyze the success of predation on two types of prey (social and individualistic). Our simulations revealed that social flocking (as opposed to individualistic behavior) is the optimal anti-predatory response to predators attacking mainly isolated individuals.
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Siffert, Alexandra, Fabian Cahenzli, Patrik Kehrli, Claudia Daniel, Virginie Dekumbis, Barbara Egger, Jana Furtwengler, et al. "Predation on Drosophila suzukii within Hedges in the Agricultural Landscape." Insects 12, no. 4 (March 30, 2021): 305. http://dx.doi.org/10.3390/insects12040305.
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The invasive Drosophila suzukii feeds and reproduces on various cultivated and wild fruits and moves between agricultural and semi-natural habitats. Hedges in agricultural landscapes play a vital role in the population development of D. suzukii, but also harbor a diverse community of natural enemies. We investigated predation by repeatedly exposing cohorts of D. suzukii pupae between June and October in dry and humid hedges at five different locations in Switzerland. We sampled predator communities and analyzed their gut content for the presence of D. suzukii DNA based on the COI marker. On average, 44% of the exposed pupae were predated. Predation was higher in dry than humid hedges, but did not differ significantly between pupae exposed on the ground or on branches and among sampling periods. Earwigs, spiders, and ants were the dominant predators. Predator communities did not vary significantly between hedge types or sampling periods. DNA of D. suzukii was detected in 3.4% of the earwigs, 1.8% of the spiders, and in one predatory bug (1.6%). While the molecular gut content analysis detected only a small proportion of predators that had fed on D. suzukii, overall predation seemed sufficient to reduce D. suzukii populations, in particular in hedges that provide few host fruit resources.
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Hillesland, Kristina L., Gregory J. Velicer, and Richard E. Lenski. "Experimental evolution of a microbial predator's ability to find prey." Proceedings of the Royal Society B: Biological Sciences 276, no. 1656 (October 2008): 459–67. http://dx.doi.org/10.1098/rspb.2008.1098.
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Foraging theory seeks to explain how the distribution and abundance of prey influence the evolution of predatory behaviour, including the allocation of effort to searching for prey and handling them after they are found. While experiments have shown that many predators alter their behaviour phenotypically within individual lifetimes, few have examined the actual evolution of predatory behaviour in light of this theory. Here, we test the effects of prey density on the evolution of a predator's searching and handling behaviours using a bacterial predator, Myxococcus xanthus . Sixteen predator populations evolved for almost a year on agar surfaces containing patches of Escherichia coli prey at low or high density. Improvements in searching rate were significantly greater in those predators that evolved at low prey density. Handling performance also improved in some predator populations, but prey density did not significantly affect the magnitude of these gains. As the predators evolved greater foraging proficiency, their capacity diminished to produce fruiting bodies that enable them to survive prolonged periods of starvation. More generally, these results demonstrate that predators evolve behaviours that reflect at least some of the opportunities and limitations imposed by the distribution and abundance of their prey.
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Arias-Del Razo, Itzel, Lucina Hernández, John W. Laundré, and Lourdes Velasco-Vázquez. "The landscape of fear: habitat use by a predator (Canis latrans) and its main prey (Lepus californicus and Sylvilagus audubonii)." Canadian Journal of Zoology 90, no. 6 (June 2012): 683–93. http://dx.doi.org/10.1139/z2012-036.
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We evaluated the degree of mutual exclusivity of distributions of coyotes ( Canis latrans Say, 1823) and their main prey (two lagomorph species: the black-tailed jackrabbit, Lepus californicus Gray, 1837, and the desert cottontail rabbit, Sylvilagus audubonii (Baird, 1858)) within the landscape by testing two models. The first assumes that prey seek high resource patches and, subsequently, predators seek prey within these patches, and predicts a high degree of overlap in patch use by both. The second model assumes that predator and prey balance not only food resources but reciprocal levels of predation risk and predation success in making decisions on whether or not to use a patch. This model predicts discordance in patch use between predator and prey. We used a combination of GPS-telemetry and camera-trapping data to assess habitat use patterns of predator and prey. Results from this study support the second model regarding spatial use of the landscape by a predator and its prey. Where the use of the landscape by predators and prey seem to be mediated by environmental constraints, both will adjust their predatory or antipredatory strategies based on these constraints. This results in a partial spatial separation of predator and prey across the landscape, providing patches of relative safety for prey but sufficient areas of overlap for predators to be successful.
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Tull, Debra S., and Katrin Böhning-Gaese. "Patterns of drilling predation on gastropods of the family Turritellidae in the Gulf of California." Paleobiology 19, no. 4 (1993): 476–86. http://dx.doi.org/10.1017/s0094837300014093.
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Predatory marine snails and their prey provide a unique look at many aspects of predation events, allowing behavioral inference and studies of coevolution. This study examines differential predation patterns, rates, and success of two co-occurring gastropod predator families which drill two co-occurring species of Turritella (Turritellidae: Gastropoda) in the Gulf of California. Both naticid and muricid predators, identified by the shapes of their respective boreholes, attacked the thinner-shelled Turritella leucostoma more frequently than the thicker-shelled Turritella gonostoma. Both species were drilled more frequently and more successfully by naticid, as compared to muricid, predators. Naticids drilled prey in the 40- to 70-mm size class most frequently. Prey over 100 mm in length were relatively safe from all drilling predators. Predator size (estimated by borehole diameter) in naticids was correlated with prey size in both species, but for a given-sized prey, predators on T. gonostoma were proportionally larger. There was no size correlation for muricid predators. Unsuccessful attempts (incomplete drilling) were started on the suture more often than were completed holes, for both predator families on both prey species. Naticids began drilling T. leucostoma on the suture significantly less than expected by chance. We looked for possible changes over evolutionary time by analyzing prey shells from Pleistocene and Recent storm deposits. We found no evidence of change in any aspect of implied predatory behavior over the past 100 k.y.
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Dunlap, Kent D., Alex Tran, Michael A. Ragazzi, Rüdiger Krahe, and Vielka L. Salazar. "Predators inhibit brain cell proliferation in natural populations of electric fish, Brachyhypopomus occidentalis." Proceedings of the Royal Society B: Biological Sciences 283, no. 1824 (February 10, 2016): 20152113. http://dx.doi.org/10.1098/rspb.2015.2113.
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Compared with laboratory environments, complex natural environments promote brain cell proliferation and neurogenesis. Predators are one important feature of many natural environments, but, in the laboratory, predatory stimuli tend to inhibit brain cell proliferation. Often, laboratory predatory stimuli also elevate plasma glucocorticoids, which can then reduce brain cell proliferation. However, it is unknown how natural predators affect cell proliferation or whether glucocorticoids mediate the neurogenic response to natural predators. We examined brain cell proliferation in six populations of the electric fish, Brachyhypopomus occidentalis , exposed to three forms of predator stimuli: (i) natural variation in the density of predatory catfish; (ii) tail injury, presumably from predation attempts; and (iii) the acute stress of capture. Populations with higher predation pressure had lower density of proliferating (PCNA+) cells, and fish with injured tails had lower proliferating cell density than those with intact tails. However, plasma cortisol did not vary at the population level according to predation pressure or at the individual level according to tail injury. Capture stress significantly increased cortisol, but only marginally decreased cell proliferation. Thus, it appears that the presence of natural predators inhibits brain cell proliferation, but not via mechanisms that depend on changes in basal cortisol levels. This study is the first demonstration of predator-induced alteration of brain cell proliferation in a free-living vertebrate.
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Omkar, Geetanjali Mishra, Bhupendra Kumar, Neha Singh, and Garima Pandey. "Risks associated with tandem release of large and small ladybirds (Coleoptera: Coccinellidae) in heterospecific aphidophagous guilds." Canadian Entomologist 146, no. 1 (December 23, 2013): 52–66. http://dx.doi.org/10.4039/tce.2013.56.
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AbstractMultiple interactions occurring within aphidophagous guilds determine their final predation outcomes, i.e., antagonistic, additive, or synergistic. Based on these predatory outcomes, the suitability of guilds in suppressing aphid pests is determined. The present study assesses the efficacy of 11 guilds, formed from both larval and adult stages of four locally abundant aphidophagous coccinellids (Coleoptera: Coccinellidae), while exploiting the pea aphid, Acyrthosiphon pisum Harris (Hemiptera: Aphididae). The observed antagonistic effects within these guilds are resultants of enhanced predator–predator interactions due to the size and diversity of guild predators. Smaller ladybird predators maintained their usual body mass, probably by increasing their conversion efficiencies to compensate for their reduced prey consumption. However, larger ladybirds reported loss in their body mass, owing to their higher energy needs. The overall guild conversion efficiencies and growth rates were reduced. Among the experimental guilds, the observed prey mortalities were relatively higher in two-predator guilds, and within these two-predator combinations, the higher prey mortalities were recorded in those guilds where Coccinella septempunctata was one of the predators.
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Gunzburger, M. S., and J. Travis. "Effects of multiple predator species on green treefrog (Hyla cinerea) tadpoles." Canadian Journal of Zoology 83, no. 7 (July 1, 2005): 996–1002. http://dx.doi.org/10.1139/z05-093.
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Prey species that occur across a range of habitats may be exposed to variable communities of multiple predator species across habitats. Predicting the combined effects of multiple predators can be complex. Many experiments evaluating the effects of multiple predators on prey confound either variation in predator density with predator identity or variation in relative predator frequency with overall predation rates. We develop a new experimental design of factorial predator combinations that maintains a constant expected predation rate, under the null hypothesis of additive predator effects. We implement this design to evaluate the combined effects of three predator species (bass, aeshnid and libellulid odonate naiads) on mortality rate of a prey species, Hyla cinerea (Schneider, 1799) tadpoles, that occurs across a range of aquatic habitats. Two predator treatments (libellulid and aeshnid + libellulid) resulted in lower tadpole mortality than any of the other predator treatments. Variation in tadpole mortality across treatments was not related to coarse variation in microhabitat use, but was likely due to intraguild predation, which occurred in all predator treatments. Hyla cinerea tadpoles have constant, low survival values when exposed to many different combinations of predator species, and predation rate probably increases linearly with predator density.
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Fonseca, Aldeiza M., and Bruno S. Sant'Anna. "Predation on eggs of the apple snail Pomacea dolioides (Reeve, 1856) in rural and urban areas of the Amazon." Marine and Freshwater Research 71, no. 6 (2020): 662. http://dx.doi.org/10.1071/mf19095.
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This study investigated the predation of eggs of the apple snail Pomacea dolioides in Itacoatiara, Amazonas, Brazil. Predation was compared between rural and urban areas, period of day, shaded and unshaded clutches. In addition, we evaluated clutch height and the behaviour of predators. Between April 2017 and July 2018, 962 egg clutches were observed at different times of the day: 492 in rural areas with predation of 68 egg clutches and 470 in urban areas with predation of only 9 egg clutches. Significant differences were recorded for predation rate and differences were recorded for egg clutch height in the areas. In the rural areas, the most frequent predators during the day were ants Solenopsis invicta, Crematogaster cf. carinata and the most abundant were S. invicta, Wasmannia aff. iheringi and C. cf. carinata. During the night, S. invicta was the most frequent and abundant predator. In urban areas, the frequency of predation and abundance of S. invicta were higher during the day and night than those of other predators. Populations of P. dolioides in rural areas are more affected by egg predation, mostly by S. invicta and C. cf. carinata, and predatory behaviour depended on the species of the predator.
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Brossman, Kelly H., Bradley E. Carlson, Amber N. Stokes, and Tracy Langkilde. "Eastern Newt (Notophthalmus viridescens) larvae alter morphological but not chemical defenses in response to predator cues." Canadian Journal of Zoology 92, no. 4 (April 2014): 279–83. http://dx.doi.org/10.1139/cjz-2013-0244.
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Prey traits are often modified in response to exposure to predators, a phenomenon known as predator-induced phenotypic plasticity. Morphological plasticity in response to predator cues is well documented in amphibians; however, predator-induced chemical defenses have received relatively little attention. The Eastern Newt (Notophthalmus viridescens (Rafinesque, 1820)), which possesses tetrodotoxin—a toxin for chemical defense, is most vulnerable to predation during its larval stage. We assessed whether exposing Eastern Newt larvae to predator scent cues (from dragonfly larvae) would elicit change in their morphological and chemical defenses. Newt larvae exposed to scent cues of predatory dragonfly larvae exhibited significantly greater tail depths, which should increase survival of attempted predation by allowing them to swim faster, but did not differ in mass, snout–vent length, or tail length. Toxin concentrations in newt larvae were not significantly affected by exposure to these predator cues. Larval toxicity may be derived maternally or environmentally and is inflexible, or induced toxicity may only be detectable later in development. Predator-induced phenotypic plasticity, especially of chemical defenses, warrants greater attention, as potentially important outcomes of species interactions remain unclear.
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Catania, S. V. L., J. Koprivnikar, and S. J. McCauley. "Size-dependent predation alters interactions between parasites and predators." Canadian Journal of Zoology 94, no. 9 (September 2016): 631–35. http://dx.doi.org/10.1139/cjz-2016-0088.
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Increasing evidence indicates that parasites play an important role within many systems as prey for higher trophic levels. Predation on parasites can decrease their numbers and may affect host infection rates. Cercariae, a free-living infectious stage of trematode parasites, are abundant in freshwater systems and are directly consumed by a number of freshwater predators. However, few studies have tested whether predators exhibit a preference for cercariae when alternative prey are available or how these preferences vary across predator body sizes. We assessed whether dragonfly larvae (dot-tailed whiteface, Leucorrhinia intacta (Hagen, 1861)), top predators in freshwater systems without fish, foraged preferentially when presented with two prey types, cercariae and zooplankton, and whether foraging preferences changed across predator body size. Body size of larval dragonfly predators was found to be significantly, and negatively, related to the fraction of cercariae in the diet. Larger bodied dragonfly larvae shifted their diet choice from cercariae to zooplankton. Changes in foraging selectivity as body size increases across a predator’s ontogeny can alter the strength of predator–prey interactions. Further investigation into size-selective foraging on parasites may provide new insights into the effects of predation on parasite abundance and transmission in natural systems.
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Ferrari, Maud C. O., Adega Gonzalo, François Messier, and Douglas P. Chivers. "Generalization of learned predator recognition: an experimental test and framework for future studies." Proceedings of the Royal Society B: Biological Sciences 274, no. 1620 (May 22, 2007): 1853–59. http://dx.doi.org/10.1098/rspb.2007.0297.
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While some prey species possess an innate recognition of their predators, others require learning to recognize their predators. The specific characteristics of the predators that prey learn and whether prey can generalize this learning to similar predatory threats have been virtually ignored. Here, we investigated whether fathead minnows that learned to chemically recognize a specific predator species as a threat has the ability to generalize their recognition to closely related predators. We found that minnows trained to recognize the odour of a lake trout as a threat (the reference predator) generalized their responses to brook trout (same genus as lake trout) and rainbow trout (same family), but did not generalize to a distantly related predatory pike or non-predatory suckers. We also found that the intensity of antipredator responses to the other species was correlated with the phylogenetic distance to the reference predator; minnows responded with a higher intensity response to brook trout than rainbow trout. This is the first study showing that prey have the ability to exhibit generalization of predator odour recognition. We discuss these results and provide a theoretical framework for future studies of generalization of predator recognition.
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Bannister, H., R. Brandle, and K. Moseby. "Antipredator behaviour of a native marsupial is relaxed when mammalian predators are excluded." Wildlife Research 45, no. 8 (2018): 726. http://dx.doi.org/10.1071/wr18060.
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Context Predator-controlled environments can lead to prey species losing costly antipredator behaviours as they exploit their low-risk environment, creating a ‘predator-naïve’ population. If individuals lacking suitable antipredator behaviours are used as source populations for reintroductions to environments where predators are present, their behaviour could result in high post-release predation. In contrast, animals sourced from environments with predators (‘predator-exposed’) may show effective antipredator behaviours and thus higher survival post-release. Aims The aim was to compare the antipredator behaviour of brushtail possums (Trichosurus vulpecula) at predator-exposed and predator-naïve source populations, and then compare post-release survival after their reintroduction to a low predator environment. Methods Data were collected from possums at two sites, one with and one without mammalian predators. The behavioural responses of possums to a spotlighter, their willingness to use supplementary feeders at ‘safe’ and ‘risky’ heights, whether they avoided predator odour at traps and their general willingness to enter traps were recorded. Key results Predator-naïve possums showed weaker antipredator responses, were often found at ground level, engaged with novel objects, did not avoid predator scents and utilised different habitats regardless of associated predation risk. In contrast, predator-exposed possums had higher antipredator responses, chose connected trees, were rarely found at ground level and were generally difficult to capture. Post-translocation survival was high for both source populations. Predator-naïve-sourced female possums began to avoid predator urine (feral cat; Felis catus) 12 months after translocation. Conclusions Our research demonstrates that environmental predation risk can predict prey naïvety in brushtail possums. Some aspects of prey naïvety behaviour appear to be able to change in response to altered predation risk. Implications With many threatened species now existing only in feral predator-free areas, these results have implications for future reintroductions into unbounded areas where feral predators are present, and for the management of fenced reserves. The addition of a small number of predators to fenced reserves may aid in retaining antipredator behaviours in fenced prey populations.
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Chiba, Tomoki, and Shin’ichi Sato. "Climate-mediated changes in predator–prey interactions in the fossil record: a case study using shell-drilling gastropods from the Pleistocene Japan Sea." Paleobiology 42, no. 2 (February 9, 2016): 257–68. http://dx.doi.org/10.1017/pab.2015.38.
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AbstractPaleoecological studies enhance our understanding of biotic responses to climate change because they consider long timescales not accessible through observational and experimental studies. Using predatory drillholes produced on fossil bivalve shells by carnivorous gastropods, we provide an example of how climate change affected predator–prey interactions. We quantitatively examine temporal changes in fossil molluscan assemblages and predation patterns from the Pleistocene Japan Sea, which experienced drastic environmental changes in relation to glacial–interglacial climate cycles. We found significant changes in predation patterns associated with a decline in the abundance of warm-water molluscan species. Climate-mediated fluctuations in the eustatic sea level and resultant weakening of the Tsushima Warm Current caused a decline in a warm-water shell-drilling predator, which moderated the predation pressure and size relationship between the predators and the bivalve prey. Our results indicate that climate-mediated range shifts of species in present-day and future marine ecosystems can likewise increase altered predator–prey interactions.
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Morrison, Colin R. "Predation of top predators: cane toad consumption of bullet ants in a Panamanian lowland wet forest." Journal of Tropical Ecology 34, no. 6 (October 30, 2018): 390–94. http://dx.doi.org/10.1017/s0266467418000342.
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Abstract:Despite a clear consensus about the major roles that predators play in shaping ecological communities, descriptive studies of interactions between ecologically important top predator species are underreported. Native cane toad consumption of predatory bullet ant nests was verified through multiple, independent observations taken on Pipeline Road, Panama. Cane toad predation led to the extirpation of 42% of the nests within a 1.05 km2 area that is characterized as a late-successional wet forest. This predation pressure could be significant given the high rate of predation events and low bullet ant nest density observed here (0.12 nests ha−1). Implications of this interaction for the local bullet ant population, possible top-down effects and trophic cascades resulting from this top predator interaction are discussed.
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Beckmann, Christa, Peter A. Biro, and John R. Post. "Asymmetric impact of piscivorous birds on size-structured fish populations." Canadian Journal of Zoology 84, no. 11 (November 2006): 1584–93. http://dx.doi.org/10.1139/z06-151.
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Fish are frequently considered the top predator in freshwater food web models despite evidence that predatory birds can impact fish populations. In this study, we quantified bird predation rates on experimental populations of rainbow trout ( Oncorhynchus mykiss (Walbaum, 1792)) created by stocking nine small lakes in British Columbia, Canada. Combining estimates of fish mortality with estimated bird predation rates allowed us to partition fish mortality into that due to birds versus cannibalism. Our results indicated that bird predators had significant impacts on age-1 trout populations, but little impact on age-0 trout. Common loons ( Gavia immer Brunnich, 1764) were the principle predator among eight predatory bird species present, apparently consuming nearly 50% of all stocked age-1 trout and explaining almost 50% of variation in mortality rates. Age-1 trout mortality did not differ significantly from zero in lakes without loons. Birds consumed a small proportion of age-0 trout, and estimated consumption explained none of the variation in age-0 trout mortality among lakes. We conclude that birds affect fish populations by asymmetric predation on different age (size) classes and can be important top predators that should not be ignored when characterizing freshwater food webs in lakes.
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van der Meeren, Gro I. "Predation on hatchery-reared lobsters released in the wild." Canadian Journal of Fisheries and Aquatic Sciences 57, no. 9 (September 1, 2000): 1794–803. http://dx.doi.org/10.1139/f00-134.
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Predation on hatchery-reared lobsters (Homarus gammarus) in the wild was studied in order to identify predators in southwestern Norway on rocky and sandy substrates in winter and summer. Lobsters of 12-15 mm carapace length were tagged with magnetic microtags. About 51 000 juvenile lobsters were released on 10 occasions at three locations. Predator samplings were by trammel nets, eel traps, and videorecordings during the 24 h immediately following the releases. In summer, loss to predators occurred on both rocky and sandy substrates. The loss was lower in winter when lobsters were found as prey in predators caught on sand. The risk of fish predation was highest in the first hours after release, when the lobsters were out of shelter. The wrasses Labrus bergylta and Labrus mixtus were the major predators of lobsters, while Atlantic cod (Gadus morhua), shorthorn sculpin (Myoxocephalus scorpius), and crab (Cancer pagurus) were mainly winter predators. Winter predators were never as abundant as summer predators. To minimise predatory loss of reared and costly lobsters, they should be released onto rocky substratum in winter. Due to the damage to the predated lobsters, it was not possible to correlate survival against lobster size.
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Ward, Darren M., Keith H. Nislow, and Carol L. Folt. "Seasonal shift in the effects of predators on juvenile Atlantic salmon (Salmo salar) energetics." Canadian Journal of Fisheries and Aquatic Sciences 68, no. 12 (December 2011): 2080–89. http://dx.doi.org/10.1139/f2011-123.
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Predator effects on prey populations are determined by the number of prey consumed and effects on the traits of surviving prey. Yet the effects of predators on prey traits are rarely evaluated in field studies. We measured the effects of predators on energetic traits (consumption and growth rates) of juvenile Atlantic salmon ( Salmo salar ) in a large-scale field study. Salmon fry were released at 18 sites that encompassed a wide range of predatory slimy sculpin ( Cottus cognatus ) abundance. We sampled salmon after 21 and 140 days to measure salmon growth and estimate consumption using a mass-balance model of methylmercury accumulation. Salmon population density was reduced fivefold at sites with abundant sculpin. Over the early season, salmon consumed less where sculpin were abundant, suggesting that reduced foraging under predation risk contributed to predator-caused mortality. In contrast, over the late season, salmon grew more where sculpin were abundant, suggesting that compensatory growth at reduced salmon population density moderated predator-caused mortality. Predator effects on prey energetics can drive variation in survival and growth, with important consequences for population dynamics.
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Connors, B. M., M. Krkošek, and L. M. Dill. "Sea lice escape predation on their host." Biology Letters 4, no. 5 (June 17, 2008): 455–57. http://dx.doi.org/10.1098/rsbl.2008.0276.
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Parasites seldom have predators but often fall victim to those of their hosts. How parasites respond to host predation can have important consequences for both hosts and parasites, though empirical investigations are rare. The exposure of wild juvenile salmon to sea lice ( Lepeophtheirus salmonis ) from salmon farms allowed us to study a novel ecological interaction: the response of sea lice to predation on their juvenile pink and chum salmon hosts by two salmonid predators—coho smolts and cut-throat trout. In approximately 70% of trials in which a predator consumed a parasitized prey, lice escaped predation by swimming or moving directly onto the predator. This trophic transmission is strongly male biased, probably because behaviour and morphology constrain female movement and transmission. These findings highlight the potential for sea lice to be transmitted up marine food webs in areas of intensive salmon aquaculture, with implications for louse population dynamics and predatory salmonid health.
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Watson, Sue-Ann, Jennifer B. Fields, and Philip L. Munday. "Ocean acidification alters predator behaviour and reduces predation rate." Biology Letters 13, no. 2 (February 2017): 20160797. http://dx.doi.org/10.1098/rsbl.2016.0797.
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Ocean acidification poses a range of threats to marine invertebrates; however, the emerging and likely widespread effects of rising carbon dioxide (CO 2 ) levels on marine invertebrate behaviour are still little understood. Here, we show that ocean acidification alters and impairs key ecological behaviours of the predatory cone snail Conus marmoreus . Projected near-future seawater CO 2 levels (975 µatm) increased activity in this coral reef molluscivore more than threefold (from less than 4 to more than 12 mm min −1 ) and decreased the time spent buried to less than one-third when compared with the present-day control conditions (390 µatm). Despite increasing activity, elevated CO 2 reduced predation rate during predator–prey interactions with control-treated humpbacked conch, Gibberulus gibberulus gibbosus ; 60% of control predators successfully captured and consumed their prey, compared with only 10% of elevated CO 2 predators. The alteration of key ecological behaviours of predatory invertebrates by near-future ocean acidification could have potentially far-reaching implications for predator–prey interactions and trophic dynamics in marine ecosystems. Combined evidence that the behaviours of both species in this predator–prey relationship are altered by elevated CO 2 suggests food web interactions and ecosystem structure will become increasingly difficult to predict as ocean acidification advances over coming decades.
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Zimmerman, Mara S. "Predator communities associated with brook stickleback (Culaea inconstans) prey: patterns in body size." Canadian Journal of Fisheries and Aquatic Sciences 63, no. 2 (February 1, 2006): 297–309. http://dx.doi.org/10.1139/f05-216.
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Prey body size is often inversely correlated with largest size of coexisting predators, yet few studies have examined this relationship in the context of entire predator communities. Using field surveys and laboratory trials, this study tested whether a size relationship exists between brook stickleback (Culaea inconstans) prey and the largest coexisting predator in the context of nested predator communities at 26 sites across Michigan's upper peninsula. Small predators, limited to consuming small sticklebacks, were widely distributed and equally common in pond, breached pond, and stream habitats. Large predators consumed all stickleback sizes, occurred at fewer sites, and were found more frequently in stream than in pond and breached pond habitats in one of the two survey years. Predator communities were categorized as small-predator and mixed-predator communities. Small-predator communities included small, gape-limited predators only. Sticklebacks apparently reached a size refugia from predation (>42 mm standard length) in this community type. Mixed-predator communities included both small and large predators and had no size refugia for sticklebacks. Although predator distributions were nested in this system, prey size was correlated with the largest predator size at each site. Stickleback length was negatively correlated with maximum predator length and was smaller in mixed-predator than in small-predator communities.
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Watve, Mukta, Sebastian Prati, and Barbara Taborsky. "Simulating more realistic predation threat using attack playbacks." PeerJ 7 (December 19, 2019): e8149. http://dx.doi.org/10.7717/peerj.8149.
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Use of virtual proxies of live animals are rapidly gaining ground in studies of animal behaviour. Such proxies help to reduce the number of live experimental animals needed to stimulate the behaviour of experimental individuals and to increase standardisation. However, using too simplistic proxies may fail to induce a desired effect and/or lead to quick habituation. For instance, in a predation context, prey often employ multimodal cues to detect predators or use specific aspects of predator behaviour to assess threat. In a live interaction, predator and prey often show behaviours directed towards each other, which are absent in virtual proxies. Here we compared the effectiveness of chemical and visual predator cues in the cooperatively breeding cichlid Neolamprologus pulcher, a species in which predation pressure has been the evolutionary driver of its sociality. We created playbacks of predators simulating an attack and tested their effectiveness in comparison to a playback showing regular activity and to a live predator. We further compared the effectiveness of predator odour and conspecific skin extracts on behaviours directed towards a predator playback. Regular playbacks of calmly swimming predators were less effective than live predators in stimulating a focal individual’s aggression and attention. However, playbacks mimicking an attacking predator induced responses much like a live predator. Chemical cues did not affect predator directed behaviour.
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Cairns, Johannes, Felix Moerman, Emanuel A. Fronhofer, Florian Altermatt, and Teppo Hiltunen. "Evolution in interacting species alters predator life-history traits, behaviour and morphology in experimental microbial communities." Proceedings of the Royal Society B: Biological Sciences 287, no. 1928 (June 3, 2020): 20200652. http://dx.doi.org/10.1098/rspb.2020.0652.
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Predator–prey interactions heavily influence the dynamics of many ecosystems. An increasing body of evidence suggests that rapid evolution and coevolution can alter these interactions, with important ecological implications, by acting on traits determining fitness, including reproduction, anti-predatory defence and foraging efficiency. However, most studies to date have focused only on evolution in the prey species, and the predator traits in (co)evolving systems remain poorly understood. Here, we investigated changes in predator traits after approximately 600 generations in a predator–prey (ciliate–bacteria) evolutionary experiment. Predators independently evolved on seven different prey species, allowing generalization of the predator's evolutionary response. We used highly resolved automated image analysis to quantify changes in predator life history, morphology and behaviour. Consistent with previous studies, we found that prey evolution impaired growth of the predator, although the effect depended on the prey species. By contrast, predator evolution did not cause a clear increase in predator growth when feeding on ancestral prey. However, predator evolution affected morphology and behaviour, increasing size, speed and directionality of movement, which have all been linked to higher prey search efficiency. These results show that in (co)evolving systems, predator adaptation can occur in traits relevant to foraging efficiency without translating into an increased ability of the predator to grow on the ancestral prey type.
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Dingemanse, Niels J., Fons Van der Plas, Jonathan Wright, Denis Réale, Maarten Schrama, Derek A. Roff, Els Van der Zee, and Iain Barber. "Individual experience and evolutionary history of predation affect expression of heritable variation in fish personality and morphology." Proceedings of the Royal Society B: Biological Sciences 276, no. 1660 (January 6, 2009): 1285–93. http://dx.doi.org/10.1098/rspb.2008.1555.
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Predation plays a central role in evolutionary processes, but little is known about how predators affect the expression of heritable variation, restricting our ability to predict evolutionary effects of predation. We reared families of three-spined stickleback Gasterosteus aculeatus from two populations—one with a history of fish predation (predator sympatric) and one without (predator naive)—and experimentally manipulated experience of predators during ontogeny. For a suite of ecologically relevant behavioural (‘personality’) and morphological traits, we then estimated two key variance components, additive genetic variance ( V A ) and residual variance ( V R ), that jointly shape narrow-sense heritability ( h 2 = V A /( V A + V R )). Both population and treatment differentially affected V A versus V R , hence h 2 , but only for certain traits. The predator-naive population generally had lower V A and h 2 values than the predator-sympatric population for personality behaviours, but not morphological traits. Values of V R and h 2 were increased for some, but decreased for other personality traits in the predator-exposed treatment. For some personality traits, V A and h 2 values were affected by treatment in the predator-naive population, but not in the predator-sympatric population, implying that the latter harboured less genetic variation for behavioural plasticity. Replication and experimental manipulation of predation regime are now needed to confirm that these population differences were related to variation in predator-induced selection. Cross-environment genetic correlations ( r A ) were tight for most traits, suggesting that predator-induced selection can affect the evolution of the same trait expressed in the absence of predators. The treatment effects on variance components imply that predators can affect evolution, not only by acting directly as selective agents, but also by influencing the expression of heritable variation.
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Filgueiras, Rosenya Michely Cintra, Jairo De Almeida De Almeida Mendes, Eduardo Pereira De Sousa Neto, Neville Vieira Monteiro, and José Wagner Da Silva Melo. "Neoseiulus barkeri Hughes (Acari: Phytoseiidae) as a potential control agent for Raoiella indica Hirst (Acari: Tenuipalpidae)." Systematic and Applied Acarology 25, no. 4 (April 4, 2020): 593–606. http://dx.doi.org/10.11158/saa.25.4.1.
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Raoiella indica Hirst (Acari: Tenuipalpidae) is a pest species that has expanded not only in geographical distribution but also in the number of host plants. Control measures are still being evaluated in recently invaded countries. In some countries and for some crops, spraying with botanical extracts has been used to reduce R. indica populations. Laboratory and field studies point to the predatory mite Amblyseius largoensis (Muma) (Acari: Phytoseiidae) as promising for combating R. indica. However, this predator has not yet been commercially available. Thus, the present study aimed to evaluate the potential of another predatory mite Neoseiulus barkeri Hughes, a commercially available generalist predator as a biological control agent of R. indica. The consumption and oviposition rate of N. barkeri were determined across the developmental stages of R. indica. The predation and oviposition capacity of N. barkeri and A. largoensis when fed R. indica eggs in the laboratory were compared. In the field, releases of the predator N. barkeri at densities of 900, 600 and 300 predators per plant were compared to spraying with botanical extracts such as cottonseed oil and azadirachtin to control R. indica. Our results suggested that N. barkeri is an effective predator to control R. indica. The consumption of N. barkeri was inversely related to the life stage of R. indica, and all developmental stages of R. indica enabled the reproduction of N. barkeri. The predation and oviposition of N. barkeri were higher than those of A. largoensis, and the releases of N. barkeri at densities of 900 and 600 predators/plant resulted in significant reductions in R. indica populations.
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Kersch-Becker, Mônica F., André Kessler, and Jennifer S. Thaler. "Plant defences limit herbivore population growth by changing predator–prey interactions." Proceedings of the Royal Society B: Biological Sciences 284, no. 1862 (September 6, 2017): 20171120. http://dx.doi.org/10.1098/rspb.2017.1120.
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Plant quality and predators are important factors affecting herbivore population growth, but how they interact to regulate herbivore populations is not well understood. We manipulated jasmonate-induced plant resistance, exposure to the natural predator community and herbivore density to test how these factors jointly and independently affect herbivore population growth. On low-resistance plants, the predator community was diverse and abundant, promoting high predator consumption rates. On high-resistance plants, the predator community was less diverse and abundant, resulting in low predator consumption rate. Plant resistance only directly regulated aphid population growth on predator-excluded plants. When predators were present, plant resistance indirectly regulated herbivore population growth by changing the impact of predators on the herbivorous prey. A possible mechanism for the interaction between plant resistance and predation is that methyl salicylate, a herbivore-induced plant volatile attractive to predators, was more strongly induced in low-resistance plants. Increased plant resistance reduced predator attractant lures, preventing predators from locating their prey. Low-resistance plants may regulate herbivore populations via predators by providing reliable information on prey availability and increasing the effectiveness of predators.
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Epp, Kristen J. "Threat sensitivity in the San Marcos salamander: effects of predator diet and prey experience." Behaviour 150, no. 6 (2013): 617–34. http://dx.doi.org/10.1163/1568539x-00003073.
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Prey must constantly balance foraging and predator avoidance demands. Avoidance response efficiency may be improved when prey match the intensity of their avoidance behaviours to a perceived level of predatory threat (threat sensitivity). Additionally, experience with predators may influence the intensity of avoidance responses. I examined the possibility that experience with predators in the natural habitat would influence threat sensitive avoidance behaviours of an aquatic salamander, Eurycea nana, by comparing the intensity of avoidance responses to predators that had been fed a neutral diet (low-risk) or a diet of conspecifics (high-risk) between laboratory-reared and recently-collected adult salamanders. I found that laboratory-reared salamanders exhibited graded responses to low- and high-risk predators consistent with threat-sensitive predator avoidance. Predator-experienced salamanders (recently-collected), however, responded less intensely to all predators and their responses showed little evidence of threat sensitivity. These less intense responses observed in experienced salamanders may result from mechanisms of adaptive forgetting, which allow prey to respond to environmental variation. I discuss implications of these results for E. nana and other prey as well as highlighting the need for researchers to consider the longer-term experiences of prey used in studies of predation risk.
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Lester, P. J., J. M. Yee, S. Yee, J. Haywood, H. MA Thistlewood, and R. Harmsen. "Does altering patch number and connectivity change the predatory functional response type? Experiments and simulations in an acarine predator–prey system." Canadian Journal of Zoology 83, no. 6 (June 1, 2005): 797–806. http://dx.doi.org/10.1139/z05-072.
Full textAbstract:
In multipatch landscapes, understanding the role of patch number and connectivity is key for the conservation of species under processes such as predation. The functional response is the most basic form of the predatorprey interaction. Two common response types exist: a decelerating curvilinear increase in prey consumption with prey density to a plateau (type II) and a sigmoidal-shaped curve (type III). Type II responses have been observed for a variety of predators, though only type III responses allow long-term persistence and are demographically stabilizing. We tested the hypothesis that the functional response type can change from a type II to a type III with increasing patch number and (or) decreasing connectivity. The predatory mite Amblyseius fallacis (Garman, 1948) has previously been shown to have a type II response when feeding on Panonychus ulmi (Koch, 1839). We examined this predatorprey interaction using experiments that varied in patch number, and simulations that varied in both patch number and connectivity. In no experimental or simulation trial did altering patch number or connectivity change the predator's functional response from type II to type III, even with an 80-fold decrease in patch connectivity. How do predators with this demographically destabilizing functional response persist? Hypotheses regarding metapopulations and alternative prey are discussed.
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Xu, Yu, Susan N. Ellis-Felege, and John P. Carroll. "Parental Risk-Taking at Natural Northern Bobwhite Nests." Avian Biology Research 10, no. 2 (May 2017): 69–75. http://dx.doi.org/10.3184/175815617x14836196626746.
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Parental risk-taking at the nest is critical to examining the trade-offs between current and future reproduction. Using Northern Bobwhites ( Colinus virginianus) at camera-monitored nests in the natural environment, we examined how parental and offspring characteristics, predator community, and predator type affected flush distance of incubating birds to approaching predators. During 1999–2006, we monitored 118 predation interactions at nests at two pairs of study sites in southern Georgia and northern Florida, USA where mesomammalian predators were experimentally reduced or not reduced. The results showed that incubating parent birds allowed closer approaches by predators that typically only consumed eggs ( e.g. Nine-banded Armadillos Dasypus novemcinctus, Virginia Opossums Didelphis virginiana, and snakes) than by predators that could harm the adults (including Bobcats Lynx rufus and Raccoons Procyon lotor) prior to flushing from the nest. Our data did not support the hypotheses that parent-offspring characteristics and predator community affect parental risk-taking at the nest. Our findings suggest that parent birds incorporate information about predator identity over parental and offspring characteristics or predator community into anti-predator decisions at the nest in systems with high predation risk.
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Bilgrami, Anwar L., and Randy Gaugler. "Feeding behaviour of the predatory nematodes Laimydorus baldus and Discolaimus major (Nematoda: Dorylaimida)." Nematology 7, no. 1 (2005): 11–20. http://dx.doi.org/10.1163/1568541054192207.
Full textAbstract:
Abstract Feeding activities of the predatory nematodes Laimydorus baldus and Discolaimus major were studied under laboratory conditions in relation to temperature (5–40°C), prey density (25–250 individuals), predator starvation (0–12 days) and prey incubation (4–24 h) using the rice root nematode, Hirschmanniella oryzae, as prey. Prey search duration, rate of predation, and the number and duration of predators feeding and aggregating at feeding sites were studied. Discolaimus major killed more prey, and fed and aggregated longer than L. baldus. Predator activities at the feeding site were optimal at 30°C. Predators starved for 6 days required the briefest prey search duration, and remained aggregated at the feeding site for a longer duration. Predators were increasingly efficient at search prey as prey density increased. Prey search and feeding durations were shortest when prey nematodes were incubated between 8–16 h. Predation rate was optimal when prey were incubated for 16 h. Prey search and killing abilities of L. baldus and D. major were governed by temperature, prey density, starvation and prey incubation, and depended upon feeding duration, number of predators feeding and aggregating at the feeding sites.
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Torgersen, Thomas. "Aggregated predators and vulnerability-independent mortality of prey." Canadian Journal of Fisheries and Aquatic Sciences 64, no. 7 (July 1, 2007): 941–55. http://dx.doi.org/10.1139/f07-066.
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I present a mechanistic predation model with explicit representation of predator aggregation for analysing the relationship between mortality rate of prey and their vulnerability (e.g., conspicuousness, escape ability). The model is developed for an aquatic setting with plankton as prey and planktivores as predators, but the principle is general. When predators are aggregated, encounters between prey and predators are not independent events. This means that a prey that runs into one predator is more likely to run into more predators, and any prey that runs into a high number of predators will eventually be perceived and captured, almost irrespective of how cryptic it is or how well it escapes attacks. A prey that has not run into a predator yet is more likely to continue to not run into predators and may therefore avoid predation even if it displays no crypsis or anti predation behaviour. Therefore, the predation risk from aggregated predators is less dependent on prey vulnerability than the intuitive proportionality relationship that applies to predation risk from solitary predators. This has important implications for patterns of mortality within prey communities (e.g., size dependency of plankton mortality).
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Vermeij, Geerat J. "Evolution in the Consumer Age: Predators and the History of Life." Paleontological Society Papers 8 (October 2002): 375–94. http://dx.doi.org/10.1017/s1089332600001169.
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Three properties of predation make this form of consumption an important agency of evolution: universality (all species have predators), high frequency (encounters of prey with predators test both parties often), and imperfection (many predatory attacks fail, enabling antipredatory selection to take place). On long time scales, predators have two principal effects: they influence their victims' phenotypes, and prey species that are highly vulnerable to all phases of predatory attacks are evolutionarily restricted to environments where predators are rarely encountered. Although predator and prey can affect each other's behavior and morphology on timescales commensurate with individual lifespans, predators have the evolutionary upper hand over the long run, especially in the expression of sensory capacities, locomotor performance, and the application of force. Only in passive defenses (armor, toxicity, large body size) does escalation favor the prey. In a review of methods for inferring predation in the geological past, I argue against the use of whole assemblages, which combine species of contrasting adaptive type, Instead, I strongly favor species-level and clade-level approaches (including examples of clade replacement) in which comparisons among places and among time intervals are made within the same adaptive types and the same physical environments. The available evidence, much of which comes from studies of shell drilling and shell breakage, points to temporal increases in both predator power and prey defenses. Escalation between species and their enemies, including predators, has proceeded episodically against a backdrop of generally increasing productivity and increasing top-down evolutionary control by high-energy predators during the Phanerozoic, the consumer age.
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Walzer, A., H. F. Paulus, and P. Schausberger. "Ontogenetic shifts in intraguild predation on thrips by phytoseiid mites: the relevance of body size and diet specialization." Bulletin of Entomological Research 94, no. 6 (December 2004): 577–84. http://dx.doi.org/10.1079/ber2004329.
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AbstractIn greenhouse agroecosystems, a guild of spider mite predators may consist of the oligophagous predatory mite Phytoseiulus persimilis Athias-Henriot, the polyphagous predatory mite Neoseiulus californicus McGregor (both Acari: Phytoseiidae) and the primarily herbivorous but facultatively predatory western flower thrips Frankliniella occidentalis Pergande (Thysanoptera: Thripidae). Diet-specialization and the predator body size relative to prey are crucial factors in predation on F. occidentalis by P. persimilis and N. californicus. Here, it was tested whether the relevance of these factors changes during predator ontogeny. First, the predator (protonymphs and adult females of P. persimilis and N. californicus): prey (F. occidentalis first instars) body size ratios were measured. Second, the aggressiveness of P. persimilis and N. californicus towards F. occidentalis was assessed. Third, survival, development and oviposition of P. persimilis and N. californicus with F. occidentalis prey was determined. The body size ranking was P. persimilis females > N. californicus females > P. persimilis protonymphs > N. californicus protonymphs. Neoseiulus californicus females were the most aggressive predators, followed by highly aggressive N. californicus protonymphs and moderately aggressive P. persimilis protonymphs. Phytoseiulus persimilis females did not attack thrips. Frankliniella occidentalis larvae are an alternative prey for juvenile N. californicus and P. persimilis, enabling them to reach adulthood. Females of N. californicus but not P. persimilis sustained egg production with thrips prey. Within the guild studied here, N. californicus females are the most harmful predators for F. occidentalis larvae, followed by N. californicus and P. persimilis juveniles. Phytoseiulus persimilis females are harmless to F. occidentalis.
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Chuirazzi, Catherine, Melissa Ocampo, and Mizuki K. Takahashi. "Influence of prey diet quality on predator-induced traits in wood frog tadpoles (Lithobates sylvaticus)." Amphibia-Reptilia 42, no. 3 (May 26, 2021): 331–41. http://dx.doi.org/10.1163/15685381-bja10059.
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Abstract Diet quality and predation are two critical factors in determining the growth and development of organisms. Various anurans are susceptible to phenotypic changes influenced by these factors. Yet, few studies examined prey diet quality as potential influence over predator-induced traits. Using wood frog tadpoles (Lithobates sylvaticus) as a model species, we investigated the effects of three diet compositions (plant-based, animal-based, omnivorous) crossed with presence or absence of chemical cues from predatory dragonfly larvae (Aeshnidae). After 35 days, we recorded 11 morphological measurements, Gosner stage, and intestinal length of tadpoles to assess phenotypic changes under the six different experimental conditions. Our results showed the additive effects of both diet quality and predator chemical cue without detection of interactions between the two. Tadpoles receiving the omnivorous diet grew and developed faster with wider denticle rows than those receiving the plant or animal diets. The growth and development of tadpoles receiving only the animal diet were significantly hindered. These results emphasize the importance of diet quality in the growth and development of larval wood frogs. Chemical cues from predators significantly reduced tadpole body size but, in contrast to previous findings, did not affect tail size. Our experimental procedure of providing water containing predator and injured conspecific chemical cues on a weekly basis likely provided relatively weak predation risk perceived by tadpoles compared to previous studies using caged predators. The predator environment in our experiment, however, represents one ecologically relevant scenario in which predation risk is not urgent.
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Bennett, A. M., and D. L. Murray. "Carryover effects of phenotypic plasticity: embryonic environment and larval response to predation risk in Wood Frogs (Lithobates sylvaticus) and Northern Leopard Frogs (Lithobates pipiens)." Canadian Journal of Zoology 93, no. 11 (November 2015): 867–77. http://dx.doi.org/10.1139/cjz-2015-0129.
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Limitations of phenotypic plasticity affect the success of individuals and populations in changing environments. We assessed the plasticity-history limitation on predator-induced defenses in anurans (Wood Frogs, Lithobates sylvaticus (LeConte, 1825), and Northern Leopard Frogs, Lithobates pipiens (Schreber, 1782)), predicting that plastic responses to predation risk by dragonfly larvae (family Aeshnidae) in the embryonic environment would limit the defensive response to predators in the larval environment. Predator-conditioned Wood Frog embryos increased relative tail depth in response to those same cues as larvae, whereas predator-naive tadpoles did not. However, no carryover effect was noted in the behavioural response of Wood Frog tadpoles to predation risk. Predator-naive Northern Leopard Frog tadpoles increased relative tail depth in response to predation risk in the larval environment. Predator-conditioned Northern Leopard Frog embryos hatched with, and maintained, a marginal increase in tail depth as larvae in the absence of predation risk. Predator-conditioned Northern Leopard Frog embryos exposed to predation risk as larvae showed no morphological response. While we find no strong support for the plasticity-history limitation per se, carryover effects across embryonic and larval life-history stages were noted in both Wood Frog and Northern Leopard Frog, suggesting that predation risk early in ontogeny can influence the outcome of future interactions with predators.