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1
Hillesland, Kristina L., Gregory J. Velicer e Richard E. Lenski. "Experimental evolution of a microbial predator's ability to find prey". Proceedings of the Royal Society B: Biological Sciences 276, n. 1656 (ottobre 2008): 459–67. http://dx.doi.org/10.1098/rspb.2008.1098.
Testo completoAbstract (sommario):
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.
2
Daniell, Tara L., Mark N. Hutchinson, Phil Ainsley e Michael G. Gardner. "Recognition of reptile predator scent is innate in an endangered lizard species". Australian Journal of Zoology 68, n. 2 (2020): 76. http://dx.doi.org/10.1071/zo20064.
Testo completoAbstract (sommario):
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.
3
Mogali, Santosh M., Srinivas K. Saidapur e 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, n. 1 (29 giugno 2020): 93–98. http://dx.doi.org/10.11606/issn.2316-9079.v19i1p93-98.
Testo completoAbstract (sommario):
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.
4
Ferrari, Maud C. O., Adega Gonzalo, François Messier e 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, n. 1620 (22 maggio 2007): 1853–59. http://dx.doi.org/10.1098/rspb.2007.0297.
Testo completoAbstract (sommario):
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.
5
MacDonald, F. H., G. P. Walker, N. J. Larsen e A. R. Wallace. "Naturally occurring predators of Bactericera cockerelli in potatoes". New Zealand Plant Protection 63 (1 agosto 2010): 275. http://dx.doi.org/10.30843/nzpp.2010.63.6583.
Testo completoAbstract (sommario):
In recent intensive sampling of insecticidefree potatoes at Pukekohe several insect predators and spiders have been found in association with the new pest Bactericera cockerelli tomatopotato psyllid (TPP) Micromus tasmaniae (brown lacewing) Melanostoma fasciatum (small hover fly) Coccinella undecimpunctata (11spotted ladybird) and sheet web spiders (Linyphiidae) were collected from potatoes at Pukekohe Research Station and reared in the laboratory to assess their potential as predators against TPP nymphs Individual predators were presented every 24 h to a maximum of 10 TPP nymphs of different instars ranging from 2nd to 4th instar depending on the size of the predator All predator species fed on TPP nymphs and all predatory life stages were capable of consuming more than five nymphs per day Ongoing studies with these species show that all predatory life stages of all predatory species feed on all life stages of TPP Together with separate data on predator incidence these results suggest that naturally occurring predators are likely to be important biological control agents of TPP particularly early in the season when TPP infestations are low
6
Mendes, Jairo A., Debora B. Lima, Eduardo P. Sousa Neto, Manoel G. C. Gondim Jr e Jose Wagner S. Melo. "Functional response of Amblyseius largoensis to Raoiella indica eggs is mediated by previous feeding experience". Systematic and Applied Acarology 23, n. 10 (5 ottobre 2018): 1907. http://dx.doi.org/10.11158/saa.23.10.3.
Testo completoAbstract (sommario):
The mechanisms involved in the acceptance and choice of prey by predatory mites are still poorly understood. The present study was designed to determine whether previous feeding experience of Amblyseius largoensis (Muma) (Acari: Phytoseiidae) on Raoiella indica Hirst (Acari: Tenuipalpidae) eggs could influence the predator’s functional response and related parameters. The consumption of R. indica eggs by experienced and naïve female A. largoensis was evaluated under increasing densities of eggs. Regardless of the predators’ previous experience, a gradual increase in the number of eggs consumed and a tendency to stabilize at higher densities were observed. Proportionally, egg consumption decreased with increasing egg densities, indicating a type II functional response for both experienced and naïve predators. Experienced and naïve predators also had the same attack rate. However, naïve predators had a handling time almost 50% longer than experienced predators and showed lower variation in egg consumption and lower peak egg consumption. The results of the present study demonstrate that previous feeding experience may alter parameters of the functional response of A. largoensis to R. indica eggs but not the type of response. Possibly, longer associations between native populations of A. largoensis and R. indica results in more aggressive predator populations.
7
Mirza, Reehan S., e 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, n. 1 (1 gennaio 2003): 126–32. http://dx.doi.org/10.1139/z02-225.
Testo completoAbstract (sommario):
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.
8
Brown, Joel S., Keren Embar, Eric Hancock e 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, n. 3-4 (18 maggio 2016): 196–204. http://dx.doi.org/10.1080/15659801.2016.1207298.
Testo completoAbstract (sommario):
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.
9
Brooker, Rohan M., e Danielle L. Dixson. "Comparable cross-taxa risk perception by means of chemical cues in marine and freshwater crustaceans". Marine and Freshwater Research 68, n. 4 (2017): 788. http://dx.doi.org/10.1071/mf16062.
Testo completoAbstract (sommario):
Rapid identification of predation risk and modification of subsequent behaviour is essential for prey survival. In low-visibility aquatic environments, chemical cues emitted by hetero- and conspecific organisms may be an important information source if they identify risk or alternatively, indicate safety or resource availability. This study tested whether ecologically similar shrimp from disparate habitats have a comparable ability to identify predators from a range of taxa based on chemical cues. Shrimp from both temperate marine (Palaemon affinis) and tropical freshwater habitats (Caridina typus) exhibited similar behavioural responses, avoiding chemical cues from predatory heterospecifics, showing no response to non-predatory heterospecific cues, and preferring conspecific cues. These chemical cues also affected habitat selection, with structurally complex microhabitats favoured in the presence of predator cues but avoided in the presence of conspecific cues. The ability to differentiate predators from non-predators irrespective of taxa suggests identification might be due to the predator’s diet. An ability to alter behaviour based on vision-independent perception of ambient risk is likely to reduce capture risk while allowing individuals to maximise time spent on essential processes such as foraging.
10
Cooper, Scott D., Daniel W. Smith e James R. Bence. "Prey Selection by Freshwater Predators with Different Foraging Strategies". Canadian Journal of Fisheries and Aquatic Sciences 42, n. 11 (1 novembre 1985): 1720–32. http://dx.doi.org/10.1139/f85-216.
Testo completoAbstract (sommario):
We observed several freshwater predators, including the odonate larvae Pachydiplax longipennis and Anax junius, the hemipterans Notonecta unifasciata and Buenoa scimitra, the dytiscid larva Acilius semisulcatus, and juvenile Gambusia affinis, feeding on a variety of microcrustacean prey and determined the frequency of the component parts of predator–prey interactions (encounter, attack, capture, ingestion). Encounter rates were the most important determinant of predator selectivity when predators were presented with a variety of microcrustacean prey. When only copepod species were used as prey, however, both encounter rates and capture success were important in determining predator diets. We used our data to test hypotheses concerning relationships between predator foraging mode and patterns of prey selection: mobile predators exhibited stronger selection for sedentary prey than did sit-and-wait predators; our own and literature data also indicated that macroinvertebrate sit-and-wait predators are better able to capture, and have higher selectivity for evasive prey than do mobile predators. A predator's attack acceleration, however, may be a better predictor of its selectivity for evasive versus nonevasive prey than its mean swimming speed.
11
HE, MINGFENG, PU LI e CHANGQUAN NI. "MODEL ODOR-ORIENTED PREDATORS AND PREY". International Journal of Modern Physics C 17, n. 05 (maggio 2006): 711–20. http://dx.doi.org/10.1142/s0129183106009217.
Testo completoAbstract (sommario):
The model of predators and prey, in which the predator judges the direction of prey's movement on the basis of the density of prey's odor will be researched in this article. The predator' s sensitivity to prey's odor is defined, so that can be simulated by Monte Carlo in L × L. It suggests the relationship between system stability and each value of Predator's sensitivity. We get three system states for different value of α (predator's sensitivity): the grass only, prey and the grass, three species in coexistence, with predators, prey and grass. But the probability of each system state is different. Their corresponding distribution will be given in this article.
12
Buitenhuis, R., L. Shipp e 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, n. 2 (7 maggio 2009): 167–73. http://dx.doi.org/10.1017/s0007485309006944.
Testo completoAbstract (sommario):
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.
13
Thompson, Kevin A., Selina S. Heppell e Grant G. Thompson. "The effects of temperature and predator densities on the consumption of walleye pollock (Gadus chalcogrammus) by three groundfish in the Gulf of Alaska". Canadian Journal of Fisheries and Aquatic Sciences 71, n. 8 (agosto 2014): 1123–33. http://dx.doi.org/10.1139/cjfas-2013-0260.
Testo completoAbstract (sommario):
Many multispecies models have assumed that prey density determines per-capita predator consumption rates, following a functional response relationship. However, empirical evidence suggests that a predator’s diet can also be influenced by a variety of environmental factors, including interactions with other predators. We used diet and abundance data from National Marine Fisheries Service (NMFS) bottom trawl surveys for three groundfish predators (Pacific cod (Gadus macrocephalus), Pacific halibut (Hippoglossus stenolepis), and sablefish (Anoplopoma fimbria)) in the Gulf of Alaska (GOA) to determine whether temperature or other species influence the consumption of walleye pollock (Gadus chalcogrammus). Using an information-theoretic approach, we tested for relationships between walleye pollock observed in predator stomachs and predator length, bottom temperature, prey availability (walleye pollock catch per unit effort (CPUE) scaled by observed prey lengths), and CPUE of the three predators and arrowtooth flounder (Atheresthes stomias). Predator length was positively related to walleye pollock presence and proportion of total diet mass in all predators. Increased temperatures negatively affected consumption of walleye pollock by Pacific halibut, but not the other predators. We found evidence for a number of interpredator effects of co-occurring predators, both positive (facultative) and negative (competitive). Surprisingly, observed prey density was not statistically significant with respect to consumption for these predators, suggesting that trawls sample the environment far differently than walleye pollock predators or species interactions are more complex than those used in previous multispecies models. These factors should be considered for future models contributing to ecosystem-based management.
14
Thorp, Corey J., Mhairi E. Alexander, James R. Vonesh e John Measey. "Size-dependent functional response of Xenopus laevis feeding on mosquito larvae". PeerJ 6 (26 ottobre 2018): e5813. http://dx.doi.org/10.7717/peerj.5813.
Testo completoAbstract (sommario):
Predators can play an important role in regulating prey abundance and diversity, determining food web structure and function, and contributing to important ecosystem services, including the regulation of agricultural pests and disease vectors. Thus, the ability to predict predator impact on prey is an important goal in ecology. Often, predators of the same species are assumed to be functionally equivalent, despite considerable individual variation in predator traits known to be important for shaping predator–prey interactions, like body size. This assumption may greatly oversimplify our understanding of within-species functional diversity and undermine our ability to predict predator effects on prey. Here, we examine the degree to which predator–prey interactions are functionally homogenous across a natural range of predator body sizes. Specifically, we quantify the size-dependence of the functional response of African clawed frogs (Xenopus laevis) preying on mosquito larvae (Culex pipiens). Three size classes of predators, small (15–30 mm snout-vent length), medium (50–60 mm) and large (105–120 mm), were presented with five densities of prey to determine functional response type and to estimate search efficiency and handling time parameters generated from the models. The results of mesocosm experiments showed that type of functional response of X. laevis changed with size: small predators exhibited a Type II response, while medium and large predators exhibited Type III responses. Functional response data showed an inversely proportional relationship between predator attack rate and predator size. Small and medium predators had highest and lowest handling time, respectively. The change in functional response with the size of predator suggests that predators with overlapping cohorts may have a dynamic impact on prey populations. Therefore, predicting the functional response of a single size-matched predator in an experiment may misrepresent the predator’s potential impact on a prey population.
15
Olson, Randal S., Arend Hintze, Fred C. Dyer, David B. Knoester e Christoph Adami. "Predator confusion is sufficient to evolve swarming behaviour". Journal of The Royal Society Interface 10, n. 85 (6 agosto 2013): 20130305. http://dx.doi.org/10.1098/rsif.2013.0305.
Testo completoAbstract (sommario):
Swarming behaviours in animals have been extensively studied owing to their implications for the evolution of cooperation, social cognition and predator–prey dynamics. An important goal of these studies is discerning which evolutionary pressures favour the formation of swarms. One hypothesis is that swarms arise because the presence of multiple moving prey in swarms causes confusion for attacking predators, but it remains unclear how important this selective force is. Using an evolutionary model of a predator–prey system, we show that predator confusion provides a sufficient selection pressure to evolve swarming behaviour in prey. Furthermore, we demonstrate that the evolutionary effect of predator confusion on prey could in turn exert pressure on the structure of the predator's visual field, favouring the frontally oriented, high-resolution visual systems commonly observed in predators that feed on swarming animals. Finally, we provide evidence that when prey evolve swarming in response to predator confusion, there is a change in the shape of the functional response curve describing the predator's consumption rate as prey density increases. Thus, we show that a relatively simple perceptual constraint—predator confusion—could have pervasive evolutionary effects on prey behaviour, predator sensory mechanisms and the ecological interactions between predators and prey.
16
El Balaa, Rayan, e 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, n. 4 (aprile 2013): 203–11. http://dx.doi.org/10.1139/cjz-2012-0232.
Testo completoAbstract (sommario):
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.
17
L.A., Escudero-Colomar, Creus E., Chorąży A. e Walzer A. "Intraguild aggressiveness between an alien and a native predatory mite". Systematic and Applied Acarology 24, n. 11 (7 novembre 2019): 2094–105. http://dx.doi.org/10.11158/saa.24.11.5.
Testo completoAbstract (sommario):
The predatory mite Amblydromalus limonicus, non-native in Europe, can be used legally in several European countries as greenhouse biocontrol agent against thrips species, although this species is also able to feed on whiteflies and gall mites. The first record of the unintended occurrence of A. limonicus in apple orchards in Europe comes from Catalonia (Spain), where A. limonicus is well established in the native predatory mite community since 2011. The dominant species in this community is Amblyseius andersoni, which has a similar life-style as A. limonicus (large, aggressive predator with broad diet range) making intraguild (IG) interactions between the two predators likely. Thus, we tested the IG aggressiveness of native and alien female predators, when provided with IG prey (larvae). Alien females of A. limonicus proved to be highly aggressive IG predators against native larvae of A. andersoni, which were attacked earlier and more frequently than alien larvae by the native predator. Nearly all attacks by the alien predator resulted in the death of native IG prey, whereas about 10% of the alien intraguild prey escaped the attacks of the native predator. Additionally, native IG prey is smaller than alien prey, which should facilitate the overwhelming by the alien predator. We argue that the strong aggressive intraguild behavior of A. limonicus is contributing to its establishment success in the native predatory mite community.
18
Beattie, Molly C., e Paul A. Moore. "Predator recognition of chemical cues in crayfish: diet and experience influence the ability to detect predation threats". Behaviour 155, n. 6 (2018): 505–30. http://dx.doi.org/10.1163/1568539x-00003501.
Testo completoAbstract (sommario):
AbstractAquatic prey often alter their morphology, physiology, and/or behaviour when presented with predatory chemical cues which are heavily influenced by the diet of the predator. We tested the roles that diet and prey familiarity with predators play in the ability of prey to recognize predator threats. Odours from two fish, bass and cichlid fed a vegetarian, protein, heterospecific, and a conspecific diet, were collected and presented to virile crayfish in a choice arena. Our results show that crayfish altered their behaviour in the presence of odours containing conspecific, as opposed to heterospecific diets, but only from familiar predators. A reduced anti-predator response was measured with odours from an unfamiliar predator fed conspecific crayfish. Therefore, crayfish may be able to determine different threat levels based on the different dietary cues from a potential predator, but only when the prey have familiarity with the predators.
19
Tull, Debra S., e Katrin Böhning-Gaese. "Patterns of drilling predation on gastropods of the family Turritellidae in the Gulf of California". Paleobiology 19, n. 4 (1993): 476–86. http://dx.doi.org/10.1017/s0094837300014093.
Testo completoAbstract (sommario):
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.
20
Gu, Xin-yao, Guang-yun Li e 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, n. 7 (14 luglio 2020): 1247–56. http://dx.doi.org/10.11158/saa.25.7.7.
Testo completoAbstract (sommario):
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.
21
Vermeij, Geerat J. "Evolution in the Consumer Age: Predators and the History of Life". Paleontological Society Papers 8 (ottobre 2002): 375–94. http://dx.doi.org/10.1017/s1089332600001169.
Testo completoAbstract (sommario):
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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Folt, Brian, e Craig Guyer. "Habitat-dependent effects of predatory spiders on prey frogs in a Neotropical wet forest". Journal of Tropical Ecology 37, n. 5 (16 agosto 2021): 214–21. http://dx.doi.org/10.1017/s0266467421000274.
Testo completoAbstract (sommario):
AbstractIn seasonal wet Neotropical forests, many studies have suggested that species-rich terrestrial frog assemblages are regulated bottom-up by the abundance of leaf litter. However, terrestrial frogs are prey to a diverse community of predators, and no studies have tested for top-down effects of predators on this or other anuran assemblages. Here, we used an extensive field dataset to model the relative contribution of food resources, microhabitat resources and predators towards the occupancy and detection of two frog species (Craugastor bransfordii and Oophaga pumilio) at La Selva, Costa Rica. Frog occupancy was most strongly influenced by predatory spiders and secondarily influenced by the abundance of leaf litter. Predators exerted stronger effects on frogs than food resources, and frogs avoided predators more as leaf litter decreased. Detection probability was elevated when predators were present. We found support for bottom-up effects of leaf litter on the terrestrial frog assemblage, but top-down effects by predators exerted stronger effects on frog occupancy and detection. Because predator avoidance varied along a resource gradient, predator and resource effects appear to be dependent, supporting interactions between top-down and bottom-up mechanisms. Climate-driven decreases in leaf litter may drive decreased availability of frog refugia and increased interactions between frogs and predators.
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Kent, Maud I. A., James E. Herbert-Read, Gordon McDonald, A. Jamie Wood e Ashley J. W. Ward. "Fine-scale behavioural adjustments of prey on a continuum of risk". Proceedings of the Royal Society B: Biological Sciences 286, n. 1903 (22 maggio 2019): 20190448. http://dx.doi.org/10.1098/rspb.2019.0448.
Testo completoAbstract (sommario):
In the wild, prey species often live in the vicinity of predators, rendering the ability to assess risk on a moment-to-moment basis crucial to survival. Visual cues are important as they allow prey to assess predator species, size, proximity and behaviour. However, few studies have explicitly examined prey's ability to assess risk based on predator behaviour and orientation. Using mosquitofish, Gambusia holbrooki , and their predator, jade perch, Scortum barcoo , under controlled conditions, we provide some of the first fine-scale characterization of how prey adapt their behaviour according to their continuous assessment of risk based on both predator behaviour and angular distance to the predator's mouth. When these predators were inactive and posed less of an immediate threat, prey within the attack cone of the predator showed reductions in speed and acceleration characteristic of predator-inspection behaviour. However, when predators became active, prey swam faster with greater acceleration and were closer together within the attack cone of predators. Most importantly, this study provides evidence that prey do not adopt a uniform response to the presence of a predator. Instead, we demonstrate that prey are capable of rapidly and dynamically updating their assessment of risk and showing fine-scale adjustments to their behaviour.
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Dunlap, Kent D., Alex Tran, Michael A. Ragazzi, Rüdiger Krahe e 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, n. 1824 (10 febbraio 2016): 20152113. http://dx.doi.org/10.1098/rspb.2015.2113.
Testo completoAbstract (sommario):
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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Elvidge, Chris K., e Grant E. Brown. "Visual and Chemical Prey Cues as Complementary Predator Attractants in a Tropical Stream Fish Assemblage". International Journal of Zoology 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/510920.
Testo completoAbstract (sommario):
To date, little attention has been devoted to possible complementary effects of multiple forms of public information similar information on the foraging behaviour of predators. In order to examine how predators may incorporate multiple information sources, we conducted a series of predator attraction trials in the Lower Aripo River, Trinidad. Four combinations of visual (present or absent) and chemical cues (present or absent) from each of two prey species were presented. The occurrences of three locally abundant predatory species present within a 1 m radius of cue introduction sites were recorded. The relative attractiveness of cue type to each predator was directly related to their primary foraging modes, with visual ambush predators demonstrating an attraction to visual cues, benthivores to chemical cues, and active social foragers demonstrating complementary responses to paired cues. Predator species-pair counts were greatest in response to cues from the more abundant prey species, indicating that individuals may adopt riskier foraging strategies when presented with more familiar prey cues. These differences in predator attraction patterns demonstrate complementary effects of multiple sensory cues on the short-term habitat use and foraging behaviour of predators under fully natural conditions.
26
Priyadarshana, Tharaka Sudesh. "Do predatory adult odonates estimate their adult prey odonates’ body size and dispersal ability to proceed with a successful attack?" Journal of Threatened Taxa 13, n. 7 (26 giugno 2021): 18949–52. http://dx.doi.org/10.11609/jott.7198.13.7.18949-18952.
Testo completoAbstract (sommario):
Predator-prey encounters are one of the most challenging behaviors that animals engage in and play a key role in structuring trophic linkages within food webs. Empirical studies suggest that predators (except pathogens, parasites, and parasitoids) tend to be larger in body size and have better dispersal ability than their prey items; however, when predators prey upon members of the same taxonomic group, it is unclear whether such relationships exist between predators and their prey items since both groups may have similar body sizes and dispersal abilities. Adult odonates can be used to test this as they prey upon other odonates within the same suborder, family, genus or species, although such records are uncommon. Using a dataset collected from Sri Lanka and India from 2012 to 2020, this study identified three types of predation behaviors between two suborders of Odonata, i.e., (i) Anisoptera (dragonflies) prey upon Anisoptera, (ii) Anisoptera prey upon Zygoptera (damselflies), and (iii) Zygoptera prey upon Zygoptera. There was no evidence of Anisoptera predation by Zygoptera. Study results showed strong evidence that there is a significant difference in body size (i.e., body length) and dispersal ability (i.e., hind-wing length) between adult predatory odonates and adult prey odonates for all three types of predations. This may indicate that predatory odonates estimate other odonate prey precisely to proceed with a successful attack.
27
Wikenros, Camilla, Dries P. J. Kuijper, Robert Behnke e Krzysztof Schmidt. "Behavioural responses of ungulates to indirect cues of an ambush predator". Behaviour 152, n. 7-8 (2015): 1019–40. http://dx.doi.org/10.1163/1568539x-00003266.
Testo completoAbstract (sommario):
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.
28
Epp, Kristen J. "Threat sensitivity in the San Marcos salamander: effects of predator diet and prey experience". Behaviour 150, n. 6 (2013): 617–34. http://dx.doi.org/10.1163/1568539x-00003073.
Testo completoAbstract (sommario):
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.
29
Sario, Sara, Conceição Santos, Fátima Gonçalves e Laura Torres. "DNA screening of Drosophila suzukii predators in berry field orchards shows new predatory taxonomical groups". PLOS ONE 16, n. 4 (8 aprile 2021): e0249673. http://dx.doi.org/10.1371/journal.pone.0249673.
Testo completoAbstract (sommario):
Drosophila suzukii (spotted wing drosophila, SWD) is a pandemic quarantine pest that attacks mostly red fruits. The high number of life cycles per year, its ability to rapidly invade and spread across new habitats, and highly polyphagous nature, makes this a particularly aggressive invasive species, for which efficient control methods are currently lacking. The use of native natural predators is particularly promising to anchor sustainable and efficient measures to control SWD. While several field studies have suggested the presence of potential predatory species in infested orchards, only a few confirmed the presence of SWD DNA in predators’ gut content. Here, we use a DNA-based approach to identify SWD predators among the arthropod diversity in South Europe, by examining the gut content of potential predator specimens collected in SWD-infested berry fields in North Portugal. These specimens were morphologically identified to the family/order, and their gut content was screened for the presence of SWD DNA using PCR. New SWD predatory taxonomical groups were identified, as Opiliones and Hemerobiidae, in addition to known SWD predators, such as Hemerobiidae, Chrysopidae, Miridae, Carabidae, Formicidae and Araneae. Additionally, the presence of a spider family, Uloboridae, in the orchards was recorded for the first time, posing this family as another SWD-candidate predator. This study sets important bases to further investigate the potential large-scale use of some of these confirmed predator taxa for SWD control in South Europe.
30
Weissburg, Marc, e Jeffrey Beauvais. "The smell of success: the amount of prey consumed by predators determines the strength and range of cascading non-consumptive effects". PeerJ 3 (19 novembre 2015): e1426. http://dx.doi.org/10.7717/peerj.1426.
Testo completoAbstract (sommario):
We examined whether chemically mediated risk perception by prey and the effects of changes in prey behavior on basal resources vary as a function of the amount of prey biomass consumed by the predator. We studied these issues using a tritrophic system composed of blue crabs,Callinectes sapidus(top predator), mud crabsPanopeus herbstii(intermediate prey), and oystersCrassostrea virginica(basal resource). Working in a well characterized field environment where experiments preserve natural patterns of water flow, we found that biomass consumed by a predator determines the range, intensity and nature of prey aversive responses. Predators that consume large amounts of prey flesh more strongly diminish consumption of basal resources by prey and exert effects over a larger range (in space and time) compared to predators that have eaten less. Less well-fed predators produce weaker effects, with the consequence that behaviorally mediated cascades preferentially occur in refuge habitats. Well-fed predators affected prey behavior and increased basal resources up to distances of 1–1.5 m, whereas predators fed restricted diet evoked changes in prey only when they were extremely close, typically 50 cm or less. Thus, consumptive and non-consumptive effects may be coupled; predators that have a greater degree of predatory success will affect prey traits more strongly and non-consumptive and consumptive effects may fluctuate in tandem, with some lag. Moreover, differences among predators in their degree of prey capture will create spatial and temporal variance in risk cue availability in the absence of underlying environmental effects.
31
Karindah, Sri. "Predation of Five Generalist Predators on Brown Planthopper (Nilaparvata lugens Stål)". Jurnal Entomologi Indonesia 8, n. 2 (27 settembre 2015): 55–62. http://dx.doi.org/10.5994/jei.8.2.55-62.
Testo completoAbstract (sommario):
Two generalist predators of brown planthopper,Metioche vittaticollis and Anaxipha longipennis (Gryllidae) have not been much studied in Indonesia. This research was conducted to study and compare the predatory ability of M. vittaticollis, A. longipennis (Gryllidae) and three coleopterans, Paederus fuscipes (Staphylinidae), Ophionea sp. (Carabidae),and Micraspis sp. (Coccinellidae) against brown planthopper (fourth and fifth instars) under laboratory condition. In total, 20 nymphs of N. lugens were exposed for 2 hour to each predator for 5 consecutive days. Prey consumptions by the predatory crickets, M. vittaticollis and A. longipennis were greater than the other predators and followed by A. longipennis, Micraspis sp., P. fuscipes, and Ophionea sp. respectively. Consumption rates of M. vittaticolis and A. longipenis were also higher than other predators. Micraspis sp was more active on predation in the morning,while M. vittaticollis, A. longipennis, P. fuscipes, and Ophionea sp. were more active both in the morning and the night but not in the afternoon. However, all five species of predators were not so active in preying during the afternoon. In conclusion, a major effort should be extended to conserve these predatory crickets especially M. vittaticollis and A. longipennis.
32
Lenhart, Paul A., Kelly A. Jackson e Jennifer A. White. "Heritable variation in prey defence provides refuge for subdominant predators". Proceedings of the Royal Society B: Biological Sciences 285, n. 1879 (30 maggio 2018): 20180523. http://dx.doi.org/10.1098/rspb.2018.0523.
Testo completoAbstract (sommario):
Generalist predators with broadly overlapping niches commonly coexist on seemingly identical sets of prey. Here, we provide empirical demonstration that predators can differentially exploit fine-grained niches generated by variable, heritable and selective defences within a single prey species. Some, but not all, clones of the aphid Aphis craccivora are toxic towards the dominant invasive predatory ladybeetle, Harmonia axyridis . However, other less competitive ladybeetle species are not affected by the aphid's toxic trait. In laboratory and open field experiments, we show: (i) that subdominant ladybeetle species were able to exploit the toxic aphids, benefitting from the suppression of the dominant predator; and (ii) that this narrow-spectrum toxicity can function as an anti-predator defence for the aphid, but depends on enemy community context. Our results demonstrate that niche differentiation among generalist predators may hinge upon previously underappreciated heritable variation in prey defence, which, in turn, may promote diversity and stability of enemy communities invaded by a dominant predator.
33
Catania, S. V. L., J. Koprivnikar e S. J. McCauley. "Size-dependent predation alters interactions between parasites and predators". Canadian Journal of Zoology 94, n. 9 (settembre 2016): 631–35. http://dx.doi.org/10.1139/cjz-2016-0088.
Testo completoAbstract (sommario):
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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Langi, Yohanes. "Analisis Kestabilan Model Interaksi Dua Pemangsa-Satu Mangsa Dengan Daya Dukung Lingkungan Pada Sistem Mangsa". d'CARTESIAN 2, n. 2 (30 settembre 2013): 50. http://dx.doi.org/10.35799/dc.2.2.2013.3809.
Testo completoAbstract (sommario):
Abstrak Interaction on every living in this world have positive effect, negative. Effect, and also have no effect to other living things. This paper would talk about interaction model between two predators-one prey with environmental support to predator system which based on Lotka-Volterra model. Model arranged by variable R (number of predators), H (number of main predators), C (number of predators which commensalisms to H), u (predators grow up level R), v (predatorily level C), w (predatorily level H), (conversion efficiently C), (conversion efficiently H), x (predator’s deadly level C), y (predator’s deadly level H), z (commensalisms relation between predators C with predator H),(environmental support which could contain predator’s grow). Research’s result give stability point at fixed point which there is only main predator (H) and prey in using the environmental support will reduce as big as main predatorily level to prey (T2.). Stability point also happen on fixed point where there only prey in using environmental support which will reduce as big as predatorily level to prey ((T3.). Keywords : Predator –pray, Stability, Differential Equation Abstrak Interaksi antar makhluk hidup dalam kehidupan ini ada yang berdampak positif,negative, dan ada pulah ynag tidak berpengaruh terhadap mahkluk hidup lain. Tulisan ini akan membahas model interaksi antara dua pemangsa-satu mangsa dengan daya dukung lingkungan pada system mangsa yang di dasari dari model lotka – Volterra .Pada model yang dikembangkan diasumsikan bahwa interaksi antar pemangsa bersifat komensalis.Model model yang disusun disini terdiri atas varibel-variabel R (banyaknya mangsa), H (banyaknya mangsa inang), C (banyaknya pemangsa yang komensalis terhadap H), u (tingkat pertumbuhan mangsa R), v (tingkat pemangsaan pemangsa C), w (tingkat pemangsaan pemangsa H), (efisiensi konversi C), (efisiensi konversi H), x (tingkat kematian pemangsa C), y (tingkat kematian pemangsa H), z (hubungan komensalisme antara pemangsa C dan pemangsa H), (daya dukung lingkungan yang masih dapat menampung pertumbuhan mangsa). Dari hasil penelitian diperoleh titik kestabilan pada titik tetap dimana hanya terdapat pemangsa inang (H) dan mangsa dalam menggunakan daya dukung lingkungan yang ada akan berkurang sebesar tingkat pemangsaan pemangsa inang terhadap mangsa (T2). Titik kesatabilan juga terjadi pada titik tetap dimana hanya terdapat mangsa dalam menggunakan daya dukung lingkungan yang ada akan berkurang sebesar tingkat pemangsa inang terhadap mangsa( T3 ). Kata Kunci : Mangsa-Pemangsa, Kestabilan, Persamaan Difrensial
35
Gallagher, Austin J., Michael J. Lawrence, Sofia M. R. Jain-Schlaepfer, Alexander D. M. Wilson e Steven J. Cooke. "Avian predators transmit fear along the air–water interface influencing prey and their parental care". Canadian Journal of Zoology 94, n. 12 (dicembre 2016): 863–70. http://dx.doi.org/10.1139/cjz-2016-0164.
Testo completoAbstract (sommario):
The nonconsumptive consequences of predators on prey behavior, survival, and demography have recently garnered significant attention by ecologists. However, the impacts of top predators on free-ranging prey are challenging to evaluate because the most common fright response for prey is to leave the area of risk. Additionally, the top-down impacts of avian predators on aquatic environments are surprisingly overlooked. Here we investigated the nonconsumptive effects of avian predators on parental care in pumpkinseed (Lepomis gibbosus (L., 1758)) through use of a realistic model of a predatory bird, the Osprey (Pandion haliaetus (L., 1758)). Our predator model exacted dramatic metabolic fright responses and inducible defenses in experimental fish resulting in significant behavioral changes with respect to their parental care. Key parental behaviors including in-nest rotations and egg and nest maintenance were noticeably altered by predator treatments demonstrating as much as an order of magnitude difference in parental performance, suggesting that even transient predation risk might decrease reproductive fitness. Our data provide important new insights on how the landscape of fear operates along the air–water interface and suggests that avian predators may have greater controlling effects on fish populations than previously thought.
36
Putra, Ichsan Luqmana Indra, Novia Saphira Prakusya e Defi Yuliasari. "Insect predator of spodoptera frugiperda J. E. Smith in Sleman and Gunungkidul regency, Indonesia". International Research Journal of Insect Sciences 8, n. 1 (3 febbraio 2023): 15–21. http://dx.doi.org/10.18488/irjis.v8i1.3278.
Testo completoAbstract (sommario):
This research was conducted to identify and found the abundance of predatory insect species of S. frugiperda in Sleman and Gunungkidul Regencies, Yogyakarta Province, Indonesia. This research was conducted in June 2021 - March 2022 on corn plantations in Sleman and Gunungkidul Regencies. Determination of the sampling location was determined by stratified random sampling. Corn land used in sampling was determined by purposive. Insect predator caught by using sweeping net and hand picking. The results showed that there are 3 orders, 8 families, and 16 species of insect predators. 3 orders of the insect predators that found in the Sleman and Gunungkidul Regencies were Coleoptera, Hymenoptera, and Hemiptera. Insect predator families that found in Sleman dan Guungkidul Regencies were Coccinellidae, Carabidae, Staphylinidae, Formicidae, Vespidae, Pentatomidae and Reduviidae. Insect predators species that was most commonly found was Menochilus sexmaculatus with 467 individuals and the least was Sycanus sp. with 1 individual. The conclusion of this study is that there were 16 species of predators from S. frugiperda in Sleman and Gunungkidul Regencies. Practical implications of this research were the insect predators that found in Sleman and Gunungkidul Regencies can be used to maintain the population of Spodoptera frugiperda in two regencies.
37
Mirza, Reehan S., e Douglas P. Chivers. "Predator-recognition training enhances survival of brook trout: evidence from laboratory and field-enclosure studies". Canadian Journal of Zoology 78, n. 12 (1 dicembre 2000): 2198–208. http://dx.doi.org/10.1139/z00-164.
Testo completoAbstract (sommario):
In this study we tested whether brook trout (Salvelinus fontinalis) can learn to recognise predators through releaser-induced recognition learning and whether this learning enhances survival of trout during encounters with a predator. In our initial experiment, we exposed hatchery-reared predator-naïve brook trout to chemical stimuli from predatory chain pickerel (Esox niger) paired with alarm signals released by damaged trout, disturbance signals, or distilled water. In subsequent tests 24 h later, when only pickerel odour was presented, trout conditioned with damage-released alarm signals exhibited antipredator behaviour (i.e., decreased movement and altered foraging patterns), in contrast to the other treatments, thereby demonstrating learned recognition of the predator. In our second experiment we showed that trout retained the ability to recognise the predator for at least 10 days. In the next series of experiments we explicitly tested whether training trout to recognise predators confers a survival benefit. During staged encounters with chain pickerel (in both the laboratory and the field), trained fish were better able to evade the predator than nontrained fish. Ours is the first study to demonstrate that fish trained to recognise predators gain a survival benefit during staged encounters with a predator.
38
Riyanto, Riyanto, Siti Herlinda, Chandra Irsan e Abu Umayah. "KELIMPAHAN DAN KEANEKARAGAMAN SPESIES SERANGGA PREDATOR DAN PARASITOID Aphis gossypii DI SUMATERA SELATAN". Jurnal Hama dan Penyakit Tumbuhan Tropika 11, n. 1 (29 gennaio 2011): 57–68. http://dx.doi.org/10.23960/j.hptt.11157-68.
Testo completoAbstract (sommario):
This study was aimed to analysis abundance and species diversity of predatory insects and parasitoid of Aphis gossypii from lowland and highland areas of South Sumatra. Survey of was conducted in 11 vegetable centers of South Sumatra. The results showed that 20 species of predatory insects and 3 species of parasitoids were found from the survey. The predatory insects consisted of 15 species of coccinellid beetles, two species of syrphids, and one species of chamaemyiid, mantid and staphylinid. Parasitoid found were 2 species of Aphidiidae (Diaretiella rapae and Aphidius sp.) and a species of Aphelinidae (Aphelinus sp.). The highest abundance of the predator was found in Soak (42.61 larvae and adults) and the highest abundance of the parasitoid was found in Talang Buruk (25.99 adults). The highest species diversity of the predator and the parasitoid were found in Soak (15 species and H’= 0.94) and in Talang Buruk (2 species and H’ = 0.27), respectively. Abundance and species diversity of the predators and parasitoids were higher in the dry season than those in rainy season. Thus, the abundance and species diversity of the predators and parasiotids were higher in the lowland than highland areas in South Sumatra, while the seasons affected the abundance and species diversity of the predators and parasitoids.
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Wagner, E. A., e P. A. Zani. "Escape behavior of Side-blotched Lizards (Uta stansburiana) in response to model predators". Canadian Journal of Zoology 95, n. 12 (dicembre 2017): 965–73. http://dx.doi.org/10.1139/cjz-2016-0255.
Testo completoAbstract (sommario):
Few field studies have tested for geographic variation in escape behavior and even fewer have examined responses of prey to multiple predators despite most prey occurring in multipredator environments. We performed 458 escape trials on Side-blotched Lizards (Uta stansburiana Baird and Girard, 1852) from 10 populations that differed in predator abundances. We quantified escape behavior of Side-blotched Lizards when approached with one of two model predators: a lizard (Great Basin Collared Lizard (Crotaphytus bicinctores N.M. Smith and Tanner, 1972)) or a snake (Western Yellow-bellied Racer (Coluber mormon Baird and Girard, 1852)). Our results suggest that the escape responses of Side-blotched Lizards (flight initiation distance, distance fled, refuge entry) do not differ when approached by either a model predatory lizard or a model predatory snake. Nor do the escape responses of individual Side-blotched Lizards differ in relation to the abundances of predatory lizards or snakes in the local environment. Rather, only the directness of fleeing toward a refuge differed based on model predator type with Side-blotched Lizards fleeing more directly toward a refuge in response to a model lizard. These findings suggest that Side-blotched Lizards tend to use a more generalized escape response to approaching predators.
40
Omkar, Geetanjali Mishra, Bhupendra Kumar, Neha Singh e Garima Pandey. "Risks associated with tandem release of large and small ladybirds (Coleoptera: Coccinellidae) in heterospecific aphidophagous guilds". Canadian Entomologist 146, n. 1 (23 dicembre 2013): 52–66. http://dx.doi.org/10.4039/tce.2013.56.
Testo completoAbstract (sommario):
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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Demšar, Jure, e Iztok Lebar Bajec. "Simulated Predator Attacks on Flocks: A Comparison of Tactics". Artificial Life 20, n. 3 (luglio 2014): 343–59. http://dx.doi.org/10.1162/artl_a_00135.
Testo completoAbstract (sommario):
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.
42
Dale, Jonathan J., Carl G. Meyer e Christian E. Clark. "The Ecology of Coral Reef Top Predators in the Papahānaumokuākea Marine National Monument". Journal of Marine Biology 2011 (2011): 1–14. http://dx.doi.org/10.1155/2011/725602.
Testo completoAbstract (sommario):
Coral reef habitats in the Papahānaumokuākea Marine National Monument (PMNM) are characterized by abundant top-level predators such as sharks and jacks. The predator assemblage is dominated both numerically and in biomass by giant trevally (Caranx ignobilis) and Galapagos sharks (Carcharhinus galapagensis). A lower diversity of predatory teleosts, particularly groupers and snappers, distinguishes the PMNM from other remote, unfished atolls in the Pacific. Most coral reef top predators are site attached to a “home” atoll, but move extensively within these atolls. Abundances of the most common sharks and jacks are highest in atoll fore reef habitats. Top predators within the PMNM forage on a diverse range of prey and exert top-down control over shallow-water reef fish assemblages. Ecological models suggest ecosystem processes may be most impacted by top predators through indirect effects of predation. Knowledge gaps are identified to guide future studies of top predators in the PMNM.
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Lester, P. J., J. M. Yee, S. Yee, J. Haywood, H. MA Thistlewood e 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, n. 6 (1 giugno 2005): 797–806. http://dx.doi.org/10.1139/z05-072.
Testo completoAbstract (sommario):
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.
44
Igic, Branislav, Jessica McLachlan, Inkeri Lehtinen e Robert D. Magrath. "Crying wolf to a predator: deceptive vocal mimicry by a bird protecting young". Proceedings of the Royal Society B: Biological Sciences 282, n. 1809 (22 giugno 2015): 20150798. http://dx.doi.org/10.1098/rspb.2015.0798.
Testo completoAbstract (sommario):
Animals often mimic dangerous or toxic species to deter predators; however, mimicry of such species may not always be possible and mimicry of benign species seems unlikely to confer anti-predator benefits. We reveal a system in which a bird mimics the alarm calls of harmless species to fool a predator 40 times its size and protect its offspring against attack. Our experiments revealed that brown thornbills ( Acanthiza pusilla ) mimic a chorus of other species' aerial alarm calls, a cue of an Accipiter hawk in flight, when predators attack their nest. The absence of any flying predators in this context implies that these alarms convey deceptive information about the type of danger present. Experiments on the primary nest predators of thornbills, pied currawongs ( Strepera graculina ), revealed that the predators treat these alarms as if they themselves are threatened by flying hawks, either by scanning the sky for danger or fleeing, confirming a deceptive function. In turn, these distractions delay attack and provide thornbill nestlings with an opportunity to escape. This sophisticated defence strategy exploits the complex web of interactions among multiple species across several trophic levels, and in particular exploits a predator's ability to eavesdrop on and respond appropriately to heterospecific alarm calls. Our findings demonstrate that prey can fool predators by deceptively mimicking alarm calls of harmless species, suggesting that defensive mimicry could be more widespread because of indirect effects on predators within a web of eavesdropping.
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Ruzicka, Rebekah E., e Michael R. Conover. "Influence of Wind and Humidity on Foraging Behavior of Olfactory Mesopredators". Canadian Field-Naturalist 125, n. 2 (1 aprile 2011): 132. http://dx.doi.org/10.22621/cfn.v125i2.1196.
Testo completoAbstract (sommario):
Many mammalian predators rely on scents to locate prey and weather conditions that affect an odor plume (i.e., scents suspended in air) or depositional odor (i.e., scents laid on the ground) should affect predator foraging behavior. We predicted that wind speed, wind direction, and humidity would influence the foraging behavior of olfactory mesopredators. We tested these predictions by conducting spotlight surveys for foraging Red Foxes (Vulpes vulpes), Striped Skunks (Mephitis mephitis), and Raccoons (Procyon lotor) along the dike surrounding Willard Bay Reservoir in Willard, Utah, from August 2008 to August 2009. We recorded predator species, locations, numbers, and weather conditions at the time each predator was observed. While humidity had no effect on foraging, wind speed and direction were significant predictors of a predator's nightly foraging activity, with most predators observed when wind speeds were 2 to 4 m/s and winds were blowing perpendicularly over the dike the dike rather than parallel to the dike. Wind speed and direction also influenced where predators foraged on the dike, with predators being more likely to forage on the windward side of the dike when wind speeds were high enough to cause turbulence. We detected differences among predator species in their response to wind speed: Raccoons were more active than Striped Skunks and Red Foxes when the wind was calm and blowing parallel to the dike. Overall, our results indicate that these predator species alter their foraging behavior based on wind speed and wind direction. By foraging when winds were light and blowing perpendicularly over the dike, predators could likely enhance their ability to locate food using olfaction.
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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, n. 1 (20 luglio 2020): 1–7. http://dx.doi.org/10.37478/agr.v10i1.75.
Testo completoAbstract (sommario):
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.
47
Cheon, Geum Su, Chae Hoon Paik, Geon Hwi Lee e Sang Soo Kim. "Toxicity of Spirodiclofen to the Predatory Mite, Amblyseius womersleyi (Acari: Phytoseiidae), and its Prey, Tetranychus urticae (Acari: Tetranychidae)". Journal of Entomological Science 42, n. 1 (1 gennaio 2007): 44–51. http://dx.doi.org/10.18474/0749-8004-42.1.44.
Testo completoAbstract (sommario):
The relative toxicity of spirodiclofen to the predatory mite, Amblyseius womersleyi Schicha (Acari: Phytoseiidae), and its prey, Tetranychus urticae Koch (Acari: Tetranychidae), was evaluated in laboratory bioassays. Spirodiclofen was much less toxic to A. womersleyi than to T. urticae. Although the survival rate of adult females of A. womersleyi tended to decrease with increasing concentrations of spirodiclofen, 62–96% of the predators survived at concentrations of 22.5–180 ppm. Reproduction of adult female predators was only significantly affected at high concentrations (90 and 180 ppm). Spirodiclofen did not affect the hatch of A. womersleyi eggs at any concentration tested. Survival of immature predators was significantly decreased with increasing spirodiclofen concentration, however, 30–78% of immature predators reached adulthood at 22.5–45 ppm. Adult female predators survived on a diet of spider mites treated with spirodiclofen, and their fecundity was not significantly affected. Moreover, immature predators developed normally on prey treated with spirodiclofen. Spirodiclofen at selective sublethal concentrations (i.e., 22.5–45 ppm) could be of value in adjusting the prey/predator ratio in integrated management of T. urticae.
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Sen, Deeptajyoti, Sergei Petrovskii, S. Ghorai e Malay Banerjee. "Rich Bifurcation Structure of Prey–Predator Model Induced by the Allee Effect in the Growth of Generalist Predator". International Journal of Bifurcation and Chaos 30, n. 06 (maggio 2020): 2050084. http://dx.doi.org/10.1142/s0218127420500844.
Testo completoAbstract (sommario):
Prey–predator models are building blocks for many food-chain and food-web models in theoretical population biology. These models can be divided into two groups depending on the nature of predators, namely, specialist predator and generalist predator. Generalist predators can survive in the absence of prey but specialist predators go to extinction. Prey–predator models with specialist predator and Allee effect in prey growth have been investigated by several researchers and various types of interesting dynamics have been reported. In this paper, we consider a prey–predator model with generalist predator subject to Allee effect in predator’s growth rate. In general, a prey–predator system with saturating functional response can be destabilized due to the increase of the carrying capacity of prey which is known as paradox of enrichment. In our model with Allee effect in predator growth, we have shown that increase in carrying capacity of prey helps the populations to survive in a coexistence steady state. The considered model is capable of producing bistable dynamics for a reasonable range of parameter values. The complete dynamics of the system are quite rich and all possible local and global bifurcations are studied to understand the dynamics of the model. Analytical results are verified with numerical examples and successive bifurcations are identified with the help of bifurcation diagrams.
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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, n. 9 (1 settembre 2000): 1794–803. http://dx.doi.org/10.1139/f00-134.
Testo completoAbstract (sommario):
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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Massaro, Marcela, Matheus Montrazi, José Wagner S. Melo e Gilberto J. de Moraes. "Small-Scale Production of Amblyseius tamatavensis with Thyreophagus cracentiseta (Acari: Phytoseiidae, Acaridae)". Insects 12, n. 10 (22 settembre 2021): 848. http://dx.doi.org/10.3390/insects12100848.
Testo completoAbstract (sommario):
Amblyseius tamatavensis, a predatory mite, has been mentioned as potentially useful for the control of Bemisia tabaci. The objective of this work was to compare the production rates of A. tamatavensis in closed units containing T. cracentiseta as food, at different combinations of numbers of predator inoculated, periods of production and volumes of rearing units. Final predator densities increased with increasing production periods up to 30–45 days, reducing afterward. Likewise, maximum final densities increased with increasing predator inoculation levels, up to 200 predators per rearing unit. The results led us to select the proportion of 150 predators per unit for a production period of 30 days to evaluate the effect of the size of the experimental unit. Then, in the second part of the study, a direct relationship was observed between volume and final predator density (y = 8610.25x + 2166.04; R2 = 0.99; p < 0.0001). It was also calculated that ri value was quite stable (0113–0.119), with a calculated value of 0.115 at all volumes of rearing units. It can be concluded that progressively larger numbers of predators can be obtained with progressively larger rearing units.