Prey Capture Success Research Articles

Thermal responses and temperature tolerance of a dessert ant-lion larva

1. 1. Cueta trivirgata larvae construct pits in the dry Kuiseb River bed in the Namib Desert. 2. 2.An art, Ocymyrmex robustior comprises 65.4% of the biomass of prey consumed by the ant-lions. 3. 3. O. robustior is active between surface temperatures of 27–68°C. 4. 4.Ant-lions tolerate high body temperatures (LD 50 = 53.4°C). 5. 5.By exploiting the pit microclimate and by digging below the surface during extreme thermal loads, ant-lions can capture prey at surface temperatures of 13–63°C. 6. 6.These behavioural and physiological adaptations enable ant-lions to maximize the duration of vigilance and hence prey capture success.

Antlion Pit Construction and Kleptoparasitic Prey

At a site on Archbold Biological Field Station (Lake Placid, Florida), 25% of the diet of antlion larvae (Myrmeleon spp.) consisted of a single species of an ant (Conomyrma sp.); however, in about 10% of antlion pits containing prey, Conomyrma successfully kleptoparasitized, or stole prey from, the antlion. Stolen prey were significantly larger than other prey items. Features that increase the capture efficiency of the pit (steep slope and a layer of fine sand on the walls) are disrupted during the attempted escape of large prey; this decreases the risk of predation by antlions on kleptoparasitic ants. In the laboratory, antlions preferred fine sand over coarse, and moved longer distances when placed on coarse sand. The former behavior will increase prey capture success and reduce the risk of kleptoparasitism. The latter behavior increases the probability of finding a more suitable habitat.

Predator-prey interactions between the digger waspClypeadon laticinctusand the harvester antPogonomyrmex occidentalis

Females of the digger wasp Clypeadon laticinctus prey exclusively on workers of the western harvester ant Pogonomyrmex occidentalis. There is considerable variability in the size of ant workers both within and between ant mounds, and wasps tend to select larger workers as prey. Worker ants were most likely to be outside the nest at surface temperatures of 25–35°C. Wasps were seen at ant mounds most frequently when surface temperatures were between 40 and 50°C. Wasps captured ants outside and inside ant nests. Predation attempts were equally likely to result in a successful capture in either location, but entering the ant nests was more time consuming. Approximately 63% of visits by wasps to ant mounds resulted in a successful prey capture. In general, ant mounds that were visually conspicuous or close to wasp nest aggregations were more likely to be visited by wasps. However, frequency of visitation and rates of predation at a given mound varied considerably from week to week. Agonistic interactions between female wasps involving chases and occasional fights were likely to occur whenever two wasps were simultaneously present at an ant mound, especially when the only access to prey was by entering the mound.

Search behavior of the checker-throated antwren foraging in aerial leaf litter

Checker-throated antwrens (Formicariidae: Myrmotherula fulviventris) live in lowland neotropical forests and forage from dead curled leaves in the understory. Because they search each leaf individually they provide an opportunity to study the use of potential visual cues by an insectivorous bird. Long and highly curled leaves contain the most arthropods and checker-throated antwrens were more successful when foraging at those leaves. Yet, they used leaves at random with respect to these potential cues. Antwrens spent longer searching for arthropods in each highly curled leaf than in less curled leaves. Because of this additional search time, prey capture success per unit foraging time was only slightly greater for highly curled leaves than at the average dead leaf in the aerial leaf litter. Thus, the cues that antwrens could use to locate richer leaves are those features that obscure the prey from avian predators. Unlike other foraging systems, the antwrens appear to have no reliable cues indicating more profitable foraging sites.

Mechanics and Functions of Jaw Protrusion in Teleost Fishes: A Review

The more recent and definitive studies on the mechanics and functions of jaw protrusion in teleost fishes are reviewed. Four basic mechanisms characterize the system: In the Type A or depression of jaw protrusion, depression of the mandible pulls or pushes the premaxilla into the protruded state. The force may be transferred to the upper jaw via bones, ligaments or tendons. Twisting of the maxilla around its longitudinal axis may occur passively in this case. The Type B or maxilla utilizes twisting of the maxilla round its longitudinal axis to drive or pull the premaxilla into the protruded position. Twisting of the maxilla is initiated by either depression of the mandible or contraction of the Al division of the adductor mandibulae. In the Type C or decoupled of jaw protrusion the neurocranium is lifted independently from the premaxilla such that the premaxilla is protruded and the Type D or suspensorial abduction augments the latter two mechanisms by abducting the suspensorium to produce tension in the palatopalatine ligament, squeezing the ascending process of the premaxilla such that protrusion of the premaxilla occurs. The first mechanism is shown to be more widespread among the teleosts studied and some of the conclusions concerning the twisting maxilla model are suspect. Previous distinctions among various taxonomic groups based partly on the mechanisms of protrusion are shown to be at least partially incorrect. Hypothesized, and yet untested, functions of jaw protrusion are discussed. Protrusion may either result in a decrease in predation and/or feeding may be energetically more efficient than without it, as a result of a) greater prey capture success with protrusion, b) decreased energy necessary to capture or ingest prey. Lastly, suggestions for the future direction and methodologies of such studies are outlined.

Feeding by marine fish larvae: developmental and functional responses

The relationship between prey consumption rate and prey concentration (functional response), and its change with growth (developmental response) were examined in the laboratory for three species of marine fish larvae: bay anchovy Anchoa mitchilli (Engraulidae), sea bream Archosargus rhomboidalis (Sparidae) and lined sole Achirus lineatus (Soleidae). The major objective was to determine relative predatory abilities of the larvae by fitting feeding rate data to developmental and functional response models. Feeding success, prey capture success, attack rates, handling times and search rates were estimated. Prey consumption rates and attack rates of bay anchovy usually were highest, but at the lowest prey level (50 per liter) first-feeding sea bream larvae had the highest consumption rate. Sea bream could consume prey at near-maximum rates at prey levels lower than those required by the other species. As larvae grew, time searching per attack decreased rapidly for all species, especially at low prey levels. Handling time also decreased, but most rapidly for bay anchovy. Search rates were highest for bay anchovy and lowest for lined sole. Bay anchovy had the best apparent predation ability, but when previous results on larval growth rates, survival rates and growth efficiencies were considered, sea bream larvae were the most efficient predators and the least likely of the three species to be limited by low prey levels.

Visual mechanisms of hunting behaviour inTrite planiceps,a jumping spider (Araneae: Salticidae)

Abstract Jumping spiders rely on visual stimuli when catching their prey. Each of the hunting actions employed is mediated by one or more of the three pairs of eyes responsible for this behaviour. No function has yet been demonstrated for the tiny fourth pair of eyes. Two distinct post-detection hunting strategies are used; one enables spiders to catch their prey on the run, and the other controls the capture of stationary prey. Exclusive components of each of these strategies are (i) chasing, which is a function of the anterior-lateral eyes, and (ii) stalking, which is a function of the anterior-median eyes; collaborative visual mechanisms result in a smooth transition from one mode of behaviour to another. In addition, both strategies employ common behavioural elements that exploit specialised properties of the four anterior eyes; successful prey capture is a measure of their physiological and behavioural synchronisation. ‘Short jumps’ towards targets moving at an angular velocity of more than 15°/s are...

Behavior of juvenile pink salmon (Oncorhynchus gorbuscha Walbaum) toward novel prey: influence of ontogeny and experience

The behavior of individual, juvenile pink salmon toward novel prey (Artemia salina) under laboratory conditions is described. Two aspects of predatory behavior, namely latency time to initial prey-capture attempt and prey-capture success, are quantified in relation to chronological age and feeding experience. Initially, mean latency time declined slightly with increasing age up to Day 19 (post-emergence from gravel), but increased sharply to an asymptote with further aging. Mean percentage capture success gradually increased from 7.88% on Day 1 to 92.9% on Day 45. Prior feeding experience on the prey resulted in a decline (to a stable level) in mean latency time in experienced fish compared to control fish. Mean percentage capture success was not significantly altered by prior feeding experience on the prey.

The Nature of Prey Selection by Planktivorous Fish

The nature of prey selection by planktivorous fish is presented as a model. The model conceptualization is based on the predation cycle, and the effects of prey distribution, encounter rate, handling time, capture success, and optimal foraging on food selection are explicit. The model as presented assumes a multiple species prey assemblage admitting within—species size variation. Conditions are given so that the optimal strategy of prey utilization can be expressed as a breadth of diet, and the specific components of the predator—prey interaction of fish and zoo plankton are discussed in detail. A reduced form of model is applied to two experimental situations. Specific factors which influence prey selection are also discussed.

Daylength and the Hummingbirds' Use of Time

PHYSIOLOGIcAL homeostasis is maintained with energy that a bird must extract from its environment. Effective investment of the bird's time in exchange for the necessary energy must be the objective of maintenance strategy. If the rate of intake is less than the metabolic rate over a period of time, homeostasis is impossible. The temporal aspects involved in attainment of energy balance by a diurnal bird include duration of adequate light for effective foraging, cyclic availability of food, flight time to a food source or successful prey capture, duration of the nocturnal fast, and the daily environmental temperature cycle that will influence the overall energy cost. In summer the length of daylight for foraging increases with latitude, and the duration of the nocturnal fast decreases. In winter, the ratio of feeding time to fasting time is reduced with increasing latitude. The endurance of fasting would be directly proportional to the amount of energy in reserve and inversely related to the rate of degradation of the reserves: