Prey Arrival Research Articles

Temperature and nutrient conditions modify the effects of phenological shifts in predator-prey communities.

Although there is mounting evidence indicating that the relative timing of predator and prey phenologies determines the outcome of trophic interactions, we still lack a comprehensive understanding of how the environmental context (e.g., abiotic conditions) influences this relationship. Environmental conditions not only frequently drive shifts in phenologies, but they can also affect the very same processes that mediate the effects of phenological shifts on species interactions. Therefore, identifying how environmental conditions shape the effects of phenological shifts is key to predicting community dynamics across a heterogeneous landscape and how they will change with ongoing climate change in the future. Here I tested how environmental conditions shape the effects of phenological shifts by experimentally manipulating temperature, nutrient availability, and relative phenologies in two predator-prey freshwater systems (mole salamander-bronze frog vs. dragonfly larvae-leopard frog). This allowed me to (1) isolate the effects of phenological shifts and different environmental conditions; (2) determine how they interact; and (3) evaluate how consistent these patterns are across different species and environments. I found that delaying prey arrival dramatically increased predation rates, but these effects were contingent on environmental conditions and the predator system. Although nutrient addition and warming both significantly enhanced the effect of arrival time, their effect was qualitatively different across systems: Nutrient addition enhanced the positive effect of early arrival in the dragonfly-leopard frog system, whereas warming enhanced the negative effect of arriving late in the salamander-bronze frog system. Predator responses varied qualitatively across predator-prey systems. Only in the system with a strong gape limitation were predators (salamanders) significantly affected by prey arrival time and this effect varied with environmental context. Correlations between predator and prey demographic rates suggest that this was driven by shifts in initial predator-prey size ratios and a positive feedback between size-specific predation rates and predator growth rates. These results highlight the importance of accounting for temporal and spatial correlations of local environmental conditions and gape limitation when predicting the effects of phenological shifts and climate change on predator-prey systems.

Behavioral differences between pit-building antlions and wormlions suggest limits to convergent evolution.

Antlions and wormlions are distantly related insect taxa, both digging pits in loose soil and ambushing arthropod prey. Their hunting method, which is rare in the animal kingdom, is a clear example of convergent evolution. There is little research directly comparing the 2 pit-building taxa. Using the same experimental platform to investigate how they respond to biotic and abiotic environmental factors enables an examination of their convergence and its limits. We investigated the response of antlions and wormlions to 3 factors common in their daily life: disturbance to the pits, prey arrival, and conspecific competitors. Although both increased the pit size following disturbance, wormlions increased it faster than antlions. Antlions responded to prey faster than wormlions, but wormlions improved their response time over days. The most diverging response was toward conspecifics. Whereas antlions relocated their pits fast in response to increasing conspecific density, wormlions never relocated. We suggest explanations for the behavioral differences between the taxa. Our results imply that despite the similar hunting method of the 2 taxa they may differ greatly in their behavior, which in turn might have consequences for their habitat use and population dynamics.

Operant conditioning in antlion larvae and its impairment following exposure to elevated temperatures

Although ambush predators were previously considered limited in their cognitive abilities compared to their widely foraging relatives, there is accumulating evidence it does not hold true. Pit-building antlions are already known to associate vibrations in the sand with the arrival of prey. We used a T-maze and successfully trained antlions to turn right or left against their initial turning bias, leading to a suitable substrate for digging traps. We present here the first evidence for operant conditioning and T-maze solving in antlions. Furthermore, we show that exposure of second instar larvae to an elevated temperature led to impaired retention of what was learned in a T-maze when tested after moulting into the third instar, compared to larvae raised under a more benign temperature. We suggest that climate change, involving an increase in mean temperatures as well as rare events (e.g., heatwaves) might negatively affect the retention of operant conditioning in antlions, alongside known, more frequently studied effects, such as changes in body size and distribution.

Interspecific correlations toward climatic factors in migratory raptor species across Mt. Sega, Karangasem, Bali

It has been known that climate change can affect organisms in various ways. For example, studies found that climate change affect phenology i.e. migratory arrival of migratory species. This study was aimed to find out whether the migratory arrival of five species of bird of prey flying across Mt. Sega Karangasem – Bali correlates with climate factors in the region. This study took place from 1 October to 30 November 2018 by using look up method, and found that air temperature, cloud cover, humidity, and air pressure had a stronger correlation toward the migratory bird of prey species that crossed over the Mt. Sega compared to wind speed and precipitation. The air temperature, cloud cover and wind speed had a positive correlation toward the migratory bird of prey arrival, whereas the negative correlation was demonstrated by humidity, air pressure, and precipitation. The presence of the Chinese Sparrow-hawk and the Short-toed Snake Eagle were correlated with the humidity. Whereas the presence of the Peregrine falcon was correlated with the cloud cover. The presence of the Oriental Honey Buzzard was correlated with the wind speed, while the precipitation and air pressure were correlated with the presence of the Japanese Sparrow-hawk. The Japanese Sparrow-hawk arrived earlier at 10.00 whereas the other four species arrived later at around 12.00.

Factors That Can Affect the Spatial Positioning of Large and Small Individuals in Clusters of Sit-and-Wait Predators.

Shadow competition, the interception of prey by sit-and-wait predators closest to the source of prey arrival, is prevalent in clusters of sit-and-wait predators. Peripheral positions in the cluster receive more prey and should thus be more frequently occupied. Models predicting spatial positioning in groups, however, usually ignore variability among group members. Here, I used a simulation model to determine conditions under which small and large sit-and-wait predators, which differ in their attack range, should differ in their spatial positions in the cluster. Small predators occupied peripheral positions more frequently than large predators at the simulation beginning, while the opposite held true as time advanced. Because of the large and small attack range of large and small predators, respectively, small predators mistakenly relocated away from peripheral positions, while large predators did not relocate fast enough from inferior central positions. Any factor that moderated the frequent relocations of small predators or had the opposite effect on large predators assisted small or large predators, respectively, in reaching the more profitable peripheral positions. Furthermore, any factor elevating shadow competition led to longer occupation of the periphery by large predators. This model may explain why sit-and-wait predators are not homogenously distributed in space according to size.

Kicking kangaroo rats deter rattlesnakes

![Graphic][1] Rattlesnakes represent the quintessential ambush predator. They can withstand months of starvation whilst they patiently await the arrival of prey within striking distance. Only then can a snake launch an attack to envenomate, subdue and consume its meal. Whilst studying this

Comparison of wormlion behavior under man-made and natural shelters: urban wormlions more strongly prefer shaded, fine-sand microhabitats, construct larger pits and respond faster to prey.

Urban habitats differ from their natural surroundings in various aspects, such as a higher temperature and a distinct species composition. It is therefore not surprising that animal behavior too differs between these habitat types. We studied the foraging and habitat selection behavior of a pit-building predator, a wormlion, originating from either an urban or a more natural site. Wormlions occur in nature under structures that provide shelter from sunlight and rain, such as caves, and are also common in cities, occurring under artificial shelters. Wormlions construct pit-traps to hunt arthropods, and the pits constructed by urban wormlions were larger than those constructed by wormlions from caves. Urban wormlions responded faster to prey falling into their pit, probably leading to a higher capture success. We suggest that these 2 findings indicate the higher investment of urban wormlions in foraging, resulting from the higher abundance of potential prey in the city. Urban wormlions were choosier regarding their preferred microhabitat. While both fine sand and shaded microhabitats were preferred by wormlions, urban wormlions demonstrated a greater preference for such conditions. We suggest that relocation is more likely to lead wormlions in cities to find microhabitats of a higher quality compared with wormlions inhabiting caves. This is probably due to the larger areas in the city available for wormlions. Wormlions from the caves possessed more lipids, suggesting that they employ a conservative growth strategy, intended to contend with the uncertainty of prey arrival, in contrast to the city, where potential prey are more abundant.

Seagrass corridors and tidal state modify how fish use habitats on intertidal coral reef flats

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 581:135-147 (2017) - DOI: https://doi.org/10.3354/meps12311 Seagrass corridors and tidal state modify how fish use habitats on intertidal coral reef flats Jean P. Davis1,2,*, Kylie A. Pitt1, Andrew D. Olds1,3, Alastair R. Harborne4,5, Rod M. Connolly1 1Australian Rivers Institute - Coast and Estuaries, and Griffith School of Environment, Griffith University, Gold Coast, QLD 4222, Australia 2California Department of Fish and Wildlife, Marine Region, Los Alamitos, CA 90720, USA 3School of Science and Engineering, University of the Sunshine Coast, Maroochydore, QLD 4558, Australia 4Department of Biological Sciences, Florida International University, North Miami, FL 33181, USA 5Marine Spatial Ecology Laboratory and Australian Research Council Centre of Excellence for Coral Reef Studies, School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia *Corresponding author: jeanpepper@gmail.com ABSTRACT: Identifying pathways that animals use to move among ecosystems has become a focus for improving conservation planning. The function of habitat corridors in facilitating animal movement among terrestrial ecosystems is well established. By contrast, the role of habitat corridors for the movement of marine animals is poorly understood. We used underwater video cameras to evaluate the effects of seagrass corridors and water depth on fish abundance, and the arrival of prey and predatory species on intertidal coral reef flats in eastern Australia. Cameras were placed in intertidal seagrass and unvegetated habitats during incoming tides and recorded fish that moved across these habitats. We found some evidence that fish were more abundant over intertidal seagrass, particularly garfish Hyporhamphus regularis ardelio, striped barracuda Sphyraena obtusata and striped grunter Pelates sexlineatus, but most species did not appear to use the intertidal seagrass as a corridor. Prey fish were generally more abundant at shallower water depths, whereas predators were more common in deeper water, but many species were present over intertidal flats throughout the incoming tide. Our findings show that the movement of fishes across intertidal flats is dynamic, and depends on the species of interest, the composition of intertidal seascapes and tidal condition. Understanding how biotic and abiotic factors interact to influence fish movement and shape patterns in habitat use is a critical challenge for conservation planning in shallow coral reef seascapes. KEY WORDS: Habitat corridor · Predation refuge · Underwater video · Mangrove Full text in pdf format Supplementary material PreviousNextCite this article as: Davis JP, Pitt KA, Olds AD, Harborne AR, Connolly RM (2017) Seagrass corridors and tidal state modify how fish use habitats on intertidal coral reef flats. Mar Ecol Prog Ser 581:135-147. https://doi.org/10.3354/meps12311 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 581. Online publication date: October 13, 2017 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2017 Inter-Research.

Differential effects of variance in prey arrival on foraging success and growth rate of two pit‐building antlion species

AbstractAnimals in nature generally face fluctuating rather than constant environmental conditions. When given a choice, animals usually seek to minimize the variance of gain. However, it is clear that the avoidance of variance in energetic gain depends on several factors, including hunger level. While holding the mean prey encountered constant, we studied the effect of variance in prey arrival on the growth rates of two pit‐building antlion species, Myrmeleon hyalinus and Cueta lineosa. Both species construct pit‐traps in loose soils and ambush small prey in the same desert habitats, while differing in their preferred microhabitat: shaded vs. exposed to direct sunlight. We expected the light‐preferring species to better tolerate variance in feeding than the shade‐preferring species, owing to the former's higher stress tolerance and natural occurrence in microhabitats that are more likely poor with prey. While increasing variance in prey arrival reduced the growth rates of both species, this decrease was more pronounced in the species inhabiting the shaded and most likely prey‐richer microhabitat. The greater variance tolerance of the light‐preferring species stems from its ability to capture several prey items when almost simultaneously encountered. It could also be that this species has lower basal metabolic rate, which improves its starvation tolerance. These two antlion species differed in their prey capture success, starvation and thermal tolerance, and we thus suggest that their tolerance to variance in feeding opportunities and functional response offer an additional axis that enables them to coexist in the same desert habitats.

Sedentary antlion larvae (Neuroptera: Myrmeleontidae) use vibrational cues to modify their foraging strategies.

Learning abilities are exhibited by many animals, including insects. However, sedentary species are typically believed to have low capacities and requirements for learning. Despite this view, recent studies show that even such inconspicuous organisms as larval antlions, which employ an ambush predation strategy, are capable of learning, although their learning abilities are rather simple, i.e., limited to the association of vibrational cues with the arrival of prey. This study demonstrates, for the first time, that antlion larvae can use vibrational cues for complex modifications of their foraging strategies. Specifically, antlion larvae rapidly learn to differentiate between the vibrational cues associated with prey of different sizes, and they save resources by ignoring smaller prey in favour of larger, more energetically profitable prey. Moreover, antlion larvae can learn to associate vibrational cues with the loss of their prey, and they respond by burying their victims under the sand more often and more rapidly than do individuals with no opportunities to form such associations. These findings provide not only new insights into the cognitive abilities of animals but also support for the optimal foraging strategy concept, suggesting the importance of maximizing fitness output by balancing the costs and benefits of alternative foraging strategies.Electronic supplementary materialThe online version of this article (doi:10.1007/s10071-016-1000-7) contains supplementary material, which is available to authorized users.

Examining growth rate and starvation endurance in pit‐building antlions from Mediterranean and desert regions

Stressful or stochastic environments may have significant selective effects, leading to increased plasticity or stress resistance. Starvation is a type of stress commonly encountered among organisms inhabiting stochastic environments. Indeed, starvation endurance is an important trait, especially in sit‐and‐wait predators, which experience frequent fluctuations in prey arrivals because of their limited mobility. Differences in starvation endurance between antlions originating from Mediterranean (benign and predictable) and desert (harsher and stochastic) regions were investigated by exposing them to starvation in a fully factorial experiment using climate chambers simulating Mediterranean or desert climatic conditions. A trade‐off between growth rate and starvation endurance was also investigated by feeding the antlions at two different frequencies pre‐starvation. Additionally, the existence of growth compensation was tested for by measuring relative growth rate when feeding was resumed post‐starvation. Population of origin did not significantly affect rates of body mass loss during starvation or relative growth rates when feeding was resumed. Antlions that were fed less frequently during the feeding phase lost mass faster during the starvation phase, but grew faster during the compensation phase. This study emphasises the importance of testing responses to stress when investigating life‐history trade‐offs. Some phenotypic differences between populations might be apparent only when exposing the experimental organisms to external stress. Conversely, phenotypic differences apparent under stress‐free conditions might be masked by the effects of the stress factor. Adopting such an integrative approach allows elucidation of the level of plasticity in response to stress in different populations.

Olfactory responses of Phytoseiulus persimilis to rose plants with or without prey or competitors

Predators of herbivores use plant volatiles to find patches with prey. Plants benefit from this attraction as predators will reduce herbivore damage. Plants also benefit from arresting predators before prey arrival, as this will minimize future herbivore damage. For predators, however, the benefits of being attracted to clean plants depends on alternative food and on the degree of competition on other plants. Although the interactions between the predatory mite Phytoseiulus persimilis and its plant host are well-studied on cucumber or bean, that with other plants remain largely unknown. Here, we studied the olfactory response of P. persimilis to volatiles of rose plants that were either clean (i.e., empty), occupied by their prey (Tetranychus urticae) or by conspecific competitors, using bean and cucumber as comparisons. We found that, relative to clean air, predators were attracted to clean plants, and also to plants with prey. On cucumber and bean, naive predators preferred plants with prey over clean plants, but no such discrimination occurred on rose plants. However, after 24 hours of experience with rose plants infested with T. urticae, predators preferred those plants to clean roses. Predators avoided plants with prey and conspecifics, even without any previous experience. Our results show that predator attraction to plants hinges on the plant species and on experience. Attracting predators to clean plants may favour biological control, as plants may become better guarded from herbivores, but it may also be detrimental, as predators may starve on those plants.

Slow growth improves compensation ability: examining growth rate and starvation endurance in pit-building antlions from semi-arid and hyper-arid regions

Different environments are expected to exert differential selective pressures, often generating distinct sets of traits in organisms inhabiting different geographic regions. Starvation endurance is an important trait for organisms in harsh (i.e., extreme climate and/or biotically poor) and unpredictable environments. This is especially true for sit-and-wait predators, such as antlions, which experience stronger fluctuations in prey arrivals than do actively searching predators. We conducted an experimental comparison of starvation endurance in pit-building antlions, originating from semi-arid and hyper-arid environments. We hypothesized that individuals from the climatically harsher and biotically poor environment (i.e., hyper-arid) should be better adapted to endure long starvation periods. Additionally, we posited that faster-growing individuals are expected to be more sensitive to starvation because of their need to sustain higher metabolic rates. We found that antlions originating from the semi-arid region maintained higher activity levels, which led to slightly higher mass loss rates during starvation, but enabled faster recovery when food supply was renewed. Conversely, antlions originating from the hyper-arid region had lower activity levels, consistent with their lower rate of mass loss during starvation, but this came at the expense of decreased response to prey and lower growth rate when food became available again. Each strategy holds its advantages for coping with long starvation periods, and we cannot say decisively which strategy is better. Results from both regions were consistent with the predictions of the growth compensation phenomenon: antlions that were fed less frequently pre-starvation grew at faster rates when food supply was renewed. Our study demonstrates that individuals originating from different environments adopt different strategies in order to endure starvation, exemplifying antlions’ ability to compensate for mass lost during starvation.

Estimation of feeding patterns for piscivorous fish using individual prey data from stomach contents

The problem of estimating temporal feeding patterns using stomach data is considered, where the time of ingestion for each prey item can be predicted through a gastric evacuation model. The arrival of prey is modelled as a nonhomogeneous Poisson process with known periodic intensity. A maximum likelihood approach is used to estimate the intensity, which is assumed to be the same for all predators, incorporating different uncertainties for the arrival time of each prey item. The method is applied to a case where a population of whiting ( Merlangius merlangus ) is feeding on sandeel ( Ammodytes marinus ), and peak feeding periods around dusk and dawn are identified.

Specialized learning in antlions (Neuroptera: Myrmeleontidae), pit-digging predators, shortens vulnerable larval stage.

Unique in the insect world for their extremely sedentary predatory behavior, pit-dwelling larval antlions dig pits, and then sit at the bottom and wait, sometimes for months, for prey to fall inside. This sedentary predation strategy, combined with their seemingly innate ability to detect approaching prey, make antlions unlikely candidates for learning. That is, although scientists have demonstrated that many species of insects possess the capacity to learn, each of these species, which together represent multiple families from every major insect order, utilizes this ability as a means of navigating the environment, using learned cues to guide an active search for food and hosts, or to avoid noxious events. Nonetheless, we demonstrate not only that sedentary antlions can learn, but also, more importantly, that learning provides an important fitness benefit, namely decreasing the time to pupate, a benefit not yet demonstrated in any other species. Compared to a control group in which an environmental cue was presented randomly vis-à-vis daily prey arrival, antlions given the opportunity to associate the cue with prey were able to make more efficient use of prey and pupate significantly sooner, thus shortening their long, highly vulnerable larval stage. Whereas “median survival time,” the point at which half of the animals in each group had pupated, was 46 days for antlions receiving the Learning treatment, that point never was reached in antlions receiving the Random treatment, even by the end of the experiment on Day 70. In addition, we demonstrate a novel manifestation of antlions' learned response to cues predicting prey arrival, behavior that does not match the typical “learning curve” but which is well-adapted to their sedentary predation strategy. Finally, we suggest that what has long appeared to be instinctive predatory behavior is likely to be highly modified and shaped by learning.

Horseshoe bats make adaptive prey-selection decisions, informed by echo cues

Foragers base their prey-selection decisions on the information acquired by the sensory systems. In bats that use echolocation to find prey in darkness, it is not clear whether the specialized diet, as sometimes found by faecal analysis, is a result of active decision-making or rather of biased sensory information. Here, we tested whether greater horseshoe bats decide economically when to attack a particular prey item and when not. This species is known to recognize different insects based on their wing-beat pattern imprinted in the echoes. We built a simulation of the natural foraging process in the laboratory, where the bats scanned for prey from a perch and, upon reaching the decision to attack, intercepted the prey in flight. To fully control echo information available to the bats and assure its unambiguity, we implemented computer-controlled propellers that produced echoes resembling those from natural insects of differing profitability. The bats monitored prey arrivals to sample the supply of prey categories in the environment and to inform foraging decisions. The bats adjusted selectivity for the more profitable prey to its inter-arrival intervals as predicted by foraging theory (an economic strategy known to benefit fitness). Moreover, unlike in previously studied vertebrates, foraging performance of horseshoe bats was not limited by costly rejections of the profitable prey. This calls for further research into the evolutionary selection pressures that sharpened the species's decision-making capacity.

Learning in a sedentary insect predator: Antlions (Neuroptera: Myrmeleontidae) anticipate a long wait

Pit-building antlions, the larvae of a winged adult insect, capture food by digging funnel-shaped pits in sand and then lying in wait, buried at the vertex, for prey to fall inside. The sedentary nature of this sit-and-wait predatory behaviour and, especially, antlions' innate ability to detect prey arrival, do not fit the typical profile of insects that possess learning capabilities. However, we show, for the first time, that learning can play an important role in this unique form of predation. In three separate experiments, individual antlions received, once per training day, either a vibrational cue presented immediately before the arrival of food or that same cue presented independently of food arrival. Signalling of food not only produced a learned anticipatory behavioural response (Experiment 1), but also conferred a fitness advantage: Associative learning enabled antlions to dig better pits (Experiments 2 and 3), extract food more efficiently (Experiments 2 and 3), and, in turn, moult sooner (Experiment 3) than antlions not receiving the associative learning treatment.

Temporal clumping of prey and coexistence of unequal interferers: experiments on social forager groups of brown trout feeding on invertebrate drift

Environmental fluctuations have been proposed to enhance the coexistence of competing phenotypes. Evaluations are here presented on the effects of prey density and short‐term temporal clumping of prey availability on the relative foraging success of unequal interferers in social forager groups of juvenile brown trout Salmo trutta feeding on drifting invertebrate prey (frozen chironomids). Groups of three trout with established linear dominance hierarchies (dominant, intermediate and subordinate) were subjected to three different total numbers of prey, combined with three different levels of temporal clumping of prey arrival, resulting in nine treatment combinations. Higher total number of prey increased the consumption for all dominance ranks, while higher temporal clumping decreased the consumption for the dominant individuals and increased the consumption for the subordinate individuals. The proportion of prey eaten was smaller at high prey numbers. Similarly, there was a trend that increased temporal clumping also decreased the proportion of prey eaten. We conclude that density and temporal clumping of prey contribute to the coexistence of unequal interferers, and that there is a potential positive feedback between prey behaviour and phenotypic coexistence through decreased per capita predation risk for prey that drift synchronously in high densities.

Evidence against maximization of gross rate of seed delivery to the burrow in food-hoarding eastern chipmunks, Tamias striatus

The central place foraging model predicts the optimal load sizes of prey carried back to a central place. When the rate of prey loading at the patch declines with time spent in the patch, the optimal, rate-maximizing load sizes increase with round-trip travel times between patch and central place. Numerous tests of this rate-maximizing currency have been carried out with eastern chipmunks carrying loads of seeds to their burrow. All tests have provided consistent qualitative support for the model (load sizes increase with distance) as well as consistent quantitative rejection of the model (loads carried are always considerably smaller than optimal). Confidence in the repeated rejections of the currency is weak because the predicted optimal load sizes stem from extrapolations of the loading function beyond the data used to estimate it. In this study, we provided subjects in the field with a food patch that provided the same increasing interval schedule of prey arrival at 2 m and 15 m from their burrow. Results confirm the quantitative failure of the rate-maximizing currency for the central place foraging model. We propose that the consistent failures of rate maximization with chipmunks are probably due to the higher predation danger when collecting seed from a patch compared to travelling.

Why do Juvenile Chinese Pit‐Vipers (Gloydius shedaoensis) Select Arboreal Ambush Sites?

AbstractOntogenetic shifts in habitat use are widespread, especially in ectothermic taxa in which juveniles may be an order of magnitude smaller than large adult conspecifics. The factors that generate such habitat shifts are generally obscure, but we studied an unusual system that allowed us to compare consequences of habitat selection between adults and juveniles. Pit‐vipers (Gloydius shedaoensis) on a small island in north‐eastern China feed almost entirely on seasonally migrating birds. During the spring bird‐migration period, individual snakes consistently re‐used either arboreal or terrestrial ambush sites. Snakes in trees were smaller (and more philopatric) than snakes on the ground. This ontogenetic shift in habitat use may reflect the difficulty of capturing birds on the ground, especially by small snakes. In laboratory trials, large (adult) pit‐vipers struck faster, further and more accurately than did small (juvenile) snakes. In experiments with free‐ranging snakes, the proportion of strikes hitting the bird was lower for juveniles than for adults, and lower for terrestrial snakes than for arboreal snakes. Additionally, adult snakes generally seized the bird by the head whereas juveniles frequently struck the body or wings (and thus, obtained a less secure grip). Arboreal ambush sites may facilitate prey capture not only because they give access to smaller birds but also because they render the bird's location more predictable and, hence, enable the snake to position itself optimally prior to the prey's arrival. Because juvenile pit‐vipers are less capable strikers, and are small relative to available prey items, they may benefit from the greater ease of prey capture from branches. Thus, the ontogenetic shift in habitat selection within this species may be because of ontogenetic shifts in the vipers’ ability to capture and ingest large, mobile prey.