Influence of Some Potential Predation Risk Factors and Interaction between Predation Risk and Cost of Fleeing on Escape by the Lizard Sceloporus virgatus

Escape theory predicts that flight initiation distance (predator–prey distance when escape begins) increases as predation risk increases and decreases as cost of fleeing increases. Scant information is available about the effects of some putative predation risk factors and about interaction between simultaneously operating risk and cost of fleeing factors on flight initiation distance and distance fled. By simulating an approaching predator, I studied the effects of body temperature (BT), distance to nearest refuge, and eye contact with a predator, as well as simultaneous effects of predator approach speed and female presence/absence on escape behavior by a small ectothermic vertebrate, the lizard Sceloporus virgatus. Flight initiation distance decreased as BT increased, presumably because running speed increases as BT increases, facilitating escape. Distance to nearest refuge was unrelated to BT or flight initiation distance. Substrate temperature was only marginally related, and air temperature was not related to flight initiation distance. Eye contact did not affect flight initiation during indirect approaches that bypassed lizards by a minimum of 1 m, but an effect of eye contact found in other studies during direct approach might occur. Predator approach speed and presence of a female interactively affected flight initiation distance, which increased as speed increased and decreased when a female was present. In the presence of a female, flight initiation distance was far shorter than when no female was present. The high cost of forgoing a mating opportunity accounts for the interaction because the difference between female presence and absence is greater when risk is greater.     

The ontogeny of escape behavior,locomotor performance,and the hind limb in Sceloporus woodi

Flight initiation distance describes the distance at which an animal flees during the approach of a predator. This distance presumably reflects the tradeoff between the benefits of fleeing versus the benefits of remaining stationary. Throughout ontogeny, the costs and benefits of flight may change substantially due to growth-related changes in sprint speed; thus ontogenetic variation in flight initiation distance may be substantial. If escape velocity is essential for surviving predator encounters, then juveniles should either tolerate short flight initiation distances and rely on crypsis, or should have high flight initiation distances to remain far away from their predators. We examined this hypothesis in a small, short-lived lizard (Sceloporus woodi). Flight initiation distance and escape velocity were recorded on an ontogenetic series of lizards in the field. Maximal running velocity was also quantified in a laboratory raceway to establish if escape velocities in the field compared with maximal velocities as measured in the lab. Finally a subset of individuals was used to quantify how muscle and limb size scale with body size throughout ontogeny. Flight initiation distance increased with body size; larger animals had higher flight initiation distances. Small lizards had short flight initiation distances and remained immobile longer, thus relying on crypsis for concealment. Escape velocity in the field did not vary with body size, yet maximum velocity in the lab did increase with size. Hind limb morphology scaled isometrically with body size. Isometric scaling of the hind limb elements and its musculature, coupled with similarities in sprint and escape velocity across ontogeny, demonstrate that smaller S. woodi must rely on crypsis to avoid predator encounters, whereas adults alter their behavior via larger flight initiation distance and lower (presumably less expensive) escape velocities.     

风险对两种南非蜥蜴逃跑启始距离和逃避策略的影响

逃避理论预测,不逃跑若增大适合度代价则导致逃跑启始距离加长,逃跑若增大代价则导致逃跑启始距离缩短。逃跑路径和去向等受生境结构影响。作者通过模拟捕食者逼近研究喀拉哈里树石龙子(Trachylepis sparsa)和黑环蜥(Cordylus niger)逃避策略和风险因子对逃跑启始距离的影响。与迂回逼近相比较,直接逼近不仅提高蜥蜴逃跑几率还能缩短其逃跑启始距离。喀拉哈里树石龙子在两种逼近方式下的逃跑启始距离有显著差异,这种差异对黑环蜥而言是边缘性的。喀拉哈里树石龙子以树为避所,树上个体可逼近的距离短于地面个体;快速逼近地面个体的逃跑启始距离比慢速逼近更长。习惯于有人环境的黑环蜥逃跑启始距离比人迹罕至环境中的个体更短。地面喀拉哈里树石龙子多遁至树上而很少逃入倒木或倒伏编巢中。树上喀拉哈里树石龙子通常奔逃至远侧和高处,有时遁入树洞或编巢中;黑环蜥则逃入石缝中。所有发现都证实逃避理论中有关逃跑启始距离的预测。逃跑策略的种间差异表明每一种蜥蜴都利用其生境中逃跑路径和避所的有利条件。在风险不同的生境中,生境结构可影响逃跑启始距离,似乎对逃跑策略亦有重要影响。     

Flight initiation distance and escape behavior in the black redstart (Phoenicurus ochruros)

There are many anti‐predatory escape strategies in animals. A well‐established method to assess escape behavior is the flight initiation distance (FID), which is the distance between prey and predator at which an animal flees. Previous studies in various species throughout the animal kingdom have shown that group size, urbanization, and distance to refuge and body mass affect FID. In most species, FID increases if body mass, group size or distance to refuge decreases. However, how age and sexual dimorphism affect FID is rather unknown. Here, we assess the escape behavior and FID of the black redstart (Phoenicurus ochruros), a small turdid passerine. When approached by a human, males initiated flights later, that is allowing a closer approach than females. Males of this species are more conspicuous, and therefore, may exhibit aposematism to deter potential predators or are less fearful than females. Additionally, juveniles fled at shorter distances and fled to lower heights than adults. Lastly, concerning escape strategy, black redstarts, unless other passerine birds, fled less often into cover, but rather onto open or elevated spots. Black redstarts are especially prone to predation by ambushing predators that might hide in cover. Hence, this species most likely has a higher chance of escaping by fleeing to an open spot rather than to a potentially risky cover.     

Plesiomorphic Escape Decisions in Cryptic Horned Lizards (Phrynosoma) Having Highly Derived Antipredatory Defenses

Escape theory predicts that the probability of fleeing and flight initiation distance (predator–prey distance when escape begins) increase as predation risk increases and decrease as escape cost increases. These factors may apply even to highly cryptic species that sometimes must flee. Horned lizards (Phrynosoma) rely on crypsis because of coloration, flattened body form, and lateral fringe scales that reduce detectability. At close range they sometimes squirt blood‐containing noxious substances and defend themselves with cranial spines. These antipredatory traits are highly derived, but little is known about the escape behavior of horned lizards. Of particular interest is whether their escape decisions bear the same relationships to predation risk and opportunity costs of escaping as in typical prey lacking such derived defenses. We investigated the effects of repeated attack and direction of predator turning on P. cornutum and of opportunity cost of fleeing during a social encounter in P. modestum. Flight initiation distance was greater for the second of two successive approaches and probability of fleeing decreased as distance between the turning predator and prey increased, but was greater when the predator turned toward than away from a lizard. Flight initiation distance was shorter during social encounters than when lizards were solitary. For all variables studied, risk assessment by horned lizards conforms to the predictions of escape theory and is similar to that in other prey despite their specialized defenses. Our findings show that these specialized, derived defenses coexist with a taxonomically widespread, plesiomorphic method of making escape decisions. They suggest that escape theory based on costs and benefits, as intended, applies very generally, even to highly cryptic prey that have specialized defense mechanisms.     

Escape tactics and effects of perch height and habituation on flight initiation distance in two Jamaican anoles (Squamata: polychrotidae)

Escape by Anolis lizards is influenced by microhabitats and fight initiation distance increases with predation risk. Differences in microhabitat use among ecomorphs affect escape behavior, but only two studies have reported ecomorphological differences in flight initiation distance among Greater Antillean species. I studied effects of predation risk and microhabitats on escape behavior by conducting field experiments using two species of anoles, Anolis lineatopus and A. grahami, on the campus of the University of the West Indies at Mona, Jamaica. Because ecomorphological variation of anoles has evolved independently within each island of the Greater Antilles, but relationships between ecomorphs and escape behaviors are poorly known, I characterized microhabitat use and escape tactics, and determined relationships between flight initiation distance and two risk factors, habituation to human presence and perch height, in Anolis lineatopus, a trunk-ground anole and A. grahami, a trunk-crown anole. Sample sizes for A. lineatopus and A. grahami were 214 and 93, for microhabitat use and escape destinations, 74 and 34 for human presence and 125 and 34 for perch height. The two species occurred in similar microhabitats and exhibited similar escape tactics, but exhibited key differences expected for their ecomorphs. Both species were sighted frequently on the ground and on trees, but A. lineatopus were more frequently on ground and were perched lower than A. grahami. Both species escaped from ground to trees and when on trees hid on far sides and escaped without changing climbing direction with equal frequency. The frequency of fleeing upward was greater for A. grahami than A. lineatopus. Both species exhibited habituation by having shorter flight initiation distances in areas with more frequent exposure to people. In both species flight initiation distance increased as perch height decreased because, lizards had to climb farther to be out of reach when perched lower. The relationship between flight initiation distance and perch height may apply to other anole ecomorphs that flee upward when low perched on trees.     

Optimal flight initiation distance

Decisions regarding flight initiation distance have received scant theoretical attention. A graphical model by Ydenberg and Dill (1986. The economics of fleeing from predators. Adv. Stud. Behav. 16, 229-249) that has guided research for the past 20 years specifies when escape begins. In the model, a prey detects a predator, monitors its approach until costs of escape and of remaining are equal, and then flees. The distance between predator and prey when escape is initiated (approach distance = flight initiation distance) occurs where decreasing cost of remaining and increasing cost of fleeing intersect. We argue that prey fleeing as predicted cannot maximize fitness because the best prey can do is break even during an encounter. We develop two optimality models, one applying when all expected future contribution to fitness (residual reproductive value) is lost if the prey dies, the other when any fitness gained (increase in expected RRV) during the encounter is retained after death. Both models predict optimal flight initiation distance from initial expected fitness, benefits obtainable during encounters, costs of escaping, and probability of being killed. Predictions match extensively verified predictions of Ydenberg and Dill's (1986) model. Our main conclusion is that optimality models are preferable to break-even models because they permit fitness maximization, offer many new testable predictions, and allow assessment of prey decisions in many naturally occurring situations through modification of benefit, escape cost, and risk functions.     

Escape and alerting responses by Balearic lizards (Podarcis lilfordi) to movement and turning direction by nearby predators

Escape theory predicts that prey monitoring an approaching predator delay escape until predation risk outweighs costs of fleeing. However, if a predator is not detected until it is closer than the optimal flight initiation distance (FID = distance between predator and prey when escape begins), escape should begin immediately. Similarly, if a change in a nearby predator’s behavior indicates increased risk, the optimal FID increases, sometimes inducing immediate escape. If a predator that has been standing immobile near a prey suddenly turns toward the prey, greater risk is implied than if the predator turns away. If the immobile predator suddenly moves its foot without turning, it might be launching an attack. Therefore, we predicted that frequency of fleeing and preparation to flee are greater when a predator turns toward than away from prey and that frequency of fleeing when a predator suddenly moves decreases as distance between predator and prey increases. We verified these predictions in the Balearic lizard Podarcis lilfordi in field experiments in which an investigator simulated the predator. Lizards fled and performed alerting responses indicating readiness to flee more frequently when the predator turned toward than away from them, and fled more frequently the nearer the predator.     

Predator–prey interactions,flight initiation distance and brain size

Prey avoid being eaten by assessing the risk posed by approaching predators and responding accordingly. Such an assessment may result in prey–predator communication and signalling, which entail further monitoring of the predator by prey. An early antipredator response may provide potential prey with a selective advantage, although this benefit comes at the cost of disturbance in terms of lost foraging opportunities and increased energy expenditure. Therefore, it may pay prey to assess approaching predators and determine the likelihood of attack before fleeing. Given that many approaching potential predators are detected visually, we hypothesized that species with relatively large eyes would be able to detect an approaching predator from afar. Furthermore, we hypothesized that monitoring of predators by potential prey relies on evaluation through information processing by the brain. Therefore, species with relatively larger brains for their body size should be better able to monitor the intentions of a predator, delay flight for longer and hence have shorter flight initiation distances than species with smaller brains. Indeed, flight initiation distances increased with relative eye size and decreased with relative brain size in a comparative study of 107 species of birds. In addition, flight initiation distance increased independently with size of the cerebellum, which plays a key role in motor control. These results are consistent with cognitive monitoring as an antipredator behaviour that does not result in the fastest possible, but rather the least expensive escape flights. Therefore, antipredator behaviour may have coevolved with the size of sense organs, brains and compartments of the brain involved in responses to risk of predation.     

Optimal escape theory predicts escape behaviors beyond flight initiation distance： risk assessment and escape by striped plateau lizards Sceloporus virgatus

Escape theory predicts that flight initiation distance (FID=distance between predator and prey when escape begins) is longer when risk is greater and shorter when escape is more costly. A few tests suggest that escape theory applies to distance fled. Escape models have not addressed stochastic variables, such as probability of fleeing and of entering refuge, but their economic logic might be applicable. Experiments on several risk factors in the lizard Sceloporus virgatus confirmed all predictions for the above escape variables. FID was greater when approach was faster and more direct, for lizards on ground than on trees, for lizards rarely exposed to humans, for the second of two approaches, and when the predator turned toward lizards rather than away. Lizards fled further during rapid and second consecutive approaches. They were more likely to flee when approached directly, when a predator turned toward them, and during second approaches. They were more likely to enter refuge when approached rapidly. A novel finding is that perch height in trees was unrelated to FID because lizards escaped by moving out of sight, then moving up or down unpredictably. These findings add to a growing body of evidence supporting predictions of escape theory for FID and distance fled. They show that two probabilistic aspects of escape are predictable based on relative predation risk levels. Because individuals differ in boldness, the assessed optimal FID and threshold risks for fleeing and entering refuge are exceeded for an increasing proportion of individuals as risk increases[Current Zoology 55(2):123-131,2009].     

Complex Relationships amongst Parasite Load and Escape Behaviour in an Insular Lizard

Economic escape models predict escape decisions of prey which are approached by predators. Flight initiation distance (FID, predator–prey distance when prey begins to flee) and distance fled (DF) are major variables used to characterize escape responses. In optimal escape theory, FID increases as cost of not fleeing also increases. Moreover, FID decreases as cost of fleeing increases, due to lost opportunities to perform activities that may increase fitness. Finally, FID further increases as the prey's fitness increases. Some factors, including parasitism, may affect more than one of these predictors of FID. Initially, parasitized prey may have lower fitness as well as impaired locomotor ability, which would avoid predation and/or reduce their foraging ability, further decreasing the opportunity of fleeing. For example, if parasites decrease body condition, prey fitness is reduced and escape ability may be impaired. Hence, the overall influence of parasitism on FID is difficult to predict. We examined relationships between escape decisions and different traits: parasite load, body size and body condition in the Balearic lizard, Podarcis lilfordi. Lizards that showed higher haemogregarines load had longer FID and shorter DF. Although results did not confirm our initial predictions made on the basis of optimal escape theory, our findings suggest that parasites can alter several aspects of escape behaviour in a complex way.     

Costs of Refuge Use Affect Escape Decisions of Iberian Rock Lizards Lacerta monticola

Theoretical models of anti-predator escape behaviour suggest that prey may adjust their escape response such that the optimal flight distance is the point at which the costs of staying exceed the costs of fleeing. Anti-predatory decisions should be made based also on consequences for long-term expected fitness, such as the costs of refuge use. For example, in lizards, the maintenance of an optimal body temperature is essential to maximize physiological processes. However, if unfavourable thermal conditions of refuges can decrease the body temperature of lizards, their escape decision should be influenced by refuge conditions. Analyses of the variation in flight distances and emergence latency from a refuge for the lizard Lacerta monticola under two different predation risk levels, and their relationship with the thermal environment, supported these predictions. When risk increased, lizards had longer emergence latencies, and thus costs of refuge use increased (a greater loss of time and body temperature). In the low-risk situation, lizards that were farther from the refuge had longer flight distances, whereas thermal conditions were less important. When risk increased, lizards had longer flight distances when refuges were farther off, but also when the external heating rate and the refuge cooling rate were lower. The results suggest that, in addition to the risk of predation, expected long-term fitness costs of refuges can also affect escape decisions.     

Sex and social costs of escaping in the striped plateau lizard Sceloporus virgatus

As a predator approaches, prey base decisions about when toflee on a balance between degree of predation risk and costsof escaping. Lost opportunities to perform activities that mayincrease fitness are major escape costs. Paramount among theseare chances to increase fitness by courting and mating and bydriving away sexual rivals. Because sexual selection imposesdifferent social demands on the sexes, social opportunitiescan have different consequences for males and females, but effectsof sex differences in social opportunity costs on escape behaviorare unknown. We conducted a field experiment showing that malestriped plateau lizards (Sceloporus virgatus) given the opportunityto court or perform aggressive behavior permit closer approachbefore fleeing, but females do not. Males allowed a simulatedpredator to approach closer before initiating escape if a tetheredmale or female rather than a control stimulus was introducedto them, but females initiated escape at similar distances inall conditions. For males, a trade-off between the greater predationrisk accepted before fleeing due to the likelihood of enhancingfitness by sexual or aggressive behavior accounts for closerapproach allowed in the presence of conspecifics. Mating opportunitiesare not limiting for females in most species and females oftenhave little to gain by interacting aggressively with other females.Therefore, presence of a conspecific male or female may notjustify taking greater risk. Results confirm the predictionof optimal escape theory that flight initiation decreases ascost of escaping increases. The sex difference in effect ofpresence of conspecifics on flight initiation distance is aconsequence of the sex difference in costs of escaping.     

Effects of risk assessment, predator behavior, and habitat on escape behavior in Columbian black-tailed deer

The relationship between preflight risk assessment by prey andthe escape behaviors they perform while fleeing from predatorsis relatively unexplored. To examine this relationship, a humanobserver approached groups of Columbian black-tailed deer (Odocoileushemionus columbianus), varying his behavior to simulate moreor less threatening behavior. We measured the focal deer's angleof escape, distance moved during flight, duration of trottingand stotting behavior, and change in elevation during flight.Analyses revealed positive relationships between the distancemoved during flight and the distance at which they fled. Whenflight was initiated when the approacher was close, deer fledrelatively shorter distances and took flight paths at more acuteangles, a property that would force a real predator to changedirection suddenly. Our results indicate that deer do not compensatefor allowing the observer to approach more closely by fleeinggreater distances. Rather, distance moved and flight initiationdistance are linked by level of reactivity and habituation:more reactive or less habituated deer both flee at a greaterdistance and move away to a greater distance during flight.More threatening behavior by the approacher led to longer durationsof rapid flight behavior (e.g., trotting and stotting), anddeer tended to flee uphill and into taller vegetation, usingthese landscape features as refuge from danger. Finally, weprovide the first evidence for Pitcher's untested "antiambush"hypothesis for the function of stotting and discuss its significance.In general, both preflight predator behavior and habitat featuresinfluence both duration and direction of escape.     

Senescence in relation to latitude and migration in birds

Senescence is the age‐related deterioration of the phenotype, explained by accumulation of mutations, antagonistic pleiotropy, free radicals or other mechanisms. I investigated patterns of actuarial senescence in a sample of 169 species of birds in relation to latitude and migration, by analysing longevity records adjusted for sampling effort, survival rate and body mass. Senescence might decrease at low latitudes because of elevated adult survival rates and generally slow life histories. Alternatively, the rate of senescence might increase at low latitudes because of the greater impact of biological interactions such as parasitism, predation and competition on fitness through differential effects of age‐specific mortality (e.g. because immunologically naïve young individuals and immuno‐senescent old individuals might die more frequently than individuals belonging to intermediate age classes). Bird migration entails extensive exercise twice annually, with migrants spending more time in benign environments with little abiotic mortality than residents, migrants having higher adult survival rate and lower annual fecundity than residents, and migrants suffering more from the consequences of oxidative stress than residents. The rate of senescence increased with latitude, as expected because of slow life histories at low latitudes. Independently, rate of senescence decreased with increasing migration distance. These findings were robust to control for potentially confounding effects of body mass, age of first reproduction and phenotypic similarity among species because of common descent.     

Brains and bravery: Little evidence of a relationship between brain size and flightiness in shorebirds

The ability of birds to perceive, assess and appropriately respond to the presence of relatively novel threats is important to their survival. We hypothesized that the cognitive capacity of birds will influence their ability for accurate response to novelty. We used brain volume as a surrogate for cognitive capacity and postulated that larger brained birds would moderate their responses when presented with a benign, frequently occurring stimulus, such as a person, because they would habituate more readily. We conducted phylogenetic generalized least square regression to investigate the relationship between brain volume and flight initiation distance (FID; the distance to which a bird can be approached before initiating escape behaviour), while controlling for confounding factors including body size (body mass and wing length) and migration status. We compared seven different models using combinations of these parameters using Akaike's information criterion to determine the best approximating model(s) explaining FID. The two best‐supported models included only wing length and only body mass with Akaike weights of 0.396 and 0.311 respectively. No model including brain volume had an Akaike weight greater than 0.083 and brain volume was poorly correlated with FID in models after controlling for body mass. Thus, brain volume does not appear to strongly relate to bravery among these shorebirds.     

Choosing among alternative refuges: Distances and directions

Many prey flee to refuges to escape from approaching predators, but little is known about how they select one among many refuges available. The problem of choice among alternative refuges has not been modeled previously, but a recent model that predicts flight initiation distance (FID = predator–prey distance when escape starts) for a prey fleeing to a refuge provides a basis for predicting which refuge should be chosen. Because fleeing is costly, prey should choose to flee to the refuge permitting the shortest FID. The model predicts that the more distant of two refuges can be favored if it is not too far and if the prey's trajectory to the farther refuge is more away from the predator than the direction to the nearer refuge. The difference in predicted FID between the farther and nearer refuges increases curvilinearly as the interpath angle for the farther refuge increases. The difference in predicted FID between the farther and nearer refuges increases linearly as the distance to the farther refuge increases. An isocline describing where nearer and farther refuges are equally favored shows a negative curvilinear relationship between interpath angle and prey distance to the farther refuge. In the region below the isocline, the farther refuge is favored, whereas above the isocline the prey should flee to the nearer refuge.     

Three-dimensional analysis of aphid landing behaviour in the laboratory and field

The final second of the landing approach of black bean aphids, Aphis fabae, was analysed in three dimensions using video techniques. A yellow landing platform was placed upwind or downwind from aphids aggregating under a ceiling light in a laboratory wind tunnel with 10, 20, 30, 40 or 50 cm s^–1 wind speeds, and up-tunnel or down-tunnel in still air. As individual aphids flew to the platform, body orientation (assessed by direct observation) was predominantly into-wind whether the initial flight direction to the landing platform was upwind or downwind. A greater proportion showed into-wind body orientation as wind speed increased. Flight track parameters which differed significantly between wind speeds were the track length, linear start to finish distance, linearity index, horizontal ground speed, speed vertical to the ground, vertical turning rate, and horizontal turning rate. The position of the landing platform was important for track length, linear start to finish distance, horizontal ground speed, three-dimensional turning rate, horizontal turning rate, vertical turning rate, and sinuosity. As wind speed increased above 30 cm s^–1 the ground speed became more consistent and indicated considerable variation in air speed to adjust for ground speed. For the majority of aphids there was a strong preference (88%) for into-wind landings with initial upwind directed flight, while for downwind flights a significant number (55%) of insects reversed initial flight direction and landed into-wind. Field recorded landings showed that 66% of aphids landed into-wind and there was a mean bearing to the wind of 71 ± 42°, a similar finding to wind-tunnel studies.     

Influence of gaze and directness of approach on the escape responses of the Indian rock lizard, Psammophilus dorsalis (Gray, 1831)

Animals often evaluate the degree of risk posed by a predator and respond accordingly. Since many predators orient their eyes towards prey while attacking, predator gaze and directness of approach could serve as conspicuous indicators of risk to prey. The ability to perceive these cues and discriminate between high and low predation risk should benefit prey species through both higher survival and decreased energy expenditure. We experimentally examined whether Indian rock lizards (Psammophilus dorsalis) can perceive these two indicators of predation risk by measuring the variation in their fleeing behaviour in response to type of gaze and approach by a human predator. Overall, we found that the gaze and approach of the predator influenced flight initiation distance, which also varied with attributes of the prey (i.e. size/sex and tail-raise behaviour). Flight initiation distance (FID) was 43% longer during direct approaches with direct gaze compared with tangential approaches with averted gaze. In further, exploratory, analyses, we found that FID was 23% shorter for adult male lizards than for female or young male (FYM) lizards. In addition, FYM lizards that showed a tail-raise display during approach had a 71% longer FID than those that did not. Our results suggest that multiple factors influence the decision to flee in animals. Further studies are needed to test the generality of these factors and to investigate the proximate mechanisms underlying flight decisions.     

Effects of Increased Flight on the Energetics and Life History of the Butterfly Speyeria mormonia

Movement uses resources that may otherwise be allocated to somatic maintenance or reproduction. How does increased energy expenditure affect resource allocation? Using the butterfly Speyeria mormonia, we tested whether experimentally increased flight affects fecundity, lifespan or flight capacity. We measured body mass (storage), resting metabolic rate and lifespan (repair and maintenance), flight metabolic rate (flight capacity), egg number and composition (reproduction), and food intake across the adult lifespan. The flight treatment did not affect body mass or lifespan. Food intake increased sufficiently to offset the increased energy expenditure. Total egg number did not change, but flown females had higher early-life fecundity and higher egg dry mass than control females. Egg dry mass decreased with age in both treatments. Egg protein, triglyceride or glycogen content did not change with flight or age, but some components tracked egg dry mass. Flight elevated resting metabolic rate, indicating increased maintenance costs. Flight metabolism decreased with age, with a steeper slope for flown females. This may reflect accelerated metabolic senescence from detrimental effects of flight. These effects of a drawdown of nutrients via flight contrast with studies restricting adult nutrient input. There, fecundity was reduced, but flight capacity and lifespan were unchanged. The current study showed that when food resources were abundant, wing-monomorphic butterflies living in a continuous meadow landscape resisted flight-induced stress, exhibiting no evidence of a flight-fecundity or flight-longevity trade-off. Instead, flight changed the dynamics of energy use and reproduction as butterflies adopted a faster lifestyle in early life. High investment in early reproduction may have positive fitness effects in the wild, as long as food is available. Our results help to predict the effect of stressful conditions on the life history of insects living in a changing world.