Antipredator Behavior Research Articles

Assessing predator-prey interactions in a chemically altered aquatic environment: the effects of DDT on Xenopus laevis and Culex sp. larvae interactions and behaviour.

Behavioural assays are used as a tool to understand ecotoxicological effects on organisms, but are often not applied in an ecologically relevant context. Assessment of the effect of chemical contaminants on behaviours relating to fitness and trophic interactions for example, requires incorporating predator-prey interactions to create impact assessments. Dichlorodiphenyltrichloroethane (DDT) is a controlled substance but is still regularly used as a form of mosquito control. There is little explicit information on the effect of DDT on animal behaviour and the consequent effects upon trophic interactions. This study uses a 3 × 2 factorial design to assess the feeding behaviour of Xenopus laevis toward Culex sp. larvae when supplied with different prey cues. We also assess the behavioural responses of mosquito larvae when supplied with no threat cue and predator threat cues when exposed to 0 µg/L, 2 µg/L and 20 µg/L DDT. There was a significant "DDT exposure" x "prey cue" interaction whereby DDT significantly decreased the foraging behaviour of X. laevis towards live prey cues, however there was no effect of DDT on X. laevis response to olfactory prey cues. Dichlorodiphenyltrichloroethane exposure caused mosquito larvae to appear hyperactive regardless of DDT concentration. Mosquito larvae anti-predator response was significantly dampened when exposed to 2 µg/L DDT, however when exposed to 20 µg/L the anti-predator responses were not impaired. Our results indicate a complex interplay in trophic interactions under DDT exposure, wherein effects are mediated depending on species and concentration. There are possible implications regarding reduced anti-predator behaviour in the prey species but also reduced foraging capacity in the predator, which could drive changes in ecosystem energy pathways. We demonstrate that in order to quantify effects of pesticides upon trophic interactions it is necessary to consider ecologically relevant behaviours of both predator and prey species.

Evidence for discrimination between feeding sounds of familiar fish and unfamiliar mammal-eating killer whale ecotypes by long-finned pilot whales.

Killer whales (KW) may be predators or competitors of other cetaceans. Since their foraging behavior and acoustics differ among populations ('ecotypes'), we hypothesized that other cetaceans can eavesdrop on KW sounds and adjust their behavior according to the KW ecotype. We performed playback experiments on long-finned pilot whales (Globicephala melas) in Norway using familiar fish-eating KW sounds (fKW) simulating a sympatric population that might compete for foraging areas, unfamiliar mammal-eating KW sounds (mKW) simulating a potential predator threat, and two control sounds. We assessed behavioral responses using animal-borne multi-sensor tags and surface visual observations. Pilot whales barely changed behavior to a broadband noise (CTRL-), whereas they were attracted and exhibited spyhops to fKW, mKW, and to a repeated-tonal upsweep signal (CTRL+). Whales never stopped nor started feeding in response to fKW, whereas they reduced or stopped foraging to mKW and CTRL+. Moreover, pilot whales joined other subgroups in response to fKW and CTRL+, whereas they tightened individual spacing within group and reduced time at surface in response to mKW. Typical active intimidation behavior displayed to fKW might be an antipredator strategy to a known low-risk ecotype or alternatively a way of securing the habitat exploited by a heterospecific sympatric population. Cessation of feeding and more cohesive approach to mKW playbacks might reflect an antipredator behavior towards an unknown KW ecotype of potentially higher risk. We conclude that pilot whales are able to acoustically discriminate between familiar and unfamiliar KW ecotypes, enabling them to adjust their behavior according to the perceived disturbance type.

Global Dynamics of a Prey-Predator Model with Antipredator Behavior and Two Predators

In this work, we establish a new model of one prey and two predators with antipredator behavior. The basic properties on the positivity and boundedness of solutions and the existence of equilibria are established. Through analyzing the global dynamics, we find that there exist some values of the parameters such that one of the predators can be driven into being extinct by another. Furthermore, the coexistence of the three species is investigated which shows that the antipredator behavior makes the species coexist by periodic oscillation. The results give a new insight into the influence of antipredator behavior in nature selection.

Anti-predator behaviour of native prey (Daphnia) to an invasive predator (Bythotrephes longimanus) is influenced by predator density and water clarity

Bythotrephes longimanus is an invasive zooplankton predator, negatively impacting zooplankton abundance and diversity in North American lakes. Previous studies have shown that Daphnia populations in lakes move to deeper waters during the day, in the presence of Bythotrephes, a visual predator occupying well-lit regions. However, Daphnia vertical position can be influenced by a variety of biotic and abiotic factors. We conducted a survey to determine (1) if Daphnia daytime vertical position differed between invaded and uninvaded lakes and (2) if Daphnia vertical position in invaded lakes was affected by water chemistry variables linked to water clarity, UV exposure, and phytoplankton production, and Bythotrephes density. Invaded lakes had a lower proportion of epilimnetic Daphnia as compared to uninvaded lakes. Daphnia vertical position was species-dependent, and with a lower proportion of epilimnetic Daphnia mendotae and greater proportion of epilimnetic D. longiremis observed in invaded lakes. D. mendotae were deeper in the water column in high Bythotrephes density lakes with low dissolved organic carbon levels. Our results show Daphnia vertical position response to Bythotrephes is species specific, dependent on Bythotrephes density and influenced by local abiotic conditions, with important implications for community structure and ecosystem function in invaded lakes.

Fear contagion in zebrafish: a behaviour affected by familiarity

Emotional contagion has recently been described in fish but whether it is affected by familiarity is not known. We tested whether the sight of a distressed conspecific elicited fear in zebrafish, and whether this was modulated by familiarity. Groups of six zebrafish were housed together in the same tanks for 7 days to create familiar conditions. The behaviour of individual fish was then recorded in paired tanks within sight of either a familiar or an unfamiliar individual, before and after distilled water or an alarm substance was added to the demonstrator, but not to the observer. As expected, addition of distilled water did not elicit any behavioural change in either the demonstrator or the observer. However, addition of an alarm cue triggered anti-predatory behaviours in the demonstrator which caused the expression of anti-predatory behaviours in the observer, suggesting the existence of fear contagion. Furthermore, the extent of fear contagion was affected by familiarity, and observers were more active, swam closer to the bottom and further away from the demonstrator when they watched a distressed familiar neighbour than when they watched an unfamiliar fish. Our results have implications for fish welfare because they show that fish can become stressed by simply watching others become stressed. They also have implications for experimental design because fish housed in separate tanks cannot be assumed to be statistically independent if they can eavesdrop on their neighbours.

A Non-Invasive Method to Reduce the Negative Impact of Black-Headed Gulls Chroicocephalus ridibundus on the Breeding Success of Common Terns Sterna hirundo

Two or three gull species (Laridae) commonly breed together in one colony, often caused by a shortage of optimal breeding sites or as an anti-predator behaviour. Observers usually assume that the benefits of colonial breeding outweigh potential costs. Still, our study shows that the costs can be substantial. We show that short distances between nests of Black-headed Gulls and Common Terns breeding in a colony often lead to aggressive interactions between these birds in which terns lose eggs during laying and incubation. We created a buffer zone between the nests of terns and gulls to reduce losses in the terns' clutches. All nests of Black-headed Gulls closer than 120 cm to nests of Common Terns were gradually moved away over 1–4 consecutive days, reducing the terns' egg losses by almost six times. Our results show that our method was safe for both species, and is non-invasive, cheap and easy. This conservation measure could be used in those regions of Europe and North America where breeding Common Terns are declining and perhaps globally in other mixed Larid colonies where species are under threat.

Active anti-predator behaviour of red titi monkeys (Plecturocebus cupreus).

Due to their inconspicuous behaviour and colouration, it has been assumed that titi monkeys' main anti-predator behaviour is passive crypsis and hiding. So far, active predator mobbing has been documented only for black-fronted titi monkeys, Callicebus nigrifrons. Here we report for the first time mobbing behaviour of red titi monkeys, Plecturocebus cupreus (previously Callicebus cupreus), as reaction to an ocelot (Leopardus pardalis) and a Boa constrictor. We also report other active anti-predator behaviours, such as alarm calling and approaching, as reactions to tayras (Eira barbara) and raptors. Our observations provide additional evidence for sex differences in anti-predator behaviour, possibly related to the evolution and maintenance of social monogamy.

Top predators induce habitat shifts in prey within marine protected areas.

Emerging conservation efforts for the world's large predators may, if successful, restore natural predator-prey interactions. Marine reserves, where large predators tend to be relatively common, offer an experimental manipulation to investigate interactions between large-bodied marine predators and their prey. We hypothesized that southern stingrays-large, long-lived and highly interactive mesopredators-would invest in anti-predator behavior in marine reserves where predatory large sharks, the primary predator of stingrays, are more abundant. Specifically, we predicted southern stingrays in marine reserves would reduce the use of deep forereef habitats in the favor of shallow flats where the risk of shark encounters is lower. Baited remote underwater video was used to survey stingrays and reef sharks in flats and forereef habitats of two reserves and two fished sites in Belize. The interaction between "protection status" and "habitat" was the most important factor determining stingray presence. As predicted, southern stingrays spent more time interacting with baited remote underwater videos in the safer flats habitats, were more likely to have predator-inflicted damage inside reserves, and were less abundant in marine reserves but only in the forereef habitat. These results are consistent with a predation-sensitive habitat shift rather than southern stingray populations being reduced by direct predation from reef sharks. Our study provides evidence that roving predators can induce pronounced habitat shifts in prey that rely on crypsis and refuging, rather than active escape, in high-visibility, heterogeneous marine habitats. Given documented impacts of stingrays on benthic communities it is possible restoration of reef shark populations with reserves could induce reef ecosystem changes through behavior-mediated trophic cascades.

The behavioral repertoire of Drosophila melanogaster in the presence of two predator species that differ in hunting mode.

The fruit fly, Drosophila melanogaster, has proven to be an excellent model organism for genetic, genomic and neurobiological studies. However, relatively little is known about the natural history of D. melanogaster. In particular, neither the natural predators faced by wild populations of D. melanogaster, nor the anti-predatory behaviors they may employ to escape and avoid their enemies have been documented. Here we observe and describe the influence of two predators that differ in their mode of hunting: zebra jumping spiders, Salticus scenicus (active hunters) and Chinese praying mantids, Tenodera sinensis (ambush predators) on the behavioral repertoire of Drosophila melanogaster. We documented three particularly interesting behaviors: abdominal lifting, stopping, and retreat—which were performed at higher frequency by D. melanogaster in the presence of predators. While mantids had only a modest influence on the locomotory activity of D. melanogaster, we observed a significant increase in the overall activity of D. melanogaster in the presence of jumping spiders. Finally, we observed considerable among-individual behavioral variation in response to both predators.

Maternal effects across life stages: larvae experiencing predation risk increase offspring provisioning

1. Maternal provisioning can reduce offspring vulnerability to predators by promoting offspring growth and eliciting of antipredator behaviours. Mothers perceiving predation risk may improve offspring survival if producing larger, higher‐quality offspring. However, empirical evidence suggests that offspring quality is often reduced, probably reflecting predator‐induced physiological costs, or a selfish maternal strategy aimed at producing more offspring by sacrificing their quality. While perception and impact of predators can vary across the prey's life stage, a majority of studies have focused on understanding how reproductive allocation decisions are influenced by the risk of predation during adulthood.2. In this study, Leptinotarsa decemlineata beetles were used to examine if the risk of predation during the larval stage: (i) impacts the mother's physiological condition, including body mass and metabolic rate; and (ii) alters maternal allocation of reproductive resources to offspring quantity versus quality.3. Results revealed that L. decemlineata mothers responded to perceived predation risk by producing clutches with fewer but larger eggs, thus increasing offspring provisioning. Surprisingly, while females that had faced predation risk as larva emerged with a similar body mass to control females, they exhibited lower metabolic rates.4. Although predation risk in L. decemlineata larvae is known to impair their ability to acquire and maintain energy resources, adult females appeared to ameliorate such costs by improving their metabolic efficiency and by allocating more of their limited reproductive resources to produce fewer but better‐quality offspring.

High human disturbance decreases individual variability in skink escape behavior.

Animals living around people may modify their antipredator behavior as a function of proximity to humans, and this response has profound implications for whether or not a population can coexist with humans. We asked whether inland blue-tailed skinks Emoia impar modified their individual antipredator behavior as a function of differential exposure to humans. We conducted multiple consecutive flushes and recorded 2 measures of antipredator response: flight initiation distance (FID), the distance from a threatening stimulus at which an individual flees, and distance fled, the distance an individual fled after a flush. We used a multiple model comparison approach to quantify variation in individual escape behavior across multiple approaches and to test for differences in between-individual variation among populations. We found that individuals tolerated closer approach and fled shorter distances at locations with relatively less human disturbance than at locations with medium and high human disturbance, respectively. In addition, skinks living at high human disturbance sites had less variable FIDs than at low human disturbance sites. Two theories may explain these results. Selection against less favorable phenotypes has reduced behavioral variation in urban habitats and behavioral plasticity allows individuals to flexibly adjust their behavioral patterns in response to human disturbance. These results highlight the importance of studying variation within populations, at the individual level, which may better elucidate the impact that human disturbance has on the behavioral composition of populations.

Assessing blue wildebeests’ vigilance, grouping and foraging responses to perceived predation risk using playback experiments

Two aspects of reactive antipredator behaviour are still unclear for ungulates. First, when there is a direct predation threat, how do prey balance antipredator and social vigilance to learn a predator’s location and assess the risk? Second, how do an individual’s group and environment affect its responses? We tested the responses of adult females in 101 groups of wildebeest to playbacks of lion roars or car noises in Etosha National Park, Namibia. We analysed how the times they spent in different types categories of vigilance, and their within-group density, were affected by the playbacks and how a range of social and environmental variables affected those responses. Females increased their antipredator vigilance but not their social vigilance, after lion roars but not car noises, suggesting that they mostly relied on their own vigilance rather than social information to try to find the source of the lion roars. Females’ antipredator vigilance increased more when they were further from cover and with other prey species, suggesting that both circumstances increased their perception of risk. They ‘bunched’ more after lion roars than car noises and their bite rates decreased as they bunched. Animals’ use of social information about threats is likely to be context-dependent.

Fear alone reduces energy processing by resident ‘keystone’ prey threatened by an invader; a non-consumptive effect of ‘killer shrimp’ invasion of freshwater ecosystems is revealed

Non-consumptive effects (NCEs) of predators – so called ‘fear’ responses – encompass costly antipredator behaviours, such as reduced feeding efficiency. NCEs can influence prey population dynamics and community structure, if prey are ‘keystone’ species such as Gammarus spp. amphipod ‘shrimps’. These freshwater macroinvertebrates have the ecosystem functional role of shredding fallen leaf litter, making it accessible to other taxa. Across Europe, the invasive predatory ‘killer shrimp’ Dikerogammarus villosus is replacing resident Gammarus spp., potentially threatening this vital ecosystem function. While predation (consumptive effects (CEs)) of this invader has been well studied, for the first time we test whether NCEs can be evident in prey only exposed to D. villosus presence and whether this could potentially impact on the prey's functional role. In mesocosms, exposure to constrained D. villosus did not result in mortalities of any of three Gammarus prey species but the leaf shredding efficiencies of all prey were significantly reduced compared to a control treatment. This clear NCE has the potential to propagate through the ecological community via decreased energy processing. This study demonstrates the potential for fear of invasive predator presence alone to impact on ecosystem function.

Can California Ground Squirrels Reduce Predation Risk to Burrowing Owls?

In northern California, USA, western Burrowing Owls (Athene cunicularia) use burrows in active California ground squirrel (Otospermophilus beecheyi) colonies for nesting and protection. Ground squirrels have well-developed, anti-predator alarm-calling behavior, but the potential benefits of such alarm calling to Burrowing Owls have not been examined. The objective of this study was to assess the rate and types of predator interactions experienced by Burrowing Owls and the extent to which they may benefit from alarm calls given by California ground squirrels. We studied interactions of California ground squirrels and Burrowing Owls at Moffett Federal Airfield in urban Santa Clara County, California, during two Burrowing Owl breeding seasons, in 2012 and 2013, using cameras and direct observations. We detected 177 approaches by predators, four of which resulted in predation events on owls. The rate of predator approach during diurnal periods, as determined by direct observation, was 0.93/hr. Ground squirrels called in response to predator approaches before owls did 66% of the time, which was approximately proportional to the abundance of ground squirrels and Burrowing Owls. When squirrels called first, an estimated 75% of owls exhibited alert responses, including alarm calling, running to the burrow, and scanning, indicating that owls benefited from ground squirrel alarm calls in response to approaching predators. Our research suggests that healthy ground squirrel populations may provide important predator alert services to Burrowing Owls, especially in the context of increasing populations of urban predator species.

Experimental evidence for heterospecific alarm signal recognition via associative learning in wild capuchin monkeys

Many vertebrate taxa respond to heterospecific alarm calls with anti-predator behaviours. While it is unclear how apparent recognition is achieved, learned associations between the occurrence of the call and the presence of a predator are considered the most likely explanation. Conclusive evidence that this behaviour is indeed underpinned by learning, however, is scarce. This study tested whether wild black capuchin monkeys (Sapajus nigritus) learn to associate novel sounds with predators through a two-phase field experiment. During an initial training phase, three study groups were each presented with a playback of one of the three novel sounds together with a simulated felid predator on four occasions over an 8- to 12-week period. This was followed by a test phase, wherein each of the three sounds was played back to individuals in all three groups, allowing each sound to serve as both a test stimulus for individuals trained with that sound, and a control stimulus for individuals trained with another sound. Antipredator responses were significantly stronger in response to test sounds than to controls. Limited observations suggest that antipredator responses persisted for at least 2 years without reinforcement of the predator–sound link. Additionally, responses to noisier sounds were typically stronger than were those to more tonal sounds, although the effect of sound type cannot be disentangled from potential effects of group. This study provides the strongest evidence to date that learning affects the responses of primates to sounds such as heterospecific alarm calls, and supports the contention that signals provide receivers with information.

The effect of hypoxia and hydrocarbons on the anti-predator performance of European sea bass (Dicentrarchus labrax)

Hydrocarbons contamination and hypoxia are two stressors that can coexist in coastal ecosystems. At present, few studies evaluated the combined impact of these stressors on fish physiology and behavior. Here, we tested the effect of the combination of hypoxia and petrogenic hydrocarbons on the anti-predator locomotor performance of fish. Specifically, two groups of European sea bass (Dicentrarchus labrax) were exposed to clean water (Ctrl) or oil-contaminated water (Oil). Subsequently, fish of both groups were placed in normoxic (norx) or hypoxic (hyp) experimental tanks (i.e. four groups of fish were formed: Ctrl norx, Ctrl hyp, Oil norx, Oil hyp). In these tanks, escape response was elicited by a mechano-acoustic stimulus and recorded with a high speed camera. Several variables were analyzed: escape response duration, responsiveness (percentage of fish responding to the stimulation), latency (time taken by the fish to initiate a response), directionality (defined as away or toward the stimulus), distance-time variables (such as speed and acceleration), maneuverability variables (such as turning rate), escape trajectory (angle of flight) and distancing of the fish from the stimulus. Results revealed (i) effects of stressors (Ctrl hyp, Oil norx and Oil hyp) on the directionality; (ii) effects of Oil norx and Oil hyp on maneuverability and (iii) effects of Oil hyp on distancing. These results suggest that individual stressors could alter the escape response of fish and that their combination could strengthen these effects. Such an impact could decrease the probability of prey escape success. By investigating the effects of hydrocarbons (and the interaction with hypoxia) on the anti-predator behavior of fish, this work increases our understanding of the biological impact of oil spill. Additionally, the results of this study are of interest for oil spill impact evaluation and also for developing new ecotoxicological tools of ecological significance.

Vertical and horizontal vegetation cover synergistically shape prey behaviour

An animal's perception of predation risk varies across a heterogeneous landscape. Animals rely on indirect cues in the environment, including availability of protective cover, openness of sightlines and distance to refuge to evaluate potential predation risk. Interactions between the indirect cues that influence an animal's perception of predation risk are poorly understood, especially for prey at risk of avian and terrestrial predation. We conducted a giving-up density (GUD) study to examine how interactions between terrestrial predator presence, ceiling (canopy) cover, wall (shrub/grass) cover and distance to nearest tree influence fox squirrel, Sciurus niger, risk perception. The GUD indicates an animal's perceived predation risk, such that increased GUD (decreased foraging) corresponds to greater perceived risk. We found that fox squirrels perceived cues of predation risk in response to a synergistic interaction between ceiling and wall cover. In open canopy areas, fox squirrels increased GUD where there was also increased wall cover. However, fox squirrels reduced GUD in closed canopy areas where there was also increased wall cover. We attribute the differential effects of wall cover depending on ceiling cover to the effectiveness of open sightlines in decreasing predation risk from avian or terrestrial predators. Our study shows that the effect of vegetation structure on prey risk perception and antipredator behaviour depends on the relative risk posed by avian and terrestrial predators that use different hunting strategies.

Who’s where? Ecological uncertainty shapes neophobic predator avoidance in Trinidadian guppies

Neophobic predator avoidance (NPA), the fear response exhibited by prey animals exposed to novel stimuli, is a plastic trait thought to be induced by exposure to elevated chronic risk of predation. Indeed, prey experiencing low levels of background risk fail to display NPA, while those experiencing high background risk do display NPA. Recent work has suggested that the trigger for inducing and maintaining NPA may not be background risk per se but rather uncertainty in the predation environment. Here, we designed two experiments on wild-caught neophobic Trinidadian guppies (Poecilia reticulata) to test the ‘uncertainty hypothesis’. In the first experiment, we tested if the diversity of novel stimuli encountered by guppies would affect the maintenance of their NPA. We found that exposure to a single novel odour once per day for 3 days was sufficient to extinguish the neophobic response to that odour (Experiment 1A) but not a new odour (Experiment 1B). However, when guppies were exposed to multiple novel odours so that each odour was encountered once a day for 3 days, they retained their NPA to both a previously encountered novel odour (Experiment 1A) and a new odour (Experiment 1B). In our second experiment, we repeatedly exposed guppies to a novel cue in a spatially predictable vs. unpredictable location and found that spatial unpredictability interfered with the reduction of NPA to that cue. Combined, our results suggest that uncertainty of risk experienced by prey in time and space shapes the retention of NPA. When prey face uncertainty, or lack of complete information, about risk in their environment, they engage in adaptive antipredator behaviours such as neophobic predator avoidance. Showing a fear response to a novel stimulus in a high-risk environment is likely adaptive if we assume that most species in that environment are threats. Here, we aim to show how uncertainty, as opposed to simply background levels of risk, may influence the maintenance of neophobic responses in prey. On the basis of two experiments, we showed that prey experiencing increased uncertainty, via increased diversity and spatial unpredictability of novel cues, maintain their neophobic responses more so than prey experiencing lower uncertainty. Understanding the effects of ecological uncertainty on prey behaviour, particularly neophobia, will shed light on how prey might respond as uncertainty increases with climate change, invasive species and anthropogenic habitat modification.

Contagious fear: Escape behavior increases with flock size in European gregarious birds.

Flight initiation distance (FID), the distance at which individuals take flight when approached by a potential (human) predator, is a tool for understanding predator–prey interactions. Among the factors affecting FID, tests of effects of group size (i.e., number of potential prey) on FID have yielded contrasting results. Group size or flock size could either affect FID negatively (i.e., the dilution effect caused by the presence of many individuals) or positively (i.e., increased vigilance due to more eyes scanning for predators). These effects may be associated with gregarious species, because such species should be better adapted to exploiting information from other individuals in the group than nongregarious species. Sociality may explain why earlier findings on group size versus FID have yielded different conclusions. Here, we analyzed how flock size affected bird FID in eight European countries. A phylogenetic generalized least square regression model was used to investigate changes in escape behavior of bird species in relation to number of individuals in the flock, starting distance, diet, latitude, and type of habitat. Flock size of different bird species influenced how species responded to perceived threats. We found that gregarious birds reacted to a potential predator earlier (longer FID) when aggregated in large flocks. These results support a higher vigilance arising from many eyes scanning in birds, suggesting that sociality may be a key factor in the evolution of antipredator behavior both in urban and rural areas. Finally, future studies comparing FID must pay explicit attention to the number of individuals in flocks of gregarious species.

Influence of artificial selection for duration of death feigning on pre- and post-copulatory traits in male Tribolium castaneum

In many animals, investment in anti-predator traits can affect reproductive success. Conversely, males that invest more resources in mating success may have relatively fewer resources to devote to anti-predator traits, leading to increased predation risk. Although previous studies have reported a trade-off in investment between anti-predator traits and reproductive traits in male animals, few studies have specifically investigated the effects of anti-predator behavior on male reproductive traits. Many animals engage in death-feigning as an anti-predator behavior. Herein, we investigated the relationship between the death-feigning behavior and pre- and post-copulatory reproductive traits of male red flour beetles, Tribolium castaneum. In a previous study, we used artificial selection to establish T. castaneum strains with a genetically longer (L-strain) or shorter (S-strain) duration of death-feigning behavior. In the present study, we compared the attractiveness (a pre-copulatory trait) and paternity success (a post-copulatory trait) between L- and S-strain males. The results showed no significant difference in attractiveness or paternity success between the two strains. The results suggest that death-feigning behavior is not correlated with pre- or post-copulatory reproductive traits in male T. castaneum.