Antipredator Behavior Research Articles

Predator identity dominates non-consumptive effects in a disease-impacted rocky shore food web.

Predicting the effects of predator diversity loss on food webs is challenging, because predators can both consume and induce behavioral responses in their prey (i.e., non-consumptive effects or NCEs). Studies manipulating predator diversity and investigating NCEs are rare, especially in marine systems. Recently, a severe outbreak of sea star wasting syndrome (SSWS) on the west coast of North America resulted in unprecedented declines of the sea star Pisaster ochraceus. We investigated the consequences of Pisaster loss on an abundant grazer, the black turban snail Tegula funebralis, through NCEs. We combined a laboratory experiment and field surveys to examine the importance of identity vs. diversity in a predator assemblage (Pisaster, crabs, and octopuses) on Tegula behavior, feeding, and growth. Laboratory and field results indicated that predator identity, not diversity, drives Tegula behavior and causes NCEs. Mesocosm treatments with Pisaster caused greater NCEs on Tegula than assemblages without Pisaster. Tegula's distribution in the field, which is driven primarily by anti-predator behavior, was strongly associated only with Pisaster abundance, and not with the abundance of crabs, octopuses, and other predatory sea stars (Leptasterias spp.). We conclude that Pisaster primarily drives Tegula vertical distribution and may be having strong NCEs on Tegula on northern California rocky shores. Furthermore, predator diversity in northern California does not provide functional redundancy, in terms of NCEs on Tegula, to buffer the system from Pisaster loss. Thus, predator-induced vertical distributions and grazing suppression may not be maintained in areas where Pisaster populations are reduced or slow to recover from SSWS.

Look at the time: diel variation in the flight initiation distance of a nectarivorous bird

When approached by a predator, foraging animals should adjust escape behavior based on their current energetic status to minimize opportunity costs (foraging time) and maximize the chance of escape. Animals should therefore be more reluctant to leave a foraging patch when their energy reserves are low and should flee using low-energy escape tactics, but be quicker to flee and use the best escape tactic when satiated. Nectarivorous birds have little capacity for energy storage; thus, they should be particularly sensitive to variation in nutritional status throughout the day. We tested whether New Holland honeyeaters (Phylidonyris novaehollandiae) alter their antipredator behavior by testing whether flight initiation distance (FID—the distance at which an individual flees from an approaching predator) and escape tactic (hopping or flying) vary over the course of the day. Honeyeater FID was shortest in the morning, following the overnight fast, and longest at midday. In the evening, though FID tended to shorten, responses were more variable overall, likely due to individual variation in foraging success. In the morning, honeyeaters were equally likely to hop or fly when approached, but increasingly favored flight as the day progressed. These results suggest a strong link between individual energetic condition and antipredator responses. We suggest that time of day is a useful and important variable influencing escape behavior, the potential effects of which should be more consistently considered as a covariate in the widely used FID protocol. Diel variation in internal and external conditions can alter behavioral responses. In this study, we observed antipredator response behaviors in foraging New Holland honeyeaters, small passerines sensitive to changes in energy status throughout the day. We found that honeyeaters allowed researchers to approach more closely in the morning and evening before fleeing and escaped by flying more often than hopping as the day progressed. Our results suggest that antipredator behaviors are sensitive to current energy status and impending energy needs. In addition, we show that time of day is an important consideration in the experimental design and statistical analysis of behavior studies.

Ship Noise Inhibits Colour Change, Camouflage, and Anti-Predator Behaviour in Shore Crabs

The marine environment is experiencing unprecedented levels of anthropogenic noise. This is known to have adverse effects across a range of taxa, directly affecting sensory systems and behaviours. Stress caused by noise pollution may affect physiological processes that do not have obvious links to the acoustic environment. We show that noise from shipping reduces colour change and consequent camouflage in juvenile shore crabs (Carcinus maenas). Furthermore, ship noise causes maladaptive defensive responses, with crabs less likely to flee a simulated predator attack. In contrast, loud natural noises at the same intensity have none of the same negative effects. Our study shows that anthropogenic noise is likely to be more disruptive than anticipated. Its effects are not confined to species that are reliant upon auditory communication, and may be more severe than would be predicted based only on the amplitude of the sound.

Variation in anti-predator behaviors of white-tailed deer (Odocoileus virginianus) in a multi-predator system

Anti-predator responses to perceived predation risk can influence population demography. Understanding the relative effect of predator exposure and intraspecific interactions across a variety of anti-predator behaviors provides important insight into inter- and intra-specific drivers of species-specific behaviors. We merged classical behavioral observation methods with camera trapping techniques to examine anti-predator behaviors of white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) relative to variation in predator exposure and interspecific interactions. We coded 772 behavioral observations from >180 000 images spanning 605 trap-nights. Seasonal differences in behavioral responses to diminishing returns on foraging effort indicated that deer are risk-averse foragers and are more likely to exhibit risky behaviors in the presence of a concentrated food resource when the nutritional value of food resources are high. However, deer tended to spend less time at a site as resources diminished, supporting marginal value theories of habitat use. Intraspecific interaction predicted vigilance and the amount of time spent at a site. Similar to many other species, deer tended to be less vigilant and spend more time at a site as group size increased. Our research suggests that white-tailed deer in Wisconsin make foraging decisions based on factors associated with individual fitness, presence of conspecifics, and habitat characteristics.

Correction to 'Evidence for individual discrimination and numerical assessment in collective antipredator behaviour in wild jackdaws (Corvus monedula)'.

You have accessMoreSectionsView PDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Cite this article Coomes Jenny R., McIvor Guillam E. and Thornton Alex 2019Correction to ‘Evidence for individual discrimination and numerical assessment in collective antipredator behaviour in wild jackdaws (Corvus monedula)’Biol. Lett.152019074020190740http://doi.org/10.1098/rsbl.2019.0740SectionYou have accessCorrectionsCorrection to ‘Evidence for individual discrimination and numerical assessment in collective antipredator behaviour in wild jackdaws (Corvus monedula)’ Jenny R. Coomes Jenny R. Coomes http://orcid.org/0000-0002-6196-5370 Google Scholar Find this author on PubMed Search for more papers by this author , Guillam E. McIvor Guillam E. McIvor http://orcid.org/0000-0003-3922-7651 Google Scholar Find this author on PubMed Search for more papers by this author and Alex Thornton Alex Thornton http://orcid.org/0000-0002-1607-2047 Google Scholar Find this author on PubMed Search for more papers by this author Jenny R. Coomes Jenny R. Coomes http://orcid.org/0000-0002-6196-5370 Google Scholar Find this author on PubMed Search for more papers by this author , Guillam E. McIvor Guillam E. McIvor http://orcid.org/0000-0003-3922-7651 Google Scholar Find this author on PubMed Search for more papers by this author and Alex Thornton Alex Thornton http://orcid.org/0000-0002-1607-2047 Google Scholar Find this author on PubMed Search for more papers by this author Published:06 November 2019https://doi.org/10.1098/rsbl.2019.0740This article corrects the followingResearch ArticleEvidence for individual discrimination and numerical assessment in collective antipredator behaviour in wild jackdaws (Corvus monedula)https://doi.org/10.1098/rsbl.2019.0380 Jenny R. Coomes, Guillam E. McIvor and Alex Thornton volume 15issue 10Biology Letters02 October 2019Biol. Lett.15, 20190380. (Published online 2 October 2019) (doi:10.1098/rsbl.2019.0380)We would like to add the following acknowledgements statement to the publication:Many thanks to Richard Woods for acoustic advice and help with statistics and to Sophie Darnton for coding videos. We are very grateful to the Gluyas family and staff at Pencoose Farm and to Odette Eddy and the people of Stithians where this work was conducted. We are grateful to Ally Phillimore for statistical advice and to three anonymous reviewers for their valuable input. Previous Article VIEW FULL TEXT DOWNLOAD PDF FiguresRelatedReferencesDetailsCited by Gómez-Laplaza L and Gerlai R (2020) Food Quantity Discrimination in Angelfish (Pterophyllum scalare): The Role of Number, Density, Size and Area Occupied by the Food Items, Frontiers in Behavioral Neuroscience, 10.3389/fnbeh.2020.00106, 14 Related articlesEvidence for individual discrimination and numerical assessment in collective antipredator behaviour in wild jackdaws (Corvus monedula)02 October 2019Biology Letters This IssueNovember 2019Volume 15Issue 11 Article InformationDOI:https://doi.org/10.1098/rsbl.2019.0740PubMed:31690210Published by:Royal SocietyOnline ISSN:1744-957XHistory: Published online06/11/2019Published in print29/11/2019 License:© 2019 The Author(s)Published by the Royal Society. All rights reserved. Citations and impact Subjectsbehaviourcognition Large datasets are available through Biology Letters' partnership with Dryad

Low concentrations of the benzodiazepine drug oxazepam induce anxiolytic effects in wild-caught but not in laboratory zebrafish

Pollution by psychoactive pharmaceuticals has been found to disrupt anti-predator behaviors of wild fish. The challenge is now to identify which of the many psychoactive drugs pose the greatest threat. One strategy is to screen for behavioral effects of selected pharmaceuticals using a single, widely available fish species such as zebrafish. Here, we show that although such high-throughput behavioral screening might facilitate comparisons between pharmaceuticals, the choice of strain is essential. While wild-caught zebrafish exposed to concentrations of the anxiolytic drug oxazepam as low as 0.57 μg L−1 showed a reduction in the response to conspecific alarm pheromone, laboratory strain AB did not respond to the alarm cue, and consequently, the anxiolytic effect of oxazepam could not be measured. Adaptation to the laboratory environment may have rendered laboratory strains unfit for use in some ecotoxicological and pharmacological studies, since the results might not translate to wild fish populations.

Body size, but not age‐at‐maturation or context, affects the expression of predator‐induced behavioural plasticity in female green swordtails (Xiphophorus hellerii)

AbstractBehavioural plasticity is a form of reversible phenotypic plasticity in which a genotype can express different behavioural phenotypes under different environmental conditions. Though an interest in among‐individual differences in behavioural plasticity has flourished in recent decades, few studies have considered the effects of intrinsic factors, such as life‐history or morphological traits, in tandem with extrinsic factors, such as presence of conspecifics in different social contexts, on predator‐induced behavioural plasticity. Here, we present a study conducted with female green swordtail fishes, Xiphophorus hellerii, designed to assess the effects of age‐at‐maturation and body size on the expression of predator‐induced behavioural plasticity in two social contexts: (a) female‐only (two females) and (b) female‐and‐male (two females and a male). We further examined the extent to which individual expression of behavioural plasticity is consistent across these two social contexts. We found that in the presence of a predator, focal females were more timid in response to the stimulus and more tolerant of the non‐focal female, and small females expressed this change from bold/less tolerant to timid/more tolerant to a greater degree than large females, regardless of age‐at‐maturation. However, individuals were not consistent in the degree or direction of plasticity expressed in the behaviours of interest between the female‐only and the female‐and‐male context. Here, we show that within‐ and among‐individual differences in behavioural expression are common but inconsistent. How intrinsic and extrinsic factors independently or together drive expression of plasticity in antipredator and agonistic behaviours is varied and warrants further study.

Presence of parents during early rearing affects offspring responses towards predators

Social learning about predation threat during early ontogeny can be beneficial in developing appropriate antipredator behaviours. While such learning can be achieved through direct interactions between offspring and parents, it is unknown whether young animals can also learn appropriate responses towards different heterospecifics posing different levels of threat through inadvertent information obtained from witnessing parental interactions with these heterospecifics. In this study, we split sibling groups of the cooperatively breeding cichlid Neolamprologus pulcher and raised them with or without parents. Both rearing groups repeatedly received visual and olfactory cues from four types of fish (predators, egg predators, herbivores and conspecifics) during a 4-week experience phase. After a ‘neutral phase’ of 4 months under identical conditions and without further fish stimuli, individuals from both rearing conditions were tested for their response towards the same four stimulus species. Unlike those reared with parents, the fish reared without parents spent significantly more time in safety and were more vigilant towards the predator, whereas responses to the other three species did not differ. As during the experience phase parental responses towards the stimulus fish were unexpectedly low and indiscriminate, our results suggest that young N. pulcher reverse their innate fear of predators when observing parents being unresponsive to a threat (‘observational conditioning’). We suggest that learned reduction of fear can be a potent mechanism to prevent responding to false alarms and mitigate potentially harmful effects of chronically elevated predation stress.

Lines selected for different durations of tonic immobility have different leg lengths in the red flour beetle Tribolium castaneum

Abstract Tonic immobility is an adaptive anti-predator behaviour observed in many species. This anti-predator behaviour is often correlated with a species’ movement motivation, so a relationship between the duration of tonic immobility and morphological traits supporting movement would be expected. Using the red flour beetle, Tribolium castaneum, we carried out two-way artificial selection for the duration of tonic immobility over more than 43 generations, establishing populations with longer (L) and shorter (S) tonic immobility durations compared to those of a non-selected control (C) population. Here, we investigated differences in walking motivation and leg length between the selected populations. Walking motivation was significantly higher in beetles from the S population than that in those from the L population. Moreover, S-population beetles of both sexes had significantly longer legs than those from L and C populations. The present results suggest the evolution of longer legs in response to selection pressure for a shorter duration of tonic immobility in T. castaneum.

Human habituation reduces hyrax flight initiation distance in Serengeti

AbstractMany animal populations are exposed to disturbance originating from human activities. In response to human disturbance, certain animals display a variety of potentially costly behavioural responses, such as increased antipredator behaviour or relocation to new areas. In contrast, other animals seemingly thrive in the presence of humans and benefit from human‐derived resources. Flight initiation distance (FID: the distance between predator and prey when prey starts to flee) is a measure commonly used to assess animals’ tolerance to humans. In this study, we tested how FID changes in relation to human presence in two hyrax species in Serengeti National Park. Hyraxes living on kopjes (rock outcrops) among human settlements showed a significantly shorter FID than hyraxes living on kopjes without human settlements. In addition, we found that hyraxes feeding before the experiment had shorter FID than hyraxes resting or being vigilant, and hyraxes disturbed during the early morning had shorter FID than hyraxes disturbed during late morning. We did not find any significant effects of group size or species composition on FID. Our results suggest that hyraxes living in the presence of humans are habituated and are not adversely affected by human settlements.

Hissing females of great tits (Parus major) have lower breeding success than non‐hissing individuals

AbstractAntipredator strategies vary remarkably between individuals within populations. Parents tend to take greater risks when brood value is increased. Moreover, individuals consistently differ in a whole suite of correlated behaviours that may cause distinctive responses to predators. It is likely that individual differences in antipredator behaviour may co‐vary with proxies for fitness such as reproductive success. We used a 4‐year data from wild great tits (Parus major) to test whether passive and active antipredator strategies (females with no response vs. those giving hissing calls towards a nest predator) during the incubation stage can reflect variation in breeding success. Although clutch size did not depend on hissing behaviour, the number of surviving offspring from eggs and neonates to fledglings was higher for non‐hissing than hissing birds. We conclude that females with distinct antipredator strategies can prioritize different fitness components.

Transcriptomic comparison between beetle strains selected for short and long durations of death feigning

The molecular basis of death feigning, an antipredator behavior that has received much attention recently, was analyzed. We compared the gene expression profiles of strains with different behaviors, i.e., different durations of death feigning, in the beetle Tribolium castaneum. Beetles artificially selected for short (S) and long (L) durations of death feigning for many generations were compared thoroughly by RNA sequencing. We identified 518 differentially expressed genes (DEGs) between the strains. The strains also showed divergence in unexpected gene expression regions. As expected from previous physiological studies, genes associated with the metabolic pathways of tyrosine, a precursor of dopamine, were differentially expressed between the S and L strains; these enzyme-encoding genes were expressed at higher levels in the L strain than in the S strain. We also found that several genes associated with insulin signaling were expressed at higher levels in the S strain than in the L strain. Quantitative real-time PCR analysis showed that the relative expression levels of Tchpd (encoding 4-hydroxyphenylpyruvate dioxygenase, Hpd) and Tcnat (encoding N-acetyltransferase, Nat) were significantly higher in the L strain than in the S strain, suggesting the influence of these enzymes on the supply of dopamine and duration of death feigning.

Frogs with denser group-spawning mature later and live longer

The understanding of the intrinsic and extrinsic causes of longevity variation has deservedly received much attention in evolutionary ecologist. Here we tested the association between longevity and spawning-site groups across 38 species of Chinese anurans. As indicators of group-spawning we used spawning-site group size and spawning-site density, which we measured at 152 spawning sites in the field. We found that both spawning-site density and group size were positively associated with longevity. Male group-spawning (e.g., male spawning-site density and male spawning-site group size) was also positively correlated with longevity. A phylogenetic path analysis further revealed that longevity seems directly associated with spawning-site density and group size, and that the association in part depend on the ‘groups-spawning-age at first reproduction’ association. Our findings suggest that the increased group-spawning are likely to benefit in declining extrinsic mortality rates and living longer through improving total anti-predator behaviour under predation pressure.

Listening to your gut: immune challenge to the gut sensitizes body wall nociception in the caterpillar Manduca sexta.

Immune-nociceptor connections are found in animals across phyla. Local inflammation and/or damage results in increased nociceptive sensitivity of the affected area. However, in mammals, immune responses far from peripheral nociceptors, such as immune responses in the gut, produce a general increase in peripheral nociceptive sensitivity. This phenomenon has not, to our knowledge, been found in other animal groups. We found that consuming heat-killed pathogens reduced the tactile force needed to induce a defensive strike in the caterpillar Manduca sexta. This increase in the nociceptive sensitivity of the body wall is probably part of the reconfiguration of behaviour and physiology that occurs during an immune response (e.g. sickness behaviour). This increase may help enhance anti-predator behaviour as molecular resources are shifted towards the immune system. This article is part of the Theo Murphy meeting issue 'Evolution of mechanisms and behaviour important for pain'.

Anti-predator behavior along elevational and latitudinal gradients in dark-eyed juncos.

Flight-initiation distance (FID), the distance between an individual and experimenter when it begins to flee, can be used to quantify risk-assessment. Among other factors, prior studies have shown that latitude explains significant variation in avian FID: at lower latitudes, individuals and species have longer FIDs than those living at higher latitudes. No prior studies have focused on the effect of elevation on FID. Given the similar patterns of seasonality, climate, and potentially predator density, that covary between latitude and elevation, birds at higher elevations might tolerate closer approaches. We asked whether elevation or latitude would explain more variation in the FID of a common passerine bird species, dark-eyed juncos (Junco hyemalis). Juncos live in a variety of habitats along both latitudinal and elevational gradients. We found that statistical models containing elevation as a variable explained more of the variation in FID than did models containing latitude. We also found, unexpectedly, that birds at higher elevation fled at greater distances. While more predators were sighted per hour at higher elevations than at lower elevations, the frequency of predator sightings did not explain a significant amount of variation in FID. This result questions whether predator density is the main driver of risk perception along elevational gradients. Nonetheless, because elevation explains more variation in FID than latitude in at least one species, these findings have direct implications on how human impacts on birds are managed. Specifically, those designing set-back zones to reduce human impact on birds may consider modifying them based on both latitude and elevation.

The fate of 0+ asp (Leuciscus aspius) after being stocked in a reservoir

Artificial enhancement of fish populations by stocking is widespread practice. Yet, very little is known about short-term dispersal, capture efficiency and the effect of fish size and habitat suitability. Asp (Leuciscus aspius Linnaeus, 1758) was chosen as a model species, because of its protection in the Svihov Reservoir and common stocking to increase predator fish abundance in many biomanipulated waters. 0+ fluorescent-marked asp were stocked in dam, middle and tributary sites of Svihov Reservoir and subsequently monitored weekly for three weeks intervals by boat electrofishing for two consecutive years. Despite similar numbers of asp stocked, the recapture was six-times lower in a year with low water level and high macrophyte density. All captured asp were identified as of hatchery origin. In the dam site most asp were recaptured in or close to the semi-closed bay with shallow water, where they were stocked. In the middle site asp spread from the unsuitable site of stocking in all directions and only very few individuals were recaptured. In the tributary site, asp dispersion was the most evident in 2017 in the direction towards the dam in the littoral zone opposite the bank that was the bank of stocking. In comparison the highest recapture was found at the site of stocking in 2018. The recaptured asp were of similar or larger size than the average stocked asp, which may suggest size-dependent mortality. The mortality of stocked asp may be affected by failure in foraging and antipredator behaviour. This research highlights the importance of post-release monitoring.

Antipredator function of vigilance re-examined: vigilant birds delay escape

Vigilance is considered an effective antipredator behaviour in animals, and hence it should reflect fearfulness. While numerous aspects of vigilance have been extensively studied, there is a paucity of evidence regarding the role of vigilance in escaping from predators. In a multispecies approach, we measured vigilance (as the proportion of time spent in a head-up posture) and three consecutive components of escape behaviour, predetection distance, assessment interval and flight initiation distance, of wild birds in urban and rural habitats in three European countries. Escape behaviour was induced by a human observer walking towards the focal bird whose vigilance was measured beforehand. More vigilant individuals did not detect predators earlier than less vigilant ones. In addition, more vigilant individuals spent more time on risk assessment and escaped later. Body mass was positively correlated with vigilance for birds on higher perches, where we expected vigilance to be less important. Finally, urban birds were more vigilant than rural birds, suggesting that distractions in urban habitats might have a more profound impact on vigilance than the expected lower predation risk. These results challenge the underlying assumption that more vigilant individuals have a higher perceived risk of predation and hence better odds at avoiding predation. We explain our results in the context that higher levels of vigilance compensate for environmental distractions and for innate deficiencies or lack of experience that constrain the detection of predators. We suggest that a re-examination of the basic functions and markers of vigilance is needed before using it as a measure of fearfulness in birds.

Foraging ecology drives social information reliance in an avian eavesdropping community.

Vertebrates obtain social information about predation risk by eavesdropping on the alarm calls of sympatric species. In the Holarctic, birds in the family Paridae function as sentinel species; however, factors shaping eavesdroppers' reliance on their alarm calls are unknown. We compared three hypothesized drivers of eavesdropper reliance: (a) foraging ecology, (b) degree of sociality, and (c) call relevance (caller‐to‐eavesdropper body‐size difference). In a rigorous causal‐comparative design, we presented Tufted Titmouse (Baeolophus bicolor) alarm calls to 242 individuals of 31 ecologically diverse bird species in Florida forests and recorded presence/absence and type (diving for cover or freezing in place) of response. Playback response was near universal, as individuals responded to 87% of presentations (N = 211). As an exception to this trend, the sit‐and‐wait flycatcher Eastern Phoebe (Sayornis phoebe) represented 48% of the nonresponses. We tested 12 predictor variables representing measures relevant to the three hypothesized drivers, distance to playback speaker, and vulnerability at time of playback (eavesdropper's microhabitat when alarm call is detected). Using model‐averaged generalized linear models, we determined that foraging ecology best predicted playback response, with aerial foragers responding less often. Foraging ecology (distance from trunk) and microhabitat occupied during playback (distance to escape cover) best predicted escape behavior type. We encountered a sparsity of sit‐and‐wait flycatchers (3 spp.), yet their contrasting responses relative to other foraging behaviors clearly identified foraging ecology as a driver of species‐specific antipredator escape behavior. Our findings align well with known links between the exceptional visual acuity and other phenotypic traits of flycatchers that allow them to rely more heavily on personal rather than social information while foraging. Our results suggest that foraging ecology drives species‐specific antipredator behavior based on the availability and type of escape cover.

Behavioral and chemical antipredator mechanisms in ground beetles: an attempt to reconcile within a phylogenetic frame

Like other coleopterans, Carabids are recognized for the use of passive and active strategies against their enemies. They are known to produce dangerous and distasteful chemicals and to use anti-predator behaviors such crypsis/mimicry, gregariousness, intra- and interspecific helpful interactions, sound production and aposematism. While defensive chemicals have been an important element in the successful diversification of ground beetles, in many tribes of this wide adephagan family many other systems have evolved and discovered. Here we present a review on the current knowledge of the avoidance mechanisms in carabids, with a discussion of data on chemical products, morphological adaptations and behaviors used against vertebrate and invertebrate predators. The most widespread strategy is discouragement of the predators using pygidial gland secretions, but passive anti-predator strategies are also displayed as group-protecting behavior through intraspecific aggregations or communal roosting. Most adult carabids tend to be dark in color and thus less detectable, but chemically well-protected taxa use the opposite strategy, displaying bright colors related to mimicry or aposematism. In aposematic species, group-protecting behavior has probably evolved from intraspecific gregariousness into multispecies aggregations. Larval behavioral strategies are related more closely to the epigean or underground lifestyle. In surface-living larvae, cannibalism avoidance and the usage of defensive substances have been reported for Chlaeniini. In this tribe we found an interesting coincidence between a high level of toxicity/distastefulness and a complex larval behavior. Based mainly on the genus-level supertree of Beutel et al. (2008) and the phylogenetic analyses of Ober & Maddison (2008) we reconstructed the evolutionary relationships among the chemical classes isolated inside the tribes. The scenario shows that several semiochemical classes (quinone/benzoquinones, formic acid, m-cresol, methacrylic acid, isovaleric acid, ß-necrodol, benzaldehyde, etc.) found in carabids are at least in part related to their life style and habitat selection. The proposed relationship still lacks other chemical data of the missing genera/species and even if the knowledge of carabid anti-predator strategies still seems to be in the pioneer stage, future studies on carabid anti-predator behavior look very promising.

Behavioral responses of goitered gazelles to potential threats

Prey species have to recognize a predator, assess its potential threat, and adjust its behavioral responses according to the magnitude of the perceived predation risk. In many studies of antipredator behavior in prey animals, simulated threats, such as human activities (movements, approaching prey), have been used as experimental threat factors, often in controlled circumstances, while prey responses to other animals in natural environments have been less investigated. This paper discusses the responses of goitered gazelles in the wild during encounters with various animals in their natural habitat to evaluate their cues used to assess the magnitude of potential threats. This study found that the goitered gazelles’ behavioral responses to perceived risk differed across the various species sharing their habitat, with kulan recognized as a minimal threat and Siberian ibex the most threatening among ungulates. Among predators, the fox caused the least fear, while a horseman with a dog was identified as the greatest threat, with a wolf falling in between. Goitered gazelles adjusted their responses depending on the traits of the species encountered, while the features and conditions in their local environment played a less significant role. During encounters with other species, the gazelles ranked them according to their potential risk level based on the animal’s appearance and behavior. The gazelles did distinguish between predators and other species and reacted to them differently: from pursuing and harassing the smallest (fox), to a panicky, running escape from their most dangerous natural predator (wolf), and especially from their most lethal, non-natural “predator” (herdsmen—mainly local poachers). Thus, this study suggested that goitered gazelles differentiate between predator species, assess their traits and intentions in each particular setting, and respond in the most advantageous way to each threat challenge.