Antipredator Signals Research Articles

The effect of biofluorescence on predation upon Cope’s gray treefrog: A clay model experiment

Biofluorescence, the ability to absorb light and reemit it at a longer wavelength, is present in many taxa but has been examined only recently in amphibians. Over half of the studies documenting biofluorescence in the last century suggest this fluorescent signal may affect predation; however, to date, only one other experimental study has tested this hypothesis. To address this question, we experimentally tested the effect of biofluorescence on predation through the study of the Cope’s Gray Treefrog, Hyla chrysoscelis. First, we quantified the spectral characteristics of a novel biofluorescence pattern in H. chrysoscelis. In both sexes of this species, the fluorescent signal is concentrated in an area that contains a proposed aposematic pattern to warn predators of the frog’s toxic secretions. We hypothesized that the biofluorescent trait may increase the conspicuousness of this pattern and enable the frogs to deter predators more effectively. Second, we tested this prediction by conducting a clay model field experiment to assess differences in predation attempts on fluorescent versus non-fluorescent H. chrysoscelis models by various predator types. We found no effect of biofluorescence on the overall presence, type, or location of predation, suggesting that biofluorescence alone does not act as an antipredator signal of H. chrysoscelis. This study represents one of the first attempts to experimentally test the effect of biofluorescence on predation in any organism and the first to do so in amphibians. Further work is needed to explore the role of this trait in predation in other systems and to investigate alternative functions for the biofluorescent signal in H. chrysoscelis.

The impact of high temperatures on bird responses to alarm calls

Given the current pace of climate change, high temperature events will become increasingly frequent in many parts of the world. Predicting how high temperatures will impact the behavior of songbirds—highly sensitive to temperature change due to their tendency to be small in size, and to have high metabolic rates and diurnal habits—is therefore crucial and urgent. However, the behavioral impacts of high temperatures on acoustic communication in birds have rarely been studied. Responsiveness to antipredator signals is an important behavior to consider because failure to detect such signals could be lethal. We investigated whether, in great tits (Parus major), high temperatures would affect behavioral responses to playback of conspecific mobbing calls. We found a significant lag effect of temperature on how closely great tits would approach the playback speaker, with birds approaching less closely at higher temperatures. Further, we found that the emission of mobbing calls by great tits was affected by the current ambient temperature, with birds calling less at higher temperatures. The results suggest that at high temperatures, great tits change their tactic from active defense to less active response. High temperatures can thus induce behavioral shifts in great tits. In the current context of increasing average temperatures, such effect of temperature on response to vital indicators such as antipredator signals could impact survival when inducing greater risk of depredation.Significance statementClimate change is causing heatwaves to increase in number and intensity. High temperatures can reduce the ability of birds to respond to vocalizations. Here, we test if high temperatures affect the ability of great tits (Parus major) to respond to conspecific mobbing calls—these calls generally serve to mob a predator and to recruit conspecifics and heterospecifics to join the caller. At higher temperatures, great tits produce fewer mobbing vocalizations and approach the loudspeaker broadcasting mobbing calls less often.

Avian Alarm Calls Do Not Induce Anti-Predator Response in Three Anuran Species.

Many species produce alarm calls in response to predators, and the anti-predator signals are often used by other species. Eavesdropping on heterospecific alarm calls has been widely found in bird and mammal species. Other taxa, such as reptiles and amphibians, however, receive limited attention at present. Here, we selected three types of alarm calls of Japanese Tits (Parus minor) that were evoked by the Siberian Chipmunk (Eutamias sibiricus), Eurasian Sparrow Hawk (Accipiter nisus), and model snake (Elaphe spp.), respectively, and then carried out playback experiments to test whether three frog species changed their behaviors in response to the three treatments of Japanese Tit calls while the tit's territory song was used as a control. The results showed that Little Torrent Frogs (Amolops torrentis), Ornamented Pygmy Frogs (Microhyla fissipes) and Spot-legged Treefrogs (Polypedates megacephalus) did not jump off their positions in response to the same four acoustic signals. They also did not change their calling behaviors in response to the alarm calls of Japanese Tits. This study found no evidence that these anuran species can eavesdrop on heterospecific tits' alarm signals.

Tadpole Responses to Environments With Limited Visibility: What We (Don’t) Know and Perspectives for a Sharper Future

Amphibian larvae typically inhabit relatively shallow freshwater environments, and within these boundaries there is considerable diversity in the structure of the habitats exploited by different species. This diversity in habitat structure is usually taken into account in relation to aspects such as locomotion and feeding, and plays a fundamental role in the classification of tadpoles into ecomorphological guilds. However, its impact in shaping the sensory worlds of different species is rarely addressed, including the optical qualities of each of these types of water bodies and the challenges and limitations that they impose on the repertoire of visual abilities available for a typical vertebrate eye. In this Perspective article, we identify gaps in knowledge on (1) the role of turbidity and light-limited environments in shaping the larval visual system; and (2) the possible behavioral and phenotypic responses of larvae to such environments. We also identify relevant unaddressed study systems paying special attention to phytotelmata, whose small size allows for extensive quantification and manipulation providing a rich and relatively unexplored research model. Furthermore, we generate hypotheses ranging from proximate shifts (i.e., red-shifted spectral sensitivity peaks driven by deviations in chromophore ratios) to ultimate changes in tadpole behavior and phenotype, such as reduced foraging efficiency and the loss of antipredator signaling. Overall, amphibians provide an exciting opportunity to understand adaptations to visually limited environments, and this framework will provide novel experimental considerations and interpretations to kickstart future research based on understanding the evolution and diversity of strategies used to cope with limited visibility.

Giant hornet (Vespa soror) attacks trigger frenetic antipredator signalling in honeybee (Apis cerana) colonies.

Asian honeybees use an impressive array of strategies to protect nests from hornet attacks, although little is understood about how antipredator signals coordinate defences. We compared vibroacoustic signalling and defensive responses of Apis cerana colonies that were attacked by either the group-hunting giant hornet Vespa soror or the smaller, solitary-hunting hornet Vespa velutina. Apis cerana colonies produced hisses, brief stop signals and longer pipes under hornet-free conditions. However, hornet-attack stimuli—and V. soror workers in particular—triggered dramatic increases in signalling rates within colonies. Soundscapes were cacophonous when V. soror predators were directly outside of nests, in part because of frenetic production of antipredator pipes, a previously undescribed signal. Antipredator pipes share acoustic traits with alarm shrieks, fear screams and panic calls of primates, birds and meerkats. Workers making antipredator pipes exposed their Nasonov gland, suggesting the potential for multimodal alarm signalling that warns nestmates about the presence of dangerous hornets and assembles workers for defence. Concurrent observations of nest entrances showed an increase in worker activities that support effective defences against giant hornets. Apis cerana workers flexibly employ a diverse alarm repertoire in response to attack attributes, mirroring features of sophisticated alarm calling in socially complex vertebrates.

An Evolutionary Game Model of Sex-Dependent Antipredator Signaling.

AbstractVarious prey animals behave conspicuously to approaching predators. The conspicuous behavior is considered to be an antipredator signal, and the frequency of signaling individuals in a population differs between males and females in many species. We theoretically assessed the evolution of the inter- and intrasexual dimorphism in antipredator signaling by developing an evolutionary game model. We particularly focused on the Chinese grasshopper, Acrida cinerea, in which only a proportion of males and no females escape conspicuously. In our model, the antipredator signal was assumed to be costly and affect the probabilities of predation of both the signaling individual (individual effect) and the signaling or nonsignaling conspecifics around it (collective effect). The model indicates that (1) a positive individual effect is essential for the evolution of antipredator signaling; (2) sexual dimorphism in fecundity cost for signaling individuals or natural predation probability can produce intersexual dimorphism in the signaling where all individuals of one sex and no individuals of the other sex emit signal; and (3) a positive collective effect can explain the intrasexual dimorphism where only some individuals of one sex signal. This study provides the first model of intrasexual dimorphism in antipredator signaling and brings new testable predictions.

Wood warblers learn to recognize mobbing calls of an unfamiliar species from heterospecific tutors

Mobbing, a collective harassment of a predator by multiple prey species, is ubiquitous in animals. In birds, it is often prompted by specific vocalizations (mobbing calls) produced by an individual that detects a predator; this attracts nearby conspecifics and heterospecifics in a joint assault on the predator. Mutual recognition of mobbing calls among heterospecifics, even those distantly related, is widespread in birds and learning appears important for its acquisition and maintenance. Yet, the evidence for learned recognition is mostly indirect and the specific learning mechanisms remain largely unknown. Here, I provide experimental evidence that free-living birds (wood warblers, Phylloscopus sibilatrix) can learn to recognize novel heterospecific mobbing calls through interspecific social learning, by associating mobbing calls of a previously unknown species with those of the already recognized heterospecifics during joint mobbing events. Moreover, individuals retained the learned recognition of novel mobbing calls over at least 2 weeks. These results illustrate interspecific social learning as one of the mechanisms underlying the widespread mutual recognition of mobbing calls among bird species. This mechanism of learning is likely to be common in the wild, enabling naïve individuals to utilize a wide set of possible information sources, and result in a rapid cultural transmission of novel antipredator signal recognition within avian communities.

Artificial eyespots on cattle reduce predation by large carnivores

Eyespots evolved independently in many taxa as anti-predator signals. There remains debate regarding whether eyespots function as diversion targets, predator mimics, conspicuous startling signals, deceptive detection, or a combination. Although eye patterns and gaze modify human behaviour, anti-predator eyespots do not occur naturally in contemporary mammals. Here we show that eyespots painted on cattle rumps were associated with reduced attacks by ambush carnivores (lions and leopards). Cattle painted with eyespots were significantly more likely to survive than were cross-marked and unmarked cattle, despite all treatment groups being similarly exposed to predation risk. While higher survival of eyespot-painted cattle supports the detection hypothesis, increased survival of cross-marked cattle suggests an effect of novel and conspicuous marks more generally. To our knowledge, this is the first time eyespots have been shown to deter large mammalian predators. Applying artificial marks to high-value livestock may therefore represent a cost-effective tool to reduce livestock predation.

What makes a ‘community informant’? Reliability and anti-predator signal eavesdropping across mixed-species flocks of tits

What makes a ‘community informant’? Reliability and anti-predator signal eavesdropping across mixed-species flocks of tits

Tail-flashing as an anti-predator signal in small wintering birds

Prey species use pursuit-deterrent signals to discourage an attack, by informing a predator either that the latter has been detected, or that the prey is capable of escaping if attacked. These signals tend to be conspicuous behaviors, such as bobbing, stotting, and predator inspection. Dark-eyed juncos (Junco hyemalis) show prominent tail-flashing in social displays during the breeding season, but they continue to tail-flash in winter. We examined whether such tail-flashing functions as a pursuit-deterrent signal by measuring tail-flashing rates in the presence and absence of a taxidermically mounted hawk predator. Our results showed that juncos tail-flash more in the presence of the predator and at higher rates when in direct view of the predator. This suggests that tail-flashing is directed to the predator as a pursuit-deterrent signal. Additionally, juncos reduced tail-flashing when feeding far from cover (low escape probability), suggesting that tail-flashing likely has an attraction cost. We also found a marked group size effect with solitary juncos tail-flashing more than those in large groups, indicating an additional cost to tail-flashing that need not be paid in larger groups. This additional cost is not related to food intake, since we found no negative association between food intake and tail-flashing. We observed tail-flashing in other sparrow species co-occurring with juncos at the study site, suggesting that tail-flashing as a pursuit-deterrent behavior may be widespread in this taxonomic group of birds. Many animals, and especially birds, use tail movements as a signal in various contexts. Dark-eyed juncos make extensive use of tail-flashing as a breeding signal, but they continue to tail-flash during the winter. Our experiment provides evidence that such tail-flashing serves as a pursuit-deterrent signal, a function previously not examined in these birds. Juncos tail-flashed more in the presence of a visible predator, suggesting that the signal is directed towards the predator. Tail-flashing was maximal when close to cover, indicating that tail-flashing incurs a cost of attracting predator attention. A negative relationship between flock size and tail-flashing suggests an additional cost to this behavior, which we demonstrate is not related to food intake rate. We suspect that tail-flashing functions more widely as a pursuit-deterrent signal in the broad phylogenetic group of emberizid sparrows.

A novel alarm signal in aquatic prey: Familiar minnows coordinate group defences against predators through chemical disturbance cues.

Animal signalling systems outside the realm of human perception remain largely understudied. These systems consist of four main components: a signalling context, a voluntary signal, receiver responses and resulting fitness benefits to both the signaller and receiver(s). It is often most difficult to determine incidental cues from voluntary signals. One example is chemical disturbance cues released by aquatic prey during predator encounters that may serve to alert conspecifics of nearby risk and initiate tighter shoaling. We aimed to test whether disturbance cues are released incidentally (i.e. as a cue) or are produced voluntarily depending on a specific signalling context such as the audience surrounding the individual, and thus constitute a signal. We hypothesized that if receivers use disturbance cues to communicate risk among themselves, they would produce more (or more potent) disturbance cues when present in a group of conspecifics rather than when they are isolated (presence/absence of an audience) and use disturbance cues more when present alongside familiar rather than unfamiliar conspecifics (audience composition effect). We placed fathead minnows (Pimephales promelas) in groups with familiar fish, unfamiliar fish or as isolated individuals with no audience present, and then simulated a predator chase to evoke disturbance cues. We used bioassays with independent receivers to assess whether the disturbance cues produced differed depending on the signallers' audience. We found evidence of voluntary signalling, as minnows responded to disturbance cues from groups of fish with tighter shoaling while disturbance cues from isolated minnows did not evoke a significant shoaling response (presence/absence audience effect). Receivers also increased shoaling, freezing and dashing more in response to disturbance cues from familiar groups compared to disturbance cues from unfamiliar groups or isolated minnows (audience composition effect). Together, these findings support our hypothesis that disturbance cues are used as an antipredator signal to initiate coordinated group defences among familiar conspecifics involving shoaling, freezing and dashing. This study represents the strongest evidence to date that chemicals released by aquatic prey upon disturbance by predators serve as voluntary signals rather than simply cues that prey have evolved to detect when assessing their risk of predation.

Differential responses of avian and mammalian predators to phenotypic variation in Australian Brood Frogs.

Anti-predator signaling is highly variable with numerous examples of species employing cryptic coloration to avoid detection or conspicuous coloration (often coupled with a secondary defense) to ensure detection and recollection. While the ends of this spectrum are clear in their function, how species use intermediate signals is less clear. Australian Brood Frogs (Pseudophryne) display conspicuous coloration on both their dorsum and venter. Coupled with the alkaloid toxins these frogs possess, this coloration may be aposematic, providing a protective warning signal to predators. We assessed predation rates of known and novel color patterns and found no difference for avian or mammalian predators. However, when Pseudophryne dorsal phenotypes were collectively compared to the high-contrast ventral phenotype of this genus, we found birds, but not mammals, attacked dorsal phenotypes significantly less frequently than the ventral phenotype. This study, importantly, shows a differential predator response to ventral coloration in this genus which has implications for the evolution of conspicuous signaling in Pseudophryne.

A comparative study of how British tits encode predator threat in their mobbing calls

Many species use antipredator vocalizations to signal information about potential predators, including the level of threat posed by a particular predator. It is not clear, however, why only some prey species do this. Because they use multiple mechanisms to encode threat-specific information about predators, North American Paridae species have been a particularly useful model for studying antipredator signals. Paridae as a group are also useful for examining phylogenetic conservation of vocal signals because all of these species (at least those studied previously) employ similar ways of encoding information about predator threat. To test whether the ways in which predator threat information is encoded (here measured by a bird's vocal output) are conserved across a family with similar vocalizations, we used taxidermy mounts to simulate low- and high-threat predators to induce mobbing in six species across five genera of British Paridae. We found that, like North American species, British tits all increased their call rate in response to predators compared with nonthreatening control mounts, but they all varied in the number and types of additional ways they encoded this information. Some species (blue and willow tits) used all four ways to differentiate between different threat predators, while others used only two (crested tits), one (great and coal tits) or none at all (willow tits). The variation in the way each species encoded predator threat information in their calls was not explained by phylogenetic relatedness or by variation in life history. To better understand patterns of information encoding across related species, we suggest that playback experiments to determine how encoded information is used by conspecifics and heterospecifics might provide insights about why some species encode information about predator threat in multiple ways.

Juvenile Collared Lizards Adjust Tail Display Frequency in Response to Variable Predatory Threat

AbstractAntipredator behavioral tactics have evolved in phylogenetically diverse animal clades and often involve prey initiating conspicuous display patterns when encountering potential predators. Using detailed behavioral observations in the field, we report the first description of conspicuous tail displays in juvenile collared lizards (Crotaphytus collaris), a species that does not have tail autotomy. When approached in the field, lizards gave four stereotypical displays involving the tail, suggesting that these might function as antipredator signals. To test this hypothesis, we compared the frequency of tail displays given by juveniles during approach experiments relative to control trials involving observation from afar. We then further manipulated the intensity (low threat, high threat) with which we threatened lizards by varying our angle of approach relative to the body‐axis orientation of lizards resting on a perch sloping away from the observer. Our results show that juveniles consistently performed all four types of tail displays in response to our approaches, but subjects never displayed during non‐threat control trials. Moreover, lizards were more likely to remain emergent and give tail displays when we approached them head‐on with their bodies sloping away (low threat), but were more likely to take refuge when approached from the side and behind (high threat). The positive relationship between the frequency of display and risk level suggests that tail displays function to signal that juvenile lizards have detected potential predators, which may deter further pursuit. Together, our results provide the first account of visual displays involving the tail in collared lizards and suggest that these displays function to signal potential predators.

Passive acoustic monitoring of Japanese spiny lobster stridulating sounds

The Japanese spiny lobster Panulirus japonicus is an important marine resource in Japan. In order to manage its stock, an effective methodology for population assessments is needed. In this study, we focused on the stridulating sounds produced by spiny lobsters. The stridulating sounds are widely accepted to function as an anti-predator signaling, for potential use in monitoring lobster stocks remotely. An underwater sound recorder was attached on gill nets or lobster pots around Izu Oshima and Niijima islands, within the Izu archipelago, Tokyo, Japan, where lobster fishing is common. Stridulating sounds were manually extracted from each data file. The frequency of stridulating sounds tended to increase on nights with a large tidal change. There was a positive correlation between the frequency of stridulating sounds and the number of lobsters caught in the net or lobster pot. Even in trials where no lobsters were caught, several stridulating sounds could be detected and increased at night. In this study, we describe the sound characteristics of the stridulation, and the trend of nocturnal call productions of this species. This study is the first step towards passive acoustic resource monitoring of Japanese spiny lobsters, which were quite difficult to estimate the density of remotely.

How do novel signals originate? The evolution of fairy-wren songs from predator to display contexts

Revealing the evolutionary origin of novel traits is a long-standing challenge in evolutionary biology. The dynamics of antipredator signalling and conspecific advertisement provide one framework in which to investigate this phenomenon, because shifts in signal context may lead to new signal functions, novel evolutionary pressures and ultimately novel phenotypes. Several species of fairy-wrens (Maluridae: Malurus) give song-like trills (‘Type II song’) in response to vocalizations of avian predators. Despite this predator context, in some species the trills appear to function as conspecific-directed displays. We investigated two hypotheses for the evolutionary origin of predator-elicited Type II songs: (1) they originated as antipredator signals, then shifted to a display context and subsequently became more elaborate because selection pressures changed; or alternatively (2) they originated as conspecific-directed songs, then shifted to a predator context to exploit an effective communication window. Using predator playbacks and samples of natural dawn chorus recordings, we found that many Malurus species gave trills in response to predators, but only a subset gave unprompted trills during dawn chorus displays, and ancestral state reconstructions suggested that the predator-elicited context evolved first. Additionally, species that used trills more often (in both predator and unsolicited contexts) tended to have longer trills with a faster note rate, suggesting that trills have evolved a higher performance as they became a more important part of the display repertoire. Our results support the hypothesis that trill displays originated through the elaboration of predator context calls and provide an example of a shift in signal context leading to novel signal phenotypes.

Ocean acidification and responses to predators: can sensory redundancy reduce the apparent impacts of elevated CO2 on fish?

Carbon dioxide (CO2) levels in the atmosphere and surface ocean are rising at an unprecedented rate due to sustained and accelerating anthropogenic CO2 emissions. Previous studies have documented that exposure to elevated CO2 causes impaired antipredator behavior by coral reef fish in response to chemical cues associated with predation. However, whether ocean acidification will impair visual recognition of common predators is currently unknown. This study examined whether sensory compensation in the presence of multiple sensory cues could reduce the impacts of ocean acidification on antipredator responses. When exposed to seawater enriched with levels of CO2 predicted for the end of this century (880 μatm CO2), prey fish completely lost their response to conspecific alarm cues. While the visual response to a predator was also affected by high CO2, it was not entirely lost. Fish exposed to elevated CO2, spent less time in shelter than current-day controls and did not exhibit antipredator signaling behavior (bobbing) when multiple predator cues were present. They did, however, reduce feeding rate and activity levels to the same level as controls. The results suggest that the response of fish to visual cues may partially compensate for the lack of response to chemical cues. Fish subjected to elevated CO2 levels, and exposed to chemical and visual predation cues simultaneously, responded with the same intensity as controls exposed to visual cues alone. However, these responses were still less than control fish simultaneously exposed to chemical and visual predation cues. Consequently, visual cues improve antipredator behavior of CO2 exposed fish, but do not fully compensate for the loss of response to chemical cues. The reduced ability to correctly respond to a predator will have ramifications for survival in encounters with predators in the field, which could have repercussions for population replenishment in acidified oceans.

Heterospecific information about predation risk influences exploratory behavior

Use of socially derived information from other species is common in many types of decision making, but particularly in predation avoidance. In communities with diverse prey that share generalist predators, public information concerning predator location, type, or activity is often used by heterospecifics. Given that exploration and exploitation of the environment is constrained by predator avoidance, exactly how information about predators affects subsequent prey behavior is of increasing interest. In this study, we tested how social information (predation threat encoded in antipredator vocalizations of the tufted titmouse, Baeolophus bicolor) influences the exploratory behavior (movement, vigilance, and space use) of Northern cardinals (Cardinalis cardinalis). Cardinals, placed inside a small flight cage equipped with an array of perches, experienced randomly assigned playback treatments of titmouse antipredator vocalizations that varied in threat level. Exploratory behavior was videotaped during 3 periods—Before (B), During (D), and After (A) playbacks of titmouse calls. When titmouse vocalizations encoding more dangerous and immediate predation threats were played, cardinals significantly reduced active movements but increased visual scanning relative to subjects hearing calls that encoded low threat levels. Furthermore, they were also slower to return to prethreat behavior. Thus, we conclude that cardinals interpreted the antipredator signals correctly and responded accordingly, adjusting their activities to potentially reduce risk (decreasing movement and increasing vigilance). Our work demonstrates specifically how the trade-off between exploration (comprised of both movement and sensory scanning) and predator avoidance is actuated via spatial decision making in the cardinal. Key words: antipredator vocalization, exploratory behavior, heterospecific information, novel environment. [Behav Ecol]

The function of contrasting pelage markings in artiodactyls

Comparative studies of pelage coloration in mammals suggest that certain prominent markings on an otherwise uniform pelage background serve in communication. We matched the position and coloration of contrasting markings on the bodies of all eventoed ungulates to ecological and social variables in order to ask whether marks are used in communication generally, as a signal to predators, or as a signal to conspecifics. Controlling for phylogeny, we found that many marks are located in prominent visible positions on the body; that flank marks seem to amplify stotting and leaping, which are pursuit deterrent signals; and that front leg marks may amplify foot stamping, an antipredator signal. We found that upper leg markings, particularly markings on the podials, are associated with group living hinting at an intraspecific communicatory function. Surprisingly, we found that contrasting marks do not reliably indicate position of scent glands across this taxon and that many white marks may have a cryptic function. These results extend and contradict those of previous analyses and force us to conclude that contrasting pelage marks have a number of functions in this taxon including pursuit deterrence, intraspecific signaling, and possibly even crypsis. Key words: color patches, intraspecific communication, pursuit deterrence, signals, ungulates. [Behav Ecol]

Temporal Limitations on Social Learning of Novel Predators by Indian Mynahs, Acridotheres tristis

AbstractAntipredator vocalizations of social companions are important for facilitating long‐term changes in the responses of prey to novel predator stimuli. However, dynamic variation in the time course of acoustic communication has important implications for learning of predator cues associated with auditory signals. While animals often experience acoustic signals simultaneously with predator cues, they may also at times experience signals and predator stimuli in succession. The ability to learn about stimuli that are perceived not only together, but also after, acoustic signals has the potential to expand the range of opportunities for learning about novel events. Earlier work in Indian mynahs (Acridotheres tristis) has revealed that subjects acquire a visual exploratory response to a novel avian mount after they have experienced it together with conspecific distress vocalizations, a call produced in response to seizure by a predator. The present study explored to what extent such learning occurred if the avian mount was experienced after, rather than simultaneously with, distress calls, such as might happen if call production is interrupted by prey death. Results showed that mynahs that experienced a novel avian mount simultaneously with the sound of distress calls exhibited a sustained exploratory response to the mount after training relative to before that was not apparent in birds that received distress calls and mount in succession. This finding suggests that vocal antipredator signals may only trigger learning of environmental stimuli with which they share some temporal overlap. Recipients may need to access complementary non‐vocal cues from the prey victim to learn about predator stimuli that are perceived after vocal behaviour.