Playback Of Calls Research Articles

Sex differences in behavioural and neural responsiveness to mate calls in a parrot.

Vocalisation in songbirds and parrots has become a prominent model system for speech and language in humans. We investigated possible sex differences in behavioural and neural responsiveness to mate calls in the budgerigar, a vocally-learning parrot. Males and females were paired for 5 weeks and then separated, after which we measured vocal responsiveness to playback calls (a call of their mate versus a call of an unfamiliar conspecific). Both sexes learned to recognise mate calls during the pairing period. In males, but not females, mate calls evoked significantly fewer vocal responses than unfamiliar calls at one month after separation. Furthermore, in females, there was significantly greater molecular neuronal activation in response to mate calls compared to silence in the caudomedial mesopallium (CMM), a higher-order auditory region, in both brain hemispheres. In males, we found right-sided dominance of molecular neuronal activation in response to mate calls in the CMM. This is the first evidence suggesting sex differences in functional asymmetry of brain regions related to recognition of learned vocalisation in birds. Thus, sex differences related to recognition of learned vocalisations may be found at the behavioural and neural levels in avian vocal learners as it is in humans.

Chickadee Behavioural Response to Varying Threat Levels of Predator and Conspecific Calls

Chickadees produce many vocalizations, including chick-a-dee calls which they use as a mobbing call in the presence of predators. Previous research has shown that chickadees produce more D notes in their mobbing calls in response to high-threat predators compared to low-threat predators, and may perceive predator and corresponding mobbing vocalizations as similar. We presented black-capped chickadees with playback of high- and low-threat predator calls and conspecific mobbing calls, and non-threat heterospecific and reversed mobbing calls, to examine vocal and movement behavioural responses. Chickadees produced more chick-a-dee calls in response to playback of calls produced by a high-threat predator compared to calls produced by a low-threat predator, and to reversed high-threat mobbing calls compared to normal (i.e., non-reversed) high-threat mobbing calls. Chickadees also vocalized more in response to all playback conditions consisting of conspecific mobbing calls compared to a silent baseline period. The number of D notes that the subjects produced was similar to previous findings; chickadees produced approximately one to three D notes per call in response to low-threat mobbing calls, and produced more calls containing four to five D notes in response to high-threat mobbing calls, although this difference in the number of D notes per call was not significant. The difference in chickadees’ production of tseet calls across playback conditions approached significance as chickadees called more in response to conspecific mobbing calls, but not in response to heterospecific calls. General movement activity decreased in response to playback of conspecific-produced vocalizations, but increased in response to heterospecific-produced vocalizations, suggesting that chickadees may mobilize more in response to predator playback in preparation for a “fight or flight” situation. These results also suggest that chickadees may produce more mobbing calls in response to high-threat predator vocalizations as an attempt to initiate mobbing with conspecifics, while they produce fewer mobbing calls in response to a low-threat predator that a chickadee could outmaneuver.

Vocal responses to noise reveal the presence of the Lombard effect in a frog

Many animal communication systems have evolved signal flexibility depending on environmental conditions. A common strategy of vocal communication is to increase amplitude in response to increasing noise levels. This phenomenon, known as the Lombard effect, is a widespread trait among mammals and birds. Anurans are a major group with many species that rely heavily on acoustic signals for sexual communication. Although these species often communicate in noisy environments, the presence of the Lombard effect in frogs remains unclear. We exposed male tungara frogs (Physalaemus pustulosus) to different noises with and without playback of conspecific calls. Males increased call amplitude, call rate, and call complexity in response to low-frequency noise (overlapping the species' call range) but not to high-frequency (nonoverlapping) noise. Vocal amplitude increased linearly with noise level demonstrating that tungara frogs exhibit the Lombard effect, and we discuss why different frog species may differ in their control over vocal amplitudes. Furthermore, we found the overall effect of noise to be similar to the effect of conspecific call playback. We speculate that vocal amplitude control may have evolved primarily as a response to increased competition at the cocktail party, similar to the way humans raise their voice when in a heated debate, and subsequently as a strategy to deal with background noise more generally.

Structure of distress call: implication for specificity and activation of dopaminergic system.

We conducted a set of playback experiments aimed at understanding whether distress-call structure in the greater short-nosed fruit bat Cynopterus sphinx is specific in encoding information relating to stress that attracts conspecifics. We tested the specificity by playing their distress call and its modified version at a foraging site for free-ranging bats, as well as under captive conditions involving either a small group or individuals. In a separate playback experiment, bats showed a significantly greater response when the natural call as opposed to a modified call was played back to captive as well as free-ranging bats at the foraging site. Under captive conditions, bats showed less of a response to the playback of distress calls when in a group than when alone. We subsequently found that tyrosine hydroxylase (TH) and its transcription factor-nuclear receptor related factor 1 (Nurr-1); and the dopamine transporter (DAT) and its receptor (D1DR) were elevated significantly in the amygdala of bats both emitting and responding to a distress call, but not in the case of bats responding to the modified call. These results suggest that distress-call structure encodes information on the state of stress that is capable of being conveyed to conspecifics.

Gender identification using acoustic analysis in birds without external sexual dimorphism

Zoo and wildlife management faces a problem with bird sexing, as many bird taxa have indiscernible gender differences in size and coloration. Problematic groups are geese, cranes, rails, raptors, owls, parrots, doves, auks, shearwaters and some passerines. Commonly accepted invasive sexing techniques based on genetics, laparoscopy, morphometric and on cloacal inspection, are all needed in bird capturing and handling. Capturing and subsequent manipulations may be inapplicable for free-ranging birds, whereas distant voice-based sexing is relevant for many species. This review evaluates the potential for noninvasive sexing by separate calls or duet calls, for adult birds of 69 species from 16 orders and for chicks of 11 species from 7 orders. For adult birds of 25 species, a single call per individual was sufficient for 100 % reliable sexing by ear or using spectrographic analysis. For chicks, the potential for voice-based sexing seems to be very limited. For birds calling rarely or unpredictably, we propose a simple way of provoking vocalization using playbacks of species-specific calls that are available from sound libraries. We conclude that sexing by voice may represent a feasible alternative to the classical sexing techniques, both in the wild and in captivity.

Barn swallows (Hirundo rustica) differentiate between common cuckoo and sparrowhawk in China: alarm calls convey information on threat

Morphological mimicry of sparrowhawks Accipiter spp. by cuckoos acts to deceive hosts and thus promotes parasitism by cuckoos. Recent studies have suggested that common hosts are able to identify parasites and make special alarm calls as the result of co-evolution between hosts and brood parasites. Previous studies showed that barn swallows Hirundo rustica could distinguish between common cuckoo Cuculus canorus and sparrowhawk Accipiter nisus in Denmark, but seemed unable to make this distinction in China. However, these previous studies did not investigate vocal responses in terms of alarm calls. We tested whether barn swallows, which are regular hosts of the common cuckoo in China, could distinguish between the common cuckoo and sparrowhawk in China. In Heilongjiang, in the presence of the cuckoo and, in Hainan, in its absence, we used dummies of common cuckoo, sparrowhawk, and Oriental turtle dove Streptopelia orientalis (neutral control) to induce and record alarm calls that were used to estimate response to playbacks. Barn swallows responded more strongly to playbacks of swallow hawk alarm calls than in response to swallow cuckoo or swallow dove alarm calls. Given that alarm calls conveyed information about the presence of potential threats, our study showed that barn swallows from both study regions in China were able to distinguish between common cuckoo and sparrowhawk and respond accordingly in their vocal behavior.

Effects of maternal vocalisations on the domestic chick stress response

Although natural brooding is not commercially feasible, there is great potential to simulate aspects of maternal care to improve the welfare of farmed domestic chicks. Our previous studies showed that the presence of calm broody hens can buffer mild stress responses in chicks, although the presence of more aroused broody hens has less of a social buffering effect. Maternal vocalisations are a key component of the hens’ response to chick stress; hens vocalise for around 10% of the time when their chicks are exposed to an air-puff, with some higher responding individuals calling for up to 33% of the time. We therefore sought to determine whether playback of maternal calls at 10% and 33% proportions would alleviate stress in non-brooded chicks. We also hypothesised that prior experience of the vocalisation would be necessary for this response. 72 chicks were assigned to one of two ‘Experience’ treatments, half received prior experience of maternal call playback in their home pen and half were controls. During subsequent testing, behaviour and eye temperature responses of chick pairs were monitored before and during exposure to air puffs at 30s intervals during three time intervals (T1: 0–3min, T2: 4–6min, T3: 7–9min). During testing chicks were split into 3 groups: Group 1 received no vocalisation playback (Control), Group 2 received playback of vocalisations for 10% of the time and Group 3 received playback of vocalisations for 33% of the time (n=12 pairs for each group). In response to the air-puff, chicks reduced sitting, pecking the environment and increased freezing. They also showed a reduction in eye temperature. All three chick groups spent the vast majority of their time freezing and there was no difference between the three groups in this behaviour. Group 2 chicks showed a lower eye temperature response during T2 and T3 compared to Groups 1 and 2, suggestive of a stress-alleviating effect. There was no effect of prior experience on the eye temperature response. The fact that vocalisation playback did not reduce freezing indicates that additional features of a broody hen are likely to be required to change the chicks’ behavioural repertoire.

Common urban birds continue to perceive predator calls that are overlapped by road noise

Recent studies suggest that songbird communication is negatively affected by anthropogenic noise. However, much of the current literature focuses on inter- and intra-sexual communication. Songbirds also use acoustic cues for many other functional behaviors. One example associated with fitness consequences is the identification of predatory threats through acoustic cues. To test the effect of anthropogenic noise on detection of acoustic cues, we compared the rates of seven anti-predator behavioral responses in urban dwelling songbirds foraging at bird feeders when exposed to playback of calls from predatory Cooper’s hawks under quiet conditions, and when overlapped with road noise. Only a single behavior, freeze response, decreased significantly when calls were overlapped with noise. However, freeze responses occurred in only a small percentage of playback trials, raising some question regarding the biological relevance of this observed difference. Overall, our results suggest that common urban songbirds are relatively successful at perceiving acoustic signals associated with predator presence. Whether this ability is commonplace amongst songbird species is unknown and warrants additional study. However, if this trait is not widespread, it may be an additional characteristic determining which bird species can inhabit noisy areas.

Risk-based alarm calling in a nonpasserine bird

Recent studies have demonstrated the presence of risk-based variation in alarm calling in many vertebrate species. Most of the studies on birds, however, have focused on passerine systems perhaps due to the traditional view that passerine vocalizations are more complex. We investigated the presence of a risk-based alarm calling system in a nonpasserine, the herring gull, Larus argentatus, by recording birds presented with varying degrees of threat, and experimentally exposing and quantifying responses to manipulated alarm calls. We found that herring gulls communicate threat urgency in their alarm calls using both frequency and time parameters. Sound recordings indicated that herring gulls change centre frequency modulation patterns of their alarm calls, generate frequency discontinuities in notes and increase the rate of calling with increases in perceived threat level. Playback experiments showed that conspecifics pay attention to both frequency and time parameters and respond most urgently to playbacks of high-threat calls at a high call rate. A less urgent response to high-threat calls at a low call rate and to low-threat calls at a high call rate suggests that threat urgency information is reinforced by both call type and call rate in the herring gull system. This study is one of the first demonstrations of a risk-based alarm calling system in a nonpasserine.

The Efficiency of an Integrated Program Using Falconry to Deter Gulls from Landfills.

Simple SummaryWe evaluated the long-term effect of an intensive integrated program based on falconry to deter gulls, mostly ring-billed gulls (Larus delawarensis), from a landfill. Gulls were counted at different periods each day, and the annual sum of the maximum count at any observation period each day declined from over 1.1 million to only 20,300 during the 20 years of the study. This could not be explained by a decline in the local breeding population that remained relatively large throughout this period as determined in a concomitant study. The effectiveness of the falconry program was also confirmed by tracking individual birds fitted with GPS data loggers. The tagged gulls stopped less often and spent less time at the landfill with falconry than at another one where a selective culling program was conducted. We conclude that the use of an integrated program using falconry, which we consider more socially acceptable than culling, can be effective in deterring gulls from landfills.Gulls are commonly attracted to landfills, and managers are often required to implement cost-effective and socially accepted deterrence programs. Our objective was to evaluate the effectiveness of an intensive program that integrated the use of trained birds of prey, pyrotechnics, and playback of gull distress calls at a landfill located close to a large ring-billed gull (Larus delawarensis) colony near Montreal, Quebec, Canada. We used long-term survey data on bird use of the landfill, conducted behavioral observations of gulls during one season and tracked birds fitted with GPS data loggers. We also carried out observations at another landfill located farther from the colony, where less refuse was brought and where a limited culling program was conducted. The integrated program based on falconry resulted in a 98% decrease in the annual total number of gulls counted each day between 1995 and 2014. A separate study indicated that the local breeding population of ring-billed gulls increased and then declined during this period but remained relatively large. In 2010, there was an average (±SE) of 59 ± 15 gulls/day using the site with falconry and only 0.4% ± 0.2% of these birds were feeding. At the other site, there was an average of 347 ± 55 gulls/day and 13% ± 3% were feeding. Twenty-two gulls tracked from the colony made 41 trips towards the landfills: twenty-five percent of the trips that passed by the site with falconry resulted in a stopover that lasted 22 ± 7 min compared to 85% at the other landfill lasting 63 ± 15 min. We concluded that the integrated program using falconry, which we consider more socially acceptable than selective culling, was effective in reducing the number of gulls at the landfill.

Playback experiments for Thryothorus ludovicianus in urban backyard experiments

Acoustic playback experiments were performed from June 2014 to April 2015 for Thryothorus ludovicianus (Carolina Wren) in a backyard environment in Austin, Texas. Acoustic recordings were made for pre-playback, playback, and post-playback periods for multiple song types. The songs were obtained from recordings made in the backyard and surrounding neighborhood. Recordings of both the playback and acoustic responses of the bird subjects are made in coincidence with visual observations of the bird’s behavior. Bird behavior is quantified in terms of the statistics of closest distance of approach, latency to approach, latency to sing, number of post-playback songs, number of flybys, percent of male-female duets, temporal correlation of individual song phrases, and number of singing competitions with neighboring subjects. Statistics of the properties of the measured spectrograms and spatial correlation properties for experiments are presented, and attempts are made to interpret the observed behavior and acoustical responses of the birds in the form of communication and territorial defense with the bird’s ability to estimate distance using the degradation (transmission loss and reverberation) of the playback calls. It was also observed that Thryothorus ludovicianus will respond to playback calls of Cardinalis cardinalis (Northern Cardinal) and this interaction between bird species is examined.

Isolation rearing reveals latent antisnake behavior in California ground squirrels (Otospermophilus becheeyi) searching for predatory threats.

This study of California ground squirrels (Otospermophilus beecheyi) investigated the long-term effects of isolation rearing on alarm-call recognition. Six wild-caught squirrels, trapped as yearlings, and six laboratory-reared squirrels were maintained in solitary cages for approximately 3years prior to the study. Visual searching and olfactory searching were measured as squirrels emerged from their burrow-like nest box into a laboratory room after hearing repetitive playbacks of alarm calls or control sounds consisting of pulses of white-noise or ambient laboratory sounds. Before exiting completely after hearing alarm calls, both groups exhibited similar levels of visual searching that was reliably higher than after hearing the other sounds. After exiting completely, the laboratory-reared squirrels exhibited a reliably greater amount of olfactory investigation than the wild-caught squirrels. Five laboratory-reared squirrels turned around after exiting and inspected their dark nest-box opening, three of which tail flagged repeatedly and one threw substrate into the opening. Since pups recognize snakes and engage in this behavior, this latent expression of antisnake behavior illustrates its robust organizational properties in the appropriate burrow-like context irrespective of the presumed retardation of neural development known to occur in other species of rodent subjected to similar isolation rearing.

Variable effect of playback of chickadee mobbing calls on detection probability of boreal forest birds

Modification of the point count survey method to include playback of songbird mobbing calls in an attempt to increase detection probabilities has met with mixed success. We compared detection probabilities for boreal forest songbirds using traditional point count methods and counts using broadcasts of the mobbing calls of Black-capped Chickadees (Poecile atricapillus) in an attempt to increase detection probability. We conducted 594 point counts during the 2010 breeding season in Newfoundland, Canada. Each point count consisted of an 8-min silent observation period followed by an 8-min broadcast of Black-capped Chickadee mobbing calls. Occupancy model results showed that response to playback broadcast varied across species, with detection probabilities higher for seven of 17 species during the silent portions of point counts and three species more likely to be detected during playback intervals. For all species, the number of visual detections increased during periods of playback and, averaged across species, individuals were >6 times more likely to be seen during the playback period than during the silent period. Differences in detection probability among observers were apparent during both silent and playback periods. We suggest that using playback of chickadee mobbing calls during point count surveys of common boreal forest songbird species may be most beneficial when visual detection is important. However, playback may also be useful for species-specific surveys during periods when birds are less likely to be vocal or for studies of less common species with chronically low detection probabilities. A combined silent and playback approach could also be useful, although observer and species differences should be accounted for if comparing data across species or studies. RESUMEN. Efecto variable de las grabaciones de conducta de turbas en Poecile atricapillus, en la probabilidad de detectar aves en un bosque boreal Modificaciones en los conteos de puntos, para incluir grabaciones de llamadas de turbas, en el intento de incrementar las probabilidades de deteccide aves han tenido resultados mixtos. Comparamos la probabilidad de deteccipara aves en bosques boreales, utilizando conteos de puntos tradicionales y llamadas de turbas del Carbonero Cabecinegro (Poecile atricapillus), en un intento de incrementar la probabilidad de detecci´

Differences in short-term vocal learning in parrots, a comparative study

Parrots are renowned for their vocal learning abilities. Yet only few parrot species have been investigated and empirically proven to possess vocal learning abilities. The aim of this study was to investigate if short-term vocal learning may be a widespread phenomenon among Psittaciformes. Through an interactive experiment we compare the ability of four parrot species, the peach-fronted conure (Aratinga aurea), the cockatiel (Nymphicus hollandicus), the peach-faced lovebird (Agapornis roseicollis) and the budgerigar (Melopsittacus undulatus), to vocally match playback of contact calls. All four species made an overall change to their contact call in response to the playback, and they also varied the degree of similarity with the playback call throughout the playback experiment. The peach-fronted conure showed the biggest overall changes to their contact calls by vocally matching the playback call and the budgerigar showed the least change. The cockatiel and the peach-faced lovebird showed intermediary levels of change making their calls overall less similar to the playback call. The peach-fronted conure responded with highest similarity to familiar individuals and the cockatiel responded with an overall higher similarity to female playback stimuli. Cockatiel males and budgerigar males responded with a higher call rate to playback than female conspecifics. Peach-faced lovebirds responded fastest to unfamiliar males. Based on the results we conclude that short-term vocal learning is a widespread phenomenon among parrots. The way short-term vocal learning is used however, differs between species suggesting that short-term vocal learning have different functions in different species.

Female calling? Song responses to conspecific call playbacks in nightingales, Luscinia megarhynchos

A crucial issue for understanding the evolution, functions and mechanisms of complex communicative signals such as birdsong is to disentangle signal structures that serve to convey information in different contexts. The two main singing contexts of European male songbirds are the attraction of a female and the defence of a territory from other males. The method of choice to experimentally investigate the use of song in male–male interactions is to conduct playback studies, in which song is played to a resident male. Responses to the presence of a female, however, are hardly testable this way, since females of most European bird species do not sing. However, females do call in several situations. In a playback experiment, we investigated whether free-ranging male nightingales change their nocturnal singing in response to playbacks consisting of calls produced by either female or male conspecifics. In both cases, nightingales changed their singing style as compared to their singing before playback, and these changes were different in response to male and female calls. Males sang fewer whistle songs after male call playbacks and started to produce ‘initial whistles’ earlier when hearing female calls. Male call playbacks also led to an increase in song duration. An analysis of the call characteristics of both sexes used in the playbacks uncovered acoustic parameters that may account for the differentiated response. We conclude that male nightingales distinguish between female and male calls, and discuss the song characteristics that might be used to specifically address either males or females. Call playbacks proved to be useful for disentangling song characteristics that serve the multiple functions of birdsong. • We played female and male calls to singing nightingales. • Males changed their singing when hearing calls. • Male calls led to longer songs and fewer whistle songs. • Female calls elicited initial whistles faster. • Male and female calls differ in several acoustic parameters.

Asymmetric eavesdropping between common mynas and red-vented bulbuls

Heterospecific eavesdropping on alarm calls is well documented, but less is known about the factors influencing asymmetry in the reliability of heterospecific alarm calls. Partial overlap of predators between heterospecifics has been hypothesized as 1 possible mechanism driving asymmetric eavesdropping. We tested the responses of common mynas (Acridotheres tristis) and red-vented bulbuls (Pycnonotus cafer) to reciprocal playbacks of alarm and social calls by measuring changes from baseline in the rates of fly-bys near the speaker and in rates of singing. We found an asymmetric communication network between bulbuls and mynas: bulbuls only responded to conspecific alarm calls, whereas mynas responded to both bulbul and conspecific alarm calls. This communication asymmetry may be due to a partial overlap in predators between species. Mynas were observed to spend time in both trees and on the ground and may be susceptible to both aerial and ground predators. We observed bulbuls primarily in trees and therefore may be susceptible primarily to aerial predators. If this is the case, then the alarm calls of mynas are less reliable to bulbuls compared with the reliability of alarm calls of bulbuls to mynas. However, further studies into the predators of each species are necessary before drawing a definitive conclusion. Our study demonstrates a differential responsiveness of 1 species on the alarm calls from another species for predator information and underscores the importance in considering heterospecific communication networks in the removal of species from a community.

The presence of an audience modulates responses to familiar call stimuli in the male zebra finch forebrain.

The ability to recognize familiar individuals is crucial for establishing social relationships. The zebra finch, a highly social songbird species that forms lifelong pair bonds, uses a vocalization, the distance call, to identify its mate. However, in males, this ability depends on social conditions, requiring the presence of an audience. To evaluate whether the presence of bystanders modulates the auditory processing underlying recognition abilities, we assessed, by using a lightweight telemetry system, whether electrophysiological responses driven by familiar and unfamiliar female calls in a high-level auditory area [the caudomedial nidopallium (NCM)] were modulated by the presence of conspecific males. Males had experienced the call of their mate for several months and the call of a familiar female for several days. When they were exposed to female calls in the presence of two male conspecifics, NCM neurons showed greater responses to the playback of familiar female calls, including the mate's call, than to unfamiliar ones. In contrast, no such discrimination was observed in males when they were alone or when call-evoked responses were collected under anaesthesia. Together, these results suggest that NCM neuronal activity is profoundly influenced by social conditions, providing new evidence that the properties of NCM neurons are not simply determined by the acoustic structure of auditory stimuli. They also show that neurons in the NCM form part of a network that can be shaped by experience and that probably plays an important role in the emergence of communication sound recognition.

Heterospecific alarm call eavesdropping in nonvocal, white-bellied copper-striped skinks, Emoia cyanura

Many species benefit from listening to the vocalizations of their predators as well as the alarm vocalizations of other species. This eavesdropping is an important way to acquire information regarding predator location and threat magnitude. Previous studies have investigated lizards eavesdropping on predators, while others have studied lizards eavesdropping on alarm calls. Studies that examine lizard responses to playbacks of both predatory calls and heterospecific alarm calls are absent, even though eavesdropping may be especially important in nonvocal species. By comparing both types of calls, we can assess their relative importance to skinks and understand how skinks discriminate between these calls. We broadcast sympatric predator vocalizations and both alarm call and nonalarm social vocalizations from a nonpredatory bird (red-vented bulbul, Pycnonotus cafer) to determine whether nonvocal, white-bellied copper-striped skinks could discriminate among them. Upon hearing red-vented bulbul alarm calls, white-bellied copper-striped skinks reduced their rate of looking and increased their rate of bloating compared to a baseline period. However, they did not respond significantly to red-vented bulbul social calls or to vocalizations from potential predators. Our study is the first to look at the relative magnitude of response to playbacks of predator and heterospecific vocalizations in lizards. White-bellied copper-striped skinks most likely depend on heterospecific vocalizations for predator information because they are nonvocal and found low on the forest floor, making it harder for them to identify predators directly than through alarm calls of avian heterospecifics.

Are vocal signals used to recognize individuals during male–male competition in greater prairie-chickens (Tympanuchus cupido)?

Vocal signaling can be an important component of vertebrate communication during social interactions. If vocalizations vary among individuals but are consistent within a given individual, they may be used to discriminate among individuals. In many species, territorial males use vocalizations to discriminate between neighbors and strangers and either respond more aggressively toward strangers relative to neighbors (“dear enemy” effect) or they respond more aggressively toward neighbors relative to strangers (“nasty neighbor” effect). In the greater prairie-chicken (Tympanuchus cupido), male vocalizations are an integral part of the display males produce on leks. We investigated whether male greater prairie-chickens discriminate among familiar individuals on their own territory, familiar individuals outside their normal territory and strangers from a nearby lek. Vocal characteristics varied among males, suggesting that vocalizations may potentially be used by prairie-chickens to identify individuals. Males responded to playback of prairie-chicken calls by vocalizing at a faster rate and approaching the playback speaker, but did not vary in their response to the vocalizations based on the identity of the caller. Our results suggest that variation is present among the vocalizations of individual male greater prairie-chickens, but males do not appear to discriminate among familiar individuals and strangers based solely on their “boom” vocalizations. Greater prairie-chicken vocalization likely functions as a way of announcing that a territory is occupied and defended, but it may also serve as a way of advertising to conspecifics or as a signal that is secondary to other forms of communication.

Call playback artificially generates a temporary cultural style of high affiliation in marmosets

Cultural variation can be conceptualized in two main ways: as culture-specific qualitative differences in behavioural form, and also as quantitative variation in performance of constellations of universal behaviours (cultural style). Despite observation of both types in wild nonhuman primates, diffusion of qualitative culture has been scrutinized extensively experimentally while within-species transmission of cultural style has remained entirely unexplored. Here we investigated whether a cultural style of high affiliation could be artificially generated in a nonhuman primate ( Callithrix jacchus ), by daily playback of conspecific affiliative calls simulating nearby amicable individuals. We found that vocalization playback influenced monkeys to spend more time in affiliative behaviours outside playback hours, relative to silent playback. The effect was specific to affiliation, with no impact on other categories of affect. This change did not persist into the final phase of observation after all playbacks were complete. Findings are consistent with a temporary shift in cultural style effected through vocalization playback, supporting existence of this conception of culture in wild primates and indicating auditory social contagion as a potential diffusion mechanism. The method presented here will allow researchers to test hypotheses concerning cultural transmission of cultural style, and the underlying processes, across a range of contexts and species. • Claims of cultural style in wild primates have yet to be substantiated experimentally. • This is the first experimental study of within-species diffusion of cultural style. • Call playback influenced marmosets to increase affiliation outside playback hours. • Our findings indicate that playback initiated a temporary shift in cultural style. • Supports cultural interpretation of between-group variation in behaviour rates.