Courtship Sounds Research Articles

Turning up the heat: Effects of temperature on agonistic acoustic communication in the two-spotted goby (Pomatoschistus flavescens)

Acoustic communication is linked to fitness traits in many animals, but under the current scenario of global warming, sound signals can be affected by rising temperatures, particularly in ectothermic organisms such as fishes. This study examines the effect of water temperature in acoustic communication in the two-spotted goby, Pomatoschistus flavescens. To address this, we looked at the effect of different temperatures on the acoustic features of drums produced by males during territorial defence and related it with their auditory sensitivity. We also analysed the differences in acoustic features between male agonistic drums and previously reported male courtship sounds, to better understand how acoustic communication may be affected by different temperature conditions. We recorded two-spotted goby males during territorial intrusions for 10 min at 16 °C, 19 °C, and 21 °C in the laboratory. We found that agonistic drums were shorter, had fewer pulses and shorter pulse periods at higher temperature, in contrast with the peak frequency that remained unaffected. Male agonistic and mating drums (recorded in a previous study) at 16 °C only differed in pulse period, which was higher in mating drums. Hearing thresholds obtained with Auditory Evoked Potentials at 16 °C, revealed higher sensitivity below 400 Hz, matching the main energy of agonistic and mating sounds. Our findings suggest that increasing temperature could potentially affect acoustic communication in this species by reducing the duration of agonistic drums, which might hinder effective communication. Nevertheless, the impact may not be significant as there was a good match between the best hearing sensitivity and the peak frequency range of their calls, which was not influenced by temperature. As fish and other organisms are increasingly threatened by multiple anthropogenic stressors, including warming, future research should address how changes in water temperature impact acoustic communication within a more realistic multi-stressor scenario.

Mating sounds in the two-spotted goby, Pomatoschistus flavescens: Effects of water temperature on acoustic featuresa).

Acoustic signals in teleost fishes play a fundamental role in reproduction. As fish are ectothermic animals, temperature has the potential to change their signal production and detection, with further implications for mating interactions. In this study, we describe the mating sounds made by the two-spotted goby, Pomatoschistus flavescens, for the first time and further investigate the effect of temperature on the acoustic features. Courtship sounds of 15 two-spotted goby males were recorded at three different temperatures: 16 °C, 19 °C, and 21 °C. As seen for other marine gobies, two-spotted goby produced two courtship sounds: drums and thumps. Drums showed similar acoustic features to other Pomatoschistus species already studied. Calling rates for both kinds of sound were not affected by the increases in temperature. However, pulse rate increased from 16 °C to 19 °C and stabilised between 19 °C and 21 °C, suggesting that two-spotted gobies reached their physiological limits at 19 °C. Spectral features were also affected by temperature, presenting higher values at 19 °C. Whether or not the observed changes in acoustic features with temperature lead to changes in mating remains to be addressed. Studies like the present one are fundamental to better comprehend how reproduction will be affected by global warming in soniferous fishes.

A comparison of underwater speakers for fish playback studiesa).

Acoustic playback is a key method used to determine the behavioral significance of animal sounds, including fishes. This study presents the first comparison of the acoustic quality of underwater speakers for the playback of fish sounds. Seven underwater acoustic playback systems were tested for their ability to accurately reproduce the low frequency, pulsed, courtship sounds of a small fish, Tramitichromis intermedius (Cichlidae). Results indicated that in an aquarium with low ambient noise and at low amplitude playback levels (<120 dB re 1 μPa), the Clark Synthesis speakers were the best choice for playback at moderate distances (>20 cm), and that the Electro-Voice UW30 was the best speaker for short distance (<20 cm) playback of low frequency fish sounds. However, in aquaria with higher levels of ambient noise and at higher amplitude playback levels, the Clark Synthesis speakers performed best. However, none of these speaker systems reproduced a high-fidelity quality fish sound. It is important when using underwater speakers for behavioral studies that there is a careful assessment of the played back sound and comparison to the original sound.

Acoustic innovations in courtship sounds generated by hybridization in cichlid fish

Abstract During courtship, prezygotic barriers are thought to maintain the diversity of species since differences in phenotypic traits and reproductive behaviours are likely to be involved in maintaining species boundaries. However, introgressive hybridization has been reported in many different taxa and the resulting hybrids usually possess phenotypic features, including behaviours, that are intermediate between those of the parents. The outcome of hybrids may depend on the interactions between the intrinsic viability of the hybrids, the ecological environment of the species, and the fitness of hybrids in that ecological context. In cichlids, the mechanism of hybridization is increasingly documented as an important factor in their evolutionary radiation since it may provide novel gene combinations that promote speciation and adaptive radiation by generating new transgressive phenotypes. Cichlid species are separated mostly by pre-mating isolating mechanisms. Like colour patterns, acoustic communication is involved in sexual selection, but this pattern has been much less studied and the outcome of hybridization on acoustic features has never been examined. To gain novel insights into the evolution of their acoustic communication behaviour, we performed a hybrid cross between Chindongo saulosi and Maylandia estherae. Qualitative examination of courtship showed that the three groups possess the same sequence of behaviours. However, sounds produced during courtship showed specific signatures since all three groups differ at the level of sound duration and pulse period, with both features being intermediate in hybrids in comparison to the two parent species. Colour patterns in hybrids were also different from those of the parent species. These results show that hybridization can affect at least two kinds of prezygotic barriers, which may be important in the cichlid evolutionary process. However, playback experiments are required to test the strength of these features in sexual selection.

Acoustic Playback Stimulus Experiment to Study Mating Behavioral Responses of Bactrocera cucurbitae Coquillett (Diptera: Tephritidae)

The melon fly, Bactrocera cucurbitae is serious pest attacks fruits and vegetables. The manipulation of male mating behavior that displays acoustic signals is one of the steps in the behavior-based control strategy of B. cucurbitae. The first study period determines the courtship song characteristics, frequency, and occurrence time. The recording was carried out when B. cucurbitae was mated using recording devices at 04.00–07.00 pm. The results show three sounds produced before copulation, namely, calling, courtship, and stimulating, with frequencies 274.30 ± 3.29 Hz, 284.65 ± 2.00 Hz, and 304.36 ± 1.82 Hz. B. cucurbitae courtship song began at 04.00–06.26 pm. The second study was performed to determine the effect of experimental acoustic playback stimulus on the selection of mating pairs by females. The acoustic playback stimulus is made synthetically by playback of two channels, namely, calling and courtship sounds, with frequencies of 274 and 284 Hz at a sound pressure level (SPL) of 85 dB. The experimental results of acoustic playback stimulus show that the sexual behavior of female B. cucurbitae was disrupted and marked by the decreased number of copulations during SPL is high, resulting in the overlapping calling and courtship sounds frequencies that impair signal detection.

Male acoustic display in the sand goby – Essential cue in female choice, but unaffected by supplemental feeding

Many teleost fishes use acoustic and visual signalling during courtship. Such displays may convey information about body condition. Here we experimentally altered body condition of sand goby (Pomatoschistus minutus) males to examine effects on acoustic and visual courtship and subsequent spawning decisions. Over two weeks, males fed in excess were fed daily, whereas food-deprived males were fed once a week. Females only spawned with males that produced courtship sound. However, there were no treatment effects on the occurrence of spawning and males fed in excess did not invest more in visual or acoustic courtship than food-deprived males. That said, males fed in excess built more well-covered nests, with more sand piled on top, compared to food-deprived males. Male condition measured as lipid content differed significantly between treatments. However, only males fed in excess differed in lipid content from wild caught males, indicating that in nature, males are of similar condition to males in the low condition treatment group. Apart from the importance of courtship sound, the only male or female behaviour predicting reproductive success was if male displayed in the nest opening. Males often produce courtship sounds together with a visual display in this position. A female dark-eye display did not associate with reproductive success which, together with previous results, suggest a non-ornamental function of this trait. We conclude that male courtship sounds appear to be crucial in female mate choice, but the information content of the courtship sounds and how it relates to male condition remains elusive.

Sciaenid courtship sounds correlate with juvenile appearance and abundance in the May River, South Carolina, USA

Black drum Pogonias cromis, red drum Sciaenops ocellatus, silver perch Bairdiella chrysoura, and spotted seatrout Cynoscion nebulosus belong to the family Sciaenidae and are commonly found in South Carolina (USA) estuaries. Fish within this family produce sounds that are associated with courtship behavior and spawning. By listening to estuarine soundscapes, we can identify spawning aggregations. In this study, our objectives were to investigate long-term patterns of black drum, silver perch, spotted seatrout, and red drum calling and chorusing (i.e. indicative of spawning) over a 6 yr time span; identify any shifts in seasonal sound production from one year to the next; and examine the relationship between chorusing and young-of-the-year (YOY) abundance collected through haul seines. We found that in years with warmer springs, black drum, silver perch, and spotted seatrout began chorusing earlier and had longer chorusing seasons than in the years with cooler temperatures. Inversely, cooler temperatures during late summer led to earlier and longer spawning seasons for red drum. We detected the appearance of YOY in the estuary approximately 1 mo after initiation of the chorusing season. Silver perch were the most abundant in the spring, spotted seatrout during the summer, and red drum during the fall. Additionally, we found positive correlations between chorusing and YOY abundance. In years with longer chorusing seasons, we detected higher abundance of silver perch, spotted seatrout, and red drum YOY than in the years with shorter chorusing periods. These patterns provide supporting evidence that passive acoustics can aid inmonitoring reproductive output of an estuary.

First use of acoustic calls to distinguish cryptic members of a fish species complex

AbstractAlthough molecular methods and bioacoustical analysis have been used to uncover cryptic species, the combination of both methodologies is still rare. The humbug damselfish complex, Dascyllus aruanus, is composed of at least two species with Dascyllus aruanus in the Pacific Ocean and Dascyllus abudafur in the Indian Ocean. However, genetic data suggest that additional species could be found. Therefore, we aimed to determine whether the sounds produced by different populations of fish could help to distinguish cryptic species. Recordings of chase and courtship sounds were made on humbug damselfish populations from Madagascar, Taiwan and French Polynesia. Chase sound features are more variable than courtship sounds, suggesting more constraints on courtship sounds, since they would contribute to premating isolation. Comparison between courtship sounds show the variation in acoustic features between Taiwan and Madagascar align with genetic differences, supporting that sounds could discriminate cryptic species in Teleosts. Moreover, differences in both acoustic features and genetic data are also found between Taiwan and French Polynesia, suggesting two clearly distinct populations. Consequently, the name D. emamo can be resurrected for the Polynesian humbug damselfish. External phenotype traits do not allow the distinction between populations, illustrating that only behaviour has been modified.

Underwater noise impairs social communication during aggressive and reproductive encounters

Human-generated noise pollution is of global concern, as designated by the World Health Organization ( WHO, 2011 , Burden of disease from environmental noise: Quantification of healthy life years lost in Europe. https://www.who.int/quantifying_ehimpacts/publications/e94888/en/). Increases in shipping, sonar use, pile driving, and more have all contributed to a rise in ambient underwater sound levels. Unfortunately, continuous low-intensity sounds, like shipping noise, are pervasive in shallow-shore environments where many social species live and correspond to the frequency ranges at which many fishes produce and detect acoustic stimuli. Noise has the potential to alter the sender's production of the signal, mask the signal itself (if acoustic), or change the receiver's physiology. We hypothesized that continuous tonal noise would impair social interactions and communication. To test this, we used highly social African cichlid fish, Astatotilapia burtoni, to examine inter- and intrasexual interactions that occurred in a control or noisy environment (pure tones of 100–2000 Hz). During reproductive interactions, we found that males changed the location of their courtship behaviours. Instead of producing courtship quivers (and associated sounds) immediately next to gravid females, males produced these behaviours inside their spawning shelter. This change in location decreases the likelihood of the female detecting it. Also detrimental to acoustic communication, we found that noise-exposed gravid females had lower hearing sensitivity at 100–200 Hz, a major component of male courtship sounds. In addition, males changed their visual displays during male–male territorial interactions such that they spent more time with their eyebar displayed, suggesting an increase in visual signalling. Together, these data indicate that noise may impact all three components of social communication: signal production, signal reception and the signal itself, and highlights a possible cross-modal impact of noise on visual signalling. Subtle changes to social behaviours and communication, rather than dramatic effects such as injury or mortality, are important to evaluating sublethal impacts of noise on reproductive success and species survival.

Automatic detection, classification, and quantification of sciaenid fish calls in an estuarine soundscape in the Southeast United States.

In the Southeast USA, major contributors to estuarine soundscapes are the courtship calls produced by fish species belonging to the family Sciaenidae. Long-term monitoring of sciaenid courtship sounds may be valuable in understanding reproductive phenology, but this approach produces massive acoustic datasets. With this in mind, we designed a feature-based, signal detector for sciaenid fish calls and tested the efficacy of this detector against manually reviewed data. Acoustic recorders were deployed to collect sound samples for 2 min every 20 min at four stations in the May River estuary, South Carolina, USA from February to November, 2014. Manual analysis of acoustic files revealed that four fish species, belonging to the family Sciaenidae, were the major sound producers in this estuarine soundscape, and included black drum (Pogonias cromis), silver perch (Bairdiella chrysoura), spotted seatrout (Cynoscion nebulosus), and red drum (Sciaenops ocellatus). Recorded calls served as an acoustic library of signature features that were used to create a signal detector to automatically detect, classify, and quantify the number of calls in each acoustic file. Correlation between manual and automatic detection was significant and precision varied from 61% to 100%. Automatic detection provided quantitative data on calling rates for this long-term data set. Positive temperature anomalies increased calling rates of black drum, silver perch, and spotted seatrout, while negative anomalies increased calling rates of red drum. Acoustic monitoring combined with automatic detection could be an additional or alternative method for monitoring sciaenid spawning and changes in phenology associated with climate change.

Interactions of dimorphic growth, reproductive behavior, and a size-regulated fishery: a case study using spotted seatrout Cynoscion nebulosus

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 608:233-245 (2019) - DOI: https://doi.org/10.3354/meps12795 Interactions of dimorphic growth, reproductive behavior, and a size-regulated fishery: a case study using spotted seatrout Cynoscion nebulosus Jessica Carroll1,*, Susan K. Lowerre-Barbieri1,2 1Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, Saint Petersburg, Florida 33701, USA 2University of Florida, School of Forest Resources & Conservation, Gainesville, Florida 32611, USA *Corresponding author: jessica.carroll@myfwc.com ABSTRACT: Sexual dimorphism occurs in many fishes and is expressed in a range of traits, including growth and reproductive effort. These traits can result in sex-specific fishing mortality in a size-selective fishery. Our goal was to understand the trade-offs between growth, mortality, and reproduction, for a species with sexually dimorphic growth, within a fishery context. We used gill nets and hook-and-line fishing to capture 1957 spotted seatrout Cynoscion nebulosus from Tampa Bay, Florida (USA), between 2001 and 2002. Females were significantly larger-at-age than males. This larger female size corresponded to a greater prevalence of females in the fishery, evidenced by an 8:1 ratio of females to males at harvestable size. Despite this female-biased sex ratio in the fishery, the total instantaneous mortalities (Z) between the sexes were not statistically different (female Z = 0.77 yr–1; male Z = 0.82 yr-1). We developed a conceptual model to explain the trade-offs between reproduction and growth as seen in spotted seatrout. Male reproductive effort, including greater spawning frequency and the production of courtship sounds, is hypothesized to result in lower somatic growth, as well as higher natural mortality from increased predation risk. The contrasting roles of fishing pressure on females and natural mortality in males may have important implications for population productivity and fishery management of this species. KEY WORDS: Sex-specific growth · Life history · Trade-offs · Selective harvesting · Mortality · Reproductive strategy · Sexual size dimorphism · Cynoscion nebulosus Full text in pdf format PreviousNextCite this article as: Carroll J, Lowerre-Barbieri SK (2019) Interactions of dimorphic growth, reproductive behavior, and a size-regulated fishery: a case study using spotted seatrout Cynoscion nebulosus. Mar Ecol Prog Ser 608:233-245. https://doi.org/10.3354/meps12795 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 608. Online publication date: January 03, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.

Boat noise in an estuarine soundscape – A potential risk on the acoustic communication and reproduction of soniferous fish in the May River, South Carolina

The impact of boat related noise on marine life is a subject of concern, particularly for fish species that utilize acoustic communication for spawning purposes. The goal of this study was to quantify and examine the risk of boat noise on fish acoustic communication by performing acoustic monitoring of the May River, South Carolina (USA) from February to November 2013 using DSG-Ocean recorders. The number of boats detected increased from the source to the mouth with the highest detections near the Intracoastal Waterway (ICW). Boat noise frequency ranges overlapped with courtship sounds of silver perch (Bairdiella chrysoura), black drum (Pogonias cromis), oyster toadfish (Opsanus tau), spotted seatrout (Cynoscion nebulosus), and red drum (Sciaenops ocellatus). In the May River estuary, red drum may experience the greatest risk of auditory masking because of late afternoon choruses (21% time overlap with boat noise) and only one spawning location near the noisy ICW.

Acoustic and visual courtship traits in two sympatric marine Gobiidae species – Pomatoschistus microps and Pomatoschistus minutus

Divergence in courtship traits across species can evolve as adaptations to different environments, and also through avoidance of reproductive interference and character displacement. Differences may also be explained by phylogenetic relationships. We compared different courtship traits, including male courtship sounds, in two sympatric Pomatoschistus species. Both species are characterised by having male and female courtship, and paternal care of eggs in nests under mussel shells and rocks. In addition to presenting novel observations, we reviewed the literature on courtship traits for both species and complemented it with new observations. We found that courting males of the common goby P. microps sing louder and produce sounds of shorter duration than males of the sand goby P. minutus. Furthermore, males of P. microps swim faster towards females during courtship than males of P. minutus. The eyes of P. minutus females turn black during courtship attempts, whereas this is not the case for females of P. microps. Species-specific differences in courtship sounds and behavior may lead to different susceptibility of the two species to environmental change such as noise pollution and turbidity.

Effects of temperature on sound production in the painted goby Pomatoschistus pictus

The painted goby Pomatoschistus pictus emits courtship sounds (drums) that are important in reproductive outcome. The effect of temperature (14–22°C) on courtship drum features was characterised. Pulse period (or rate) was linearly related with temperature (R2=0.83) presenting a Q10 of 2.13. Pulse period decreased by 1.95ms per 1°C and varied from 34ms to 18.6ms within the studied temperature range. Sound duration changed concomitantly from 1128ms to 658ms. Changes in sound duration were due to pulse period rather than pulse number, since the latter was not affected by temperature. Pulse duration was similarly affected by temperature, decreasing by 0.3ms per 1°C (R2=0.51, Q10=1.45) and changing from 10.0ms at 14°C to 7.5ms at 22°C. Drum emission rate, sound amplitude, fatigue and dominant frequency were also not related to temperature. The temperature effect on pulse rate likely reflects temperature-dependence of the vocal central pattern generator as observed in other animals. In contrast, shorter pulse durations likely result from temperature effects at the peripheral level of the vocal system, as muscle twitches typically shorten with rising temperatures. Because pulse rate is likely important in mate choice and conspecific recognition in fish, including P. pictus, future studies are needed to understand if temperature-related changes in pulse rate are coupled with changes in mate preference as found in insects and anurans.

Seasonal and Spatial Patterns of Fish Sound Production in the May River, South Carolina

AbstractMany fish species produce sounds that are associated with reproductive behavior, and hydrophone recordings can be used to document this behavior in soniferous fishes. We recorded the sounds produced by a fish community and determined general seasonal and spatial patterns of fish sound production in the May River, South Carolina, as a means to assess general temporal and spatial patterns of reproduction. Two‐minute sound files, temperature, salinity, and depth were recorded at 27 stations at monthly intervals along the May River in Bluffton, South Carolina, from January 2012 to December 2012. We identified species‐specific calls from Spotted Seatrout Cynoscion nebulosus, Oyster Toadfish Opsanus tau, Silver Perch Bairdiella chrysoura, Black Drum Pogonias cromis, and Red Drum Sciaenops ocellatus. General species‐specific seasonal patterns were noted; some species produced sounds within a specific time period and temperature range. Seasonally, Silver Perch, Oyster Toadfish, and Black Drum began calling in early spring and ended in May. Sound production of Spotted Seatrout began in early spring (i.e., February) and ended in early fall (i.e., end of September). The majority of Red Drum sound production occurred in August and September. Individual species had temperature‐specific ranges in which they produced sound: Silver Perch, Oyster Toadfish, and Black Drum between 21°C and 26°C; Spotted Seatrout between 22°C and 30°C; and Red Drum between 28°C and 26°C. Species‐specific spatial patterns of sound production were also observed. Fish calling rarely occurred near the source of the May River. Spotted Seatrout calls were predominately recorded at stations that displayed deep‐hole characteristics with fallen trees. Red Drum preferred deeper habitat (i.e., water depths greater than 2.7 m) at the mouth of the May River. Seasonal and spatial patterns of courtship sounds suggest that each species has specific environmental criteria that are preferred for reproduction.

Invertebrate behavior—actions or responses?

Invertebrate behavior—actions or responses?

The utility of a long‐term acoustic recording system for detecting white seabass Atractoscion nobilis spawning sounds

This study reports the use of a long-term acoustic recording system (LARS) to remotely monitor white seabass Atractoscion nobilis spawning sounds at three sites along the southern California coastline, adjacent to Camp Pendleton. On the basis of previous studies of A. nobilis sound production relative to periods of known spawning activity, LARS were set to continuously record ambient sounds for a 2 h period around sunset from April to June 2009. Acoustic analyses identified A. nobilis courtship sounds on 89, 28 and 45% of the days at the three locations, respectively. From 474 h of acoustic data, spawning-related sounds (chants) were detected on 19 occasions in 2009 with an additional 11 spawning chants recorded during a 2007 validation period. Most spawning chants occurred within 30 min of sunset during the months of May and June at a mean ±S.D. surface temperature of 18.2 ± 1.2° C. Consecutive daily spawning activity was not apparent at any sites in 2009. Atractoscion nobilis spawning chants were recorded at all three sites, suggesting that shallow rocky reefs which support kelp forests provide suitable A. nobilis spawning habitat. Results confirm the utility of passive acoustic recorders for identifying A. nobilis spawning periods and locations.

The African Cichlid Fish Astatotilapia burtoni Uses Acoustic Communication for Reproduction: Sound Production, Hearing, and Behavioral Significance

Sexual reproduction in all animals depends on effective communication between signalers and receivers. Many fish species, especially the African cichlids, are well known for their bright coloration and the importance of visual signaling during courtship and mate choice, but little is known about what role acoustic communication plays during mating and how it contributes to sexual selection in this phenotypically diverse group of vertebrates. Here we examined acoustic communication during reproduction in the social cichlid fish, Astatotilapia burtoni. We characterized the sounds and associated behaviors produced by dominant males during courtship, tested for differences in hearing ability associated with female reproductive state and male social status, and then tested the hypothesis that female mate preference is influenced by male sound production. We show that dominant males produce intentional courtship sounds in close proximity to females, and that sounds are spectrally similar to their hearing abilities. Females were 2–5-fold more sensitive to low frequency sounds in the spectral range of male courtship sounds when they were sexually-receptive compared to during the mouthbrooding parental phase. Hearing thresholds were also negatively correlated with circulating sex-steroid levels in females but positively correlated in males, suggesting a potential role for steroids in reproductive-state auditory plasticity. Behavioral experiments showed that receptive females preferred to affiliate with males that were associated with playback of courtship sounds compared to noise controls, indicating that acoustic information is likely important for female mate choice. These data show for the first time in a Tanganyikan cichlid that acoustic communication is important during reproduction as part of a multimodal signaling repertoire, and that perception of auditory information changes depending on the animal's internal physiological state. Our results highlight the importance of examining non-visual sensory modalities as potential substrates for sexual selection contributing to the incredible phenotypic diversity of African cichlid fishes.

Aeroelastic Flutter Produces Hummingbird Feather Songs

During courtship flights, males of some hummingbird species produce diverse sounds with tail feathers of varying shapes. We show that these sounds are produced by air flowing past a feather, causing it to aeroelastically flutter and generate flutter-induced sound. Scanning laser doppler vibrometery and high-speed video of individual feathers of different sizes and shapes in a wind tunnel revealed multiple vibratory modes that produce a range of acoustic frequencies and harmonic structures. Neighboring feathers can be aerodynamically coupled and flutter either at the same frequency, resulting in sympathetic vibrations that increase loudness, or at different frequencies, resulting in audible interaction frequencies. Aeroelastic flutter is intrinsic to stiff airfoils such as feathers and thus explains tonal sounds that are common in bird flight.

Acoustic, visual, and chemical signaling during courtship in an African cichlid fish.

The ability to attract and assess the quality of potential mates is critical for reproductive success, but few studies examine coincident multimodal sensory cues used for reproductive signaling within a single species. Here we examined acoustic, visual, and chemical signaling used by male African cichlid fish (Astatotilapia burtoni) during reproduction. Dominant males produced pulsed sounds in tight association with visual courtship displays where their bodies quivered vigorously in close proximity to a female. Sound production always occurred with visual courtship displays, but not all body quivers were associated with sound, which supports the hypothesis of intentional acoustic communication. Peak frequency of courtship sounds decreased with increasing male body size, possibly providing females with an honest signal of quality. Male chemical signaling, visualized as urine pulses, was higher in the presence of gravid compared to non‐gravid females, but did not occur during any specific acoustic or visual courtship displays. These data suggest that dominant males use acoustic, visual, and olfactory channels at different times during courtship possibly to convey distinct types of information such as social/dominance status, motivation to spawn, and fitness.