ABSTRACT
The increasing expansion of urban areas leads to the emergence of new noisy environments that can affect animal communication. Calls play a crucial role in the mating displays of anurans, and the negative impact of anthropogenic noise-induced auditory masking has been reported in several species. We investigated the acoustic variation in 96 males (nâ =â 971 calls) of the treefrog Boana pulchella across acoustically undisturbed sites and different noise conditions, associated with urban areas (URBAN) and roads (ROAD), in Central Argentina. We analyzed the effect of anthropogenic noise conditions on 6 temporal (call duration [CD], intercall interval, first and second note duration, internote interval, and call rate) and 3 spectral (dominant frequency of first and second note, frequency difference between them) call properties. The effects of temperature and size on acoustical variables were controlled. We observed differences in all call attributes among the noise conditions, except for intercall interval. Males exposed to URBAN and ROAD exhibited significant changes in CD, dominant frequency of the second note, and frequency difference between them. URBAN males had longest internote interval, while ROAD individuals displayed increased first and second note duration and call rates. Interestingly, ROAD males exhibited immediate changes in call rate in direct response to passing heavy vehicles. Our study emphasizes the impact of anthropogenic noise on the acoustic characteristics of B. pulchella calls. Understanding how animals adapt to noisy environments is crucial in mitigating the adverse effects of urbanization on their communication systems. Future investigations should explore whether the observed call adjustments are effective in avoiding or mitigating the negative consequences of anthropogenic noise on reproductive success.
ABSTRACT
Urbanization is one of the more important phenomena affecting biodiversity in the Anthropocene. Some organisms can cope with urban challenges, and changes in birds' acoustic communication have been widely studied. Although changes in the timing of the daily organization of acoustic communication have been previously reported, there is a significant gap regarding possible variations in song structure between dawn and dusk choruses. Considering that urbanization imposes different soundscapes for dawn and dusk choruses, we postulate two hypotheses: (i) there are variations in song parameters between dawn and dusk choruses, and (ii) such parameters within the city will vary in response to urban noise. We studied urban and extra-urban populations of Chiguanco Thrush in La Paz, Bolivia, measuring in dawn and dusk choruses: song length; song sound pressure level; minimum, maximum, range and dominant frequency; and the number of songs per individual. The results support our two hypotheses: there were more songs, and songs were louder and had larger band widths at dawn than at dusk in urban and extra-urban populations. Urban Chiguanco Thrushes sing less, the frequency of the entire song rises, and the amplitude increases as compared with extra-urban Chiguanco Thrushes. Understanding variations between dawn and dusk choruses could allow for a better interpretation of how some bird species cope with urban challenges.
ABSTRACT
Vocalization seems to be a viable source of signal for assessing broiler welfare. However, it may require an understanding of the birds' signals, both quantitatively and qualitatively. The delivery of calls with a specific set of acoustic features must be understood to assess the broiler's well-being. The present study aimed to analyze broiler chick vocalization through the sounds emitted during social isolation and understand what would be the flock size where the chicks present the smallest energy loss in vocalizing. The experiments were carried out during the first 3 days of growth, and during the trial, chicks received feed and water ad libitum. A total of 30 1-day-old chicks Cobb® breed were acquired at a commercial hatching unit. The birds were tested from 1 to 3 days old. A semi-anechoic chamber was used to record the vocalization with a unidirectional microphone connected to a digital recorder. We placed a group of 15 randomly chosen chicks inside the chamber and recorded the peeping sound, and the assessment was conducted four times with randomly chosen birds. We recorded the vocalization for 2 min and removed the birds sequentially stepwise until only one bird was left inside the semi-anechoic chamber. Each audio signal recorded during the 40 s was chosen randomly for signal extraction and analysis. Fast Fourier transform (FFT) was used to extract the acoustic features and the energy emitted during the vocalization. Using data mining, we compared three classification models to predict the rearing condition (classes distress and normal). The results show that birds' vocalization differed when isolated and in a group. Results also indicate that the energy spent in vocalizing varies depending on the size of the flock. When isolated, the chicks emit a high-intensity sound, "alarm call", which uses high energy. In contrast, they spent less energy when flocked in a group, indicating good well-being when the flock was 15 chicks. The weight of birds influenced the amount of signal energy. We also found that the most effective classifier model was the Random Forest, with an accuracy of 85.71%, kappa of 0.73, and cross-entropy of 0.2.
ABSTRACT
Studies show that specific vocal modulations, akin to those of infant-directed speech (IDS) and perhaps music, play a role in communicating intentions and mental states during human social interaction. Based on this, we propose a model for the evolution of musicality-the capacity to process musical information-in relation to human vocal communication. We suggest that a complex social environment, with strong social bonds, promoted the appearance of musicality-related abilities. These social bonds were not limited to those between offspring and mothers or other carers, although these may have been especially influential in view of altriciality of human infants. The model can be further tested in other species by comparing levels of sociality and complexity of vocal communication. By integrating several theories, our model presents a radically different view of musicality, not limited to specifically musical scenarios, but one in which this capacity originally evolved to aid parent-infant communication and bonding, and even today plays a role not only in music but also in IDS, as well as in some adult-directed speech contexts. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part II)'.
Subject(s)
Music , Voice , Humans , Social Change , SpeechABSTRACT
Research on within-individual modulation of vocal cues is surprisingly scarce outside of human speech. Yet, voice modulation serves diverse functions in human and nonhuman nonverbal communication, from dynamically signalling motivation and emotion, to exaggerating physical traits such as body size and masculinity, to enabling song and musicality. The diversity of anatomical, neural, cognitive and behavioural adaptations necessary for the production and perception of voice modulation make it a critical target for research on the origins and functions of acoustic communication. This diversity also implicates voice modulation in numerous disciplines and technological applications. In this two-part theme issue comprising 21 articles from leading and emerging international researchers, we highlight the multidisciplinary nature of the voice sciences. Every article addresses at least two, if not several, critical topics: (i) development and mechanisms driving vocal control and modulation; (ii) cultural and other environmental factors affecting voice modulation; (iii) evolutionary origins and adaptive functions of vocal control including cross-species comparisons; (iv) social functions and real-world consequences of voice modulation; and (v) state-of-the-art in multidisciplinary methodologies and technologies in voice modulation research. With this collection of works, we aim to facilitate cross-talk across disciplines to further stimulate the burgeoning field of voice modulation. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part I)'.
Subject(s)
Social Change , Voice , Emotions , Humans , Male , Nonverbal Communication , SpeechABSTRACT
Anuran males and females adopt different reproductive and behavioral strategies in different contexts. We investigated the reproductive ecology and territorial behavior of the treefrog Boana goiana (B. Lutz, 1968) from the Brazilian Cerrado. We hypothesized that competitor density/proximity would increase the behavioral responses of B. goiana males, and that mating would be assortative. We also tested if the number of eggs correlates with female size and if there is a trade-off between clutch size and egg size. We conducted two territoriality experiments to test the effects of male size, competitor proximity and competitor density. Larger males called more in the presence of a second male. In the second experiment, the largest males emitted more calls and the distance to the nearest male increased as resident males called more. In both experiments, the number of calls was influenced by either male size or spacing between males. Some males behaved as satellites, probably to avoid fights. Our analyses indicate that females choose males with similar sizes to their own, corroborating our hypothesis of size-assortative mating. We found no relationships between female size and clutch size/volume, and between egg size and number of eggs per clutch. We also report multiple spawning for this species. The low incidence of physical combats and the spacing pattern indicate that this species relies almost solely on calls to resolve contests, which could be explained by low motivation, or simply because males avoid combats to decrease injury risks. Thus, acoustic or even multimodal communication seems crucial for social interactions of B. goiana.(AU)
Subject(s)
Animals , Anura/physiology , Ecology , Sexual Behavior, AnimalABSTRACT
Anuran males and females adopt different reproductive and behavioral strategies in different contexts. We investigated the reproductive ecology and territorial behavior of the treefrog Boana goiana (B. Lutz, 1968) from the Brazilian Cerrado. We hypothesized that competitor density/proximity would increase the behavioral responses of B. goiana males, and that mating would be assortative. We also tested if the number of eggs correlates with female size and if there is a trade-off between clutch size and egg size. We conducted two territoriality experiments to test the effects of male size, competitor proximity and competitor density. Larger males called more in the presence of a second male. In the second experiment, the largest males emitted more calls and the distance to the nearest male increased as resident males called more. In both experiments, the number of calls was influenced by either male size or spacing between males. Some males behaved as satellites, probably to avoid fights. Our analyses indicate that females choose males with similar sizes to their own, corroborating our hypothesis of size-assortative mating. We found no relationships between female size and clutch size/volume, and between egg size and number of eggs per clutch. We also report multiple spawning for this species. The low incidence of physical combats and the spacing pattern indicate that this species relies almost solely on calls to resolve contests, which could be explained by low motivation, or simply because males avoid combats to decrease injury risks. Thus, acoustic or even multimodal communication seems crucial for social interactions of B. goiana.(AU)
Subject(s)
Animals , Arvicolinae/parasitology , Nociception/physiology , Analgesia/adverse effects , Seasons , Food ChainABSTRACT
ABSTRACT Anuran males and females adopt different reproductive and behavioral strategies in different contexts. We investigated the reproductive ecology and territorial behavior of the treefrog Boana goiana (B. Lutz, 1968) from the Brazilian Cerrado. We hypothesized that competitor density/proximity would increase the behavioral responses of B. goiana males, and that mating would be assortative. We also tested if the number of eggs correlates with female size and if there is a trade-off between clutch size and egg size. We conducted two territoriality experiments to test the effects of male size, competitor proximity and competitor density. Larger males called more in the presence of a second male. In the second experiment, the largest males emitted more calls and the distance to the nearest male increased as resident males called more. In both experiments, the number of calls was influenced by either male size or spacing between males. Some males behaved as satellites, probably to avoid fights. Our analyses indicate that females choose males with similar sizes to their own, corroborating our hypothesis of size-assortative mating. We found no relationships between female size and clutch size/volume, and between egg size and number of eggs per clutch. We also report multiple spawning for this species. The low incidence of physical combats and the spacing pattern indicate that this species relies almost solely on calls to resolve contests, which could be explained by low motivation, or simply because males avoid combats to decrease injury risks. Thus, acoustic or even multimodal communication seems crucial for social interactions of B. goiana.
ABSTRACT
26. Las señales acústicas producidas por animales pueden ser enmascaradas por el ruido del medio ambiente en que se encuentran, tanto de origen natural como antropogénico. Una especie que puede ver afectada su comunicación por el ruido medio ambiental es la rana de vidrio Hyalinobatrachium fleischmanni (Centrolenidae), porque la distribución actual de esta especie en gran parte se encuentra en ambientes urbanos con altos niveles de ruido. En este trabajo analizamos si existe una relación entre la variación de los niveles de ruido antropogénico a través de la noche y la actividad vocal (cantidad de vocalizaciones por unidad de tiempo) de H. fleischmanni, a lo largo de un gradiente de ruido urbano. El trabajo lo realizamos en tres sitios dentro del Campus Universitario Rodrigo Facio, San José, Costa Rica durante el mes de junio de 2015. Para contabilizar la actividad vocal de la especie en cada sitio instalamos grabadores programables de 17:00 a las 6:00 por dos días consecutivos cada dos semanas. De forma simultánea, cuantificamos el ruido en dB cada hora a lo largo del periodo de grabación utilizando sonómetros. Comparamos la abundancia promedio de vocalizaciones por hora contra los niveles de ruido promedio por hora y sitio utilizando modelos lineales mixtos. Nuestros resultados demuestran que, tanto el ruido como la actividad vocal de H. fleischmanni variaron a lo largo de la noche. Sin embargo, encontramos que en el sitio más ruidoso el patrón de actividad de H. fleischmanni difiere de los dos sitios menos ruidosos.El sitio menos ruidoso fue el que presento una mayor actividad vocal a lo largo de todo el periodo de muestreo. A pesar de que no se encontró una relación directa entre el nivel de ruido antropogénico y la actividad acústica de H. fleischmanni, sí observamos un efecto de los niveles de ruido en los patrones de actividad de la especie.
23. Acoustic signals produced by animals can be masked by natural or anthropogenic environmental noise. A high proportion of the current distribution of the glass-frog Hyalinobatrachium fleischmanni (Centrolenidae) overlaps with noisy urban habitats, and this may affect the species acoustic communication. In this work, we analyzed the relationship between changes in anthropogenic noise level throughout the night and the diel acoustic variation (vocalization per time) in H. fleischmanni, within three sites with different noise level. We conducted this study in three sites inside the Rodrigo Facio University Campus, San José, Costa Rica in June 2015. We used an automated recorder per site to record glass-frog vocalizations, from 17:00 to 6:00 h, during two consecutive days, every two weeks, for a month. Simultaneously, we measured the noise levels in dB each hour using a soundmeter. We used linear mixed models to compare the vocalization mean per hour against the noise levels per hour and site. Our results showed that noise levels and H. fleischmanni acoustic activity varied throughout the night. The H. fleischmanni acoustic activity at the noisier site was different from sites with lower noise levels. The highest acoustic activity was found in the less noisy site throughout the sampled period. Although we fail to found a direct relationship between noise level and H. fleischmanni acoustic activity, noise level variation affects vocal activity pattern in this species.
ABSTRACT
Anurans emit advertisement calls with the purpose of attracting mates and repelling conspecific competitors. The evolution of call traits is expected to be associated with the evolution of anatomical and behavioural traits due to the physics of call emission and transmission. The evolution of vocalizations might imply trade-offs with other energetically costly behaviours, such as parental care. Here, we investigated the association between body size, calling site, parental care and call properties (call duration, number of notes, peak frequency, frequency bandwidth and call structure) of the advertisement calls of glassfrogs (Centrolenidae)-a family of Neotropical, leaf-dwelling anurans-using phylogenetic comparative methods. We also explored the tempo and mode of evolution of these traits and compared them with those of three morphological traits associated with body size, locomotion and feeding. We generated and compiled acoustic data for 72 glassfrog species (46% of total species richness), including representatives of all genera. We found that almost all acoustic traits have significant, but generally modest, phylogenetic signal. Peak frequency of calls is significantly associated with body size, whereas call structure is significantly associated with calling site and paternal care. Thus, the evolution of body size, calling site and paternal care could constrain call evolution. The estimated disparity of acoustic traits was larger than that of morphological traits and the peak in disparity of acoustic traits generally occurred later in the evolution of glassfrogs, indicating a historically recent outset of the acoustic divergence in this clade.
Subject(s)
Anura , Biological Evolution , Body Size , Paternal Behavior , Vocalization, Animal , Acoustics , Animals , Ecosystem , MaleABSTRACT
Disturbance and advertisement calls of the Argentine croaker Umbrina canosai were recorded from coastal Uruguayan waters. Dissections indicate typical sciaenid extrinsic swimbladder muscles present exclusively in males. Disturbance calls were produced when captive U. canosai were startled, chased with a net or grabbed by the tail. Calls were unusual for sciaenids because each pulse consisted of multiple cycles. The number of cycles per pulse and dominant frequency did not change with U. canosai size, but pulse duration and interpulse interval increased. Advertisement calls were recorded from unseen choruses in the field and confirmed with captive individuals in a large tank. Advertisement calls were recorded throughout the known range of the species in Uruguay indicating a continuous belt of spawning populations. Tank recordings of the same individuals permitted explicit comparisons between the two calls. Advertisement call pulses averaged 2·4 more cycles (11·0-8·6) although pulses of both calls were basically similar as were durations and dominant frequencies. Pulse number, however, differed markedly, averaging 13·6 and 3·4 pulses for disturbance and advertisement calls respectively. Furthermore, disturbance calls were produced as a rapid series with an interpulse interval of 26-31 ms whereas advertisement call patterns were less stereotyped and ranged from <100 to 450 ms. Multicycle pulses distinguished U. canosai from other sympatric sciaenids.
Subject(s)
Perciformes/physiology , Vocalization, Animal/physiology , Acoustics , Air Sacs , Animals , Male , Muscles , Species Specificity , UruguayABSTRACT
The signaler-eavesdropper interaction has been investigated for a wide range of organisms, and although many flies feed on calling frogs, this dynamic has been addressed only poorly in the austral Neotropics. We investigated this interaction in southern Brazil using pairs of suction traps (acoustic + silent) broadcasting frog calls or an artificial white noise in ponds and streams. From 139 sessions, flies of the genera Corethrella (Corethrellidae), Forcipomyia (Ceratopogonidae) and Uranotaenia (Culicidae) were collected, including five Corethrella species, the most abundant of which was previously unknown and is formally described here. Additionally, we present the southernmost records of Corethrella lopesi, C. alticola and C. atricornis. Numbers of Forcipomyia midges and Uranotaenia mosquitoes did not differ between silent traps and traps broadcasting frog calls, and did not differ between white noise traps and adjacent silent traps. However, the number of female Corethrella was significantly higher in traps broadcasting calls of the pond-breeding frog P. aff. gracilis compared to adjacent silent traps; calls of this frog attracted the five Corethrella species and also collected significantly more female Corethrella than the white noise. By evaluating different taxa of flies and broadcasting different sounds, we demonstrated that Corethrella midges were attracted only to the acoustic cue of P. aff. gracilis calls, while Forcipomyia and Uranotaenia were captured in traps by chance. Our results suggest that female Corethrella feed on males of the common pond-breeding frog P. aff. gracilis in southern Brazil, and highlight the utility of frog call traps in revealing the diversity of Corethrella in the austral Neotropics.
Subject(s)
Anura/physiology , Diptera/classification , Feeding Behavior , Vocalization, Animal , Animals , Anura/blood , Cues , Diptera/genetics , Female , Forests , Male , Species SpecificityABSTRACT
Understanding physiological and environmental determinants of strategies of reproductive allocation is a pivotal aim in biology. Because of their high metabolic cost, properties of sexual acoustic signals may correlate with body size, temperature, and an individual's energetic state. A quantitative theory of acoustic communication, based on the metabolic scaling with temperature and mass, was recently proposed, adding to the well-reported empirical patterns. It provides quantitative predictions for frequencies, call rate, and durations. Here, we analysed the mass, temperature, and body condition scaling of spectral and temporal attributes of the advertisement call of the treefrog Hypsiboas pulchellus. Mass dependence of call frequency followed metabolic expectations (f~M (-0.25), where f is frequency and M is mass) although non-metabolic allometry could also account for the observed pattern. Temporal variables scaled inversely with mass contradicting metabolic expectations (d~M (0.25), where d is duration), supporting instead empirical patterns reported to date. Temperature was positively associated with call rate and negatively with temporal variables, which is congruent with metabolic predictions. We found no significant association between temperature and frequencies, adding to the bulk of empirical evidence. Finally, a result of particular relevance was that body condition consistently determined call characteristics, in interaction with temperature or mass. Our intraspecific study highlights that even if proximate determinants of call variability are rather well understood, the mechanisms through which they operate are proving to be more complex than previously thought. The determinants of call characteristics emerge as a key topic of research in behavioural and physiological biology, with several clear points under debate which need to be analysed on theoretical and empirical grounds.
Subject(s)
Anura , Temperature , Acoustics , Animals , Body Size , RanidaeABSTRACT
Dendropsophus nanus was described from Resistencia, Argentina. The species distribution is widespread in South America east of the Andes. Despite its wide distribution, little information about its advertisement call is available in the literature. Call descriptions from type localities are especially important for the resolution of taxonomic issues, as well as for intraspecific comparisons. Herein we describe the advertisement and the male courtship calls of D. nanus from its type locality. The advertisement call of D. nanus is composed of two types of pulsed notes, herein referred to as "note A" (long note) and "note B" (short note), both with similar dominant frequencies, but different durations. The courtship call is formed by notes that are similar to notes A of the advertisement call, but emitted at lower amplitude. Previous studies demonstrated that the complex call of Eleutherodactylus coqui and Geocrinia victoriana convey separated messages to male and female. Although several previous experiments have been conducted to assess the acoustic interactions of some species of Dendropsophus, more studies are necessary to understand the functions of the two notes of the advertisement call of D. nanus and the calls of other species of the D. microcephalus group.
Dendropsophus nanus foi descrito de Resistencia, Argentina. Essa espécie está amplamente distribuída na América do Sul a leste dos Andes. Apesar da ampla distribuição, poucas informações sobre seu canto de anúncio estão disponíveis em literatura. Descrições de cantos de localidades tipo são especialmente importantes para a resolução de problemas taxonômicos, assim como para comparações intraespecíficas. Aqui, nós descrevemos os cantos de anúncio e de corte do macho de D. nanus de sua localidade tipo. O canto de anúncio de D. nanus é composto por dois tipos de notas, aqui referidas como "notas A" (nota longa) e "notas B" (nota curta), ambas com frequência dominante similar, mas com diferenças nas durações. O canto de corte é formado por notas que são similares à nota A do canto de anúncio, mas emitidas com menor amplitude. Estudos anteriores demonstraram que os cantos complexos de Eleutherodactylus coqui e Geocrinia victoriana transmitem mensagens separadas para machos e fêmeas. Embora vários experimentos anteriores terem sido realizados a fim de avaliar as interações acústicas de algumas espécies de Dendropsophus, mais estudos são necessários para entender as funções das duas notas do canto de anúncio de D. nanus e dos cantos de outras espécies do grupo de D. microcephalus.
ABSTRACT
The study of the species complex Anastrepha fraterculus (Af complex) in Brazil is especially important in a taxonomical, evolutionary and pest management context, because there are evidences that some of them may occur in sympatry. In this review, we analyzed the main results supporting evidences that three cryptic species occur in Brazil. The taxonomical and phylogenetic relationships based on eggshell morphology, adult morphometrics, as well as cytotaxonomy and genetic differentiations are discussed. We also review available information on sexual behavior including acoustic communication of males during courtship and sexual incompatibility; and chemical signals involved in the communication between sexes, with a special focus on sex pheromones. We examined the role of long- and short-range pheromones (male-produced volatiles and cuticular hydrocarbons, respectively), their implications in sexual isolation, and their possible use for chemotaxonomic differentiation of the putative species of the Af complex.
ABSTRACT
Temperature affects nearly all biological processes, including acoustic signal production and reception. Here, we report on advertisement calls of the Puerto Rican coqui frog (Eleutherodactylus coqui) that were recorded along an altitudinal gradient and compared these with similar recordings along the same altitudinal gradient obtained 23 years earlier. We found that over this period, at any given elevation, calls exhibited both significant increases in pitch and shortening of their duration. All of the observed differences are consistent with a shift to higher elevations for the population, a well-known strategy for adapting to a rise in ambient temperature. Using independent temperature data over the same time period, we confirm a significant increase in temperature, the magnitude of which closely predicts the observed changes in the frogs' calls. Physiological responses to long-term temperature rises include reduction in individual body size and concomitantly, population biomass. These can have potentially dire consequences, as coqui frogs form an integral component of the food web in the Puerto Rican rainforest.
Subject(s)
Anura/physiology , Climate Change , Tropical Climate , Vocalization, Animal , Altitude , Animals , Puerto Rico , SeasonsABSTRACT
Recordings of cougar (Puma concolor) vocalizations are rare in the wild. We made two night recordings from the same individual. The first recording was spontaneous whereas the second was made after a playback emission (using a third party recording) allowing for comparisons. We measured the calls before and after playback stimuli using Raven software and noted that only the minimum fundamental frequency presented differences between calls. As fundamental frequency is closely related to body size, a frequency reduction may indicate territoriality engagement. Our recording seems to be the first held in the Brazilian wild. Little is known about cougar natural history and behavior, and our data suggest that acoustic communication may have an important role on the species intraspecific interactions.
Registros de vocalizações de onça-parda (Puma concolor) são raros na natureza. Fizemos uma gravação espontânea da espécie à noite, em seguida tocamos o playback com uma gravação prévia disponível em bibliografia, o que fez com que a onça-parda se aproximasse e vocalizasse, permitindo que pudéssemos gravar novamente e assim comparar. Comparamos os chamados antes e depois do estímulo do playback, usando o programa Raven, e constatamos que somente a frequência fundamental mínima apresentou diferenças entre os chamados. Como a frequência fundamental está diretamente relacionada com o tamanho corporal, uma redução neste parâmetro pode significar defesa territorial. Nossas gravações aparentemente são as primeiras realizadas na natureza no Brasil. Pouco se sabe sobre história natural e comportamento da onça parda no Brasil, e nossos dados sugerem que a comunicação acústica tem um papel importante nas interações intraespecíficas desta espécie.