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Batistela, Marciela y Eliara Solange Müller. "Analysis of duet vocalizations in Myiothlypis leucoblephara (Aves, Parulidae)". Neotropical Biology and Conservation 14, n.º 2 (13 de agosto de 2019): 297–311. http://dx.doi.org/10.3897/neotropical.14.e37655.
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Bird vocalizations might be used for specific recognition, territorial defense, and reproduction. Bioacoustic studies aim to understand the production, propagation and reception of acoustic signals, and they are an important component of research on animal behavior and evolution. In this study we analyzed the sound structure of duet vocalizations in pairs of Myiothlypis leucoblephara and evaluated whether the vocal variables differ among pairs and if there are differences in temporal characteristics and frequency of duets between pairs in forest edges vs. forest interior. Vocalizations were recorded from 17 bird pairs in three remnants of Atlantic Forest in southern Brazil. Six of the bird pairs were situated at the edge of the forest remnant, and 11 were in the interior of the remnant. The duets of different pairs between forest areas showed descriptive differences in the frequency, number of notes per call, and time between issuance of calls, with the main distinguishing feature being a change in frequency of a few notes in the second part of the musical phrase. The minimum frequency of vocalization was reduced at the private area than in the other two remnants (p <0.05). The duets of birds in the forest edge and forest interior did not significantly differ in minimum or maximum frequency of phrases (p> 0.05), phrase duration (p> 0.05) or number of notes per phrase (p> 0.05). Myiothlypis leucoblephara did not show a specific pattern with respect to issue of phrases in duets, but instead showed five different patterns, which were variable among pairs. There was a sharp decline or alternation in frequency between notes in the second part of the musical phrase for recognition among pairs. Variation in vocalization among M. leucoblephara duets may play a role in pair recognition.
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Divyapriya, Chandrasekaran y Padmanabhan Pramod. "Ornithophony in the soundscape of Anaikatty Hills, Coimbatore, Tamil Nadu, India". Journal of Threatened Taxa 11, n.º 12 (26 de septiembre de 2019): 14471–83. http://dx.doi.org/10.11609/jott.4948.11.12.14471-14483.
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An attempt has been made to understand the extent of ornithophony (vocalization of birds) in the soundscape of Anaikatty Hills. The study was limited to 13 hours of daylight from dawn to dusk (06.00–19.00 h) between January 2015 and October 2016. Six replicates of 5-minute bird call recordings were collected from each hour window in 24 recording spots of the study area. Each 5-minute recording was divided into 150 ‘2-sec’ observation units for the detailed analysis of the soundscape. A total of 78 recordings amounting to 390 minutes of acoustic data allowed a preliminary analysis of the ornithophony of the area. A total of 62 bird species were heard vocalizing during the study period and contributed 8,629 units. A total of 73.75% acoustic space was occupied by birds, among which the eight dominant species alone contributed to 63.65% of ornithophony. The remaining 26% of acoustic space was occupied by other biophonies (12.60%), geophony (5.57%), indistinct sounds (7.66%), and anthropogenic noise (0.41%). Passerines dominated the vocalizations with 7,269 (84.24%) and non-passerines with 1,360 (15.76%) units. Birds vocalized in all 13 observation windows, with a peak in the first three hours of the day (06.00–09.00 h). Vocalizations of non-passerines were prominent in the dusk hours (18.00–19.00 h).
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Raposo, Marcos A. y Elizabeth Höfling. "Overestimation of vocal characters in Suboscine taxonomy (Aves: Passeriformes: Tyranni): causes and implications". Lundiana: International Journal of Biodiversity 4, n.º 1 (2 de diciembre de 2022): 35–42. http://dx.doi.org/10.35699/2675-5327.2003.21833.
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The difference in treatment of vocal features in Oscines and Suboscines passerine birds characterizes a large portion of the current studies on their taxonomy. In the former taxon, vocalization is supposed to be molded by learning, and consequently is not regarded as taxonomically informative. In the latter, a strong emphasis is given to vocalization because it supposedly reflects the genetic structure of populations. This paper reviews the various assumptions related to this difference in treatment, including the overestimation of the vocal characters in suboscine alpha taxonomy due to the alleged importance of vocalization under the framework of the species mate recognition system. The innate origin of suboscine vocalizations remains to be rigorously demonstrated and the use of vocalization as “super-characters” is prejudicial to bird taxonomy. Despite the possibility of being learned, vocalization should also be used in the taxonomic studies of oscine passerines.
Keywords: Vocalization, Oscines, Suboscines, Birds, Passeriformes
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Abdel-Kafy, El-Sayed M., Samya E. Ibraheim, Alberto Finzi, Sabbah F. Youssef, Fatma M. Behiry y Giorgio Provolo. "Sound Analysis to Predict the Growth of Turkeys". Animals 10, n.º 5 (17 de mayo de 2020): 866. http://dx.doi.org/10.3390/ani10050866.
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Protocols for manual weighing of turkeys are not practical on turkey farms because of the large body sizes, heavy weights and flighty nature of turkeys. The sounds turkeys make may be a proxy for bird weights, but the relationship between turkey sounds and bird weights has not been studied. The aim of this study was to correlate peak frequency (PF) of vocalization with the age and weight of the bird and examine the possibility using PF to predict the weight of turkeys. The study consisted of four trials in Egypt. Sounds of birds and their weights were recorded for 11 days during the growth period in each trial. A total 2200 sounds were manually analyzed and labelled by extracting individual and general sounds on the basis of the amplitude and frequency of the sound signal. The PF of vocalizations in each trial, as well as in pooled trails, were evaluated to determine the relationship between PF and the age and weight of the turkey. PF exhibited a highly significant negative correlation with the weight and age of the turkeys showing that PF of vocalizations can be used for predicting the weight of turkeys. Further studies are necessary to refine the procedure.
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Monteiro, Ronan de Azevedo, Carolina Demetrio Ferreira y Gilmar Perbiche-Neves. "Vocal repertoire and group-specific signature in the Smooth-billed Ani, Crotophaga ani Linnaeus, 1758 (Cuculiformes, Aves)". Papéis Avulsos de Zoologia 61 (30 de julio de 2021): e20216159. http://dx.doi.org/10.11606/1807-0205/2021.61.59.
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Vocal plasticity reflects the ability of animals to vary vocalizations according to context (vocal repertoire) as well as to develop vocal convergence (vocal group signature) in the interaction of members in social groups. This feature has been largely reported for oscine, psittacine and trochilid birds, but little has been investigated in birds that present innate vocalization. The smooth-billed ani (Crotophaga ani) is a social bird that lives in groups between two and twenty individuals, and which presents innate vocalization. Here we analyzed the vocal repertoire of this species during group activities, and further investigated the existence of a vocal group signature. The study was conducted in the Southeast of Brazil between May 2017 and April 2018. Two groups of smooth-billed anis were followed, Guararema and Charqueada groups, and their vocalizations were recorded and contextualized as to the performed behavior. The vocal repertoire was analyzed for its composition, context and acoustic variables. The acoustic parameters maximum peak frequency, maximum fundamental frequency, minimum frequency, maximum frequency and duration were analyzed. To verify the vocal signature of the group, we tested whether there was variation in the acoustic parameters between the monitored groups. We recorded ten vocalizations that constituted the vocal repertoire of the Smooth-billed Ani, five of which (“Ahnee”, “Whine”, “Pre-flight”, “Flight” and “Vigil”) were issued by the two groups and five exclusive to the Charqueada group. There were significant differences in the acoustic parameters for “Flight” and “Vigil” vocalizations between the groups, suggesting vocal group signature for these sounds. We established that the Smooth-billed Ani has a diverse vocal repertoire, with variations also occurring between groups of the same population. Moreover, we found evidence of vocal group signature in vocalizations used in the context of cohesion, defense and territory maintenance.
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Arato, Jozsef y W. Tecumseh Fitch. "Phylogenetic signal in the vocalizations of vocal learning and vocal non-learning birds". Philosophical Transactions of the Royal Society B: Biological Sciences 376, n.º 1836 (6 de septiembre de 2021): 20200241. http://dx.doi.org/10.1098/rstb.2020.0241.
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Some animal vocalizations develop reliably in the absence of relevant experience, but an intriguing subset of animal vocalizations is learned: they require acoustic models during ontogeny in order to develop, and the learner's vocal output reflects those models. To what extent do such learned vocalizations reflect phylogeny? We compared the degree to which phylogenetic signal is present in vocal signals from a wide taxonomic range of birds, including both vocal learners (songbirds) and vocal non-learners. We used publically available molecular phylogenies and developed methods to analyse spectral and temporal features in a carefully curated collection of high-quality recordings of bird songs and bird calls, to yield acoustic distance measures. Our methods were initially developed using pairs of closely related North American and European bird species, and then applied to a non-overlapping random stratified sample of European birds. We found strong similarity in acoustic and genetic distances, which manifested itself as a significant phylogenetic signal, in both samples. In songbirds, both learned song and (mostly) unlearned calls allowed reconstruction of phylogenetic trees nearly isomorphic to the phylogenetic trees derived from genetic analysis. We conclude that phylogeny and inheritance constrain vocal structure to a surprising degree, even in learned birdsong. This article is part of the theme issue ‘Vocal learning in animals and humans’.
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Czyżowski, Piotr, Sławomir Beeger, Mariusz Wójcik, Dorota Jarmoszczuk, Mirosław Karpiński y Marian Flis. "Analysis of the Territorial Vocalization of the Pheasants Phasianus colchicus". Animals 12, n.º 22 (19 de noviembre de 2022): 3209. http://dx.doi.org/10.3390/ani12223209.
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The aim of the study was to assess the impact of the duration of the mating season and the time of day on the parameters of the vocalization pheasants (duration of vocalization, frequency of the sound wave, intervals between vocalizations). In the study, pheasant vocalization recorded in the morning (600–800) and in the afternoon (1600–1800) between April and June 2020 was analyzed. In total, the research material consisted of 258 separate vocalizations. After recognition of the individual songs of each bird, frequency-time indicators were collected from the samples to perform statistical analysis of the recorded sounds. The duration of the first syllable [s], the duration of the second syllable [s], the duration of the pause between the syllables [s], the intervals between successive vocalizations [min], and the peak frequency of the syllables I and II [Hz] were specified for each song. The duration of the syllables and the pauses between the syllables and vocalizations were determined through evaluation of spectrograms. The peak amplitude frequencies of the syllables were determined via time-frequency STFT analysis. Statistically significant differences in the distributions of the values of all variables between the analyzed months were demonstrated. The longest duration of total vocalization and the shortest time between vocalizations were recorded in May. Therefore, this month is characterized by the highest frequency and longest duration of vocalization, which is related to the peak of the reproductive period. The time of day was found to exert a significant effect on all variables except the duration of syllable II. The duration of vocalization was significantly shorter in the morning, which indicates that the cooks are more active at this time of day in the study area. The highest peak amplitude frequencies of both syllables were recorded in April, but they decreased in the subsequent months of observation. The time of day was also shown to have an impact on the peak amplitude frequencies, which had the highest values in the morning.
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Pedroza, Angel David, José I. De la Rosa, Rogelio Rosas, Aldonso Becerra, Jesús Villa, Gamaliel Moreno, Efrén González y Daniel Alaniz. "Acoustic Individual Identification in Birds Based on the Band-Limited Phase-Only Correlation Function". Applied Sciences 10, n.º 7 (31 de marzo de 2020): 2382. http://dx.doi.org/10.3390/app10072382.
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A new technique based on the Band-Limited Phase-Only Correlation (BLPOC) function to deal with acoustic individual identification is proposed in this paper. This is a biometric technique suitable for limited data individual bird identification. The main advantage of this new technique, in contrast to traditional algorithms where the use of large-scale datasets is assumed, is its ability to identify individuals by the use of only two samples from the bird species. The proposed technique has two variants (depending on the method used to analyze and extract the bird vocalization from records): automatic individual verification algorithm and semi-automatic individual verification algorithm. The evaluation of the automatic algorithm shows an average precision that is over 80% for the identification comparatives. It is shown that the efficiencies of the algorithms depend on the complexity of the vocalizations.
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Larsen, O. N. y F. Gollerf. "Role of syringeal vibrations in bird vocalizations". Proceedings of the Royal Society of London. Series B: Biological Sciences 266, n.º 1429 (22 de agosto de 1999): 1609–15. http://dx.doi.org/10.1098/rspb.1999.0822.
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Blumstein, Daniel T. "The evolution of functionally referential alarm communication". Evolution of Communication 3, n.º 2 (31 de diciembre de 1999): 135–47. http://dx.doi.org/10.1075/eoc.3.2.03blu.
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Many species produce specific alarm vocalizations when they encounter predators. There is considerable interest in the degree to which bird, ground-dwelling sciurid rodent, and primate alarm calls denote the species or type of predator that elicited the vocalization. When there is a tight association between the type or species of predator eliciting an alarm call, and when a played-back alarm call elicits antipredator responses qualitatively similar to those seen when individuals personally encounter a predator, the alarm calls are said to be functionally referential. In this essay I aim to make two simple points about the evolution of functionally referential alarm communication. Firstly, functionally referential communication is likely to be present only when a species produces acoustically distinct alarm vocalizations. Thus, to understand its evolution we must study factors that influence the evolution of alarm call repertoire size. Secondly, and potentially decoupled from the ability to produce acoustically distinctive alarm vocalizations, species must have the perceptual and motor abilities to respond differently to acoustically-distinct alarm vocalizations. Thus, to understand the evolution of functionally referential communication we also must study factors that influence the evolution of context-independent perception. While some factors may select for functionally referential alarm communication, constraints on production or perception may prevent its evolution.
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Pepperberg, Irene M. "Referential mapping: A technique for attaching functional significance to the innovative utterances of an African Grey parrot (Psittacus erithacus)". Applied Psycholinguistics 11, n.º 1 (marzo de 1990): 23–44. http://dx.doi.org/10.1017/s0142716400008274.
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ABSTRACTA set of procedures called referential mapping has been used to assign meaning to spontaneous vocalizations of an African Grey parrot. These spontaneous vocalizations were combinations and phonological variations of specific vocal English labels that the bird had previously acquired in a study on interspecies communication. These recombinations were not necessarily intentionally used to describe or request novel objects or circumstances, even though our earlier data demonstrated that the bird could use vocalizations referentially and intentionally to identify, request, refuse, and categorize various objects. The procedures for dealing with this bird's spontaneous modifications neither attempted to nor needed to evaluate the intentionality of his behavior. Rather, the procedures instructed his trainers to respond to the novel speech acts as though he were intentionally commenting about or requesting objects, actions, or information. The success of such procedures in attaching functional significance to his spontaneous vocalizations and in encouraging subsequent innovation suggests that the technique might be applicable to intervention programs for humans with specific communicative deficits.
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Zhao, Yilin, Jingli Yan, Jiali Jin, Zhenkai Sun, Luqin Yin, Zitong Bai y Cheng Wang. "Diversity Monitoring of Coexisting Birds in Urban Forests by Integrating Spectrograms and Object-Based Image Analysis". Forests 13, n.º 2 (8 de febrero de 2022): 264. http://dx.doi.org/10.3390/f13020264.
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In the context of rapid urbanization, urban foresters are actively seeking management monitoring programs that address the challenges of urban biodiversity loss. Passive acoustic monitoring (PAM) has attracted attention because it allows for the collection of data passively, objectively, and continuously across large areas and for extended periods. However, it continues to be a difficult subject due to the massive amount of information that audio recordings contain. Most existing automated analysis methods have limitations in their application in urban areas, with unclear ecological relevance and efficacy. To better support urban forest biodiversity monitoring, we present a novel methodology for automatically extracting bird vocalizations from spectrograms of field audio recordings, integrating object-based classification. We applied this approach to acoustic data from an urban forest in Beijing and achieved an accuracy of 93.55% (±4.78%) in vocalization recognition while requiring less than ⅛ of the time needed for traditional inspection. The difference in efficiency would become more significant as the data size increases because object-based classification allows for batch processing of spectrograms. Using the extracted vocalizations, a series of acoustic and morphological features of bird-vocalization syllables (syllable feature metrics, SFMs) could be calculated to better quantify acoustic events and describe the soundscape. A significant correlation between the SFMs and biodiversity indices was found, with 57% of the variance in species richness, 41% in Shannon’s diversity index and 38% in Simpson’s diversity index being explained by SFMs. Therefore, our proposed method provides an effective complementary tool to existing automated methods for long-term urban forest biodiversity monitoring and conservation.
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Parra-Hernández, Ronald M., Jorge I. Posada-Quintero, Orlando Acevedo-Charry y Hugo F. Posada-Quintero. "Uniform Manifold Approximation and Projection for Clustering Taxa through Vocalizations in a Neotropical Passerine (Rough-Legged Tyrannulet, Phyllomyias burmeisteri)". Animals 10, n.º 8 (12 de agosto de 2020): 1406. http://dx.doi.org/10.3390/ani10081406.
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Vocalizations from birds are a fruitful source of information for the classification of species. However, currently used analyses are ineffective to determine the taxonomic status of some groups. To provide a clearer grouping of taxa for such bird species from the analysis of vocalizations, more sensitive techniques are required. In this study, we have evaluated the sensitivity of the Uniform Manifold Approximation and Projection (UMAP) technique for grouping the vocalizations of individuals of the Rough-legged Tyrannulet Phyllomyias burmeisteri complex. Although the existence of two taxonomic groups has been suggested by some studies, the species has presented taxonomic difficulties in classification in previous studies. UMAP exhibited a clearer separation of groups than previously used dimensionality-reduction techniques (i.e., principal component analysis), as it was able to effectively identify the two taxa groups. The results achieved with UMAP in this study suggest that the technique can be useful in the analysis of species with complex in taxonomy through vocalizations data as a complementary tool including behavioral traits such as acoustic communication.
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O’Reilly, Colm, Naomi Harte y Hynek Burda. "Pitch tracking of bird vocalizations and an automated process using YIN-bird". Cogent Biology 3, n.º 1 (1 de enero de 2017): 1322025. http://dx.doi.org/10.1080/23312025.2017.1322025.
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HORNE, JENNIFER F. M. y LESTER L. SHORT. "AFROTROPICAL BIRD VOCALIZATIONS: A REVIEW OF CURRENT PROBLEMS". Bioacoustics 1, n.º 2-3 (enero de 1988): 159–70. http://dx.doi.org/10.1080/09524622.1988.9753089.
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Moura, Daniella Jorge de, Irenilza de Alencar Nääs, Elaine Cangussu de Souza Alves, Thayla Morandi Ridolfi de Carvalho, Marcos Martinez do Vale y Karla Andrea Oliveira de Lima. "Noise analysis to evaluate chick thermal comfort". Scientia Agricola 65, n.º 4 (2008): 438–43. http://dx.doi.org/10.1590/s0103-90162008000400018.
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The relationship between thermal environment and chick performance has widely been evaluated, however the consideration that the assessment of the comfort may be estimated by interpreting both amplitude and frequency of bird vocalization under tropical housing conditions is a new concept. This research had as objective of estimating thermal comfort for chicks during the heating phase using this new concept. An experiment was carried out inside a climate controlled chamber (A) for establishing the behavioral pattern related to environmental temperature limits. Forty five chicks were reared inside a 2.3 m² box. A video camera was placed 2.0 m above the birds and the images were captured and registered in a computer. From the pattern determined in the controlled chamber an evaluation of the results was proceeded in a commercial broiler farm (experiment B) using similar bird density in order to validate the data. Environmental temperature, and both amplitude and frequency of the vocalizations of the chick group reared under heating were continuously recorded in both experiments. A correlation between group behavioral pattern and their vocalization, was found, evaluated not only by the noise amplitude but also by the noise frequency spectrum. When the thermal inertia is maintained by adequate use of curtains the birds vocalized less which is coincident with the low sudden variation of the temperature of the environmental. It was possible to estimate the thermal comfort for chicks at the heating stage by recording the amplitude and the frequency of the noise emitted by the reared group.
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Blumstein, Daniel T., Douglas R. Mcclain, Carrie De Jesus y Gustavo Alarcón-Nieto. "Breeding bird density does not drive vocal individuality". Current Zoology 58, n.º 5 (1 de octubre de 2012): 765–72. http://dx.doi.org/10.1093/czoolo/58.5.765.
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Abstract Many species produce individually specific vocalizations and sociality is a hypothesized driver of such individuality. Previous studies of how social variation influenced individuality focused on colonial or non-colonial avian species, and how social group size influenced individuality in sciurid rodents. Since sociality is an important driver of individuality, we expected that bird species that defend nesting territories in higher density neighborhoods should have more individually-distinctive calls than those that defend nesting territories in lower-density neighborhoods. We used Beecher’s information statistic to quantify individuality, and we examined the relationship between bird density (calculated with point-counts) and vocal individuality on seven species of passerines. We found non-significant relationships between breeding bird density and vocal individuality whether regressions were fitted on species values, or on phylogenetically-independent contrast values. From these results, we infer that while individuality may be explained by social factors, breeding bird density is unlikely to be generally important in driving the evolution of individually-specific vocalizations.
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Schieck, Jim. "Biased Detection of Bird Vocalizations Affects Comparisons of Bird Abundance among Forested Habitats". Condor 99, n.º 1 (febrero de 1997): 179–90. http://dx.doi.org/10.2307/1370236.
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Wolfgang, Andrew y Aaron Haines. "Testing Automated Call-Recognition Software for Winter Bird Vocalizations". Northeastern Naturalist 23, n.º 2 (junio de 2016): 249–58. http://dx.doi.org/10.1656/045.023.0206.
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Okanoya, Kazuo y Robert J. Dooling. "Auditory filter simulations for perceptual processes of bird vocalizations". Neural Networks 1 (enero de 1988): 313. http://dx.doi.org/10.1016/0893-6080(88)90344-9.
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Pereira, Erica M., Irenilza de A. Nääs y Rodrigo G. Garcia. "Identification of acoustic parameters for broiler welfare estimate". Engenharia Agrícola 34, n.º 3 (junio de 2014): 413–21. http://dx.doi.org/10.1590/s0100-69162014000300004.
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Estimates of broiler welfare have subjective character. Nowadays, researchers seek non-invasive features or indicators that may describe this condition in animal production. The aim of this study was to identify acoustic parameters to estimate broiler welfare using the following five vocalization acoustic parameters: energy, spectral centroid, bandwidth, first formant, and second formant. The database that generated the model was obtained from a field experiment with 432 broilers, which half were Cobb® and half, Ross® breed, from day 21 to 42, containing bird vocalizations under either welfare or stress conditions. The results of the experiment generated responses to the tested conditions of gender, genetic strain, and welfare. The proposed model was based on the specific response of mean weights for each situation of stress and well-being. From the results, a model was developed to estimate the welfare condition of broilers from the registered information linked to their vocalization.
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Noakes, David L. G. y Jeffrey D. Noakes. "A note on bird song: Samuel Hearne’s observations on the Snow Bunting (Plectrophenax nivalis)". Canadian Field-Naturalist 128, n.º 3 (16 de octubre de 2014): 269. http://dx.doi.org/10.22621/cfn.v128i3.1606.
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In 1795, the Arctic explorer Samuel Hearne recorded detailed observations on the distribution, ecology, molt, and behaviour of the Snow Bunting (Plectrophenax nivalis). The most significant of his observations was that Snow Buntings imitated the vocalizations of Atlantic Canaries (Serinus canarius) when housed with that species. His account has apparently not been widely recognized by ornithologists, but it is one of the first such observations on bird’s acquisition of vocalizations.
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Nicol, C. J. y S. J. Pope. "A Comparison of the Behaviour of Solitary and Group-Housed Budgerigars". Animal Welfare 2, n.º 3 (agosto de 1993): 269–77. http://dx.doi.org/10.1017/s0962728600015918.
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AbstractA comparison was made of the behaviour of budgerigars housed singly in commercially available cages obtained from a pet supplier, and budgerigars housed in a group of six in a small aviary. Budgerigars housed in the aviary consumed significantly more food and were more active, performing more wing stretching and flying. Caged budgerigars performed significantly more vocalizations. When tested individually, aviary birds were more active in a novel test chamber and were significantly more likely to approach an unfamiliar bird. Cage birds were generally reluctant to approach an unfamiliar bird, but showed an increasing tendency to approach when allowed a longer period of familiarization. Pet budgerigars are commonly housed in isolation from conspecifics, with little consideration of potential effects on welfare. The aim of this study was to provide some initial information about the effects of social isolation on the behaviour of budgerigars.
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Kershenbaum, Arik, Amiyaal Ilany, Leon Blaustein y Eli Geffen. "Syntactic structure and geographical dialects in the songs of male rock hyraxes". Proceedings of the Royal Society B: Biological Sciences 279, n.º 1740 (18 de abril de 2012): 2974–81. http://dx.doi.org/10.1098/rspb.2012.0322.
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Few mammalian species produce vocalizations that are as richly structured as bird songs, and this greatly restricts the capacity for information transfer. Syntactically complex mammalian vocalizations have been previously studied only in primates, cetaceans and bats. We provide evidence of complex syntactic vocalizations in a small social mammal: the rock hyrax ( Procavia capensis : Hyracoidea). We adopted three algorithms, commonly used in genetic sequence analysis and information theory, to examine the order of syllables in hyrax calls. Syntactic dialects exist, and the syntax of hyrax calls is significantly different between different regions in Israel. Call syntax difference is positively correlated to geographical distance over short distances. No correlation is found over long distances, which may reflect limited dispersal movement. These findings indicate that rich syntactic structure is more common in the vocalizations of mammalian taxa than previously thought and suggest the possibility of vocal production learning in the hyrax.
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Sumitani, Shinji, Reiji Suzuki, Takaya Arita, Kazuhiro Nakadai y Hiroshi G. Okuno. "Non-Invasive Monitoring of the Spatio-Temporal Dynamics of Vocalizations among Songbirds in a Semi Free-Flight Environment Using Robot Audition Techniques". Birds 2, n.º 2 (21 de abril de 2021): 158–72. http://dx.doi.org/10.3390/birds2020012.
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To understand the social interactions among songbirds, extracting the timing, position, and acoustic properties of their vocalizations is essential. We propose a framework for automatic and fine-scale extraction of spatial-spectral-temporal patterns of bird vocalizations in a densely populated environment. For this purpose, we used robot audition techniques to integrate information (i.e., the timing, direction of arrival, and separated sound of localized sources) from multiple microphone arrays (array of arrays) deployed in an environment, which is non-invasive. As a proof of concept of this framework, we examined the ability of the method to extract active vocalizations of multiple Zebra Finches in an outdoor mesh tent as a realistic situation in which they could fly and vocalize freely. We found that localization results of vocalizations reflected the arrangements of landmark spots in the environment such as nests or perches and some vocalizations were localized at non-landmark positions. We also classified their vocalizations as either songs or calls by using a simple method based on the tempo and length of the separated sounds, as an example of the use of the information obtained from the framework. Our proposed approach has great potential to understand their social interactions and the semantics or functions of their vocalizations considering the spatial relationships, although detailed understanding of the interaction would require analysis of more long-term recordings.
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Deneva, Prolet y Todor Ganchev. "GMM-Based Parameterization of the Characteristic Melody of Bird Vocalizations". Geometry Integrability and Quantization 21 (2020): 118–26. http://dx.doi.org/10.7546/giq-21-2020-118-126.
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Sandoval, Luis. "Transmission properties of vocalizations in a year-round territorial bird". Journal of the Acoustical Society of America 138, n.º 3 (septiembre de 2015): 1903. http://dx.doi.org/10.1121/1.4933982.
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Narins, Peter M., Albert S. Feng, Wenyu Lin, Hans-Ulrich Schnitzler, Annette Denzinger, Roderick A. Suthers y Chunhe Xu. "Old World frog and bird vocalizations contain prominent ultrasonic harmonics". Journal of the Acoustical Society of America 115, n.º 2 (febrero de 2004): 910–13. http://dx.doi.org/10.1121/1.1636851.
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Chen, Zhixin y Robert C. Maher. "Semi-automatic classification of bird vocalizations using spectral peak tracks". Journal of the Acoustical Society of America 120, n.º 5 (noviembre de 2006): 2974–84. http://dx.doi.org/10.1121/1.2345831.
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Branfield, Andy. "Vocalizations of European Honey Buzzards (Pernis apivorus) in Southern Africa". Afrotropical Bird Biology: Journal of the Natural History of African Birds 1, n.º 1 (13 de diciembre de 2021): 1–6. http://dx.doi.org/10.15641/abb.v1i.1068.
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Contrary to some sources, the European Honey Buzzard is not silent in Africa. This study documents 51 records of the species vocalizing on the continent. Vocalizations were given by birds apparently encountered alone (n=30) and when accompanied by another European Honey Buzzard (n=22). Where age was known, 11 calling birds were adults and ten were juveniles. Where details were available, most calls were given by birds in flight (n=30), with 11 from perched birds and two from birds heard calling while both in flight and perched. In most cases the sex of the bird was not recorded (n=42) and young birds (first- and second-years) are difficult to sex with certainty; of the remainder, two were males and nine were females. Most calls were the typical flight call of the species (n=43), with apparent alarm calls (n=7) the next most frequent call type. Most calls were delivered in flight (n=31), 19 by single birds and 12 by two birds together in flight. The calling by two birds was associated with flight displays similar to those described on the breeding grounds and occurred especially in late summer (December onwards; 25/40 records). A relatively high proportion of calls occurred during interactions between two European Honey Buzzards (n=18). Calling associated with two birds together and accompanied by aerial displays has not been described in Africa before, and is suggestive of either early pairing of the adult birds prior to migration or breeding activity locally in Africa. Vocalizations between young birds though may be more social as opposed to sexual in nature. The large (5X) increase in records of European Honey Buzzards in South Africa in recent years likely increases the chances of conspecific interaction. It also raises the possibility of breeding, especially in more-temperate South Africa.
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Duque, F. G., C. A. Rodriguez-Saltos, S. Uma, I. Nasir, M. F. Monteros, W. Wilczynski y L. L. Carruth. "High-frequency hearing in a hummingbird". Science Advances 6, n.º 29 (julio de 2020): eabb9393. http://dx.doi.org/10.1126/sciadv.abb9393.
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Some hummingbirds produce unique high-frequency vocalizations. It remains unknown whether these hummingbirds can hear these sounds, which are produced at frequencies beyond the range at which most birds can hear. Here, we show behavioral and neural evidence of high-frequency hearing in a hummingbird, the Ecuadorian Hillstar (Oreotrochilus chimborazo). In the field, hummingbirds responded to playback of high-frequency song with changes in body posture and approaching behavior. We assessed neural activation by inducing ZENK expression in the brain auditory areas in response to the high-frequency song. We found higher ZENK expression in the auditory regions of hummingbirds exposed to the high-frequency song compared to controls, while no difference was observed in the hippocampus between groups. The behavioral and neural responses show that this hummingbird can hear sounds at high frequencies. This is the first evidence of the use of high-frequency vocalizations and high-frequency hearing in conspecific communication in a bird.
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Baklová, Aneta, Eva Baranyiová y Hana Šimánková. "Antipredator behaviour of domestic guinea pigs (Cavia porcellus)". Acta Veterinaria Brno 85, n.º 3 (2016): 293–301. http://dx.doi.org/10.2754/avb201685030293.
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The objective of this study was to test the reactions of domestic guinea pigs to the presence of aerial and terrestrial predators in a laboratory setting. We measured the behavioural reactions of 27 adolescent guinea pigs to the presence of a dog, imitation of a bird of prey and an unknown human as control. Kruskal-Wallis ANOVA and Mann-Whitney U Test were used to analyse the differences in duration and frequency of responses (freezing, fleeing, and vigilance) to predators. When confronted with the dog, guinea pigs reacted for the longest time and most frequently by freezing. In presence of the bird of prey, they responded for the longest time and most often by freezing and fleeing. In presence of a human, they showed mostly vigilance. When comparing reactions to the dog and human, there were differences in duration and frequency of freezing and fleeing. When comparing reactions to the bird of prey and control test, we observed differences between fleeing and vigilance. The durations and frequencies of freezing, fleeing and vigilance to the dog and bird of prey were different. The only differences in reactions of males and females occurred in duration and frequency of fleeing in presence of the bird of prey. No vocalization was observed except for two occurrences, of a “drrr” and a “chirrup”. Our results indicate that domestic guinea pigs tested under laboratory conditions can discriminate between a terrestrial and an aerial predator, when exposed to them individually. Their antipredator behaviours remained functional, although their vocalizations may have been affected by the absence of signal receivers.
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Bhama, Prabhat K., Allen D. Hillel, Albert L. Merati y David Perkel. "Model for Examining Recovery of Phonation after Nerve Damage". Otolaryngology–Head and Neck Surgery 139, n.º 2_suppl (agosto de 2008): P97. http://dx.doi.org/10.1016/j.otohns.2008.05.512.
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Problem Recurrent laryngeal nerve injury remains a dominant clinical issue in laryngology. To date, no animal model of laryngeal reinnervation has offered an outcome measure that can reflect the degree of recovery based on vocal function. We present an avian model system for studying recovery of learned vocalizations following nerve injury. Methods Digital recordings of bird song were made from 11 adult male zebra finches; 9 underwent bilateral crushing of the nerve supplying the vocal organ, and two birds underwent sham surgery. Song from all birds was then recorded regularly and analyzed based on temporal and spectral characteristics using computer software. Indices were calculated to indicate the degree of similarity between pre-operative and post-operative song. Results Nerve crush caused audible differences in song quality and significant drops (p<0.05) in measured spectral and, to a lesser degree, temporal indices. Spectral indices recovered significantly (mean=43.0%; SD=40.7; p<0.02), and there was an insignificant trend towards recovery of temporal index (mean=28.0%; SD=41.4; p=0.0771). In 5/9(56%) birds, there was a greater than 50% recovery of spectral indices within a four week period. Two birds exhibited substantially less recovery of spectral indices, and two had a persistent decline in spectral indices. Recovery of temporal index was highly variable as well, ranging from persistent further declines of 45.1% to recovery of 87.0%. Neither sham bird exhibited significant (p>0.05) differences in song following nerve crush. Conclusion The songbird model system allows functional analysis of learned vocalization following surgical damage to vocal nerves. Significance The zebra finch provides an animal model for the study of phonatory function following neurolaryngeal injury. Support This project was supported by NIH grant T32DC000018.
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Hammerschmidt, K., K. Radyushkin, H. Ehrenreich y J. Fischer. "Female mice respond to male ultrasonic ‘songs’ with approach behaviour". Biology Letters 5, n.º 5 (10 de junio de 2009): 589–92. http://dx.doi.org/10.1098/rsbl.2009.0317.
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The ultrasonic vocalizations of mice are attracting increasing attention, because they have been recognized as an informative readout in genetically modified strains. In addition, the observation that male mice produce elaborate sequences of ultrasonic vocalizations (‘song’) when exposed to female mice or their scents has sparked a debate as to whether these sounds are—in terms of their structure and function—analogous to bird song. We conducted playback experiments with cycling female mice to explore the function of male mouse songs. Using a place preference design, we show that these vocalizations elicited approach behaviour in females. In contrast, the playback of whistle-like artificial control sounds did not evoke approach responses. Surprisingly, the females also did not respond to pup isolation calls. In addition, female responses did not vary in relation to reproductive cycle, i.e. whether they were in oestrus or not. Furthermore, our data revealed a rapid habituation of subjects to the experimental situation, which stands in stark contrast to other species' responses to courtship vocalizations. Nevertheless, our results clearly demonstrate that male mouse songs elicit females' interest.
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Seddon, Nathalie, Adriana Alvarez y Joseph Tobias. "VOCAL COMMUNICATION IN THE PALE-WINGED TRUMPETER (PSOPHIA LEUCOPTERA): REPERTOIRE, CONTEXT AND FUNCTIONAL REFERENCE". Behaviour 139, n.º 10 (2002): 1331–59. http://dx.doi.org/10.1163/156853902321104190.
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AbstractAdult pale-winged trumpeters produce a varied repertoire of vocalizations: apart from one loud 'tremolo song' we recorded 11 structurally discrete close-range calls, one of which (the 'mew') was individually distinct. There was significant variation across vocalization type with respect to the identity and behaviour of the caller and the response of the receiver(s). It was possible to group vocalizations into six broad contextual classes: alarm, recruitment, social, contact, feeding and territory defence. On detection of danger, trumpeters gave two acoustically different calls, one for aerial predators, and another for terrestrial predators or conspecific intruders. They also produced distinct calls on detection of large prey items such as snakes. These (alarm and snake-finding) call types seemed to evoke different responses by receivers and therefore appeared to be functionally referent. Vocal behaviour was positively correlated with dominance rank and at least two other calls had important roles in mediating social interactions within the group. Finally, the 'mew' call was only given when a trumpeter was separated from, and usually out of visual contact with the rest of the group. This call was functionally referent, eliciting a vocal response from receivers: they produced a loud 'grunt' call, which was also unique to this situation. This is the first experimental demonstration in a bird of the proximate factors motivating production of an individually distinct contact call.
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Hart, Vlastimil, Richard Policht, Vojtěch Jandák, Marek Brothánek y Hynek Burda. "Low frequencies in the display vocalization of the Western Capercaillie (Tetrao urogallus)". PeerJ 8 (8 de julio de 2020): e9189. http://dx.doi.org/10.7717/peerj.9189.
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Only a few bird species are known to produce low-frequency vocalizations. We analyzed the display vocalizations of Western Capercaillie males kept in breeding centers and identified harmonically structured signals with a fundamental frequency of 28.7 ± 1.2 Hz (25.6–31.6 Hz). These low-frequency components temporally overlap with the Whetting phase (96% of its duration) and they significantly contribute to the distinct vocal expression between individuals. The resulting model of discrimination analysis classified 67.6% vocalizations (63%, cross-validated result) correctly to the specific individual in comparison to the probability by chance of 12.5%. We discuss a possible function of low-frequency components that remains unclear. The occurrence of such low frequencies is surprising as this grouse is substantially smaller than cassowaries (Southern cassowary Casuarius casuarius and Dwarf cassowary Casuarius bennetti) , the species that produces similarly low frequencies. Because these low frequency components temporarily overlap with the Whetting phase, they are hardly audible from a distance larger than several meters.
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Goodale, Eben y Sarath W. Kotagama. "Testing the roles of species in mixed-species bird flocks of a Sri Lankan rain forest". Journal of Tropical Ecology 21, n.º 6 (19 de octubre de 2005): 669–76. http://dx.doi.org/10.1017/s0266467405002609.
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Studies of mixed-species bird flocks have found that ‘nuclear’ species, those important to flock coherence, are either intraspecifically gregarious or are ‘sentinel’ species highly sensitive to predators. Both types of species are present in flocks of a Sri Lankan rain forest: orange-billed babblers (Turdoides rufescens Blyth) are highly gregarious, whereas greater racket-tailed drongos (Dicrurus paradiseus Linnaeus) are less so, but more sensitive and reliable alarm-callers. We hypothesized that flock participants would be attracted to the playback of both species more than to the clearly non-nuclear yellow-fronted barbet (Megalaima flavifrons Cuvier). Further, we hypothesized that insectivores would prefer babbler vocalizations, as babblers could facilitate their foraging in several ways. We found that the response of insectivores was three times greater during babbler or drongo playback, and eight times greater during playback of these two species together, than during barbet playback or silence. Insectivores did not show, however, any difference in their response to babbler as compared to drongo playback; omnivores and frugivores responded relatively equally to all treatments. Our results show that birds with high propensity to flock, such as insectivores, use the vocalizations of nuclear species to locate flocks and that a sentinel species may be as attractive as a highly gregarious species.
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HAYES, FLOYD E., OSCAR RODRÍGUEZ, ERIKA R. THALMAN, EMILY A. CASTELLANOS y JOHN STERLING. "Taxonomic status of Paraguay’s only endemic bird, the Chaco Nothura Nothura chacoensis (Aves: Tinamidae)". Zootaxa 4392, n.º 2 (8 de marzo de 2018): 347. http://dx.doi.org/10.11646/zootaxa.4392.2.7.
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The Chaco Nothura Nothura chacoensis Conover is endemic to the Chaco of western Paraguay. Originally described as a subspecies of the Spotted Nothura N. maculosa (Temminck), it has been regarded by many authorities as a distinct species based on alleged sympatry with N. maculosa. However, an earlier study revealed no differences in cytochrome b sequences between the two taxa. We reanalyzed the geographic distribution and morphological variation of N. chacoensis and N. maculosa in western Paraguay based on museum specimens. There is no locality where specimens of both taxa were collected, thus there is no evidence for sympatry. Morphologically the two taxa did not differ in any size or shape variable. Plumage characters overlapped in a few specimens. We recorded vocalizations from at least four individuals of N. chacoensis within its known range. Its typical territorial song was a very rapid, relatively monotone trill that was virtually identical with the most frequent territorial song of N. maculosa in length, number of notes, rate of notes, and emphasized frequency, and differed substantially from the songs of other species of Nothura. Based on distributional, morphological, biochemical, and especially vocalization data, we conclude that N. chacoensis should be regarded as a subspecies of N. maculosa.
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Dermi, Devi Fauzia, Agung Sedayu y Ratna Komala. "VARIASI POLA VOKALISASI PADA TAKSONOMI ANAK JENIS ELANG-ULAR (Spilornis cheela) DI PKEK, GARUT, JAWA BARAT". BIOMA 13, n.º 2 (27 de febrero de 2018): 1–9. http://dx.doi.org/10.21009/bioma13(2).1.
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Crested serpent eagle (Spilornis cheela) is a bird of prey with distinctive of uniue vocal. Based on several studies mentioned that there are differences in vocalization at the level of subspecies and is often used to study the role vocalization defining the subspecies in taxonomy. This research aimed to determine the role variation of vocalization pattern in taxonomy on subspecies eagle. The research was conducted from May to September 2017 at Kamojang Eagle Conservation Center. The method used is descriptive method with continuous sampling technique. The samples was an adult eagle from three subspecies serpent eagle. The location of observation determined by purposive sampling with the provisions listening post is less than 5 meters until 30 meters. The data is collected at 7 am to 5 pm. Data were analyzed using sound analysis software. The data taken are fundamental frequency, maximum frequency (MinF), minimum frequency (MinF) and duration. Differences between subspecies were analyzed using Kruskal Wallis and Mann-Whitney U statistical test with SPSS 17.0. The result of the research is The vocalizations can be utilized in the subspecies eagle taxonomy of the species to complement the morphological data, marked by significantly different results on each parameter of vocalization between (Spilornis cheela malayensis) and (Spilornis cheela natunensis). MaxF significantly different in (Spilornis cheela malayensis) and (Spilornis cheela bido), (Spilornis cheela natunensis) and (Spilornis cheela bido).
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McDonald, Paul G. "Cooperative bird differentiates between the calls of different individuals, even when vocalizations were from completely unfamiliar individuals". Biology Letters 8, n.º 3 (18 de enero de 2012): 365–68. http://dx.doi.org/10.1098/rsbl.2011.1118.
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Hypotheses proposed to explain the evolution of cooperative behaviour typically require differentiation between either groups of conspecifics (e.g . kin/non-kin) or, more typically, individuals (e.g. reciprocal altruism). Despite this, the mechanisms that facilitate individual or class recognition have rarely been explored in cooperative species. This study examines the individual differentiation abilities of noisy miners ( Manorina melanocephala ), a species with one of the most complex avian societies known. Miners permanently occupy colonies numbering into hundreds of individuals. Within these colonies, cooperative coalitions form on a fission–fusion basis across numerous contexts, from social foraging through to mobbing predators. Birds often use individually distinctive ‘chur’ calls to recruit others to a caller's location, facilitating coalition formation. I used the habituation–discrimination paradigm to test the ability of miners to differentiate between the chur calls of two individuals that were both either: (i) familiar, or (ii) unfamiliar to the focal subject. This technique had not, to my knowledge, been used to assess vocalization differentiation in cooperative birds previously, but here demonstrated that miners could correctly use the spectral features of signals to differentiate between the vocalizations of different individuals, regardless of their familiarity. By attending to individual differences in recruitment calls, miners have a communication system that is capable of accommodating even the most complex cooperative hypotheses based upon acoustic information.
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Beckers, Gabriël J. L., Robert C. Berwick y Johan J. Bolhuis. "Comparative analyses of speech and language converge on birds". Behavioral and Brain Sciences 37, n.º 6 (diciembre de 2014): 547–48. http://dx.doi.org/10.1017/s0140525x13003956.
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AbstractUnlike nonhuman primates, thousands of bird species have articulatory capabilities that equal or surpass those of humans, and they develop their vocalizations through vocal imitation in a way that is very similar to how human infants learn to speak. An understanding of how speech mechanisms have evolved is therefore unlikely to yield key insights into how the human brain is special.
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Wilson, Andrew M., Kenneth S. Boyle, Jennifer L. Gilmore, Cody J. Kiefer y Matthew F. Walker. "Species-Specific Responses of Bird Song Output in the Presence of Drones". Drones 6, n.º 1 (21 de diciembre de 2021): 1. http://dx.doi.org/10.3390/drones6010001.
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Drones are now widely used to study wildlife, but their application in the study of bioacoustics is limited. Drones can be used to collect data on bird vocalizations, but an ongoing concern is that noise from drones could change bird vocalization behavior. To test for behavioral impact, we conducted an experiment using 30 sound localization arrays to track the song output of 7 songbird species before, during, and after a 3 min flight of a small quadcopter drone hovering 48 m above ground level. We analyzed 8303 song bouts, of which 2285, from 184 individual birds were within 50 m of the array centers. We used linear mixed effect models to assess whether patterns in bird song output could be attributed to the drone’s presence. We found no evidence of any effect of the drone on five species: American Robin Turdus migratorius, Common Yellowthroat Geothlypis trichas, Field Sparrow Spizella pusilla, Song Sparrow Melospiza melodia, and Indigo Bunting Passerina cyanea. However, we found a substantial decrease in Yellow Warbler Setophaga petechia song detections during the 3 min drone hover; there was an 81% drop in detections in the third minute (Wald test, p < 0.001) compared with before the drone’s introduction. By contrast, the number of singing Northern Cardinal Cardinalis cardinalis increased when the drone was overhead and remained almost five-fold higher for 4 min after the drone departed (p < 0.001). Further, we found an increase in cardinal contact/alarm calls when the drone was overhead, with the elevated calling rate lasting for 2 min after the drone departed (p < 0.001). Our study suggests that the responses of songbirds to drones may be species-specific, an important consideration when proposing the use of drones in avian studies. We note that recent advances in drone technology have resulted in much quieter drones, which makes us hopeful that the impact that we detected could be greatly reduced.
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Cornec, Clément, Alexandre Robert, Fanny Rybak y Yves Hingrat. "Male vocalizations convey information on kinship and inbreeding in a lekking bird". Ecology and Evolution 9, n.º 8 (28 de marzo de 2019): 4421–30. http://dx.doi.org/10.1002/ece3.4986.
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Scholes, Edwin, Julia M. Gillis y Timothy G. Laman. "Visual and acoustic components of courtship in the bird-of-paradise genusAstrapia(Aves: Paradisaeidae)". PeerJ 5 (8 de noviembre de 2017): e3987. http://dx.doi.org/10.7717/peerj.3987.
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The distinctive and divergent courtship phenotypes of the birds-of-paradise make them an important group for gaining insights into the evolution of sexually selected phenotypic evolution. The genusAstrapiaincludes five long-tailed species that inhabit New Guinea’s montane forests. The visual and acoustic components of courtship amongAstrapiaspecies are very poorly known. In this study, we use audiovisual data from a natural history collection of animal behavior to fill gaps in knowledge about the visual and acoustic components ofAstrapiacourtship. We report seven distinct male behaviors and two female specific behaviors along with distinct vocalizations and wing-produced sonations for all five species. These results provide the most complete assessment of courtship in the genusAstrapiato date and provide a valuable baseline for future research, including comparative and evolutionary studies among these and other bird-of-paradise species.
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Kello, Christopher T., Simone Dalla Bella, Butovens Médé y Ramesh Balasubramaniam. "Hierarchical temporal structure in music, speech and animal vocalizations: jazz is like a conversation, humpbacks sing like hermit thrushes". Journal of The Royal Society Interface 14, n.º 135 (octubre de 2017): 20170231. http://dx.doi.org/10.1098/rsif.2017.0231.
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Humans talk, sing and play music. Some species of birds and whales sing long and complex songs. All these behaviours and sounds exhibit hierarchical structure—syllables and notes are positioned within words and musical phrases, words and motives in sentences and musical phrases, and so on. We developed a new method to measure and compare hierarchical temporal structures in speech, song and music. The method identifies temporal events as peaks in the sound amplitude envelope, and quantifies event clustering across a range of timescales using Allan factor (AF) variance. AF variances were analysed and compared for over 200 different recordings from more than 16 different categories of signals, including recordings of speech in different contexts and languages, musical compositions and performances from different genres. Non-human vocalizations from two bird species and two types of marine mammals were also analysed for comparison. The resulting patterns of AF variance across timescales were distinct to each of four natural categories of complex sound: speech, popular music, classical music and complex animal vocalizations. Comparisons within and across categories indicated that nested clustering in longer timescales was more prominent when prosodic variation was greater, and when sounds came from interactions among individuals, including interactions between speakers, musicians, and even killer whales. Nested clustering also was more prominent for music compared with speech, and reflected beat structure for popular music and self-similarity across timescales for classical music. In summary, hierarchical temporal structures reflect the behavioural and social processes underlying complex vocalizations and musical performances.
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Schruth, David M., Christopher N. Templeton y Darryl J. Holman. "On reappearance and complexity in musical calling". PLOS ONE 16, n.º 12 (17 de diciembre de 2021): e0218006. http://dx.doi.org/10.1371/journal.pone.0218006.
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Music is especially valued in human societies, but music-like behavior in the form of song also occurs in a variety of other animal groups including primates. The calling of our primate ancestors may well have evolved into the music of modern humans via multiple selective scenarios. But efforts to uncover these influences have been hindered by the challenge of precisely defining musical behavior in a way that could be more generally applied across species. We propose an acoustic focused reconsideration of “musicality” that could help enable independent inquiry into potential ecological pressures on the evolutionary emergence of such behavior. Using published spectrographic images (n = 832 vocalizations) from the primate vocalization literature, we developed a quantitative formulation that could be used to help recognize signatures of human-like musicality in the acoustic displays of other species. We visually scored each spectrogram along six structural features from human music—tone, interval, transposition, repetition, rhythm, and syllabic variation—and reduced this multivariate assessment into a concise measure of musical patterning, as informed by principal components analysis. The resulting acoustic reappearance diversity index (ARDI) estimates the number of different reappearing syllables within a call type. ARDI is in concordance with traditional measures of bird song complexity yet more readily identifies shorter, more subtly melodic primate vocalizations. We demonstrate the potential utility of this index by using it to corroborate several origins scenarios. When comparing ARDI scores with ecological features, our data suggest that vocalizations with diversely reappearing elements have a pronounced association with both social and environmental factors. Musical calls were moderately associated with wooded habitats and arboreal foraging, providing partial support for the acoustic adaptation hypothesis. But musical calling was most strongly associated with social monogamy, suggestive of selection for constituents of small family-sized groups by neighboring conspecifics. In sum, ARDI helps construe musical behavior along a continuum, accommodates non-human musicality, and enables gradualistic co-evolutionary paths between primate taxa—ranging from the more inhibited locational calls of archaic primates to the more exhibitional displays of modern apes.
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Calviño-Cancela, Maria, Laura Piña y Julio Martín-Herrero. "Bioacoustic differentiation of calls in the chiffchaff complex". PeerJ 10 (31 de octubre de 2022): e14261. http://dx.doi.org/10.7717/peerj.14261.
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The chiffchaff complex is a group of common forest bird species, notorious for the number of cryptic taxa recently discovered, being a great example of speciation in action. Vocalizations have been crucial to unveil its hidden diversity. In this study we quantitatively analyze the acoustic characteristics of their calls with permutational analysis of variance, canonical variate analysis and a self-organizing map, to determine their variability and differences. We related these differences with the geographical and genetic distances between taxonomic groups, by means of Pearson correlations. We used recordings from Xeno-canto, an open database of bird vocalizations. Inter-taxa distances based on call traits were broadly consistent with geographic distances but not correlated with genetic distances. The Iberian Chiffchaff (Phylloscopus ibericus), presumably the most ancient lineage, was the most central in the variation space, while the Siberian Chiffchaff (P. collybita tristis) was the most peripheric and also very uniform, in contrast with the Canarian Chiffchaff (P. canariensis) highly variable, as expected by the “character release hypothesis” on islands. Calls proved to be an excellent tool, especially amenable for non-biased mathematical analyses which, combined with the wide availability of records in Xeno-canto, greatly facilitates the widespread use of this methodology in a wide range of species and geographical areas.
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Cornec, C., Y. Hingrat, T. Aubin y F. Rybak. "Booming far: the long-range vocal strategy of a lekking bird". Royal Society Open Science 4, n.º 8 (agosto de 2017): 170594. http://dx.doi.org/10.1098/rsos.170594.
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The pressures of selection acting on transmission of information by acoustic signals are particularly high in long-distance communication networks. Males of the North African houbara bustard ( Chlamydotis undulata undulata ) produce extremely low-frequency vocalizations called ‘booms’ as a component of their courtship displays. These displays are performed on sites separated by a distance of on average 550 m, constituting exploded leks. Here, we investigate the acoustic features of booms involved in species-specific identity. We first assessed the modifications of acoustic parameters during boom transmission at long range within the natural habitat of the species, finding that the frequency content of booms was reliably transmitted up to 600 m. Additionally, by testing males' behavioural responses to playbacks of modified signals, we found that the presence of the second harmonic and the frequency modulation are the key parameters for species identification, and also that a sequence of booms elicited stronger responses than a single boom. Thus, the coding–decoding process relies on redundant and propagation-resistant features, making the booms particularly well adapted for the long-range transmission of information between males. Moreover, by experimentally disentangling the presentation of visual and acoustic signals, we showed that during the booming phase of courtship, the two sensory modalities act in synergy. The acoustic component is dominant in the context of intra-sexual competition. While the visual component is not necessary to induce agonistic response, it acts as an amplifier and reduces the time of detection of the signaller. The utilization of these adaptive strategies allows houbara males to maximize the active space of vocalizations emitted in exploded leks.
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TAYLOR, HOLLIS. "Whose Bird Is It? Messiaen's Transcriptions of Australian Songbirds". Twentieth-Century Music 11, n.º 1 (marzo de 2014): 63–100. http://dx.doi.org/10.1017/s1478572213000194.
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AbstractThis article examines the meeting point of Olivier Messiaen, Australia and birdsong, particularly as it relates to the transcription of pied butcherbird (Cracticus nigrogularis) vocalizations. It draws upon correspondence from Messiaen to the Australian ornithologist Sydney Curtis, printed here for the first time, as well as two recordings not previously available to musicologists, from which Messiaen transcribed. Both the recorded birdsong models and Messiaen's transcription of them in hiscahiersare subjected to sonographic and waveform analysis. In analytical scrutiny of eight of these transcriptions, I demonstrate that Messiaen's pied butcherbird transcriptions conform to their models in a partial and highly personal way. I propose a provisional template for Messiaen's approach to birdsong transcription, in order to answer Alexander Goehr's question: ‘Why do birds sound like birds, but Messiaen's birds sound like Messiaen?’
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Farrow, Lucy F., Ahmad Barati y Paul G. McDonald. "Cooperative bird discriminates between individuals based purely on their aerial alarm calls". Behavioral Ecology 31, n.º 2 (17 de diciembre de 2019): 440–47. http://dx.doi.org/10.1093/beheco/arz182.
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Abstract From an evolutionary perspective, the ability to recognize individuals provides great selective advantages, such as avoiding inbreeding depression during breeding. Whilst the capacity to recognize individuals for these types of benefits is well established in social contexts, why this recognition might arise in a potentially deadly alarm-calling context following predator encounters is less obvious. For example, in most avian systems, alarm signals directed toward aerial predators represent higher predation risk and vulnerability than when individuals vocalize toward a terrestrial-based predator. Although selection should favor simple, more effective alarm calls to these dangerous aerial predators, the potential of these signals to nonetheless encode additional information such as caller identity has not received a great deal of attention. We tested for individual discrimination capacity in the aerial alarm vocalizations of the noisy miner (Manorina melanocephala), a highly social honeyeater that has been previously shown to be able to discriminate between the terrestrial alarm signals of individuals. Utilizing habituation–discrimination paradigm testing, we found conclusive evidence of individual discrimination in the aerial alarm calls of noisy miners, which was surprisingly of similar efficiency to their ability to discriminate between less urgent terrestrial alarm signals. Although the mechanism(s) driving this behavior is currently unclear, it most likely occurs as a result of selection favoring individualism among other social calls in the repertoire of this cooperative species. This raises the intriguing possibility that individualistic signatures in vocalizations of social animals might be more widespread than currently appreciated, opening new areas of bioacoustics research.