Advances in Bioacoustics II

Stink bug communication through plants during mating
Andrej Cokl (Nacionalni inøtitut za biologijo, Ljubljana, Slovenia)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, pp7–35 (2006)

Full paper (pdf file, 154 KB)

Abstract
Different aspects of substrate-borne sound communication in stink bugs are reviewed. Vibrational communication follows aggregation on the same plant, enables mate location and together with other senses promotes species recognition and copulation. Stink bug vibratory signals produced by body vibrations are transmitted with low attenuation through green host plants which resonant frequency is tuned with signal spectral characteristics. This phenomenon enables communication through the same plant at the distance of up to several meters. Species specific male and female calling and courtship songs were recorded, analyzed and described in more than 20 species of the subfamily Pentatominae. Male-male vibratory interaction occurs during rivalry. All recorded vibratory emissions have similar frequency characteristics with the fundamental and dominant frequency around 100 Hz and harmonic peaks generally not exceeding 500 Hz. Species and sex specificity of signals is preserved in their amplitude modulation and time pattern. The subgenual organ, leg joint chordotonal organs and campaniform sensilla together with antennal mechanoreceptors constitute the receptor system which sensitivity exceeds the intensity of emitted signals for about 60 dB. Male vibrational directionality is enabled by resolution.

 

Entropy calculations for measuring bird song diversity: The case of the White-vented Violet-ear (Colibri serrirostris) (Aves, Trochilidae)
Maria Luisa da Silva (Universidade Federal do Pará, Brazil) & Jacques Vielliard (Universidade Estadual de Campinas, Brazil)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 37–49 (2006)

Full paper (pdf file, 367 KB; updated version to correct printing error)

Abstract
The White-vented Violet-ear (Colibri serrirostris) is a common and brilliantly colored Brazilian hummingbird that sings a series of high-pitched and evenly spaced short notes with a repertoire size of 3 to 5 note types. We analyzed the song of 17 individuals from 10 localities in relation to note types, repertoire size and non-conditioned and conditioned entropy. Despite the small repertoire size, each singer presented different note types and sequences. Neighbors can share note types, but maintain distinct sequences and entropy values. The entropy values were useful to objectively differentiate between more or less versatile songs with the same repertoire size. Conditioned entropy, a calculation that shows the distribution of the combinations of two consecutive notes, revealed the more versatile singers, which were not evident from the repertoire size only nor the non-conditioned entropy. Despite the rare presence of note sharing in our sample, we did not find any cue of dialects or geographic patterns of variation, but individual variation. The variability of C. serrirostris song in note structures, sequences and entropy is evidence of vocal learning and creative capacity, a poorly described communication strategy in non passerine birds.

 

Differences between the auditory system of humans and Bottlenose Dolphins
Gennadi L. Zaslavskiy (Tel-Aviv University, Israel)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 51–74 (2006)

Full paper (pdf file, 2616 KB)

Abstract
There is a widely accepted notion of functional similarity between the auditory system of dolphins and humans. Although similarities mostly concern the perception of tone-like signals, dolphins are believed to process high frequency echolocation clicks using the same auditory mechanisms known for humans. Contrary to this view we found that, at least as far as the auditory analysis of the brief signals associated with the dolphin sonar is concerned, there are more functional differences between Bottlenose Dolphins (Tursiops truncatus) and humans than similarities. With the time resolution as high as 0.02-0.03 ms the auditory system of Bottlenose Dolphins is a time domain analyzer rather than a frequency analyzer. The spatial hearing in dolphins appears to be based on directional reception and transmission and performs similarly to a monaural rather than the binaural system of humans. There are some functional differences between the auditory systems of humans and dolphins even at audio frequencies of humans hearing.

Teaching a musical code to a parrot: Frequency discrimination and the concept of rhythm in a Grey Parrot (Psittacus erithacus)
Luciana Bottoni, Simone Masin, Daniela Lenti (Università degli Studi Milano Bicocca, Italy) & Boero & Renato Massa (Università della Val D’Aosta, Italy)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 75–86 (2006)

Full paper (pdf file, 540 KB)

Abstract
Music competence and perception should be considered in evaluating human cognitive processes, unfortunately, evolutionary onset of music is still unclear. Although connections between human language and other animal communication patterns remain limited and controversial, humans share musical “language” at least with birds. Recently, many studies seem to point out that in many vertebrate species’ song there could be structures comparable to those of human music. African Grey Parrot (Psittacus erithacus) is well known for his ability in song and speech learning. In our study we tried to understand if a female African Grey, Theo, were able to learn and properly use some basic elements of the musical language, in particular we choose the intonation and rhythm. We taught first Theo to answer with sequences of “notes” to some simple melodies played with an electric piano, then we recorded every “musical” output sung by Theo. Peak frequency analysis and comparison between parrot’s sequences and random generated strings, confirmed the acquisition of the intonation concept and notes amplitude peak showed Theo’s tendency to maintain a rhythmic regularity. Furthermore, data analysis stressed the great complexity and innovation in the musical sequences uttered by the bird, that led us to exclude the simple imitation process.

 

Individual recognition of Scops Owls (Otus scops) by spectrographic analysis of their calls: a preliminary study
Katarina Denac (Ljubljana, Slovenia) & Tomi Trilar (Slovenian Museum of Natural History, Ljubljana, Slovenia)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 87–97 (2006)

Full paper (pdf file, 225 KB)

Abstract
Numerous studies have confirmed that males of several species can be individually identified by spectrographic analysis of their vocalizations. Spectrographic analysis of 12 recordings of Scops Owl (Otus scops) males made on Ljubljansko barje (central Slovenia) and in Istria (NW Croatia) revealed that this method is suitable for individual recognition of males. Average values for the following three parameters of calls were calculated (±SE): length of call 278.3±3.69 ms (min 228-max 371 ms), time interval between calls 2.72±0.05 s (min 2.08-max 3.39 s) and fundamental frequency of call 1.32±0.01 kHz (min 1.17-max 1.50 kHz). Discriminant function analysis successfully separated recordings of different males on the basis of above mentioned parameters (Wilkins’?=0.0027, P<0.001). Variables considered in the model were length of call and time interval between calls, whereas fundamental frequency was omitted as its variance between individuals was too low. Both discriminant functions were statistically significant (p<0.001), the first one accounting for 90% of variance, and both together for 100% of variance. Considering the fact that Scops Owls may form larger calling groups and may breed in loose colonies where conditions are favourable, this method represents a very important tool for accurate determination of the number of calling males. Recordings of Scops Owl are relatively easy to obtain as the species is highly vocal and males respond well to playback of another male. The method is also less time-consuming for the surveyor and less disturbing for the bird, compared to capturing and banding.

 

Interspecific territorial vocal activity of the Ural Owl (Strix uralensis) towards Tawny Owl (Strix aluco), sympatric owl competitor: A playback experiment
Petra Vrh (Ribnica, Slovenia) & Al Vrezec (National Institute of Biology, Ljubljana, Slovenia)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 99–105 (2006)

Full paper (pdf file, 70 KB)

Abstract
Territoriality in birds is more often displayed as vocal communication than as aggressive attack, so playback experiments are commonly used approach in studying territorial interactions. We tested the interspecific territoriality of the Ural Owl (Strix uralensis) towards closely related and smaller sympatric owl competitor, the Tawny Owl (Strix aluco). We preformed playback experiments on 28 territories of Ural Owls on Mt. Krim (central Slovenia) during spring and autumn between years 2003 and 2005. We measured the response rate of the Ural Owl on the broadcast territorial song of the male of the Ural, Tawny, and Great Grey Owl (Strix nebulosa). The last is playback of allopatric species used as a control and was considered as a non-territorial response versus conspecific playback of the Ural Owl considered as a territorial response. Ural Owl territorial vocal activity was very low since response rate reached only 34%. However, in the analysis we confirmed that Ural Owl was interspecific territorial towards Tawny Owl since the level of response of the Ural Owl to the Tawny Owl playback was as similar as to the conspecific playback. Therefore we are concluding that interspecific territoriality is a very important mechanism in spatial segregation of these two highly competitive species.

 

Social context and response to female voice: Audience effect in the male Zebra Finch (Taeniopygia guttata)
Nicolas Mathevon (Université Jean Monnet, France), Clémentine Vignal (‘The BioAcoustics Team’, Université Paris XI, France), Stéphane Mottin (Université Jean Monnet, France) & Thierry Aubin (‘The BioAcoustics Team’, Université Paris XI, France)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 107–116 (2006)

Full paper (pdf file, 290 KB)

Abstract
How behaviour and underlying brain functions are shaped by social context remains a poorly explored domain. Here, we review two recent studies on Zebra Finches (Taeniopygia guttata) which focus on this question. In this species, communication behaviour within male and female pair appears to be strongly regulated by the presence of other individuals. Investigation at brain level shows that the sound-induced immediate early gene response is also highly sensitive to the audience effect.

 

Vocal imitation in African Savannah Elephants (Loxodonta africana)
Joyce H. Poole (Amboseli Trust for Elephants, Kenya), Peter L. Tyack (Woods Hole Oceanographic Institution, USA), Angela S. Stoegerhorwath (University of Vienna, Austria) & Stephanie Watwood (Woods Hole Oceanographic Institution, USA)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 117–124 (2006)

Full paper (pdf file, 800 KB)

Abstract
There are a few mammalian species that can modify their vocalizations in response to auditory experience. We describe two examples of vocal imitation by African Savannah Elephants (Loxodonta africana), a terrestrial mammal that lives in a multitiered fission-fusion society. The first case of vocal imitation involves Mlaika, an adolescent female African Elephant who lived in a semi-captive group of orphaned elephants in the Tsavo National Park, Kenya. Trucks were audible from a highway 3 km from the night stockade. Mlaika emitted truck-like sounds for several hours after sunset, the optimal time for the transmission of low frequency sound in African savannahs. The second case involves Calimero, an adult male African Elephant who spent 18 years living with two female Asian Elephants (Elephas maximus) at the Rome zoo. Calimero imitated the chirping sounds typically produced by Asian Elephants, though not by African Elephants. Our findings favour a role for vocal imitation that has already been proposed for primates, birds, bats and marine mammals: it is a useful form of acoustic communication that helps to maintain individual-specific bonds within social changing groupings.

 

Acoustic features of Red Deer (Cervus elaphus) stags vocalizations in the Cansiglio Forest (NE Italy, 2001-2002)
Andrea Favaretto (University of Padova, Italy), Renzo De Battisti (Corpo Forestale dello Stato, Padova, Italy), Gianni Pavan (University of Pavia, Italy) & Alberto Piccin (Corpo Forestale dello Stato, Vittorio Veneto, Italy)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 125–138 (2006)

Full paper (pdf file, 2230 KB)

Abstract
During the rut in the years 2001-2002 in the Cansiglio Forest (NE Italy), more then 1300 vocalizations of red deer stags were recorded and analyzed. The acoustic analysis showed an evident spectrographic and temporal heterogeneity, so that we could classify them in 11 different classes. In particular, for the analyzed population, we found a clear distinction between three principal temporal classes, so we described the acoustic repertoire of the stags population during the considered rutting seasons.

 

The animal sound archive at the Humboldt-University of Berlin: Current activities in conservation and improving access for bioacoustic research
Karl-Heinz Frommolt (Humboldt-University of Berlin, Germany), Rolf Bardeli, Frank Kurth & Michael Clausen (University of Bonn, Germany)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 139–144 (2006)

Full paper (pdf file, 280 KB)

Abstract
The animal sound archive of the Humboldt-University is one of the oldest and largest collections of animal sounds. It was founded in 1951 by Günter Tembrock. Presently, the collection consists of about 120,000 bioacoustical recordings comprising almost all groups of animals. Most of the recordings are still on analogue magnetic tape. Currently, these tapes are transferred to digital storage media, mainly with 96 kHz sampling rate and 24 bit resolution. In this way, more than 50% of all recordings could already be preserved in digital form. The recordings will be documented by a database. Currently, an efficient system for the exchange of bioacoustical information, both metadata and soundfiles, for scientific purposes, is under development. The system consists of a central web-based database and local file storage servers. Free access to the metadata is available at “http://www.tierstimmen.org”. Individual access to defined sound recordings will be controlled by password. The system should enable scientists to cooperate effectively in bioacoustic research.

 

Fonozoo.com a new resource in the web for the study of animal sounds
Gema Solís, Xavier Eekhout & Rafael Márquez Museo Nacional de Ciencias Naturales, Madrid, Spain)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 145–154 (2006)

Full paper (pdf file, 950 KB)

Abstract
We describe the functional structure of the Fonoteca Zoológica (FZ), a scientific collection of animal sounds in the National Natural Science Museum of Madrid. We present statistical data regarding the number of species with sounds in either the Published Sound Collection or the FZ Sound Collection. The Published Sound Collection includes commercially available sound guides published all over the world, and the FZ Sound Collection includes recordings made by researchers in the Museum and other collaborators. Comparisons in holdings are made between the different taxa, and we emphasize the use of bioacoustics for the study of animal behaviour. Finally, we introduce the recently created web page www.FonoZoo.com from where it is possible to access the database of the animal sounds kept in the Fonoteca Zoológica.

 

Acoustic website on European singing cicadas
Matija Gogala (Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 155–164 (2006)

Full paper (pdf file, 1600 KB)

Abstract
The song pattern and other song parameters like frequency and/or intensity modulation are in most cases the best characters for recognition and determination of singing cicada species. Very useful comparative papers and book chapters with descriptions of song patterns were published, but many times researchers working on faunistics and systematics of Cicadoidea would like to have also an auditory impression of song characteristics in addition to the oscillograms and spectrograms published elsewhere. This is the reason that we started to construct the web site where interested persons can play back or even download typical song samples of various species of singing cicadas. Till now we restricted our selection to the European species of singing cicadas. Every species is represented with the picture of live animal, a specimen from the collection, and habitat if available, oscillograms and spectrograms of the calling song and other acoustic signals. The references (partly also with downloadable PDF files) describing their song characteristics are listed as well. Song samples are playable as QuickTime movies and can be also downloaded. Till now 36 species are represented, in the coverpage also the contributors are introduced and in the English index page one can find a list of species and some general explanations about the graphs used to represent the songs. The following colleagues, working on bioacoustics of singing cicadas agreed to offer their recordings, illustrations and references: Michel Boulard, Matija Gogala, Andrej V. Popov, Stéphane Puissant, Jerôme Sueur, José Quartau with his team and Tomi Trilar.

 

Acoustic playback: Contributions to the study of animal communication in the last 13 years (1992-2004)
Xavier Eekhout, Gema Solís & Rafael Márquez (Museo Nacional de Ciencias Naturales, Madrid, Spain)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 165–175 (2006)

Full paper (pdf file, 95 KB)

Abstract
Two different databases of scientific publications (Zoological Record and MedLine) were studied in order to identify trends in the use of acoustic playback techniques in the last 13 years (1992-2004). The articles that mentioned the use of acoustic playbacks were classified into 5 subjective classes depending on their topic: Physics, Physiology, Descriptive Studies, Applied Studies and Ethology. Within the class Ethology five subclasses were considered: Learning, Predation, Social Structure, Sexual Selection and Territoriality. From each article we recorded the year of publication, the taxonomic group studied, the country of the research team and the language in which the article was written. We found that there has been an increase in the number of articles published which use acoustic playbacks especially in the class Ethology. The most commonly studied taxonomic group is birds, and although there are research teams from many countries, in number of articles research teams from the USA are clearly dominant.

 

Software tools for automatically detecting, measuring and classifying animal sounds
Raimund Specht (Avisoft Bioacoustics, Berlin, Germany)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 177–184 (2006)

Full paper (pdf file, 230 KB)

Abstract
Many bioacoustic investigations involve the analysis of large amounts of sound recordings. Reviewing these files manually is often both extremely time-consuming and subject to making mistakes that result from the monotony of that procedure. It is therefore desired to have tools that automate this process. Avisoft Bioacoustics has been working on software tools that accomplish this goal. There are several approaches that are suitable for various analysis requirements. This paper describes the currently available options.

 

Bird sound classification and recognition using wavelets
Arja Selin, Jari Turunen & Juha T. Tanttu (Tampere University of Technology, Pori, Finland)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 185–204 (2006)

Full paper (pdf file, 1500 KB)

Abstract
In this paper a new method for automatic classification and recognition of bird sounds is presented. Our main idea is to study, how inharmonic and transient bird sounds can be recognized efficiently. The data consisted of sounds of eight bird species. Five species, the Mallard (Anas platyrhynchos), the Graylag Goose (Anser anser), the Corncrake (Crex crex), the River Warbler (Locustella fluviatilis), and the Magpie (Pica pica) have inharmonic sounds, whereas the remaining three reference species, the Quail (Coturnix coturnix), the Spotted Crake (Porzana porzana), and the Pygmy Owl (Glaucidium passerinum) have harmonic sounds. The wavelet analysis was selected due to its ability to preserve both frequency and temporal information, and its ability to analyse signals which contain discontinuities and sharp spikes. The feature vectors calculated with the proposed algorithm from the wavelet coefficients were used as the inputs of two neural networks, the self-organizing map (SOM) and the multilayer perceptron (MLP). The results were encouraging, for the unsupervised SOM network recognized 78% and the supervised MLP network 96% of the test sounds correctly.

 

De-noising aspects in the context of feature extraction in automated bird sound recognition
Jari Turunen, Arja Selin, Juha T. Tanttu & Tarmo Lipping (Tampere University of Technology, Pori, Finland)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 205–212 (2006)

Full paper (pdf file, 820 KB)

Abstract
In this paper we demonstrate the effects of noise reduction in wavelet based bird sound recognition. The nonharmonic bird sounds are difficult to separate from the background noise in order to maintain necessary features for identification. We tested three options: (i) no filtering, (ii) adaptive filter bank and (iii) lowpass Finite Impulse Response (FIR) filter. The following identification results were obtained (i) 95.1%,(ii) 96% and (iii) 100%.

 

Sound recording of vocal activity of animals inhabiting subtropical forest on Iriomote Island in the southern Ryukyus, Japan
Shinichi Watanabe (University of the Ryukyus, Okinawa, Japan) & Hiroki Kobayashi (The University of Tokyo, Tokyo, Japan)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 213–228 (2006)

Full paper (pdf file, 370 KB)

Abstract
We developed a system to monitor distribution and activity of animals in a forest ecosystem using sound recorders. The study was conducted at 14 sites along a river in Iriomote Island in the southern Ryukyus, Japan, from September 2004 to July 2005. Vocal activity of animals was continuously recorded for a specific interval with a weatherproof automatic recording system. From the recorded data, we identified calls of 38 species of mammals, birds, reptiles, amphibians, and insects. For each species, we compared vocal activity during study periods in order to investigate the migratory periods of several species of birds, and also breeding activities of birds, frogs, and Orthoptera. In addition, we studied daily vocal activity to investigate variation during the study period. This system allows long-term consecutive and simultaneous monitoring at multiple locations without man-power, which is a great advantage for cost-effective monitoring of regional biodiversity.

 

Acoustic behaviour in Malawian Cichlids (Pseudotropheus, Cichlidae): Potential cues for species recognition and intraspecific communication
Jose Miguel Simões, Ines Duarte, Paulo Jorge Fonseca (Universidade de Lisboa, Lisbon, Portugal), G. F. Turner (University of Hull, England) & M. Clara P. Amorim (I.S.P.A., Lisbon, Portugal)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 229–236 (2006)

Full paper (pdf file, 310 KB)

Abstract
Acoustic communication may play an important role in mate recognition systems among African cichlids and may contribute to the evolutionary processes involved in their rapid speciation. Sounds produced in early courtship (during quivering) by males of three closely related Malawi species of the Pseudotropheus zebra complex (Pseudotropheus zebra, P. callainos and P. ‘zebra gold’) were recorded and compared among species. In one species (P. zebra), sounds emitted during quivering were compared to sounds produced during later courtship behaviour, such as circle and lead-swim, and with sounds emitted during male-male and female-female interactions. The following acoustic parameters were measured: sound duration (ms), number of pulses per sound, initial and mean pulse periods (ms), and peak frequency of sounds (Hz). Differences in male courtship sounds were found among species. P. ‘zebra gold’ produced longer sounds with a higher number of pulses than P. callainos, and P. zebra males showed longer initial and mean pulse periods than the other two species. In P. zebra, male courtship, male agonistic and female agonistic sounds also differed significantly in some parameters. These results suggest that in the studied species acoustic signals could be used in species-specific recognition and potentially promote reproductive isolation, and in intraspecific communication.

 

Individuality in the mating call of the male Lusitanian Toadfish (Halobatrachus didactylus)
M. Clara P. Amorim & Raquel O. Vasconcelos (I.S.P.A., Lisbon, Portugal)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 237–244 (2006)

Full paper (pdf file, 640 KB)

Abstract
During the breeding season, male Lusitanian Toadfish emit a tonal advertisement call (the boatwhistle) from their nests to attract mates. Boatwhistles begin and end with a grunt-like phase (P1 and P3) and contain a longer tonal portion in between (P2). In this study we examined individuality in the Lusitanian Toadfish boatwhistles. Recordings (5-10 min) of 13 males were made in shallow waters in the Tagus estuary, Portugal. Ten sounds were analysed per male. Boatwhistles from different individuals could easily be distinguished by the human ear, and visually by differences in their spectra and shape of the temporal envelope. Acoustic features showed very little intra-individual variation (i.e. coefficient of variations ? 0.1), including boatwhistle duration, relative duration, number of pulses and pulse period of both P1 and P2, and the relative amplitude of P1 in relation to P2 (amplitude modulation). All acoustic variables differed significantly among individuals (Kruskal-Wallis: P<0.001). Discriminant function analysis assigned 95% of calls to the correct individuals, with boatwhistle duration, P2 relative duration and amplitude modulation being the most important variables in the model. Individuality of mating sounds is unusual among fish and could be potentially used in mate choice and in spacing out territorial males.

 

Cues to orientation of a caller to a listener in biphonic and non-biphonic close range contact calls in the Dhole (Cuon alpinus)
Ilya A. Volodin, Michael M. Nagaylik (Lomonosov Moscow State University, Moscow, Russia) & Elena V. Volodina (Moscow Zoo, Moscow, Russia)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 245–255 (2006)

Full paper (pdf file, 640 KB)

Abstract
Dholes produce two call types with wide frequency ranges, potentially providing cues to orientation of a caller to a listener because of different distribution for the higher and lower frequencies. One call type is biphonic (yapsqueak), the second one (yap) includes only one fundamental with its harmonics. Here we compare the abilities the biphonic and non-biphonic, but rich in harmonics call types to encode orientation of a caller to a listener. We recorded calls and movements from three male Dholes, running singly forward and back in their identical enclosures and subdivided the recorded calls into two groups: produced toward a microphone in sector ?45°, and produced away from a microphone in sector 135-225°. For each call, within 20.3 ms time segment taken in a call centre, we calculated the amplitude ratio of sum of amplitudes higher 5 kHz to sum of amplitudes lower 5 kHz. For the pooled sample of yaps and yap-squeaks, the amplitude ratio was significantly higher for "toward" than for "from" call group. For yaps and yap-squeaks separately the results were similar. Also, Dhole showed interindividual differences both in preference of a particular call type and in reliability of cues to orientation. Overall, both biphonic yap-squeaks and non-biphonic yaps bored cues to orientation. We discuss, that the increased occurrence of biphonic yap-squeaks in the Dhole may be conditioned by their additional function as individual markers, lacking in non-biphonic yaps.

 

The ocurrence of nonlinear vocal phenomena in frustration whines of the Domestic Dog (Canis familiaris)
Elena V. Volodina (Moscow Zoo, Moscow, Russia), Ilya A. Volodin (Lomonosov Moscow State University, Moscow, Russia) & Olga A. Filatova (Moscow Zoo, Moscow, Russia)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 257–270 (2006)

Full paper (pdf file, 470 KB)

Abstract
We analyzed quantitatively the occurrence of nonlinear vocal phenomena in whines of 9 Domestic Dogs of 6 breeds. The dogs produced whines in response to a frustration-provoking situation (impossibility to perform the desired action), designed with their owners. The whines could consist two fundamental frequencies – the low (f0) and the high (g0), that could occur both singly as separate vocalizations and together within the same vocalization. The f0 varied between individuals from 0.4 to 1.4 kHz and either lacked nonlinear phenomena or bored deterministic chaos, subharmonics or frequency jumps within the f0. The g0 varied between individuals from 3.1 to 11 kHz and also either lacked nonlinear phenomena or bored sidebands. The simultaneous occurrence of f0 and g0 within the same whine resulted in biphonation, whereas the f0 following g0 resulted in frequency jump between the fundamentals. We found, that in whines of our object dogs nonlinear phenomena occurred significantly more often within the f0 than within the g0, and significantly more rarely in whines consisting both f0 and g0 than in whines consisting f0 or g0 singly. The occurrence of nonlinear phenomena showed the noticeable interindividual variability. We discuss mechanisms for production of the f0 and g0 in the Domestic Dog. Also, we propose, that the strong variability in whines of Domestic Dogs has a function to attract attention of the dog owners in situation of frustration, when a dog can’t cope with a problem. In this relation, the nonlinear phenomena may represent a mechanism, supporting the high unpredictable variability in the structure of whines.

 

Group and individual discriminability in monozygotic twins’ infant cry: A pilot study
Daniela Lenti Boero (Università della Valle d’Aosta, Italy) & Francesca Rocca (Università degli Studi di Milano, Italy)

Advances in Bioacoustics 2, Dissertationes Classis IV: Historia Naturalis, Slovenian Academy of Sciences and Arts (Ljubljana), XLVII-3, 271–280 (2006)

Full paper (pdf file, 100 KB)

Abstract
The aim of this study was to investigate the acoustic structure of groups of monozygotic twins, recorded both at term and at earlier developmental ages. Cries from three groups of monozygotic twins affected by severe prematurity, and two groups of monozygotic twins affected by moderate prematurity for a total of 13 infants were recorded. Results show that wails sampled from cries uttered by groups of monozygotic twins were ascribed to the correct group, both at early developmental age, and at term, and also that wails of single individual twins were ascribed to the proper individual within its group. Present results suggest that the fixed components of cry structure are most important in shaping the acoustic characteristics of the cry, but also that intrauterine experience might influence the temperamental characteristics of monozygotic twins.