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Sounds of passerine and non-passerine birds may provide data on body condition of a bird. Information about organism quality may be encoded by different ways. For example, a greater bird should have greater syrinx that lead to lower main frequency of sounds. Second, a longer trachea corresponds to smaller formant dispersion. More than 60 bird species have a tracheal elongation i.e. loops of trachea inside of sternum. Fitch (2000) suggested hypothesis that tracheal elongation is a way to imitate sounds of greater animal due to formant dispersion decreasing. We analyzed correlation of body mass and sound parameters in the calls of white-naped crane Grus vipio. We recorded calls of 6 captive breeding pairs i.e. 12 adult cranes. We described vocal repertoire of white-naped crane as five types of single calls and duet call - stable sequence of single calls. There are three tonal calls (guard call, bark and buzzing) and two non-tonal, rhythmical calls (purring and quacking). Non-tonal rhythmical calls are more suitable for highlighting of formants that tonal calls. We found that none of parameters of tonal calls correlated with body mass. At once, peak frequency of purring significantly correlated with body mass. Frequency parameters of duet calls significantly correlated with body mass. We suggested that sound duration should be connected with body condition. A greater animal have greater lung volume and can call longer. Nevertheless, none of call types had duration correlated with body mass. Thus, (1) peak frequency of purring correlated with body mass that support hypothesis of vocal size exaggeration and (2) duet call of white-naped crane provide information about body mass.

We describe quantitatively the song of Eugaster spinulosa (Johannson 1763), Orthoptera, Tettigoniidae. To the best of our knowledge there are no previous descriptions available of the song of any species in the genus. The description is based on acoustic recordings of 5 males from the mountains of Jebilet, Marrakech (Morocco). Recordings were made in a semi anechoic chamber, in stereo, using G.R.A.S. 40 BE (frequency range 10 Hz – 100kHz) and Sennheiser MKH 800 P48 (frequency range 30 Hz – 50 kHz) microphones, at a sampling rate of 192 kHz, on a Sound Devices 722. The calling song consisted of sequences of a variable number of echemes, each one of which comprising 2 to 11 broadband syllables, with frequency ranging from approximately 7 kHz to almost 80 kHz, but most energy concentrated between 7 kHz and 27 kHz. We also investigated the relationship between song parameters and temperature, and attempted to identify the static and dynamic parameters of the song.

The estimation of birds’ repertoire size is based on spectrographic analysis. This is the most important feature and used to describe song complexity and organization. The estimation of repertoire size is time consuming and involves the objective scoring of song elements by eye. Moreover, based on such manual approaches, it is difficult to make quantitative comparisons between individuals, because it necessitates a universal coding system of song elements at the population level, for which the observer would need to handle cognitively all the song elements found in the population. To enhance this process, we have developed a computerised scoring system, and created a sound library of song elements that is universally applicable to all 67 individuals in male collared flycatcher (Ficedula albicollis) recorded in Hungary. The manual estimation of repertoire size followed the visual scoring of spectrograms, while we wrote a computer program in Matlab environment for the automatic estimations. Based on some acoustic features (time and frequency parameters) measured automatically, the program offers a semi- and a fully automatic way to insert each syllable into the universal syllable library. The semi automatic approach relies on a decision tree method, which shows the most appropriate matches between syllables, but always request a decision from the investigator to assign each syllable. In the fully automatic way, the program uses a self-organizing map method and performs the syllable scoring directly. After the comparison we found that the automated approaches can provide reliable and repeatable estimates on song variables. The automated methods can be effectively exploited in future studies of song complexity and organisation in birds, or even other animals.

The NEMO-OvDE platform, deployed on the seabed at a depth of 2050 m, 21 km off the coast of Catania in Sicily (Italy), has provided the opportunity to better understand the presence and behaviour of sperm whales in the area. Equipped with four wideband hydrophones (30Hz-40kHz) forming a tetrahedral array of 1 m side, the platform sent digital data to the land station continuously 24h a day from January 2005 to November 2006. 7359 samples, for a total of 613 hours, were recorded and analyzed to determine the presence of sperm whales. Analyses were performed by trained operators with the use of SeaPro, a real-time spectrographic software, to distinguish species, number of individuals present and sound categories emitted. Sperm whale presence is considered as low density in the Ionian sea by an acoustic survey of IFAW in 2004 and by other works done in the vicinity. However, in our study, an unexpected presence of animals was found, with 23% of files containing animals in both years. Then, we focused our study on codas, sounds typical of social groups and with a geographical connotation, which for the Mediterranean are usually emitted as the 3+1 pattern. Not enough is known about the Mediterranean population to determine the connections between geographical areas. 3+1 remains the most common pattern, but a surprising variety of patterns was found, linking these animals to the situation present along the Hellenic trench. We used GAMs to establish seasonal variations to understand the movements of the species in the Ionian sea. Spring is the season richest in codas due to the greater presence of individuals. For the first time we demonstrate a relation between the pattern performed and the number of animals. This can be interpreted as an evidence of a different behavioural meaning.

In most species of song birds, males posses song repertoires of several different song types. Based on structural acoustic characteristics it is often possible to assign specific song types to distinct categories. These categories may be used differentiated in communication and serve different functions. For example, the production of special elements that constitute a song category might be costly and therefore, such song categories might be well suited to indicate the quality of the signaller. Playback experiments can verify whether song categories defined by acoustic similarity according to human scoring are indeed recognized as specific categories by birds, too. Nightingales have vocal repertoires of about 180 different song types per male and thus are amongst the most versatile song bird species. Some of these song types invite to be categorized according to acoustic characteristics. For example, whistle songs stick out and are hypothesised to be important to attract migrating females. Another potential category with specific communicative functions might be the so called ‘buzz song types’. Buzzes are syntactically and acoustically peculiar elements at the beginning of certain song types. These elements are produced by very fast repetitions of subunits in a narrow and rather low frequency range. We conducted playback experiments with different numbers of buzz songs to examine whether songs with buzz elements are indeed perceived as a song category by male and female nightingales. Playbacks conducted with free living spontaneous singing males did not reveal different responses to playbacks with different numbers of buzz songs. In contrast, high proportions of buzz songs did evoke stronger arousal responses in captured female nightingales. We will discuss these differences in male and female responses with regard to constraints in their production and their potential importance in close range communication.

Zebra finches memorize a song during a critical period somewhere after post-hatching day (PHD) 25. They then progressively form their own song through a sensorimotor process of matching their own vocal output with the stored memory of the tutor song. Here we show that early testosterone treatment induces premature song development. This premature singing activity involves all forebrain control region as judged from expression of the immediate early gene ZENK while the direct connection between HVC and RA of the descending song control pathway is not yet functional. The young testosterone males were exposed to the tutor song only until PHD 25 but were nevertheless able to produce copies of the tutor song in adulthood in difference to males that were not exposed to a tutor or exposed to a tutor but not treated with testosterone. The prematurely singing males show signs of sensory-motor leaning only after PHD 35 when the HVC-RA synapse is formed. Thus testosterone advances the sensitive period for song sensory learning while sensorimotor learning requires the direct synaptic connection between HVC and RA.

Calls of the Indian jungle crow as well as the Indian house crow have been recorded at some typical urban habitats in Bangalore city. Calls of the jungle crow were also recorded at the field station of Indian Institute of Science at Mudumalai National Park in Tamilnadu, India. Spectrograms of the calls were obtained and analyzed with Raven-Pro software. Between the two species of crows found in Bangalore city, house crows are found to be more capable than the jungle crow in producing vocalizations with wide spectrum and higher frequency components (15 kHz to 18 kHz or even more). Jungle crows on the other hand, are found to be more competent with regards to producing vocalizations with significant low frequency components (400 Hz to 800 Hz). A comparison between the calls of jungle crow at Mudumalai field station of IISC and those at urban habitat sites in Bangalore city reveals that jungle crows tend to produce vocalizations at higher frequencies in urban situations though they are not able to match the performance of house crows in this regard.

The recognition of food-provisioning parents is crucial for fledglings of many bird species. Vocalisations are the most commonly used cues in parent/offspring communication and it is well established that fledglings respond specifically to their parents’ contact calls. However, fledglings occasionally also react to unrelated adults. Such responses may reflect recognition errors and be related to the similarity in individual signatures among contact calls. In a playback experiment we tested whether zebra finch fledglings perceive variation in call signatures to recognize their parents individually, and whether recognition errors, i.e. the response to unrelated individuals, are related to signal properties of male and female calls? We demonstrate that fledglings are able to individually discriminate between their mother and father and reacted more and stronger to unrelated females compared to unrelated males. Male calls are learnt and show high intra-sexual variation, thereby facilitating the accurate recognition of the father’s individual signature. In contrast, contact calls of adult females are innate, show low intra-sexual variation and the mother’s call is more likely to be confused with another female call. These findings demonstrate the importance of variation in identity signals for individual recognition processes in parent/offspring communication and highlight the importance of recognition errors for understanding the costs and benefits of individual signatures.

After many studies conducted in bird species, it is now understood that most sexually selected traits are evolutionary signals that females use to select males with particular characteristics. The presence of multiple traits, such as song and coloration, can either signal different characteristics or be redundant. In the latter case, traits should be strongly correlated between individuals. Previous studies conducted in our laboratory have shown that both coloration and male song are sexually selected traits in the Serin (Serinus serinus), a small cardueline finch. The species is sexually dichromatic, with males presenting intense yellow coloration, with high concentration of carotenoids. Also, male serins sign songs at a very fast rate of sound production, maintaining high frequency amplitude, sustaining the production of very complex elements far beyond the Podos triangle. We recorded songs of a group of males of a wild population during breeding and measured their coloration by spectrophotometry in order to assess if the two traits were correlated between individuals. We found that song variables and coloration were not correlated in our sample, indicating that these two traits signal distinct things for their conspecifics.