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... songs are composed of a series of notes repeated at a constant or nearly constant frequency (Fig. 1A, B) (Table 1). The mean duration [?SD] of individual notes was 30.32 ? 6.06 msec (N = 5982) while the mean internote interval was 25.01 ? 3.79 msec (N = 5796) in duration. The duration of successive notes within bounce songs differed significantly (F = 93.34, P < 0.001). Typically, the duration of successive notes in- creased in the first ...
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... < 0.001). Typically, the duration of successive notes in- creased in the first part of a song, peaked, then decreased (Figs. 1, 2). The longest note in a typical bounce song was 1.86 times as long (N = 20 owls, Range = 1.55-2.50) ...
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... peaked, then decreased (Figs. 1, 2). The longest note in a typical bounce song was 1.86 times as long (N = 20 owls, Range = 1.55-2.50) as the shortest note. The duration of successive intemote intervals also varied within songs (F = 52.39, P < 0.001). Internote duration typically was longer at the beginning and again at the end of a "bounce" song (Figs. 1A, B; 2). Individual differences were observed in the pattern of variation for both note and internote duration (Fig. 3). For all owls combined (N = 20) the note with the longest duration was note 15 (Fig. 2); however, among individuals the note with the longest duration ranged from note 5 to note 25 (Fig. 3). Although the internote duration ...
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... variation in note structure was also observed (Fig. 1A, B). Individual owls consistently uttered notes with the same structure. Two individuals that we recorded over a period of more than one year showed no change in the structure of "bounce" song ...
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... "whinny" song has been described as a "quavering whistle (mono- tone or descending)" (Robbins et al. 1983:174). Typically, the initial part of the song exhibited a slight increase in frequency, while the latter part of the song was characterized by a gradual decrease in frequency (Fig. 1C). ...
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... "whinny" song has been described as a "quavering whistle (mono- tone or descending)" (Robbins et al. 1983:174). Typically, the initial part of the song exhibited a slight increase in frequency, while the latter part of the song was characterized by a gradual decrease in frequency (Fig. 1C). The last part of "whinny" songs often exhibited a series of rapid frequency modulations (Fig. 1C). One-way analysis of variance revealed significant individual differences (P < 0.001) for every parameter ex- amined (Table ...
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... as a "quavering whistle (mono- tone or descending)" (Robbins et al. 1983:174). Typically, the initial part of the song exhibited a slight increase in frequency, while the latter part of the song was characterized by a gradual decrease in frequency (Fig. 1C). The last part of "whinny" songs often exhibited a series of rapid frequency modulations (Fig. 1C). One-way analysis of variance revealed significant individual differences (P < 0.001) for every parameter ex- amined (Table ...
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![Figure 2. A song flowchart. [1]](profile/Alex-Ruthmann/publication/267206850/figure/fig1/AS:669539163439107@1536641984202/A-song-flowchart-1_Q320.jpg)
Universidad Internacional de La Rioja Máster Oficial en Investigación Musical Sonoridades ancestrales en la comunidad de Kotama del cantón Otavalo. Descripción y análisis técnico musical Trabajo fin de máster presentado por: Daniel Flores Días
Citations
... This does not necessarily require the ability to tell an individual apart from the rest of the population based on unique characteristics, that is, true individual recognition (Lambrechts & Dhondt, 1995;Tibbetts & Dale, 2007;Carlson et al., 2020). Many Strigiformes exhibit individually distinctive vocalizations (Cavanagh & Ritchison, 1987;Fitton, 1991;Galeotti & Pavan, 1991;Otter, 1996;Freeman, 2000;Lengagne, 2001;Holschuh & Otter, 2005;Rognan et al., 2012;Odom et al., 2013) and that is also the case for scops owls (Koenig, 1973;Galeotti & Sacchi, 2001;Dragonetti, 2007). It is therefore plausible that individuals discriminate between two familiar neighbours based on their vocal signatures. ...
Territorial animals often reduce aggression towards familiar neighbours compared to unfamiliar conspecifics. However, variation in the response to different neighbours is less known. In this work, I examined the territorial behaviour of male scops owls during countersinging interactions with two familiar neighbours and I asked whether vocal behaviour of the focal male reflected dear-enemy relationships. Analysis revealed that the focal male’s vocal frequency was associated with (1) the degree of instability of the territory boundary shared with a neighbour and (2) the motivation to persist in the dyadic interaction with that neighbour. Patterns of movement directed to specific individuals suggest that scops owls do discriminate between neighbours. A case of partial territory takeover was observed that was accompanied by temporal changes in vocal frequency in one of the opponents, confirming that vocal frequency is a flexible, context-dependent feature of the relationship of neighbouring scops owls.
... It is possible that the occurrence of vocal dimorphism has been statistically investigated in fewer than a dozen (e.g. Cavanagh and Ritchison 1987;Herting and Belthoff 2001;Grava et al. 2007;Odom and Mennill 2010) of the approximately 223 species in Strigidae (König and Weick 2008). Furthermore, female vocalizations of several species have been described as sounding more raucous than those of males (Lundberg 1980;Marshall et al. 1991;Galeotti 1998;Sick 1997;Cramp 1985 as cited in Appleby et al. 1999), though this has never been investigated in detail. ...
... The longer song duration of males in the sub-sample of sexed individuals is contrary to what was described for the Eastern Screech Owl Megascops asio (Cavanagh and Ritchison 1987) and S. varia (Odom and Mennill 2010). ...
The occurrence of vocal dimorphism in strigid owls has been known for a long time and it is widely accepted that males emit songs with lower frequency than those of females. However, there are several gaps in our knowledge about this phenomenon, which may be related to a scarcity of sound recordings of sexed individuals and difficulties in obtaining this kind of material. In this paper, we present a novel permutation-based analysis that allows the study of vocal dimorphism using recordings of unsexed individuals presumably forming breeding pairs. We used this method to investigate vocal dimorphism in the Tawny-browed Owl (Pulsatrix koeniswaldiana) alongside more conventional t tests, applied only to a subsample of individuals of known sex. Our results indicate that males of P. koeniswaldiana emit songs with lower frequencies and a narrower frequency range than those of females. There was also some evidence, which emerged only from the analysis of sexed individuals, that males emit longer songs with fewer harmonics. Even though our novel method does not estimate dimorphism directly and does not show its direction, it allows investigating it in a relatively easy and economical way and seems promising to help increase our knowledge about vocal dimorphism in strigids and other taxa.
... La variación temporal en vocalizaciones fue determinada en un estudio realizado con el Cárabo Lapón (Strix nebulosa) donde una de las hembras muestreadas un año anterior presentó una llamada totalmente distinta el siguiente año (Rognan et al., 2009). Sin embargo, la mayoría de los estudios de individualidad vocal, sugieren que las aves como los búhos que adquieren su vocalización innata, presentan una estabilidad entre temporadas (Cavanagh y Ritchison, 1987;Galeotti et al., 1993;Appleby y Redpath, 1997;Hill y Lill, 1998;Peake et al., 1998;Delport et al., 2002). La otra posible opción es la existencia de una rotación total de individuos entre temporadas en los territorios muestreados, como sucede con otros búhos, como lo reportado por Galeotti y Sacchi (2001) para el Autillo Europeo con una rotación entre el 55% y el 78% de los individuos entre temporadas. ...
La comunicación acústica es de vital importancia para las aves de hábitos nocturnos como los búhos, donde la comunicación visual es problemática. Por lo cual, el reconocimiento entre conespecíficos a través de la individualidad vocal tiene un papel fundamental en la comunicación de los búhos y puede servir como un método alternativo de monitoreo. Dado este hecho, evaluamos las características individuales de las vocalizaciones territoriales y agonísticas del Búho Café, teniendo como objetivo determinar si existen diferencias significativas en sus vocalizaciones que permitan identificar a los individuos residentes de la Reserva de la Biosfera Chamela-Cuixmala, Jalisco. La obtención de las grabaciones de las vocalizaciones de los individuos del Búho Café se realizó entre julio y agosto de 2017 y 2018, a través de monitoreos nocturnos en ocho estaciones de grabación establecidas en los senderos de la Estación de Biología Chamela. Las grabaciones de los llamados fueron analizadas a través de la extracción directa y semiautomática de las características temporales y de frecuencia de los espectrogramas. Se realizaron tres análisis estadísticos para evaluar las diferencias vocales entre individuos. Los Análisis de Función Discriminante sobre los parámetros acústicos de las vocalizaciones mostraron en ambos años el 100% de las hembras y 100% de los machos fueron clasificadas correctamente, con la agrupación de las repeticiones vocales de cada individuo de acuerdo a sus características acústicas. Además, el Árbol de Regresión mostró una elevada correcta clasificación del 100% de los machos y de 96.6% a 100% de las hembras dentro del mismo año. Asimismo, se mostró algunos individuos de 2017 clasificados dentro de los individuos del 2018, pero en lo general el análisis clasificó correctamente el 95% de las hembras y 98.9% de los machos como individuos distintos entre años. En cambio, las pruebas de Mantel mostraron bajos coeficientes de correlación de espectrogramas y de contorno de las vocalizaciones del Búho Café (promedio: r = 0.26, rango: r = 0.11 a 0.53), indicando que las características acústicas individuales están débilmente correlacionadas con la identidad de individuos. Las variables acústicas con mayor discriminación entre individuos del Búho Café fueron la frecuencia delta y la frecuencia mínima para las hembras, y el número de notas y la duración del llamado entre los machos, siendo estas las variables con mayor influencia en los análisis de función discriminante, árbol de regresión y potencial de codificación individual. Sin embargo, se requiere al menos cinco variables acústicas para lograr la discriminación individual del Búho Café. La elevada correcta clasificación individual sugiere que las vocalizaciones del Búho Café presentan diferencias significativas que permiten identificar a los individuos de la Reserva de la Biosfera Chamela-Cuixmala, Jalisco, a través de sus características vocales. Es por ello que se plantea el uso de la bioacústica como herramienta principal en futuros estudios poblacionales del Búho Café.
... In some species, female and male songs are distinct and frequent enough to allow estimates of population size for each sex based on their vocalizations. For example, the hoots of many owl species are sexspecific, and mated pairs of some species combine their calls into duets (e.g., Cavanagh and Ritchison 1987, Appleby et al. 1999, Grava et al. 2008, Odom and Mennill 2010. This sex-specificity could allow researchers to estimate the frequency of unpaired and paired individuals of both sexes across a population using acoustic surveys alone. ...
Research on bird song has contributed to important advances in diverse biological fields from neurobiology to conservation biology. Bird song has traditionally been studied as an elaborate male trait, but female song is also widespread in both temperate and tropical species and likely evolved in the early ancestors of modern songbirds. However, female song is underrepresented in biological collections compared to male song, and we lack documentation of female songs for most songbird species. Better documentation of female bird song is necessary for an understanding of the prevalence, regulation, function, evolution, and conservation applications of avian vocalizations. Therefore, we call on all researchers to disseminate their observations of female bird song, and to spread the word among other researchers, students, field technicians, and citizen scientists that many female songbirds sing. To this end, we provide resources for disseminating recordings and written documentation of female song, including best practices for documentation, venues for archiving and publishing, and our citizen science project, the Female Bird Song Project. We especially appeal to researchers studying marked populations who can accurately assess sex-specific singing behavior. Documenting female song across many species and geographic regions is a major endeavor. By working collectively, we can make the greatest progress toward applying the resultant knowledge to a wide variety of fields.
... For birds, vocal individuality has been documented extensively in passerines and seabirds over the last four decades (Beer 1970, Falls 1982, Freeman 2000, Favaro et al. 2015. By the late 1980s, vocal individuality had been employed to study secretive or nocturnal species, which are often widely dispersed and relatively difficult to locate and capture (Cavanagh and Ritchison 1987, Eakle et al. 1989, Galeotti and Pavan 1991, McGregor and Byle 1992 To be useful for assessing vocal individuality, the recorded vocalizations must have a set of variables that can be repeatedly measured with both low within-individual variation and high between-individual variation (Terry et al. 2005, Nagy andRockwell 2012). The vocalizations should also stay constant over time to allow reidentification and monitoring of same individuals over many years (Delport et al. 2002, Terry and McGregor 2002, Terry et al. 2005, Nagy and Rockwell 2012. ...
... Although we did not assess the intersexual differences in vocalizations of Sunda Scops-Owls, we suspected that such differences do exist due to the distinct differences in the call frequency for both sexes in our recordings of duets. Sexual differences have been reported in a few owl species, including Eastern Screech-Owls (Cavanagh and Ritchison 1987), Western Screech-Owls (Herting and Belthoff 2001), Eurasian Eagle-Owls (Grava et al. 2008), and Barred Owls (Odom and Mennill 2010). The differences in the vocal characteristics of the sexes for these owl species were sufficient to provide reliable sexing. ...
Like many owl species, Sunda Scops-Owls (Otus lempiji) are difficult to monitor using traditional survey techniques, because of their nocturnal habits, secretive nature, and cryptic coloration. Individual variation in vocalizations could potentially be used to distinguish individuals of this owl species, as has been demonstrated for many bird species. The objectives of this study were to describe the territorial call of Sunda Scops-Owls, to determine whether the calls can be distinguished individually, and to examine whether the calls from the same individuals were stable over time. We analyzed 75 recordings collected from 12 owls from December 2014 to June 2015 in a lowland forest and oil palm smallholdings in Selangor State, Peninsular Malaysia. Using two temporal parameters and six frequency parameters derived from spectrogram, we employed ANOVA tests and found significant differences for all parameters among individual owls. Discriminant function analysis correctly classified 97.1% of the owl calls to the correct individuals. Based on the Wilcoxon signed-rank test, all vocal parameters did not vary significantly for the six birds that were vocally active over two predetermined survey sessions within the breeding period. Our results demonstrated that Sunda Scops-Owls can be identified individually by their vocalizations. This implies that assessing vocal individuality can be useful as a noninvasive method for surveying the Sunda Scops-Owls and the method should be further tested for other little-known owl species in the tropics.
... IntRODUCtIOn the functions of male song are to attract a breeding partner, to assert territorial ownership, to communicate individual identity, to maintain contact with conspecifics and to synchronise activities (thielcke, 1962). Individual vocal variability of owls has been extensively studied over the past two decades, e.g. by Cavanagh and Ritchison (1987;Megascops asio), galeotti and Pavan (1991;Strix aluco), galeotti et al. (1993; Glaucidium passerinum), Otter (1996; Aegolius acadicus), hill and lill (1998; Ninox natalis), freeman (2000; Strix varia), galeotti and Sacchi (2001; Otus scops), lengagne (2001; Bubo bubo), Delport et al. (2002;Strix woodfordii), terry et al. (2005; Otus insularis), tripp and Otter (2006; Megascops kennicottii), Rognan et al. (2009;Strix nebulosa) and Odom et al. (2013;Bubo virginianus). variability among individuals and constancy within the individual has been often proven, as an adaptation that assures individual recognition when the use of alternative cues, such as visual communication, is limited because of nocturnal habits. ...
Territorial calls (hooting) of two tawny owl subspecies, Strix aluco aluco (the eastern European subspecies) and Strix aluco willkonskii (the Caucasian subspecies), were recorded from
October 2007 to february 2013, to study variation between individuals and subspecies. Calls of the
eastern European subspecies were recorded in Moscow region (Russia) and “gomolshanskie lesa” national Park (Ukraine). Males of the Caucasian subspecies were recorded in “bolshoi Utrish”
Reserve and “Sochinskii” national Park (Russia). the territorial calls of the eastern European and
Caucasian subspecies are compared for the first time. the discriminatory accuracy of individual
calls reached 98% for S. a. aluco and 77% for S. a. willkonskii when accounting for six frequency
and temporal parameters of their call. We found the call of the two subspecies to differ in half of the
acoustic parameters considered, suggesting that macrogeographic variation between the Eastern
European and Caucasian subspecies may have taken place.
... Such species are usual in many taxa: among geese, cranes, rails, raptors, owls, parrots, doves, auks, shearwaters and some passerines (e.g. Clapperton 1983;Cavanagh and Ritchison 1987;Carlson and Trost 1992;Ballintijn and ten Cate 1997;Smith and Jones 1997;Venuto et al. 2001;Eda-Fujiwara et al. 2004;Volodin et al. 2005aVolodin et al. , 2009Klenova et al. 2012). Sexing monomorphic birds represents a problem in both captive and wildlife management, e.g., in forming pairs for breeding and estimating sex ratios during censuses. ...
... The fundamental frequency of "bounce" of the Eastern Screech-owl (Otus asio), emitted in response to playbacks of species-specific calls, was lower in males than in females (720 and 820 Hz, respectively) (Cavanagh and Ritchison 1987). ...
Zoo and wildlife management faces a problem with bird sexing, as many bird taxa have indiscernible gender differences in size and coloration. Problematic groups are geese, cranes, rails, raptors, owls, parrots, doves, auks, shearwaters and some passerines. Commonly accepted invasive sexing techniques based on genetics, laparoscopy, morphometric and on cloacal inspection, are all needed in bird capturing and handling. Capturing and subsequent manipulations may be inapplicable for free-ranging birds, whereas distant voice-based sexing is relevant for many species. This review evaluates the potential for noninvasive sexing by separate calls or duet calls, for adult birds of 69 species from 16 orders and for chicks of 11 species from 7 orders. For adult birds of 25 species, a single call per individual was sufficient for 100 % reliable sexing by ear or using spectrographic analysis. For chicks, the potential for voice-based sexing seems to be very limited. For birds calling rarely or unpredictably, we propose a simple way of provoking vocalization using playbacks of species-specific calls that are available from sound libraries. We conclude that sexing by voice may represent a feasible alternative to the classical sexing techniques, both in the wild and in captivity.
... Individual and sex recognition is important for multiple species, and vocal communication is a common way of such recognition in birds (e.g., Falls 1982). Vocalizations allow for recognition even over long distances or when other ways of contact are not sufficient, e.g., in dense vegetation or in the dark (Cavanagh and Ritchison 1987;Neuchterlein and Buitron 1992;Jouventin 1998, 2002;Aubin et al. 2000, Herting andBelthoff 2001;Bourgeois et al. 2007;Cure et al. 2009). ...
Vocal individuality provides a method of personalization for multiple avian species. However, expression of individual vocal features depends on necessity of recognition. Here we focused on chick vocalizations of demoiselle, Siberian and red-crowned cranes that differ by their body size, developmental rates and some ecological traits. Cranes are territorial during summer, but gather in large flocks during autumn and winter. Nevertheless, parents keep feeding their chicks, even on winter grounds, despite the potential of confusing their own and alien chicks. Here we aimed to compare expression of individuality and sex in calls of three crane species between solitary and gregarious periods of a chick’s life, and between species. We found significant individual patterns of acoustic variables in the calls of all three species both before and after fledging. However, only red-crowned crane chicks increased expression of individuality significantly after the fledging. Also, we found that chicks of all three species significantly increased occurrence of non-linear phenomena, i.e., irregular oscillations of sound-producing membranes (biphonations, sidebands, and deterministic chaos), in their calls after fledging. Non-linear phenomena can be a way of increasing the potential for individual recognition as well as avoiding habituation of parents to their chicks’ calls. The older chicks are, the less their parents feed them, and chicks benefit from keeping the permanent attention of their parents in the course of early ontogeny.
... The absence of obvious differences in coloration, ornamentation, and size is commonly associated with vocal differentiation. Indeed, vocal dimorphism has been found in many species without visual sexual dimorphism, e.g., the Eastern Screech-Owl (Otus asio; Cavanagh and Ritchison 1987), Yelkouan Shearwater (Puffinus yelkouan; Bourgeois et al. 2007), and White-faced Whistling-Duck (Dendrocygna viduata; Volodin et al. 2005). We assume that vocal sexual dimorphism facilitates identification of sex when visual cues are not available. ...
Sex-related and individually unique vocal features have been demonstrated for many avian and mammalian species. Vocal identity may depend on a call's function and vary within the repertoire of a single species. Vocal features of different call types are very rarely compared in one species. We studied the potential for vocal recognition of sex and individual identity in four types of calls of the White-naped Crane (Grus vipio). We analyzed growls and contact calls (short-range communication) and flight-intention and guard calls (long-range communication). Sexual features were strongly expressed in flight-intention and guard calls; furthermore, the guard call allows reliable sexing of a bird. The sexual distinctiveness of short-range calls was less pronounced. We failed to find significant individual features in any call type. The potential for determining sex from vocalizations may be useful for the monitoring of this endangered species.
... All birds, including non-passerine species such as terns and owls, appear to have some degree of individual variation in their vocalizations (Hutchison et al., 1968;Miller, 1978;Wooller, 1978;Moseley, 1979;Cavanagh & Ritchison, 1987;Galleotti et al., 1993;Robisson et al., 1993;Peake et al., 1998;Delport et al., 2002;Lovell & Lein, 2004Wiley, 2005). Indeed, there is no reason to expect less individual variation in behavior, such as birdsong, than in morphology. ...
Unlike in temperate forests, bird communities in neo-tropical forests are largely composed of species of Tyranni, or suboscines, a suborder of passeriform birds that do not learn their songs. Thus, songs of suboscines are typically acoustically simple compared to the complex songs of Passeri, the oscine passeriforms. While a great deal is known about oscine song, few descriptions of the repertoires of tropical suboscines have been published, and relatively little is known about the use and function of song in suboscines. Additionally, whether suboscines can recognize individuals by voice alone has received little attention. One representative of these tropical suboscines is the buff-throated woodcreeper (Xiphorhynchus guttatus, Dendrocolaptinae), a bird commonly found in the forests of the tropical Americas. To investigate the possibility for individual variation in songs of this species, we recorded buff-throated woodcreepers at dawn and dusk in Amazonian Perú. From these recordings, we document two long-range song types, describe their acoustic parameters, and examine their occurrence at different times of day and across two seasons. Quantitative analysis of frequency, timing, and pattern of songs revealed that woodcreeper vocalizations varied significantly among individuals. A discriminant function analysis of song parameters successfully assigned a majority of songs to the correct individual. Despite their relatively simple structure, the vocalizations of buff-throated woodcreepers vary consistently among individuals but apparently not so distinctly as those of many oscines. Questions remain regarding whether the buff-throated woodcreeper can use these differences for individual recognition and how the two song types function in communication.
