Song Variation Research Articles

Asymmetric song recognition does not influence gene flow in an emergent songbird hybrid zone

Abstract Hybrid zones can be used to examine the mechanisms, like song recognition, that affect reproductive isolation and speciation. Song has mixed support as a driver of speciation; we did not find song to be associated with reproductive isolation in White-crowned Sparrow subspecies (Zonotrichia leucophrys pugetensis and Z. l. gambelii). We examined an emerging secondary contact zone in these subspecies by measuring song variation, song recognition, plumage, morphology, and mitochondrial DNA (mtDNA). Plumage and morphological characters provided evidence of hybridization in the contact zone, with some birds possessing intermediate phenotype and song characteristics, and some possessing discordant phenotype and mitochondrial haplotype. Playback experiments revealed asymmetric song recognition: male pugetensis displayed greater response to their own song than gambelii song, whereas gambelii did not discriminate significantly. If female choice operates similarly to male song discrimination, we predicted asymmetric gene flow, resulting in a greater number of hybrids with gambelii mtDNA. Contrary to our prediction, more gambelii and putative hybrids in the contact zone possessed pugetensis mtDNA haplotypes, possibly due to greater pugetensis abundance and female-biased dispersal.

Within-population song evolution in white-throated sparrows (Zonotrichia albicollis)

Abstract Cultural evolution of birdsong occurs when songs change over generations and such changes can spread directionally or via drift within populations. We describe the emergence and directional spread of a novel song variant within a population of White-throated Sparrows in central British Columbia, Canada. Birds in this population have been singing a doublet-ending song since the early 2000s. In 2015, we detected a novel variant, consisting of a doublet-ending song with a distinctive amplitude modulation in the first note (Modulated-Doublet). We banded and recorded birds from 2015 to 2020 and classified songs using both audio and spectrographic analysis. The proportion of birds singing the Modulated-Doublet increased, replacing the Unmodulated-Doublet over time. Additionally, the modulation became more pronounced, both across the population and within individual birds, over successive years. The rapid spread suggests there may be several transmission biases driving the adoption of this novel song over the older established variant.

Kültürel Perspektiften Diyarbakır Ermeni Müziği

Diyarbakır Ermeni toplumu yaşamış olduğu topraklarda tarih boyunca gerçekleşmiş birçok diasporalar ve değişimlere karşın, kültürel zenginliğini günümüze kadar ulaştırmıştır. Osmanlı dönemiyle birlikte Ermeniler, Anadolu’nun birçok yerleşkesinde Türkler ile kültürel birliktelik sürdürerek örf, adet, edebiyat ve musiki açısından Türk kültürünü de örnek almışlardır. Birçok medeniyete ev sahipliği yapan Diyarbakır, Ermeni toplumuna burada yaşayan toplumla iç içe yaşam olanağı sağlamıştır. Ermeni toplumu ve Diyarbakır halkı, süreç içerisinde birbirleriyle yakın ilişki kurarak birçok konuda olduğu gibi müzik alanında da birbirlerini etkilemiş ve zengin bir müzik kültürünün ortaya çıkmasını sağlamıştır. Literatür taraması ve alan araştırmasında Ermeni toplumu müzik insanları ile yapılan görüşmelerden elde edilen veriler ışığında oluşturulan çalışma, Diyarbakır’da yaşayan Ermeni toplumu özelinde gerçekleştirilen müzik uygulamalarının Türk müziği ile olan etkileşimi kültürel perspektifte değerlendirilerek, icrası sağlanan eserlerin ağırlıklı olarak aşk, ağıt, maya, hoyrat, uzun hava ve halk oyunları gibi temalardan oluştuğu tespitlerini içermektedir. Sanatın en geniş etkileşimi olan müzik, bu coğrafyada yaşayan toplumların müzik kültürünü yıllarca içinde barındırma duygusunu yansıtmaktadır. Diyarbakır’da yaşayan Ermeni toplumunun müzik dinamikleri, ortak olmayan bir dil ile karşımıza çıkmaktadır. Burada ortaya çıkan türkülerin sözel farklılıklarının asıl sebebi, iki farklı toplumun farklı iki dili konuşmasıdır. Müziğin yoruma açık üslubu ve anlam zenginliği aynı sanat perspektifi ile ayrı dillerde ifade edilmektedir. Araştırmada toplumların önemli yapı taşlarından biri olan müzik ögesi, sosyolojik yapıda bıraktığı izleri ile kültürel perspektifte Diyarbakır Ermenileri özelinde betimlenmiştir.

Subspecies Taxonomy and Inter-Population Divergences of the Critically Endangered Yellow-Breasted Bunting: Evidence from Song Variations.

Simple SummaryIdentifying the taxonomic status of subspecies or population with independent evolutionary tendencies is important for the targeted conservation of endangered species. Two subspecies of the critically endangered, Yellow-breasted Bunting Emberiza aureola have long been classified: E. a. aureola and E. a. ornata. However, populations distributed in Hokkaido, Japan, are sometimes considered another subspecies of E. a. insulana. By comparing vocal divergences, we found that the song of the Yellow-breasted Bunting Emberiza aureola has subspecies-specific properties and that insulana can be classified acoustically as a subspecies. Morphological and genetic differences should be tested further to confirm its subspecies status. Our results not only confirm the subspecies but also provide key evidence for targeted taxon conservation efforts for this critically endangered bird species, given that several Japanese populations have disappeared.The critically endangered Yellow-breasted Bunting has undergone population collapse globally because of illegal hunting and habitat deterioration. It was listed as critically endangered (CR) by the International Union for Conservation of Nature (IUCN) in 2017 and designated a Class I (highest level) national conservation bird species in China in 2021. Birdsong in the breeding season is the main communicative signal under sexual selection, and song variations have long been considered critical evidence of divergence among subspecies or populations. We compared the songs of 89 males from 18 populations to test subspecies taxonomy. We found that songs of the Yellow-breasted Bunting Emberiza aureola are subspecies specific and that three subspecies can be clearly discriminated by song divergences. Moreover, an analysis of multiple vocal traits supports the claim that insulana is distinct from aureola and ornata. Finally, at the geographic population level, populations can be clearly classified in accordance with the three subspecies, although the aureola population in Xinjiang, China is differentiated from other populations of the same subspecies. The results of this study demonstrate that all populations and subspecies are unique and should be protected to maintain intraspecies song diversity. In addition, several specific populations, such as insulana populations in Japan and the Xinjiang, China population of aureola, need to be paid special attention to prevent the extinction of unique or local taxa.

« Héros suicidaires » en orbite d’un désir d’anéantissement. À propos de… « Le Complexe de Samson. Héros suicidaires de l’épopée biblique » de Franklin Rausky

Song learning is a prime example for cultural transmission of a mating signal. Local or individual song variants are socially learned early in life and adults sing and prefer these songs. An unresolved issue in this context is the question of how learned preferences for specific variants generalise to songs sufficiently similar to the original model. Here we asked whether female zebra finches would generalise early learned song preferences along a similarity gradient based on syllable sharing between test and tutor songs. For each female, this gradient consisted of their tutor’s (father’s) song (F), two variants of unfamiliar songs edited to share 2/3 (F2/3) and 1/3 (F1/3) of syllables with father’s song and an unfamiliar song (UF) not sharing any syllables with the father’s song. Females’ preferences were measured in a 4-way operant choice arena where birds could perch on different operant perches to trigger playbacks of the four different songs. Number and duration of perch visits were positively associated with the number of syllables that the assigned stimuli shared with fathers’ songs. These results suggest that female zebra finches generalise early learned song preferences to songs sharing syllables (and/or voice characteristics) with songs learned early in life.

Generalisation of early learned tutor song preferences in female zebra finches (Taeniopygia guttata)

Song learning is a prime example for cultural transmission of a mating signal. Local or individual song variants are socially learned early in life and adults sing and prefer these songs. An unresolved issue in this context is the question of how learned preferences for specific variants generalise to songs sufficiently similar to the original model. Here we asked whether female zebra finches would generalise early learned song preferences along a similarity gradient based on syllable sharing between test and tutor songs. For each female, this gradient consisted of their tutor’s (father’s) song (F), two variants of unfamiliar songs edited to share 2/3 (F2/3) and 1/3 (F1/3) of syllables with father’s song and an unfamiliar song (UF) not sharing any syllables with the father’s song. Females’ preferences were measured in a 4-way operant choice arena where birds could perch on different operant perches to trigger playbacks of the four different songs. Number and duration of perch visits were positively associated with the number of syllables that the assigned stimuli shared with fathers’ songs. These results suggest that female zebra finches generalise early learned song preferences to songs sharing syllables (and/or voice characteristics) with songs learned early in life.

No evidence of repeated song divergence across multiple urban and non-urban populations of dark-eyed juncos (Junco hyemalis) in Southern California.

Urbanization can affect species communication by introducing new selection pressures, such as noise pollution and different environmental transmission properties. These selection pressures can trigger divergence between urban and non-urban populations. Songbirds rely on vocalizations to defend territories and attract mates. Urban songbirds have been shown in some species and some populations to increase the frequencies, reduce the length and change other temporal features of their songs. This study compares songs from four urban and three non-urban populations of dark-eyed juncos (Junco hyemalis) throughout Southern California. We examined song length, trill rate, minimum frequency, maximum frequency, peak frequency and frequency bandwidth. We also compared songs recorded from one urban junco population in San Diego nearly two decades ago with recently collected data in 2018–2020. Over all comparisons, we only found significant differences between UCLA and the 2006/2007 UCSD field seasons in minimum and maximum frequencies. These findings partially support and are partially in contrast to previous urban song studies. As urban areas expand, more opportunities will arise to understand urban song divergence in greater detail.

A highly anomalous Red-winged Blackbird (<i>Agelaius phoeniceus</i>) song

Red-winged Blackbird (Agelaius phoeniceus) is a highly vocal species with a repertoire of similar, yet acoustically distinct songs. These songs may be altered drastically if, as a nestling, the male goes deaf or becomes acoustically isolated. In deaf Red-winged Blackbirds, these dramatic song alterations may present as songs bearing slight resemblance to the introductory phrase of their normal song. Here, we present a Red-winged Blackbird song observed in Ottawa, Ontario, Canada, that is far outside any normal variation in Red-winged Blackbird songs. Given the individual’s age and the consistency of the anomalous song, it is possible that this is a deaf bird.

Cultural transmission of traditional songs in the Ryukyu Archipelago.

Geographic patterns of cultural variations are affected by how cultural traits are transmitted within and between populations. It has been argued that cultural traits are transmitted in different manners depending on their characteristics; for example, words for basic concepts are less liable to horizontal transmission between populations (i.e., borrowing) than other words. Here we examine the geographic variation of traditional songs in the Ryukyu Archipelago, southwestern islands of Japan, to explore cultural evolution of music with a focus on different social contexts in which songs are sung. Published scores of 1,342 traditional songs are coded using the CantoCore song classification scheme and distances between the songs are calculated from the codings. Neighbor-Net graphs of regions/islands are generated on the basis of the musical distances, and delta scores are obtained to examine the treelikeness of the networks. We also perform analysis of molecular variance (AMOVA) to evaluate the extent of musical diversification among regions/islands. Our results suggest that horizontal transmission between populations has played a greater role in the formation of musical diversity than that of linguistic diversity in the Ryukyu Archipelago and that the social context in which songs are sung has an effect on how they are transmitted within and between populations. In addition, we compare the observed patterns of song diversity among regions/islands with those of lexical and mitochondrial-DNA (mtDNA) diversity, showing that the variation of songs sung in the "work" context are associated with the linguistic variation, whereas no association is found between the musical and genetic variation.

Individual variation in song of Black-throated Divers (Gavia arctica)

The intention of the study was to determine whether male Black-throated Divers (Gavia arctica) can be distinguished individually by their vocalization. The songs of 19 male Black-throated Divers (BTDs) were recorded in their territories in the same lake area in 2018–2021 in Finland. The songs were recorded in one year in nine territories and in 2–4 consecutive years in ten territories. The song consists of one introductory phrase and one or more repeat phrases. Seventeen variables were measured from the spectrograms of the introductory phrase and the first repeat phrase. These variables included the frequencies and duration of different parts of the spectrogram. The discriminant analyses were used to examine the recognition of individual BTDs based on the spectral analysis of the male yodels (n = 297) in different territories (n = 19). The discriminant analysis showed that when using 14 of the variables of the yodels, the discriminant analysis classified the yodels to correct territories at a rate of almost 98% based on the cross-validation of all data. This suggests that the same individuals defend their territory from year to year.

Microgeographical variation in birdsong: Savannah sparrows exhibit microdialects in an island population

Social communication often involves vocal learning, whereby young animals learn their vocalizations early in life by imitating the sounds of adults. In animals that learn their vocalizations, it is common to find patterns of geographical variation known as ‘vocal dialects’, acoustic features shared within a cluster of animals that differ from the vocalizations of animals in nearby clusters. Dialects may form when animals learn their vocalizations early in life and then disperse short distances, or when they modify their vocalizations to match local vocal patterns after dispersal. Dialects are typically studied at a regional or continental scale, but they may also persist at smaller scales in so-called ‘microgeographical song dialects’ or ‘microdialects’. Microdialects have received little research attention. In this study, we investigate microdialects and dispersal distance in song-learning Savannah sparrows, Passerculus sandwichensis, through a 4-year study of birds living on three islands in the Bay of Fundy, Canada. Our analyses yield evidence of microgeographical variation: birds showed higher acoustic similarity to their neighbours than to faraway individuals in the same population. When we classified songs on the basis of their highly variable middle sections, we found that particular song types formed spatial clusters of similar-sounding individuals. Therefore, acoustic variation in Savannah sparrow song appears to show dialects across small geographical distances. In an analysis of dispersal from natal sites to breeding sites, we found a median distance of 189 m, consistent with previous findings. Our results suggest that limited dispersal distances, combined with the social processes of vocal learning (overproduction and selective attrition), likely contribute to the presence of microdialects.

Striatal Injury Induces Overall Brain Alteration at the Pallial, Thalamic, and Cerebellar Levels.

Simple SummaryMagnetic resonance imaging showed that striatal injury leads to structural changes within several brain areas. Here, we specify these changes via gene expression of synaptic plasticity markers, neuronal markers, assessing the number of newborn cells as well as cell densities. We found that the injury resulted in long-lasting modifications involving plasticity and neural protection mechanisms in areas directly as well as indirectly connected with the damaged striatum, including the cerebellum.The striatal region Area X plays an important role during song learning, sequencing, and variability in songbirds. A previous study revealed that neurotoxic damage within Area X results in micro and macrostructural changes across the entire brain, including the downstream dorsal thalamus and both the upstream pallial nucleus HVC (proper name) and the deep cerebellar nuclei (DCN). Here, we specify these changes on cellular and gene expression levels. We found decreased cell density in the thalamic and cerebellar areas and HVC, but it was not related to neuronal loss. On the contrary, perineuronal nets (PNNs) in HVC increased for up to 2 months post-lesion, suggesting their protecting role. The synaptic plasticity marker Forkhead box protein P2 (FoxP2) showed a bi-phasic increase at 8 days and 3 months post-lesion, indicating a massive synaptic rebuilding. The later increase in HVC was associated with the increased number of new neurons. These data suggest that the damage in the striatal vocal nucleus induces cellular and gene expression alterations in both the efferent and afferent destinations. These changes may be long-lasting and involve plasticity and neural protection mechanisms in the areas directly connected to the injury site and also to distant areas, such as the cerebellum.

Auditory and sexual preferences for a father’s song can co-emerge in female Bengalese finches

Birdsong is an important communication signal used in mate choice. In some songbird species, only the males produce songs. While the females of those species do not sing, they are sensitive to inter- and intra-species song variations, and the song preferences of females depend on their developmental experiences and/or genetic predispositions. For example, in Bengalese finches and zebra finches, adult females prefer the song to which they were exposed early in life, such as the father's song. In the current study, we aimed to test whether the preference for the father's song, as reported in previous Bengalese finch studies, can be interpreted as a mating preference. For this purpose, the subjects were raised exclusively with their family until they became sexually mature and then tested as adults. We measured copulation solicitation displays during playbacks of the father's song vs. unfamiliar conspecific songs and found that across individuals, the father's song elicited more displays than other songs. In addition, we analyzed if a bird's response to a given song could be predicted by the level of similarity of that song to the father's song. Although the birds expressed more displays to songs with greater similarity to the father's song, the effect was not statistically significant. These results suggest that female Bengalese finches can develop a strong mating preference for the father's song if they are exclusively exposed to the father's song early in life. However, it is not clear if such a preference generalizes to other cases in which birds are exposed to multiple male songs during development. In order to fully elucidate the possible contribution of experience and genetic factors in the development of female song preference in this species, future studies will need more detailed manipulation and control of the rearing conditions, including cross-fostering.

Dopamine neurons evaluate natural fluctuations in performance quality.

SUMMARYMany motor skills are learned by comparing ongoing behavior to internal performance benchmarks. Dopamine neurons encode performance error in behavioral paradigms where error is externally induced, but it remains unknown whether dopamine also signals the quality of natural performance fluctuations. Here, we record dopamine neurons in singing birds and examine how spontaneous dopamine spiking activity correlates with natural fluctuations in ongoing song. Antidromically identified basal ganglia-projecting dopamine neurons correlate with recent, and not future, song variations, consistent with a role in evaluation, not production. Furthermore, maximal dopamine spiking occurs at a single vocal target, consistent with either actively maintaining the existing song or shifting the song to a nearby form. These data show that spontaneous dopamine spiking can evaluate natural behavioral fluctuations unperturbed by experimental events such as cues or rewards.

Շիրակի ժողովրդական երգերի ուսումնասիրության խնդիրները երաժշտական ֆոլկլորագիտության առանձնահատկությունների համատեքստում / Problems of Studying Shirak Folk Songs in the Context of the Features of Musical Folkloristics

The study of the musical folklore of ethnographic regions is a topical problem of Armenian folklore. Valuable collections, individual studies and articles, published on the basis of works carried out in this field, currently are further expanding the boundaries of musicology, and require new methodological approaches to solving problems, modern methods of comparative analysis, which will lead to new assessments of the musical and artistic phenomenon. The musical folklore of Shirak is one of the richest treasures of Armenian folk music, where many folk songs, instrumental plays and musical compositions preserved in amazing purity have a deep influence of centuries-old antiquity. Many of them still retain their importance, as they are the product of popular artistic thinking. Of course, the origins of many musical works transmitted orally go deep into historical Armenia, in the province of Mush, Alashkert, Karin, etc. Comparative analysis of this extensive material opens up new research perspectives. By comparing the same genre or several variants of the same song, one can certainly trace the development of the genre or, conversely, the process of distortion of a particular song. About two dozen articles and publications by H. Apinyan are devoted to current issues of ceremonial songs of Shirak, musical and historical description of individual villages of the region, features of folk-performing art and instrumentation, some compositional-metric problems of lullaby songs, modern musical problems of Shirak musical folklore.

Тема разлуки в песенном фольклоре чувашских переселенцев Кемеровской области

This paper examines the embodiment of the theme of separation in the song texts recorded in 1951 and 2007 from the Chuvash settlers of the Kemerovo region. This theme is present in guest and recruit songs, in the songs of immigrants created in the process of forced resettlement of the Chuvash to new lands. In aphoristic short-plot songs, the theme of separation often manifests itself in the form of separate words and verbal turns – “signs” that point to it. In guest songs, the theme of separation is conveyed most often through images of memories, distant distances, abandonment, sadness. “Signs” of crying, farewell, big cities, symbolizing the foreign side, prevail precisely in recruit songs; in them, the theme of separation sounds especially dramatic and tense. In the songs of the settlers, the images present in the guest and recruit songs are summed up. In addition, in the songs of the settlers there are detailed descriptions of the move and the harsh living conditions in new places. Probably, such a topic was relevant specifically for the bearers of the tradition in the middle of the 20th century, which is associated with their memories of forced resettlement in Siberia at the beginning of the 20th century, as well as with the memory of the difficult trials of the period of the Great Patriotic War. Despite the absence of song variants in the recordings of different times considered by us, there is a certain continuity in the folklore samples of the local Chuvash tradition of the Kemerovo region. It manifests itself in the similar themes of a number of the considered songs and the features of its expression (general words are “signs” indicating the theme of separation, the principle of two-link figurative parallelism is preserved in many texts).

Seasonal song variation in male Carolina Wrens (Thryothorus ludovicianus)

Birdsong's primary function is attracting and stimulating mates and repelling rivals during the breeding season. However, many species also sing during the nonbreeding season, which raises questions about the function of nonbreeding season song and the mechanisms underlying its production. In this study, we compared spectral and temporal measurements from a large sample of breeding (N=267) and nonbreeding season songs (N=283) of the Carolina Wren (Thryothorus ludovicianus), a nonmigratory, temperate species that sings year round. We found that breeding season songs were longer than nonbreeding season songs and had more syllables within each song. Trill rate, the number of notes per syllable, minimum and maximum frequency, and frequency bandwidth did not differ detectably between the 2 seasons. This study is the first to examine seasonal song differences in Carolina Wrens and provides a basis for future investigations into the drivers behind this seasonal variation.

Song Divergence in the Group of “Brownish” Chiffchaff Forms (Phylloscopus collybita sensu lato)

Song Divergence in the Group of “Brownish” Chiffchaff Forms (Phylloscopus collybita sensu lato)

Punctuated evolution in the learned songs of African sunbirds.

Learned traits are thought to be subject to different evolutionary dynamics than other phenotypes, but their evolutionary tempo and mode has received little attention. Learned bird song has been thought to be subject to rapid and constant evolution. However, we know little about the evolutionary modes of learned song divergence over long timescales. Here, we provide evidence that aspects of the territorial songs of Eastern Afromontane sky island sunbirds Cinnyris evolve in a punctuated fashion, with periods of stasis of the order of hundreds of thousands of years or more, broken up by evolutionary pulses. Stasis in learned songs is inconsistent with learned traits being subject to constant or frequent change, as would be expected if selection does not constrain song phenotypes over evolutionary timescales. Learned song may instead follow a process resembling peak shifts on adaptive landscapes. While much research has focused on the potential for rapid evolution in bird song, our results suggest that selection can tightly constrain the evolution of learned songs over long timescales. More broadly, these results demonstrate that some aspects of highly variable, plastic traits can exhibit punctuated evolution, with stasis over long time periods.

Evolution of vocal performance and song complexity in island birds

Oceanic islands share distinctive characteristics thought to underlie a set of parallel evolutionary trends across islands and taxonomic groups – including life‐history traits, morphology and visual signals. To which extent acoustic signals also change in parallel on islands is less clear. Some important processes associated with insularity, such as founder effects and reduced sexual selection, could lead to a decrease in vocal performance and song complexity on islands. In a field‐based study, we recorded 11 insular species and their closest mainland relatives. Out of the 11 species pairs, 6 live in the tropics (São Tomé/Mount Cameroon) and 5 in the temperate region (Madeira/southern France). For each species, we measured two proxies of vocal performance (song duration and syllable rate) and one proxy of song complexity (syllable diversity). This study did not recover a clear relationship between the island environment and song traits. If as expected, syllable rate was lower in island species than in their mainland counterparts, the two other proxies showed no clear island–mainland pattern of divergence. Several factors may explain the absence of reduction for song duration and syllable diversity. Among those, relaxation of interspecific competition on islands may have led to an increase in syllable diversity, or correlations between song variables may have constrained song evolution. More studies on island species are needed to draw a better picture of divergence patterns and go beyond the confounding ecological factors that could explain peculiar song characteristics in islands.