In many songbird species,birdsong features phonological syntax,meaning that the units within their vocal se-quences are ordered in a non-random way that adheres to a rule.While such syntactical patterns have been rich...In many songbird species,birdsong features phonological syntax,meaning that the units within their vocal se-quences are ordered in a non-random way that adheres to a rule.While such syntactical patterns have been richly described in many species,comparatively little is known about how those patterns contribute to song achieving its important functions.For each of song’s main functions,territorial defense and mate attraction,evidence of a role for syntax is limited.One species for which syntax has been thoroughly described is the Hermit Thrush(Catharus guttatus),which presents song types from their repertoires in a semi-predictable order and,in doing so,rapidly cycle up and down the frequency spectrum.The objective of the present study was to explore the importance of song syntax in the Hermit Thrush through a within-subject examination of how measures of syntax,such as the predictability of song type order within song sequences,shift over the breeding season.We hypothesized that,if such syntactical characteristics are important to breeding behaviour,they would be most prominent at the start of the breeding season when activity associated with territory establishment and mate attraction is most intense.Analysis revealed that,as predicted,the rigidness of song type ordering within se-quences was highest at the start of the season and declined thereafter.That song type sequences were most predictable at the vitally important early part of the breeding season fit our hypothesis that this aspect of song syntax is important to song’s functions related to territory establishment and/or mate attraction.Future work will clarify whether that role relates to one of song’s two main functions or serves song transmission in some broader way.展开更多
Dialects are a specific form of geographic variation of birdsong with relatively sharp boundaries between distinct song characteristics,which provide opportunities for focused studies of processes underlying the emerg...Dialects are a specific form of geographic variation of birdsong with relatively sharp boundaries between distinct song characteristics,which provide opportunities for focused studies of processes underlying the emergence of spatial patterns in vocalization.Several songbird species that exhibit dialects became models for such research,and for some of them large-scale datasets were assembled that included recordings provided by the public.Among them,the Yellowhammer(Emberiza citrinella,Emberizidae) is particularly prominent,as it has been recently a subject of dedicated citizen science projects focusing on its dialect distribution.The most successful,in terms of public participation as well as the number and density of obtained recordings,was the Dialects of Czech Yellowhammers(DCY) project,which assembled detailed data at the whole-country level.A mosaic of almost all common song variants known across Europe was observed in Czechia,but the results indicated that some of the traditionally recognized Yellowhammer dialects may not represent geographically clustered song variants,at least not in Central Europe.We quantitatively analysed variation(frequency and temporal characteristics and modulation) of the terminal song element in three dialects defined by arbitrary frequency thresholds in DCY.Multivariate analyses indicated that pooling these to two distinct groups reflects the variation in the songs,as well as their spatial distribution,better than retaining the current classification to three dialects or their finer splitting to even more categories.We provide simple measures that may be used for classification of these Yellowhammer song variants in Central Europe.However,we warn from indiscriminate transposing of results from one region to another,as that may lead to substantial biases.Future studies of birdsong variation will benefit from big data assembled by citizen scientists,but to maximise their usefulness for further dialect research,careful delineation of dialect boundaries is essential.展开更多
The Bengalese finch song has been widely studied for its unique features and similarity to human language. For com-putational analysis the songs must be represented in songnote sequences. An automated approach for thi...The Bengalese finch song has been widely studied for its unique features and similarity to human language. For com-putational analysis the songs must be represented in songnote sequences. An automated approach for this purpose is highly desired since manual processing makes human annotation cumbersome, and human annotation is very heu-ristic and easily lacks objectivity. In this paper, we propose a new approach for automatic detection and recognition of the songnote sequences via image processing. The proposed method is based on human recognition process to visually identify the patterns in a sonogram image. The songnotes of the Bengalese finch are dependent on the birds and similar pattern does not exist in two different birds. Considering this constraint, our experiments on real birdsong data of different Bengalese finch show high accuracy rates for automatic detection and recognition of the songnotes. These results indicate that the proposed approach is feasible and generalized for any Bengalese finch songs.展开更多
Many species produce individually specific vocalizations and sociality is a hypothesized driver of such individuality. Previous studies of how social variation influenced individuality focused on colonial or non-colon...Many species produce individually specific vocalizations and sociality is a hypothesized driver of such individuality. Previous studies of how social variation influenced individuality focused on colonial or non-colonial avian species, and how so- cial group size influenced individuality in sciurid rodents. Since sociality is an important driver of individuality, we expected that bird species that defend nesting territories in higher density neighborhoods should have more individually-distinctive calls than those that defend nesting territories in lower-density neighborhoods. We used Beecher＇s information statistic to quantify individu- ality, and we examined the relationship between bird density （calculated with point-counts） and vocal individuality on seven spe- cies of passerines. We found non-significant relationships between breeding bird density and vocal individuality whether regres- sions were fitted on species values, or on phylogenetically-independent contrast values. From these results, we infer that while in- dividuality may be explained by social factors, breeding bird density is unlikely to be generally important in driving the evolution of individually-specific vocalizations [Current Zoology 58 （5）： 765-772, 2012].展开更多
Background In mega-biodiverse environments,where different species are more likely to be heard than seen,species monitoring is generally performed using bioacoustics methodologies.Furthermore,since bird vocalizations ...Background In mega-biodiverse environments,where different species are more likely to be heard than seen,species monitoring is generally performed using bioacoustics methodologies.Furthermore,since bird vocalizations are reasonable estimators of biodiversity,their monitoring is of great importance in the formulation of conservation policies.However,birdsong recognition is an arduous task that requires dedicated training in order to achieve mastery,which is costly in terms of time and money due to the lack of accessibility of relevant information in field trips or even specialized databases.Immersive technology based on virtual reality(VR)and spatial audio may improve species monitoring by enhancing information accessibility,interaction,and user engagement.Methods This study used spatial audio,a Bluetooth controller,and a head-mounted display(HMD)to conduct an immersive training experience in VR.Participants moved inside a virtual world using a Bluetooth controller,while their task was to recognize targeted birdsongs.We measured the accuracy of recognition and user engagement according to the User Engagement Scale.Results The experimental results revealed significantly higher engagement and accuracy for participants in the VR-based training system than in a traditional computer-based training system.All four dimensions of the user engagement scale received high ratings from the participants,suggesting that VR-based training provides a motivating and attractive environment for learning demanding tasks through appropriate design,exploiting the sensory system,and virtual reality interactivity.Conclusions The accuracy and engagement of the VR-based training system were significantly high when tested against traditional training.Future research will focus on developing a variety of realistic ecosystems and their associated birds to increase the information on newer bird species within the training system.Finally,the proposed VR-based training system must be tested with additional participants and for a longer duration 展开更多
基金partly funded by an NSERC Discovery Grant received by LS Phillmorea UNB University Research Fund grant received by SP Roach
文摘In many songbird species,birdsong features phonological syntax,meaning that the units within their vocal se-quences are ordered in a non-random way that adheres to a rule.While such syntactical patterns have been richly described in many species,comparatively little is known about how those patterns contribute to song achieving its important functions.For each of song’s main functions,territorial defense and mate attraction,evidence of a role for syntax is limited.One species for which syntax has been thoroughly described is the Hermit Thrush(Catharus guttatus),which presents song types from their repertoires in a semi-predictable order and,in doing so,rapidly cycle up and down the frequency spectrum.The objective of the present study was to explore the importance of song syntax in the Hermit Thrush through a within-subject examination of how measures of syntax,such as the predictability of song type order within song sequences,shift over the breeding season.We hypothesized that,if such syntactical characteristics are important to breeding behaviour,they would be most prominent at the start of the breeding season when activity associated with territory establishment and mate attraction is most intense.Analysis revealed that,as predicted,the rigidness of song type ordering within se-quences was highest at the start of the season and declined thereafter.That song type sequences were most predictable at the vitally important early part of the breeding season fit our hypothesis that this aspect of song syntax is important to song’s functions related to territory establishment and/or mate attraction.Future work will clarify whether that role relates to one of song’s two main functions or serves song transmission in some broader way.
基金funded by the Charles University Grant Agency (project number 312213)
文摘Dialects are a specific form of geographic variation of birdsong with relatively sharp boundaries between distinct song characteristics,which provide opportunities for focused studies of processes underlying the emergence of spatial patterns in vocalization.Several songbird species that exhibit dialects became models for such research,and for some of them large-scale datasets were assembled that included recordings provided by the public.Among them,the Yellowhammer(Emberiza citrinella,Emberizidae) is particularly prominent,as it has been recently a subject of dedicated citizen science projects focusing on its dialect distribution.The most successful,in terms of public participation as well as the number and density of obtained recordings,was the Dialects of Czech Yellowhammers(DCY) project,which assembled detailed data at the whole-country level.A mosaic of almost all common song variants known across Europe was observed in Czechia,but the results indicated that some of the traditionally recognized Yellowhammer dialects may not represent geographically clustered song variants,at least not in Central Europe.We quantitatively analysed variation(frequency and temporal characteristics and modulation) of the terminal song element in three dialects defined by arbitrary frequency thresholds in DCY.Multivariate analyses indicated that pooling these to two distinct groups reflects the variation in the songs,as well as their spatial distribution,better than retaining the current classification to three dialects or their finer splitting to even more categories.We provide simple measures that may be used for classification of these Yellowhammer song variants in Central Europe.However,we warn from indiscriminate transposing of results from one region to another,as that may lead to substantial biases.Future studies of birdsong variation will benefit from big data assembled by citizen scientists,but to maximise their usefulness for further dialect research,careful delineation of dialect boundaries is essential.
文摘The Bengalese finch song has been widely studied for its unique features and similarity to human language. For com-putational analysis the songs must be represented in songnote sequences. An automated approach for this purpose is highly desired since manual processing makes human annotation cumbersome, and human annotation is very heu-ristic and easily lacks objectivity. In this paper, we propose a new approach for automatic detection and recognition of the songnote sequences via image processing. The proposed method is based on human recognition process to visually identify the patterns in a sonogram image. The songnotes of the Bengalese finch are dependent on the birds and similar pattern does not exist in two different birds. Considering this constraint, our experiments on real birdsong data of different Bengalese finch show high accuracy rates for automatic detection and recognition of the songnotes. These results indicate that the proposed approach is feasible and generalized for any Bengalese finch songs.
文摘Many species produce individually specific vocalizations and sociality is a hypothesized driver of such individuality. Previous studies of how social variation influenced individuality focused on colonial or non-colonial avian species, and how so- cial group size influenced individuality in sciurid rodents. Since sociality is an important driver of individuality, we expected that bird species that defend nesting territories in higher density neighborhoods should have more individually-distinctive calls than those that defend nesting territories in lower-density neighborhoods. We used Beecher＇s information statistic to quantify individu- ality, and we examined the relationship between bird density （calculated with point-counts） and vocal individuality on seven spe- cies of passerines. We found non-significant relationships between breeding bird density and vocal individuality whether regres- sions were fitted on species values, or on phylogenetically-independent contrast values. From these results, we infer that while in- dividuality may be explained by social factors, breeding bird density is unlikely to be generally important in driving the evolution of individually-specific vocalizations [Current Zoology 58 （5）： 765-772, 2012].
文摘Background In mega-biodiverse environments,where different species are more likely to be heard than seen,species monitoring is generally performed using bioacoustics methodologies.Furthermore,since bird vocalizations are reasonable estimators of biodiversity,their monitoring is of great importance in the formulation of conservation policies.However,birdsong recognition is an arduous task that requires dedicated training in order to achieve mastery,which is costly in terms of time and money due to the lack of accessibility of relevant information in field trips or even specialized databases.Immersive technology based on virtual reality(VR)and spatial audio may improve species monitoring by enhancing information accessibility,interaction,and user engagement.Methods This study used spatial audio,a Bluetooth controller,and a head-mounted display(HMD)to conduct an immersive training experience in VR.Participants moved inside a virtual world using a Bluetooth controller,while their task was to recognize targeted birdsongs.We measured the accuracy of recognition and user engagement according to the User Engagement Scale.Results The experimental results revealed significantly higher engagement and accuracy for participants in the VR-based training system than in a traditional computer-based training system.All four dimensions of the user engagement scale received high ratings from the participants,suggesting that VR-based training provides a motivating and attractive environment for learning demanding tasks through appropriate design,exploiting the sensory system,and virtual reality interactivity.Conclusions The accuracy and engagement of the VR-based training system were significantly high when tested against traditional training.Future research will focus on developing a variety of realistic ecosystems and their associated birds to increase the information on newer bird species within the training system.Finally,the proposed VR-based training system must be tested with additional participants and for a longer duration
