Description of the song of the Nilgiri Thrush(Zoothera [aurea] neilgherriensis) and song differentiation across the Zoothera dauma species complex
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摘要
Background: Taxonomic treatment of the Zoothera dauma species complex is highly variable and has been hampered by the absence of song recordings for the Nilgiri Thrush(Zoothera [aurea] neilgherriensis).Methods: I obtained two recordings of the song of neigherriensis from southern Indian. Here I publish sonograms and analyze song recordings for all but one currently described taxon from the Eurasian portion of the geographic range of this species complex. Principal component analyses were used to investigate song differences between taxa.Results: The song of neigherriensis is a highly complex series of strophes remarkably similar to the song of the insular Zoothera major. Vocal analyses across the complex indicate four key groups of taxa differentiated in their songs:(1) simple flat whistled songs which include the northern aurea, toratugumi and the undescribed Taiwan population;(2) eastern populations of dauma(reported here for the first time) which sing like northern birds but with much broader bandwidth,(3) strongly down-slurred, thin whistles of tropical resident imbricata of Sri Lanka and horsfieldi of Indonesia, and(4) highly complex songs of Himalayan dauma, neilgherriensis and major.Conclusions: Zoothera dauma is unlikely to represent a single species given the simple singing populations from its eastern range and highly complex song from the Himalayan portion of its range. neilgherriensis should either be transferred from Zoothera aurea, where it is currently classified as a subspecies, and be placed as a subspecies within Z. dauma from the Himalayas or it should be recognized as a distinct species. Given the small number of songs available for analyses, I suggest the former course until it can be clearly demonstrated that neilgherriensis and Himalayan dauma are vocally distinct.
Background: Taxonomic treatment of the Zoothera dauma species complex is highly variable and has been hampered by the absence of song recordings for the Nilgiri Thrush(Zoothera [aurea] neilgherriensis).Methods: I obtained two recordings of the song of neigherriensis from southern Indian. Here I publish sonograms and analyze song recordings for all but one currently described taxon from the Eurasian portion of the geographic range of this species complex. Principal component analyses were used to investigate song differences between taxa.Results: The song of neigherriensis is a highly complex series of strophes remarkably similar to the song of the insular Zoothera major. Vocal analyses across the complex indicate four key groups of taxa differentiated in their songs:(1) simple flat whistled songs which include the northern aurea, toratugumi and the undescribed Taiwan population;(2) eastern populations of dauma(reported here for the first time) which sing like northern birds but with much broader bandwidth,(3) strongly down-slurred, thin whistles of tropical resident imbricata of Sri Lanka and horsfieldi of Indonesia, and(4) highly complex songs of Himalayan dauma, neilgherriensis and major.Conclusions: Zoothera dauma is unlikely to represent a single species given the simple singing populations from its eastern range and highly complex song from the Himalayan portion of its range. neilgherriensis should either be transferred from Zoothera aurea, where it is currently classified as a subspecies, and be placed as a subspecies within Z. dauma from the Himalayas or it should be recognized as a distinct species. Given the small number of songs available for analyses, I suggest the former course until it can be clearly demonstrated that neilgherriensis and Himalayan dauma are vocally distinct.
Background: Taxonomic treatment of the Zoothera dauma species complex is highly variable and has been hampered by the absence of song recordings for the Nilgiri Thrush(Zoothera [aurea] neilgherriensis).Methods: I obtained two recordings of the song of neigherriensis from southern Indian. Here I publish sonograms and analyze song recordings for all but one currently described taxon from the Eurasian portion of the geographic range of this species complex. Principal component analyses were used to investigate song differences between taxa.Results: The song of neigherriensis is a highly complex series of strophes remarkably similar to the song of the insular Zoothera major. Vocal analyses across the complex indicate four key groups of taxa differentiated in their songs:(1) simple flat whistled songs which include the northern aurea, toratugumi and the undescribed Taiwan population;(2) eastern populations of dauma(reported here for the first time) which sing like northern birds but with much broader bandwidth,(3) strongly down-slurred, thin whistles of tropical resident imbricata of Sri Lanka and horsfieldi of Indonesia, and(4) highly complex songs of Himalayan dauma, neilgherriensis and major.Conclusions: Zoothera dauma is unlikely to represent a single species given the simple singing populations from its eastern range and highly complex song from the Himalayan portion of its range. neilgherriensis should either be transferred from Zoothera aurea, where it is currently classified as a subspecies, and be placed as a subspecies within Z. dauma from the Himalayas or it should be recognized as a distinct species. Given the small number of songs available for analyses, I suggest the former course until it can be clearly demonstrated that neilgherriensis and Himalayan dauma are vocally distinct.
引文
Alstr?m P,Rasmussen PC,Zhao C,Xu J,Dalvi S,Cai T,Guan Y,Zhang R,Kalyakin MV,Lei FM,Olsson U.Integrative taxonomy of the plain-backed thrush(Zoothera mollissima)complex(Aves,Turdidae)reveals cryptic species,including a new species.Avian Res.2016;7:1.
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AvoCET.http://avoce t.zoolo gy.msu.edu.Accessed Oct to Dec 2017.
Clement P,Hathway R.Helm identification guides:thrushes.London:Christopher Helm;2000.
del Hoyo J,Collar NJ.ICW and BirdLife international illustrated checklist of the birds of the world:passerines.Barcelona:Lynx Edi?ions BirdLife International;2016.
del Hoyo J,Elliott A,Sargatal J.Handbook of the birds of the world.Cuckooshrikes to thrushes,vol.10.Barcelona:Lynx Edi?ions and BirdLife International;2005.
Macualay Library.http://macau layli brary.org.Accessed Oct 2017.
Rasmussen PC,Anderton JC.Birds of South Asia:the Ripley guide,vol.2.Barcelona:Lynx Edicions;2005.
Richmond CW.Descriptions of two new birds from Trong,Lower Siam.Proc Biol Soc Wash.1902;15:157-8.
R Core Team.A language and environment for statistical computing.Vienna:RFoundation for Statistical Computing;2017.http://www.R-proje ct.org.
Sangster G,Hazevoet CJ,van den Berg AB,Roselaar CS.Dutch avifaunal list:species concepts,taxonomic instability,and taxonomic changes in 1998.Dutch Bird.1998;20:22-32.
Thayer JE,Bangs O.Some Chinese vertebrates(Aves).Mem Mus Comp Zool.1912;40:137-200.
Xeno-canto.http://www.xeno-canto.org.Accessed Oct to Dec 2017.