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Journal of Threatened Taxa Building evidence for conservaton globally www.threatenedtaxa.org ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print) Article Ornithophony in the soundscape of Anaikatty Hills, Coimbatore, Tamil Nadu, India Chandrasekaran Divyapriya & Padmanabhan Pramod 26 September 2019 | Vol. 11 | No. 12 | Pages: 14471–14483 DOI: 10.11609/jot.4948.11.12.14471-14483 For Focus, Scope, Aims, Policies, and Guidelines visit htps://threatenedtaxa.org/index.php/JoTT/about/editorialPolicies#custom-0 For Artcle Submission Guidelines, visit htps://threatenedtaxa.org/index.php/JoTT/about/submissions#onlineSubmissions For Policies against Scientfc Misconduct, visit htps://threatenedtaxa.org/index.php/JoTT/about/editorialPolicies#custom-2 For reprints, contact <[email protected]> The opinions expressed by the authors do not refect the views of the Journal of Threatened Taxa, Wildlife Informaton Liaison Development Society, Zoo Outreach Organizaton, or any of the partners. The journal, the publisher, the host, and the part- Publisher & Host ners are not responsible for the accuracy of the politcal boundaries shown in the maps by the authors. Partner Member Threatened Taxa Journal of Threatened Taxa | www.threatenedtaxa.org | 26 September 2019 | 11(12): 14471–14483 Article Ornithophony in the soundscape of Anaikatty Hills, Coimbatore, Tamil Nadu, India Chandrasekaran Divyapriya 1 & Padmanabhan Pramod 2 ISSN 0974-7907 (Online) ISSN 0974-7893 (Print) 1,2 Nature Educaton Division, Sálim Ali Centre for Ornithology & Natural History (SACON), Anaikaty (P.O.), PLATINUM Coimbatore, Tamil Nadu 641108, India. 1 Bharathiar University, Marudhamalai Road, Coimbatore, Tamil Nadu 641046, India. OPEN ACCESS 1 [email protected] (corresponding author), 2 [email protected] Abstract: An atempt has been made to understand the extent of ornithophony (vocalizaton of birds) in the soundscape of Anaikaty Hills. The study was limited to 13 hours of daylight from dawn to dusk (06.00–19.00 h) between January 2015 and October 2016. Six replicates of 5-minute bird call recordings were collected from each hour window in 24 recording spots of the study area. Each 5-minute recording was divided into 150 ‘2-sec’ observaton units for the detailed analysis of the soundscape. A total of 78 recordings amountng to 390 minutes of acoustc data allowed a preliminary analysis of the ornithophony of the area. A total of 62 bird species were heard vocalizing during the study period and contributed 8,629 units. A total of 73.75% acoustc space was occupied by birds, among which the eight dominant species alone contributed to 63.65% of ornithophony. The remaining 26% of acoustc space was occupied by other biophonies (12.60%), geophony (5.57%), indistnct sounds (7.66%), and anthropogenic noise (0.41%). Passerines dominated the vocalizatons with 7,269 (84.24%) and non-passerines with 1,360 (15.76%) units. Birds vocalized in all 13 observaton windows, with a peak in the frst three hours of the day (06.00–09.00 h). Vocalizatons of non-passerines were prominent in the dusk hours (18.00–19.00 h). Keywords: Acoustc community, bird acoustcs, bird vocalizaton, diurnal singing, ornithophony, soundscape analysis. DOI: htps://doi.org/10.11609/jot.4948.11.12.14471-14483 Editor: V.V. Robin, Department of Biology, IISER Tirupat, India. Date of publicaton: 26 September 2019 (online & print) Manuscript details: #4948 | Received 13 March 2019 | Final received 02 August 2019 | Finally accepted 21 August 2019 Citaton: Divyapriya, C. & P. Pramod (2019). Ornithophony in the soundscape of Anaikaty Hills, Coimbatore, Tamil Nadu, India. Journal of Threatened Taxa 11(12): 14471–14483. htps://doi.org/10.11609/jot.4948.11.12.14471-14483 Copyright: © Divyapriya & Pramod 2019. Creatve Commons Atributon 4.0 Internatonal License. JoTT allows unrestricted use, reproducton, and distributon of this artcle in any medium by adequate credit to the author(s) and the source of publicaton. Funding: The study was self-funded by CD. Competng interests: The authors declare no competng interests. Author details and contributon: C. Divyapriya is a PhD scholar in Nature Educaton Division, Sálim Ali Centre for Ornithology & Natural History (SACON). She collected, curated, analyzed and interpreted the audio recordings of birds and major contributor in writng the manuscript. The work is part of her doctoral thesis. Dr. P. Pramod is a Principal Scientst, Sálim Ali Centre for Ornithology & Natural History (SACON) and Head of the Nature Educaton division. He conceptualized, supervised the study, reviewed the analysis and edited the draf. All authors read and approved the fnal manuscript. Acknowledgements: Authors thank The Cornell Lab of Ornithology for providing RAVEN Pro 1.4 version with 100% concession. Authors thank director, Sálim Ali Centre for Ornithology and Natural History (SACON), Coimbatore for providing facilites and encouragement. 14471 Ornithophony in the soundscape of Anaikaty Hills Divyapriya & Pramod INTRODUCTION Dabelsteen & Mathevon 2002; Brown & Handford 2003), birds probably prefer those hours for consistent The biological sound produced by vocalizing animals signal transfer. (e.g., birds and stridulatng insects (biophony)), non- The interacton of biological and non-biological biological sounds such as wind, rain, running stream sounds provides the overall framework of the acoustc (geophony) in a forest or any natural habitat (Hildebrand ecology of a landscape (Pijanowski et al. 2011). Spectral 2009) consttutes the soundscape of that area (Pijanowski frequency (Hz) analysis is a valid method for interpretng et al. 2011; Gage & Axel 2014). The man-made sounds the terrestrial soundscape (Irwin 1990; Nowicki & produced from automobile, machinery (technophony or Nelson 1990; Cardoso 2010; Cardoso & Atwell 2011). anthrophony) that dominate in urban setngs are rarely Overlapping of sound frequencies of geophony (such detected in forest habitats (Krause 1987; Pijanowski as wind, rain) or technophony (automobiles) may mask et al. 2011; Gage & Axel 2014). Vocalizaton of birds the biophony signals (Qi et al. 2008; Mullet 2017). Most (ornithophony) of a terrestrial habitat varies due to the of the technophony and a few biophonic sounds (birds) variatons in the dominant vocalizers, number of species occur in lower frequency range 1–2 kHz. Passerines involved in vocal actvity and the tme specifcity of the species’ frequency ranges between 3 and 6 kHz, birds. It is well known that many species of birds are whereas insects occupy a higher range, > 6kHz, and all more vocally actve during dawn and dusk hours as they the geophony are of low frequency ranging from 1–11 are actve in search of food and / or atractng a female kHz (Napoletano 2004; Qi et al. 2008; Joo et al. 2011; partner (Slabbekoorn 2004; Brumm, 2006; Catchpole Kasten et al. 2012; Gage & Axel 2014). & Slater 2008; Ey & Fischer 2009). Leaving aside the Biophony of the soundscape can be comprehended functonality, ornithophony is observed as one of the by examining the temporal framework across the dominant aspects of the soundscape of any natural daytme from dawn to dusk (Joo 2008; Joo et al. 2011). ecosystem, especially in forests. It also provides valuable insights on species diversity The vocal communicaton of the birds was well (Napoletano 2004; Sueur et al. 2008) and ecosystem (Qi studied, experimented and the results give insights et al. 2008). This study is a frst step to understand the about the characteristcs of avian vocal signals (Aylor biophony in the soundscape of Anaikaty Hills through 1971; Morton 1975; Wiley & Richards 1978; Brenowitz a community acoustcs’ approach on the ornithophony 1982). The environmental factors such as humidity, across daylight hours. temperature, atmospheric turbulence, or vegetaton cover infuence the signal transfer through masking, absorpton, atenuaton, reverberaton or signal METHODS scatering efect (Wiley & Richards 1978). Birds prefer a suitable environmental conditon for the efectve Study area long-distant signal transfer (Morton 1975; Kroodsma The study area is Anaikaty Hills (11.090–11.097 0N & 1977; Brenowitz 1982). As the vocal communicaton 76.778–76.792 0E; Fig. 1), in Coimbatore District, Tamil consumes signifcant energy and tme (Prestwich 1994; Nadu, India, is a part of the Nilgiri Biosphere Reserve Oberweger & Goller 2001), animals adapt their vocal (NBR), approximately 500 to 600 m, lies on the leeward signals spectrally, by altering their syllable structure and side of the Western Ghats. It receives an annual rainfall usage; or temporally, by optng for a beter daytme hour of about 700mm, which is mainly contributed by the for signal transfer (Ficken et al. 1974; Nelson & Marler north-east monsoon. The temperature varies from 17˚ C 1990; Boncoraglio & Saino 2007; Planque & Slabbekoorn to 36˚ C (Mukherjee & Bhupathy 2007). It is a secondary 2008; Ey & Fischer 2009; Velásquez et al. 2018). Birds forest area surrounded by dry deciduous forests rich reduce the interference and masking