Brief Ornithology of Blue-throated Barbet (Psilopogon asiaticus)

doi:10.21203/rs.3.rs-2186605/v1

Last year in India lockdown started on 23rd March, 2020 due to pandemic situation of COVID-19 for the outbreak of SARS-CoV-2 at first for 18 days and then extended for phase by phase with the imposition of strong restrictions for movement. During that time lockdown was already there in several countries of the World. So, all the people of Global village faced the situation like house arrest. All the social, official, commercial and institutional activities were prohibited for the people. Apart from the household work most of the people got themselves busy in the unproductive work like watching TV and using mobile phone. For morning and evening work we were compelled to use only the lawn and backyard premises of the household. During our walk we have interacted with 35 species of birds. We became fond of Blue-throated Barbets (Psilopogon asiaticus) during our walk and documented the roosting, nesting, foraging behaviour of the Blue-throated Barbets. We have found great camouflage adaptation of Blue-throated Barbets and several times only bird call/song helped us to sight the bird. We have recorded bird calls/songs and all the data related to sighting and audio were submitted to ebird platform. Spectrograms of audios were analyzed to decipher the bird call/song. Lockdown helped us to explore fundamental lessons of ornithology.

Lockdown

COVID-19

Blue-throated Barbet

Ornithology

Spectrogram

From our childhood we have learnt from our parents and teachers regarding the effective utilization of time. In school days we have written the essay on the topic of “Effective utilization of time and Human Resource Development”. So, all of we know regarding the importance of effective utilization time on Human Resource Development of a nation. But in lockdown period from 23rd March, 2020 almost all the people were compelled to wastage their valuable time in the unproductive work by staying at home due to the restriction order of Government to contain the SARS-CoV-2 i.e. COVID-19 pandemic. Data of escalating deaths of the people were engulfing all the print and electronic media during that period of Lockdown. Each and every day people were passing the day with stage of depression and death news. Lots of media reports covered that wild animals and birds were enjoying the situation by their free movement in the roads, localities and in the forest fringe non-forest areas. To overcome the monotonous and depressing situations of lockdown, people were searching and trying numerous activities by staying at home.

But during this period, I and my wife started to watch and capture the photos of the Birds by staying at our Bungalow with the purpose of effective utilization of time and to avoid the situation of depression.

As part of this study we have started studying ornithology of a beautiful bird, Blue-throated Barbet (Psilopogon asiaticus). This bird is also famous as “Nilkantha Basantbauri” (Nilkantha= Blue-throat + Harbinger of spring season = Basantbauri) (Saha and Saha, 2021). The beautiful plumage colour, songs of the bird inspired to engage ourselves in the fundamental ornithology of the Blue-throated Barbet from our backyard.

Study Area

Our actual study area was the Front and backyard of the Assistant Divisional Forest Officer’s Bungalow of Jaldapara Wild Life Division, Nilkuthi, Cooch Behar-736101, West Bengal (Photo 1). The GPS coordinates of the site is recorded as N 26°19'30.47", E 089°27'59.56".

We have observed its breeding code, foraging and resting behavior in our backyard and then documented, reported to the Cornell Lab of Ornithology and Bird Count India through the e-Bird mobile app. They have recognized our effort in their website. Actually it was a great experience to become an e-Birder with the effective utilization of time during Lock Down period. The beauty of this ebird app is that, we have got the auto generated checklist of the birds from this platform, in a tabulated user friendly manner with the details of the sightings of the birds (Table 1).

Survey design: Random repetitive Line Transects for uniform coverage of the study area

Data Analysis

Frequency of bird Call or Song = Repeated Voice or Bird Call/Time Duration

This bird is found active in between dawn to dusk and almost all the times sighted in suitable pairs (Saha and Saha, 2021). For foraging, resting, courtship this bird prefers the trees of Bombax ceiba (Semal) (Photo 1), Syzygium cumini (Jamun) (Photo 2), Terminalia bellirica (Bahera), Terminalia chebula, Elaeocarpus ganitrus (Rudrakhs), Anthocephalus cadamba (Kadam), Emblica officinalis (Amla) and snag trees (Photo 4) of the backyard (Saha and Saha, 2021). So, this type of habitat should be maintained in the available land of backyard to conserve this bird (Saha and Saha, 2021).

As per the review of literature Blue-throated Barbet prefers the fruits of Ficus benghalensis (Banyan tree) and Ficus religiosa (Peepal tree) (Saha and Saha, 2021). We have also observed that in our backyard they are eating the ripen Guava (Psidium guajava) fruits in the morning (Photo 4). During the study we have planted saplings of Guava (Psidium guajava) trees to enrich the habitat further for the Blue-throated Barbets and other backyard birds.

Deep green plumage colour of Blue-throated Barbet is showed great camouflage adaptation in the green foliage of all the above mentioned trees of the backyard of DFO Coochbehar Bungalow. They are busy bird too. So for this reasons it was very difficult to capture them in camera. With great effort, concentration and focus it was clicked ultimately with the Nikon D 7500 Camera and 18-140 tool kit lens by the 1st author of the paper. During study we have found that blue throat, cheeks and red on crown separate these birds from the deep green foliages of the Semal (Bombax ceiba) tree (Photo 3) and Guava (Psidium guajava) tree (Photo 5). Also blue throat and cheeks separate this from all but the allopatric Yellow-fronted Barbet and Blue-eared Barbet which lacks red on crown (Kazmierczak and Perlo, 2000).

Identification, positioning from Vocalization

Birds can be sighted or observed through their characteristic sound or call. The most characteristic calls and songs have been included wherever they were considered useful for identification purposes (Kazmierczak and Perlo, 2000). Actually position of the bird can be confirmed by their sound only. These vocalizations are usually fairly specific to a given species so that with practice it is possible to identify most birds simply by their calls (Kazmierczak and Perlo, 2000). Blue-throated Barbet is having characteristic sound or call. Nearly all bird species use vocalizations in order to communicate in certain basic situations (Kazmierczak and Perlo, 2000). During our study we have recorded the bird calls of Blue-throated Barbet (Psilopogon asiaticus) by the Voice Recorder software of simple mobile phone Samsung 4G Duos and also saved recording with file name. Then we have converted the recorded bird calls into WAV (preferred) audio file by online conversion mode. Then submitted all the recorded bird calls in the Mcaulay Library through the add media option of the ebird checklists of the Cornell Lab of Ornithology. Macaulay Library kept our effort of recorded bird calls of Blue-throated Barbet in their archive by graphical representation in terms of kHz Vs Time (Photo 6). The beauty of the ebird app of the Cornell Lab of Ornithology is that all this data can be used further for the protection and conservation of the birds like Blue-throated Barbets and others.

Table 1: Results of Analysis of Spectrogram of bird voice/call

Date	Repeated voice/bird call (x in No.)	Recorded Time (t in Sec)	Frequency (f = x/t in kHz)	Missed Note
14/5/2020	31	29	1.06	2
17/5/2020	34	29	1.17	5
1/6/2020	30	26	1.15	4
9/06/2020	20	16	1.25	4
Total	115	100	4.63	15
Average	28.75	25	1.15	3.75

No significant fundamental works are there regarding bird call analysis of Blue-throated Barbets. So, with the purpose of deciphering the bird call vocalizations were recorded at the different date and time of the days. The repeated notes of the bird calls were counted and recorded with the simple mobile voice recorder for specific time duration. Frequency (in kHz) of individual bird calls were calculated by dividing the total number of bird calls (All the counted notes) with the recorded time duration (in Sec).

Analysis of individual notes and sequences

After the analysis of above mentioned spectrogram we have found that Blue-throated Barbet combines sounds to create a sequence. Most songs are sequences, while calls are often isolated sounds. So here the recorded piece of combined sound sequence is most probably a song of Blue-throated barbet.

Spectrograms from Sound

A song is often defined as a relatively structured vocalization used for reproduction purposes (http://soundbirding.org/). Calls tend to be shorter, less built sounds used to communicate an anxiety or an individual’s location (http://soundbirding.org/). From the spectrogram analysis we have found that, here the recorded vocalization of Blue-throated Barbet is structured one and having the transcription as ‘Tu-Ka-Tuk’ in repetitive manner (Fig. 2 and Fig. 3). The Blue-throated Barbets are forming nest in between March to July (Dash and Ghosh, 2015). During the study vocalization were recorded in the month of May, 2021 and Jun, 2021 i.e. in between March to July (Table 1). So, it has been established that the recorded structured vocalization was used for reproduction purposes during that period. So the sound birding through spectrogram helped to identify the bird song of Blue-throated Barbets and here lays the importance of sound birding and spectrogram analysis.

Most birds you will hear singing are males, but recent articles (http://www.nature.com/articles/ncomms4379) show that female can actually sing too in most bird species. In case Blue-throated Barbets both the female and male birds can sing loudly (Dash and Ghosh, 2015). So, only sound birding will not specify either the female or male identity of the birds.

Humans are visual creature: for most of us, our visual memory is much better than our auditory memory (http://soundbirding.org/index.php/sound-and-spectrogram/). Our ears are used to understand long low-pitched sequences of syllables, but not short high-pitched notes (http://soundbirding.org/index.php/sound-and-spectrogram/). Therefore, the idea to analyze unfamiliar sounds is to…convert them into something visual (http://soundbirding.org/index.php/sound-and-spectrogram/). That’s what it is: a spectrogram is simply a two or three dimensional visualization of a sound (http://soundbirding.org/index.php/sound-and-spectrogram/). Usually there are two axes: time is displayed on the first one, while frequency is visible on the second one (http://soundbirding.org/index.php/sound-and-spectrogram/). Duration is visible on the first axis of a spectrogram (abscissa). The unit of measure is the second (s) (http://soundbirding.org/index.php/sound-and-spectrogram/). How many seconds does the sound last? The longer the duration of sound, the longer the spectrogram (http://soundbirding.org/index.php/sound-and-spectrogram/). The pitch, that is visible on the second axis of a spectrogram (ordinate) (http://soundbirding.org/index.php/sound-and-spectrogram/). Actually, it is frequency (the higher the frequency of sound waves, the higher-pitched the sound) (http://soundbirding.org/index.php/sound-and-spectrogram/). In other words, high-pitched sounds occur when the air pressure on a given place undergoes rapid changes (http://soundbirding.org/index.php/sound-and-spectrogram/). Therefore, the unit of measure of the pitch is the Hertz (Hz), and for bird sounds it is usually comprised between 1 and 10 Kilohertz (kHz) (http://soundbirding.org/index.php/sound-and-spectrogram/). Higher pitched sound was determined by the higher point on the spectrogram. Here during the analysis of ‘bird audio spectrogram’ of Blue-throated Barbet we have found that the pitch or frequency of the song of Blue-throated Barbet is 1.15 kHz and the result is at per as per the calculation of frequency by the fundamental method (Table 1). The frequencies of song of Blue-throated Barbets are same for all the individuals and it is independent recording duration, day or evening time or season of the year (Fig.1).

This work was done totally to inflict scientific temper through a citizen science approach among the masses. This innovative approach to study ornithology helped us for the effective utilization of time in a productive manner during lockdown. So this successful tested model of ornithology will help other citizens of the global village to effective utilize their time in feel good factor in a scientific manner. Gained happiness from this approach helped us to involve our valuable time in other sort of productive economic works also by avoiding depression during Lockdown.

Dash, T. and Ghosh, G., Amader Pakhi-Paschim Banglar Pakhi, Rong Route, Kolkata, 2015, p.285, 288.

http://soundbirding.org/index.php/sound-and-spectrogram/

http://www.nature.com/articles/ncomms4379

Kazmierczak, K. and Perlo, B.V., OM FIELD GUIDES-Birds of India, Christopher Helm, London, 2000, p.44.

Saha, S.K. and Saha, R.M., Counting of Blue-throated Barbet (Psilopogon asiaticus) in the Backyard during Lockdown. Indian Forester, 147 (12): 1244-1246, 2021, DOI:10.36808/if/2021/v147i12/153389

Photos 1-6 are available in the Supplementary Files section.

There is NO Competing Interest.

Photo1.png
Photo 1: Blue-throated Barbet roosting on Semal Tree (Bombax ceiba)
Photo2.png
Photo 2:Blue-throated Barbet roosting on Jamun Tree (Syzygium cumini)
Photo3.png
Photo 3: Blue-throated Barbet (Psilopogon asiaticus) with great camouflage adaptation on Semal (Bombax ceiba) tree
Photo4.png
Photo 4: Blue-throated Barbet showing great camouflage at the time of eating Guava
Photo5.png
Photo 5: Blue-throated Barbet showing great camouflage by roosting at Guava (Psidium guajava) tree
Photo6.png
Photo 6. Graphical representation (kHz Vs Time) of the bird calls of the Blue-throated Barbet

Brief Ornithology of Blue-throated Barbet (Psilopogon asiaticus)

Status:

Version 1

Abstract

Figures

Introduction

Methods

Results

Discussion

Conclusion

References

Photos

Additional Declarations

Supplementary Files

Status:

Version 1