Table Of ContentJournal of the Bombay Natural History Society, 101 (1), Jan.-Apr. 2004 26-28
THE FIRSTRECORDINGS OF CALLS OFTHEJERDON’S COURSER
RHINOPTILUSBITORQUATUS(BLYTH), FAMILYGLAREOLIDAE1
Panchapak.esan Jeganathan2 and Simon R. Wotton’
'Accepted December, 2002
2BombayNatural History Society, Hornbill House, S.B. Singh Road, Mumbai 400 023, Maharashtra, India.
Email:[email protected]
3Royal SocietyfortheProtection ofBirds,TheLodge, Sandy, Bedfordshire, SGI9 2DL, UK.
Email: [email protected]
The call ofthe Critically Endangered Jerdon’s Courser(Rhinoptilus bitorquatus) was unknown until now.
The short disyllabic call attributed to the Jerdon’s Courser was recorded and identified within the
SriLankamaleswaraWildlifeSanctuaryduringdawnanddusk. Detailsofthecallingperiod,durationofthe
call and spectrogramare given.
Key words: Jerdon’sCourser, Rhinoptilusbitorquatus callrecording,calldescription, spectrogram
,
INTRODUCTION METHODS
Jerdon’s Courser Rhinoptilus bitorquatus Since the Jerdon’s Courser is nocturnal, efforts
(Charadriiformes: Glareolidae) isanocturnal cursorial were made to listen for, and record, its calls during
birdthathasbeen categorizedasCriticallyEndangered dawn and dusk in the places where it was known
onthe IUCN Red List(Hilton-Taylor2000), because it tooccurinthe Sri LankamaleswaraWildlifeSanctuary,
is believedto have a small and decliningpopulation. It near Reddipalle, Cuddapah district, Andhra Pradesh,
was thoughtto be extinct for more than 80 years until India (Jeganathan et al. 2002). Calls were monitored
its rediscovery in 1986 (Bhushan 1986). Since then, it from about sunset to about 80 minutes after sunset,
has been seen in only a few restricted areas of the and from about 80 minutes before sunrise up to
scrub jungle in Andhra Pradesh, India (BirdLife sunrise.
International 2001). Jerdon’s Coursers are difficult to To discriminate the Jerdon’s Courser calls from
see because of their nocturnal habits, and this has those of the other birds in the Sanctuary, it was
hampered efforts to survey the population size and necessary to eliminate the calls of other species.
distribution ofthe species. Many areas in and around Other crepuscular and nocturnal species that are
the Sri Lankamaleswara Wildlife Sanctuary have now known to occur within the Sri Lankamaleswara
habitats that are superficially similar to places where Wildlife Sanctuary are Red-wattled Lapwing Vanellus
Jerdon’s Coursers are known to occur. A new method indicus. Stone-curlew, Eurasian Eagle-owl Bubobubo
,
has been developed for detecting their presence by Collared Scops-owl Otus bakkamoena. Spotted Owlet
placingtrackingstrips upon which the birds leavetheir Athene brama, Indian Jungle Nightjar Caprimulgus
distinctivefootprints(Jeganathan etal. 2002). Surveys indicus Jerdon’s Nightjar Caprimulgus atripennis,
,
usingthis method have recently detectedthe species in Common Indian Nightjar Caprimulgus asiaticus and
some new areas, but more rapid surveys might be Franklin’s Nightjar Caprimulgus affinis. Since the
possible ifthebird’scallscouldberecognized. Theonly beginning of the study, the calls of these species
published reports on the calls ofthe Jerdon’s Courser have been recorded andcataloguedalongwiththecalls
are “a plaintive cry” (Ali and Ripley 1983), “very sad; of other species occurring in the Sanctuary, which
a single note andvery soft”(Bhushan 1990), “notvery could possibly be confused with that ofthe Jerdon’s
vocal; plaintivecry: he-he-he-he-he”(Kazmierczakand Courser.
van Perlo 2000) and “kwick- kweek- kwick- kweek- The recording equipment used was a Marantz
kweek- kweek- kweek”, as described by some bird PMD222 tape recorder with an Audio Technica
trappers (Samant and Elangovan 1997). The latter AT815 unidirectional microphone, with no sound
description, however,wasthoughttobemore likelythat filters. Searches, listening and recording were carried
of the Stone-curlew Burhinus oedicnemus (Samant out mainly during clear still nights. Recordings of
and Elangovan 1997).Thispaperdescribesasuccessful calls were analyzed using the Canary 1.2.4 sound
effortat identifyingand recordingcallsoftheJerdon’s analysis package (Charif et al. 1993) on a Power
Courser. Macintosh.
FIRST RECORDINGS OF CALLS OFTHE JERDON'S COURSER
RESULTS
majorityofthe energywithin theJerdon’s Coursercall
occursbetween and4 kHz,withthesyllablesshowing
1
A call ofthe type that was later attributed to the threedistinctbandsthroughoutthe frequencyrange. In
Jerdon’s Courser was heard (by PJ) on February 17, effect, there are three notes at three different
2001,withinthecoreareaforJerdon’sCoursersightings frequencies (1 kHz, 2 kHz, 3.5 kHz), which make up
in the Sri Lankamaleswara Wildlife Sanctuary. A each syllable. The calls are repeated in a series with
Jerdon’sCourserwas sighted in thedirection ofthecall gaps ofabout 500 mS between the end ofone call and
a few seconds after it was heard. Unfortunately, it was the beginningofthe next(Fig. 2).
notpossibletogetarecordingofthiscall. Identical calls
were heard again on June 19, October 22 and October DISCUSSION
25,2001 butnobirdswere seenand norecordingswere
,
obtained. Thecall recorded by usdoesnot resembleclosely
The first recording ofthe call was obtained on anyofthe previousverbal descriptions.Thesemayrefer
November 12, 2001 at 1812 hrs local timeand again on to calls not detected by us so far, or the previous
November 13, 2001, at 1820 hrs, although the calling identificationsmayhave been mistaken. The identified
bird was not seen on either occasion. On November call ofthe Jerdon’s Coursermay beofvalue as itcould
14, 2001 the call was heard again twice, at 1816 hrs
andaJerdon’sCourserwas seen briefly(bySW)where
the call was heard from. The bird flew off when
illuminatedbyaspotlightandcalledtwice inflight.Final
confirmation that the call was made by a Jerdon’s
Courserwasobtained on May 17, 2002 at 1818 hrs (by
PJ), when a Jerdon’s Courser was observed while it
wascalling, beforedusk inamplesunlight. Thedistance
between the observer and the bird was not more than
m
50 in all ofthese instances.
Description ofthe call: The shortdisyllabic call
consists of a high-pitched first syllable, and rapidly
descending second syllable, which can be rendered as
either “kwik-koo ... kwik-koo ... kwik-koo ... kwik-
koo...” or “yak-wak yak-wak yak-wak yak-
... ... ...
wak...”. We refer to each pair of syllables as a call.
Birds have been heard to give between 2 and 16 calls
in a sequence at a rate of about one call per second.
Ononeoccasion,thefirstsyllableofthesinglecallwas
heard several times and then the bird spontaneously
called, “kwik...kwik...kwik...kwik...kwik...kwik-
koo...kwik-koo...”.
The calling period is quite brief, starting 45-50
minutes after sunset and continuing for a few minutes
toabout20 minutes. Callswere often heard from more
thanone place. Atthemost,theywere heard fromthree
differentplaces uptoabout200mapartwithin aperiod
ofafewminutes.Thepossibilityofthesamebirdmoving
and calling in such a case was unlikely, because ofthe
pattern of calling in some instances. It has been
estimated that the call can be heard from a distance of
200 to 250 m. It appears that the birds call mainly at
dusk, but the frequency ofcalling is likely to depend
upon the time ofyear and the weather.
Figure 1 showsaspectrogramofasingleJerdon’s CFiogu.r1s:eSrpecacltlrsohgorawmin(gti2mesvy.lflraebqlueesncsye)paorfaatecdompbyleatneJienrtedrovna'ls.
Coursercall, consistingoftworepeated syllables,each The spectrogram was produced by Canary 1.2.4, grid
separated by an interval of60 milliseconds (mS). The resolutions 5.8 ms, 10.77 Hz. [Y-axis=kHz, X-axis=S],
J. Bombay Nat. Hist. Soc., 101 (1), Jan.-Apr. 2004 27
.
FIRST RECORDINGS OF CALLS OF THE JERDON'S COURSER
65-
60-
5.5-
50-
4.5-
Fig 2: Spectrogram of a series of six Jerdon’s Courser calls. The spectrogram was produced by
Canary 1.2.4, grid resolutions 5.8 ms, 10.77 Hz. [Y-axis=kHz, X-axis=S],
help to find the bird in new areas and estimate its ACKNOWLEDGEMENTS
population size. It appears that Jerdon’s Coursers call
mainly at dusk and it may be possible to survey their The research project was funded by the Darwin
distribution by listening for the calls. However, initial InitiativeandcarriedoutbytheBombayNaturalHistory
observations indicatethattheshortperiodduringwhich Society, Royal Society forthe Protection ofBirds and
the birds call and the variation among evenings in University ofReading. We are grateful to the Andhra
whethertheycall atall would make itdifficulttosurvey Pradesh Forest Department for giving permission to
large areas. workintheSri LankamaleswaraWildlifeSanctuary. We
Experiments are in progress using standard thank N. Rahim for help with the fieldwork. Nigel
playback methods (e.g. Mosher et al. 1990; Haug and Butcher and Gillian Gilbert provided advice and
Diduik 1993)todeterminewhethertape playbackcould comments. Chris Bowden, Rhys Green, Ken Norris,
be usedtoelicitcallsovera longerperiod. It is hopedto Debbie Pain and Asad R. Rahmani arefellowmembers
determine the effects oftime ofthe year, time ofday of the Jerdon’s Courser project team, and provided
and weather on the bird’s response to playback. advice and comments.
REFERENCES
Ali S. & S.D. Ripley (1983): Handbook ofthe Birds ofIndiaand Hilton-Taylor, C. (compiler) (2000): IUCN Red List of
Pakistan together with those ofBangladesh. Nepal, Bhutan Threatened Species. IUCN, Gland, Switzerland and
and Sri Lanka. Oxford University Press, Bombay. 737 pp. Cambridge,UK.
Bhushan,B.(1986):RediscoveryoftheJerdon’sCourserCursorius Jeganathan,P.,R.E. Green,C.G.R. Bowden,K.Norris, D. Pain&
bitorquatus.J. Bombaynat. Hist. Soc. 83: 1-14. A.R. Rahmani (2002): Use oftrackingstrips and automatic
Bhushan, B. (1990): Jerdon’sCourserrediscovery and survey. In: camerasfordetectingcriticallyendangeredJerdon’sCoursers
Status and Ecology of the Lesser and Bengal Floricans, Rhinoptilusbitorquatus in scrub jungle in Andhra Pradesh.
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Haug, E.A. & A.B. Didiuk(1993): Useofrecorded callsto detect bitorquatus. Bombay Natural History Society, Bombay.
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2 8 J. Bombay Nat. Hist. Soc., 101 (1), Jan.-Apr. 2004
