Observations of humpback whales (Megaptera novaeangliae) on a cruise to New Caledonia and the Chesterfield Reefs

7 Pages·1995·2.5 MB·English

by  P C Gill

OBSERVATIONSOFHUMPBACKWHALES iMEGAPTERANOVAEANGUAE)ON A
CRUISETO MEWCALEDONIA ANDTHECHESTERFIELD REEFS
PETERC.GILL, ELIZABETHJ.EYRE, CLAIREGARR1GUE&WILLIAM H. DAWBIN
Gill. P.C.,Eyre,E.J.,Garrigue,C. & Dawbin.W.H. 1995 1201;Observationsofhumpback
whales(Megapteranovaeangliae)nn;icruisetoNewCaledoniaandtheChesterfieldReefs.
Memoirsqfthe QueenslandMuseum38(2):505-5IL Brisbane. ISSN0079-8835.
Duringayacht-basedsurveyintheaustralwinterof1992,lownumbersofhumpbackwhales
wereobservedaroundthemain islandofNewCaledonia, andhumpbacksongwasrecorded
there. The song, the first recorded in NewCaledonian waters, showed similaritiesto song
recordedoffeasternAustralia. Nohumpback whalesweredetectedatChesterfield Reels in
the eastern Coral Sea. despitetheirpossiblestatusasabreedingarea. Only a small portion
oftheChesterfieldPlateauwassurveyed. Reportsofsightingsthere inrecentyears indicate
*l least occasional visitationby humpback whales.
PeterC. Gill, OceanicResearchFoundation, c/- I48CopelandRdEast,BeecroftNSW2l19
Australia: Elizabeth J Evre, Marine Mammal Department. Toronto Z-oo. PO Box 20,
Mosman,NSW2028Australia; ClaireGarrigue. ORSTOM. BPA5, Noumea, New Caledo-
nia; WilliamH. Dawbin,AustralianMuseum, b-SCollegeSt.Svdne\; NSW2000Australia;
15June 1995,
Group V humpback whales feed in Antarctic METHODS
Area V O3<TE-170"W) during the austral sum-
mer and segregateintotropical breeding areas in
live southwest Pacific during winter (Dawbin, The 15-metre cutter "Iniquity" was equipped
1966). Catch data of 19th century American pe- withGPS navigation,depth sounder(max. depth
lagic whalers indicated wintering, and presum- 100m), radar, weatherfax, wind instruments ;<nd
ablybreeding,concentrationsaroundTonga,Fiji, seawater thermometer. With a minimum of 2
observers,continuousvisualmonitoringwascar-
and the Chesterfield Reefs in the Coral Sea
ried out(except when interrupted by sailing du-
(Townsend, 1935). French whalers killed hump-
hacks in the Loyalty Islands of New Caledonia, htioersi)zforno5m.d6-e6c.k7l2c-m3)mwhaibloevethseevaelsesveellw(adisstmaankcientgo
as well asat theChesterfieldReefs(du Pasquier, way In sheltered lagoon waters where whale*
1982).Many Americanwhalersalsovisitedparts were more likely to be encountered, when the
ofNewCaledonianwatersduringtheI9thcentury vessel's motion allowed, an observer was posi-
(Langdon, 1984). Humpbacks were marked by tionedupthe mast 12m a-s.1. (distancetohorizon
Dciwbin using "Discovery" tags around Vymutru 33.5km).
andthe LoyaltyIslandsdunngthe late 1950s,but "Iniquity" departedCoffsHarbour, New South
nomarkswererecovered(Dawbin, 1964). Receni
Wales on 7 July 1992. and sailed northeast to
incidental sightingsdata,unreportedal theoulset Noumea. Nearly 4 weeks were spent in New
of Ihis study, indicate that humphaek whnlex, Caledonian waters from 14July,and the passage
including newborn calves, are now frequently westward across the Coral Sea \o Queensland
seeninNewCaledonianwatersduringwinterand took place during 1 1-31 August (Fig. 1). This
spring (Garrigue andGill, 1994). There has been timing allowed the vessel to he in these areas
speculation, basedonTownsend's(1935) charts, around the estimated peak of the cast Australian
astowhetherChesterfield Reefsare still a hump- humpback breeding season (Simmons and
back breeding destination (Dawbin and Falla. Marsh, 1986: Paterson, 1991).
1949; Paterson, 1991). Humpback song may be detected over tens of
This paperdescribes a yacht-based cruise dur- kilometres (Cato, 1991), a much greater range
ing theaustral winterof1992. initially toinvesti- than visual observation permits. It is commonly
gate whether humpback whales migrate to New heard in breedingareasand on coastal migration
Caledonia and the Chesterfield Reefs. While in routes, even in darkness. On a previous yacbt
New Caledonian waters the study focused on based study in Australian waters, humpbacks
humpbacksong,neverrecordedintheregion,for weredetected3timesmoreoftenbysongthanhy
comparison withotherareas. sight(Dawbin and Gill 1991). Forthese teu
n
506 MEMOIRSOFTHEQUEENSLANDMUSEUM
1.!m NtjfttlUtpon
-,,-,,
105
AUSTRALIA LEGEND
Trackofv«*el
>-.v.- Reef
listeningstaliun
fnowhalwbeard)
A Humpli.ict*.«•>_-
MiddlwonW • Humpb«fc*heard
:,,'. . IV.M.il.ij:r
..,,. . mta
Lord Howeli
160f
FIG. 1.Mapshowingtheroutetakenbythevessel, locationsofhumpbackwhalesightings,andlisteningstations.
acoustic monitoring was regardedas theprimary posed ofunits,phrases and themes (Cato, 1991).
detection method forthis study. Forthis comparison, units were denoted by sub-
Hydrophonesoundingsweretakenforabout 1 jectivedescriptiveterms (e.g., "yap", "moan") in
min every 3-4hours while atsea (approximately the order in which they occur (Table 4). Phrases
every 30km) when conditions allowed, in order were used as the measure of aural comparison.
toensurethatthesameanimalswere notdetected Sonograms of selected segments of song were
at more than one listening station. Soundings made with a Kay Elemetrics DSP Sono-Graph
were taken not only near coastlines, islands and model 5500-1 (Fig. 2). Analysis filterbandwidth
reefs,butalsodistantfromland,inordertoascer- was 15 Hz.
tain possible migration routes (Clapham &
Mattila, 1990). Monitoring was also conducted RESULTS
whenwhalesweresighted.Aminimumof20min
was recorded whenever possible, to ensure cov- Detectionof Whales
ering at least 1 full song cycle. Acoustic equip- No humpback whales were detected at Ouvea
ment consisted of an Edmund Scientific 41759 and Lifou in the Loyalty Islands, although only
hwiytdhrohpihgohnpea,sscofnilnteercttoedavSioanay4W0MdDB6p-reCamcpalsisfeiteter TABLE 1. Humpbackwhalessighted, NewCaledonia
recorder. Systemresponse was 30Hz-6kHz.
Song fromNewCaledoniawas comparedwith Date Position Locality Number
song from Eden (southbound migration, 1991) 19Jul 1992 2126*62°45*25'E SoutheastLagoon 2
and Coffs Harbour (northbound migration,
1992),NewSouthWales(Table2).Songanalysis 27Jul 1992 2116°6575'TSE eastcoast 1
was both aural and speclrographic. Cato (1991)
has noted that humpback whale sounds are well 2Aug 1992 2T26°62°55'5S'E SoutheastLagoon 2
suitedtohumanauralperception. Songsarecom-
HUMPBACKWHALEOBSERVATIONS 507
•Phrase B2
NEW V ^'\
CALEDONIA -c\
J£S
% ^;i-
:: _, ]gto» fes
„
\-\
EDEN
-^
1 ' ' -^ 1
.
COFFS
HARBOUR
—
—PhraseGa- 1*1JL*
i 1 1 '
NEW J
CALEDONIA ->«:—~-—*3-v->.-=-41- -* ^—it*' -^"f -—^*^f;*/e 11 .. .f w..; ' j.i
_y — /
-. ,
T-fr
X
EDEN
*
-^ "X--^ U
--"*
J-3
COFFS
HARBOUR
FIG.2.SonogramsshowingcomparisonofsegmentsofsongphrasesfromNewCaledoniaandtwolocationson
theeastcoastofAustralia.Samplesshownarenotconsecutive.
508 MEMOIRSOFTHEQUEENSLAND MUSEUM
TABLE2.Locationsofhumpbacksongheard,number itored for 10 min every 2 hour except during
ofwhalessinging,anddurationofrecordings. periods ofsleep.
No humpback whales were detected in open
Date Position Locality Sing- Duration ocean waters, or during visits to Middleton and
ing
Marion Reefs in the Coral Sea (Fig. 1). After
17Nov91 3175°000'WSE AEudsetnralia: 1 90min entering the Great BarrierReefat20°15*S on 31
August, humpback song was frequently heard
06Jul92 3105°31°80'9S'E CoffsHarbour 1 90min between 20°04'S, 149°05'E and 22"54'S,
NewCaledonia: 151°05*E,wheremonitoringwasdiscontinuedon
2Aug92 2126°62°55'5S'E SLoaugtohoenas(tCap 1 107min h2e0aSredpstienmgbienrg.siAmtulttiamneesouusplyt,oa4nwdhsaelveesraclouhludmpb-e
Ndoua) backs were seen, including 4 cow-calf pairs. A
16Aug92 1196°34°45'5S'E GLraegaotonNorthern 1 19min notable exception was within the Whitsunday
Islands, where heavy vessel traffic was evident,
16Aug92 1196D33°63'5S,E GLraegaotoNnorth 1 15min and nowhaleswereseenor heard.
(LBelep)
18 Aug92 I196°33°03'3S*E LfGlra.egBaoetloeNnpo)rth 1 60min SoSnogngAsnaflryosmisthe three areas compared here
(New Caledonia Southeast Lagoon, Eden, Coffs
small areasaround these islands were examined Harbour) each have three themes, and show a
due to strong winds. Five humpbacks in 3 pods high degreeofshared phrases, as determined by
iwselraendsiogfhNteedwinCathleedeaosntiaanddursionugth4e6as3tkomfttrhaevmelaliend Casuharalareleddocn8oi9am%,paorwfihisplhoernasE(edTseawbnilteahn3bd)o.thNCeEowfdfesnCaaHlnaedrdboNoneuiwar
inlagoonwaters(Fig. I;Table 1). Thesesightings shared 78% ofphrases. A transcript of the aural
have been included in the incidental sightings
estxucdeyedofedGar3r0igkumeraHndfGoirllm(o19r°e4)t.hWaninhdalsftroefngtthhse coSmppeacrtirsoognriaspshh^owannailnysTiasbloef4.selected phrases
period spent in New Caledonian waters, making (B2, C3, C4) shows similarities in structure and
both visual and acoustic detection ofwhales dif- pattern of humpback sound types from the three
ficult at thesetimes. areas (Fig. 2).
Song was detected and recordedon fourocca-
sions in New Caledonian waters, offboth south- Discussion
castandnorthwestextremitiesofthemain island New Caledonia. Useful information was ob-
(Table 2). Song was heard during only one of tained from acoustic monitoring during this
three sightings due to wind-induced water noise study. Song was heard on four occasions, and
during the othertwo. Humpbacks were detected humpback whales sighted on three. Acoustic
in theGreat NorthLagoon ofNew Caledonia by monitoring extended the known distribution of
sound alone; visual monitoringin good toexcel- humpbacks into the Great North Lagoon, a large
lentconditionsdetected no whales. TABLE3. Sharedandunique song phrases.
No humpback whales were detected during a
1
22-hr visit to South Bellona Reef (21'53'S, Phrase Eden Coffs New
Hartwur Caledonia
159'28'E) at the southern end of Chesterfield
Plateauincalmclearconditionson20-21 August. Al X X X
The vessel was anchoredduring this period, and 2 X X X
visual and acoustic observations were made at Bl X X
2-hourIy intervals. No humpback whales were 2 X X X
detected in the Chesterfield Reefs lagoon 3 X X X
119U5.VS, )58°25'E) during 22-26 August, de- CI X X X
spite reasonable toexcellentconditions Though
the vessel traversed the lagoon twice, it was an- 2 X X X
chored most ofthe time. The entire lagoon was 3 X X X
visible, and was scanned several times per day -i X
fromthevessel'smast,whileatanchor. Ahydro- JA X
phonewascontinuouslydeployed,andwasmon- L '
HUMPBACK WHALEOBSERVATIONS 509
TABLE4. Auralcomparisonofhumpbacksong,usingsubjectivedescriptiveterms. Symbols: (R)repealed;(P)
pause; Tupward;(2)unitrepeated. Unitinbracket repeated.
Pheme Phrase Descriptivetermsforunits
A 1 gloop-lowmoan-gloop(2)-lowmoan(2)-cries-cows
2 Paynecries-shortercriesintochirps
1 [filoop-woocry(P)woocry-woocry(P)-lowereriesintowhistles]-(R)
B 2 [Tmoan-woocry(P)woocry(P)woocry-lowercriesintowhistles]-(R)
3 Tmoan-woocry(P)woocry-Tmoan-lohgmoan-raspywhisltlechirps
1 Tmoan(2)-longlowmoan-1moan-longlowmoan
c 2 (veryshortmoan-undulatingmediumgroan]-(Rj
3 [veryshortmoan-ratchetmoans]- (R)
4 yaps
Songcharacteristics;
•dominent(mostfrequent)themeisB
•phraseB2repeatedmostoften
•medium-lengthsong
h)CoffsHarbour,6July 1992
A 1 [sloop-lowmoan-gloop(2)-lowmoan-eloop(2)-eries-cows|-(R)
2 (Pavnecries-shortercriesintochirps](R
i
i 1eloop-woocry(P)woocry(P)woocry-lowercriesintowhistles] -(R)
B [Tmoan-woocry(P)woocryf2)-Tmoan-woocry-lowercriesintowhisUes]-(R)
I T moan-woonyIP) woocry- I moan-long moan(P) long moan - raspywhistlechirps
1 Tmoan(2)-longlowmoan-T moan-longlowmoan
C 2 [veryshortmoan-undulatingmediummoan]-(R)
3 [veryshortmoan-ratchetmoans]-(R)
4A upwardwhistle-yaps
Songcharacteristics
•shortsong;dominantthemeprobablyA
•themesquiteshort
•B2hasextracrysinceEden
c)NewCaledonia,2August 1992
A 1 [gloop-lowmoan-gloop(2)-lowmoan-gloop(2)-cries-cows]-(R)
2 [Paynecries-shortercriesintochirps] - ("R)
B [Tmoan-woocry(P)woocry(2)-Tmoan-woocry-lowercriesintowhistles]-(Rj
j Tmoan-woocry(P)woocry-T moan-longmoanraspywhistlechirps
T moan-longlowmoan- Tmoan-longlowmoan
1
C 2 (veryshortmoan-undulatingmedium moan]-(R)
3 [veryshortmoan-ratchetmoans]-R
4 upwardwhistle-yaps
|
Songcharacteristics
•shortsong;dominantthemeprobablyA
••Bso1moefupnrietvsinoouslBoOnTglgefrlrneopelaotnegdere.pgr.esmeonatnofC1,longmoanofB2
and rarely-visited area where no sightings had similaritiesaremostapparentintheexamples we
been reported. It also permitted the first song haveused.
comparison thatweknowofbetween songsfrom Humpbacksongisconsideredtobeanindicator
two Group V breeding areas. ofstock identity (Payne & Guinee, J983); songs
Although song was recorded after the vessel tend toshow decreased similarity with increased
entered north Queensland waters, it is not used geographical separationwithinoceanbasins,and
here forcomparison withNew Caledonian song. littleornosimilaritybetweenoceanbasins(Winn
The songs from Eden and Coffs Harbour were etai. 1981;He!wegetal., 1990;Dawbin&Eyre,
most similar in pattern to New Caledonian song, 1991). While some differences were found be-
while the north Queensland song had evolved tweenthesongscomparedhere(suchasthenum-
substantially since July 1992. Change of song ber of repetitions, or the omissions of units or
with time may be complex even along a single phrases), such variation can occur between indi-
migration path (Cato, 1991), let alone between viduals in the samearea, oreven betweendiffer-
breeding areas as well as seasons. Here we at- ent song renditions by an individual (Dawbin &
tempt only to report similarities between songs Eyre, 1991). But the song from the three areas
fromNewCaledoniaandeastAustralia,andthese was basically similar. The Coffs Harbour song
510 MEMOIRSOFTHEQUEENSLANDMUSEUM
shared as many phrases with New Caledonia as Due to bad weather thevessel did not traverse
with Eden (Table 3). while the closest resem- themainbodyofChesterfieldPlateauduringthis
blances in spectrographic structure appear to be cruise, visitingonly South Beilona and Chester-
between NewCaledoniaandEden (Fig. 2) fieldReefs, for22hoursand5days,respectively.
Given the relatively close proximity of New Duringtheseperiodsnowhaleswereobservedor
Caledonia and east Australia, and that Group V heard in good to ideal monitoring conditions.
breedinggroundsextendatleast toFiji (Dawbin, Theseobservationsareinconclusive, however,as
1966) ajid probably Tonga, the similarities in whales may have been present elsewhere on the
song reported here arenot surprising- An antici- Plateau* or at Chesterfield Reefs earlier or lata
pated migratory connection between New Cale- than the yacht's visit. The determination of the
donia and otherGroup V breeding grounds was currentstatusofChesterfield Plateau's reefsas 3
established in 1993 by a photo-identification humpbackbreedingarea thereforeawaitsa more
comprehensivestudy.
march with Hervey Bay, Queensland (Garrigue
&. Gill, 1994). The similarities in song reported
ACKNOWLEDGEMENTS
hereaddfurtherevidenceformigratoryexchange
between humpback whale sub-populations of
New Caledoniaand eastAustralia. Field assistance from Tim Edkins, Diana Da-
ChesterfieldReefs.Therearenumerousreefson vidson,PeterDrew,ChookWall-Smith,andDeb-
Ihe Chesterfield Plateau. Townsend's. (1935) bieMilhammadethestudypossible. KenSchultz
chart shows awidespreadofpointsrepresenting and Dr Doug Cato assisted with sonograms. Dr
humpbackskilledbyAmerican whalers between Peter Corkeron offered useful comments on the
JulyandOctober(approximately45%ofthem in text. MsB.JantulikpreparedFigure 1.Thestudy
August), centred around Chesterfield Reefs, to- waspartly fundedby agrantfromtheW.V.Scott
ward the northern end of the Plateau. French Estate, and was conducted under Whale Protec-
pelagic whalers operated there at least in 1862 tion Act Permit No. P1992/027. issued by the
and 1864 (du Pasquicr, 1982). The Chesterfield Australian National Parks and Wildlife Service,
Reefslagoon isthe mostsheltered body ofwater Canberra.
on the Plateau, enclosing roughly 85 sq km. It
meets the criteria cited by Whitehead 8c Moore LITERATURECITED
(1982) as humpback breeding habitat, offering
shelter,havingsuitabledepths(average50m)and CATO. D.H. 1991. Songs of humpback whales: the
apwrnaodrvmeiadwseaydteawcrhc(ae2ls3is*ntCgoinwvehAsauslgeeulssstiwni1o9tr9h2n)se.aafIrlewtahoenucllhdaoghroaaovgnee. CLAPAlHuasnAtdMrMa,luiPsa.neJ.up&emrsM3p0Ae(cT2t)Ti:vI2eL.7A7M-.e2m9D0o..iKrs19o9f0.thHeuQmupebeancsk-
Numerouswhalebones,someofthemwithmarks wMhaorlienesMoangmsmaasliSncdiiceantcoers6(o2)f:m1i5g5r-a1t6i0o.n roulcs.
from chopping implements still visible, have DAWBIN, W.H. 1964. Movements of humpback
beenlocated bydivers in the lagoon (B. Crouch, whales marked in the south west Pacific Ocean
pers. comm.). 1952 to 1962. Norsk Hvalfangst-Ttdendc 3: 68-
Onlytworeliablereportshavebeenobtainedof 78.
humpbacksatChesterfieldReefsduringthiscen- 1966. The seasonal migratory cycle of humpback
tury. In June-July 1972, 5-10 humpbacks were whales. 145-170, In K.S. Norris (ed.K 'Whales,
.seen, and song heard by divers,inside the Che! Dolphinsand Porpoises'.(UniversityofCalifor-
& n a Press- Berkeley).
terfield Reefs lagoon (R. V. Taylor, pers DAWBIN.W.H.&FALLA,R.A. 1949.Acontribution
comm.). Morerecently, a humpback mother and to the study of the humpback whale based on
calfwere observed inthesamelagoon over sev- observationsatNew Zealand shorestations. Pro-
eral weeks during September-October 1990 (B. ceedingsofthe 7thPacific ScienceCongress. 4:
Crouch,pers. comm.)Thisobserverhasnotseen 373-38^
humpbacks duringotherfrequent visits toChes- DAWBIN.W.H.&EYRE,EJ 1991.Humpbackwhale
terfield Reefs in recent winters. Several French songs along Uie coast of Western Australia and
Government (ORSTOM) scientific expeditions o.<fotmheecQoumepeanrsilsaonndwMiluhseeaustmc3o0a(s2t):so2n4g9s.-2M5e4.moirs
sduurrivnegystohef tphaestPldaetceaadue,itsienlcf,luhdainvge braetpohrytmeedtrnioc DAWBsIuNrv.eyW.aHlo.n&g tGhIeLwLe.sPt.Cc.oa1sl99o1f.AHuustmrpabliaac:kawchoaml-e
sightingsin winterand spring months (B- Richer parisonofvisualandacousticobservations.Mem-
de Forges, pers. comm) oirsoftheQueensland Musucm 30(2): 255-257.
HUMPBACKWHALEOBSERVATIONS
511
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gneurs, Grenoble). of"stocks".333-358.InR. Payne(ed.), 'Commu-
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logicalConservation70:211-218. SIMMONS, M.L. & MARSH, H. 1986. Sightings of
HELW&EGFO,RDE.SA.T,EHLEL,RMP.AHN.,19L9.0.M.C,omYpAaMriAsMonOoTfOso,ngSs. hScuimenptbiaficckRewphoarltessoifntGhreeWahtaBlaersriReersReeaerfcwhatIensrtsi.-
ofhumpback whales (Megaptera novaeangliae) tute,Tokyo37: 31-46.
recordedinJapan, HawaiiandMexicoduringthe TOWNSEND, C.H. 1935. The distribution ofcertain
winter of 1989. Scientific Reports of Cetacean whalesasshownbylogbookrecordsofAmerican
LANGRDesOeNar,chR.1:119-8240.. 'Where the whalers went'. An whaleships. Zoologica 19: 1 -50.
index to the Pacific ports and islands visited by WHITEHEAD,H.&MOORE,M.J. 1982.Distribution
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PATERSON, R.A. 1991. The migration ofhumpback HAINJ., HUDNALL, J., HAYS, H., & STEI-
whales Megaptera novaeangliae in east Austra- NER,W.W. 1981.Songofthehumpbackwhale-
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