Observations of Mate Change and Other Aspects of Pair bond in the Sarus Crane Grus Antigone

2005·2.4 MB·

by  K S Gopi Sundar

MISCELLANEOUS NOTES
Dalke, P.L. (1937): Food habitsofadultpheasants in Michiganbased Harper, J.A. (1964): Calcium in grit consumed by hen pheasants in
on crop analysis method. Ecology 18: 199-213. east-central Illinois. J. Wild/. Manage. 28: 264-270.
Ghorpade,A.M. (1975):Noteson thefeedingoftheSarusCraneGrus Law, S.C. (1930): Fish eating habit of the Sarus Crane (Antigone
antigone antigone (Linnaeus). J Bombay Nat. Hist Soc. 72: antigone). J. BombayNat. Hist. Soc. 34: 582-583.
199-200. Sadler, K. (1961): Gritselectivity by the female pheasant duringegg
Gionfriddo, J.P. & L.B. Best (1996): Grit-use patterns in North production.J Wildl. Manage. 25: 339-341.
American birds: the influence ofdiet, body size, and gender. Sundar, K.S.G (2000): Eggs in the diet ofthe Sarus Crane (Grits
Wilson Bull. 108: 685-696. antigone). J. Bombay Nat. Hist. Soc. 97: 428-429.
Hume, A.O. & C.H.T. Marshall (1879): The Game Birds of India, Weltry,J.C.& L. Baptista(1988):TheLifeofBirds.SaundersCollege
Burma & Ceylon. Vol III. John Bale, London. Pp. 4-5. Publishers,N.Y.
12. OBSERVATIONS OF MATE CHANGE AND OTHER ASPECTS OF PAIR-BOND IN
THE SARUS CRANE GRUS ANTIGONE
Sarus Cranes Grus antigone are known to be and the frequency of duet calls (which is also used for
monogamous and pair bond is thought to last throughout the advertisement during territorial defence, Archibald 1976)
livesofthebirds(AliandRipley 1989).Themaleandfemaleof increased. Inmid-August,thepairconstructedanestofTypha
apairare known to strengthen the pair bond by synchronized reeds in the marshland and the female laid two eggs, both of
behaviours such as duet calls, dance, guard-calls and alarm- which were removed byvillagers.
calls(Masatomi 1994;Archibald 1976).Theactualdurationof OnSeptember8,2000,duringaroutinevisittothearea,
pair bond, prevalence ofmate change and factors leadingto another bird was seen in the territory and repeated attempts
such changes are unknown in Sarus Cranes. In this note, I by the resident pair to chase the visitor (duet calls, tertial-
report the first evidence of divorce or separation in Sarus elevation strutsandco-ordinatedguardcalls)failedtoelicita
Cranes with observations on other aspects ofpair bond and response. In a surprising move, the visitor attacked the
territoriality. residentfemale(identifiedbysmallersizeandpostureduring
Overtwohundred and fiftybreeding,territorialpairsof duet calls). At first, the male assumed threat postures and
Sarus Cranes were monitored between December 1999-July carried out displacement preens, tertial-elevation struts, and
2002 as part ofa study on their biology and conservation in a directed walk threat at the visitor. These attempts failed to
the districts ofEtawah and Mainpuri in Uttar Pradesh. The displace the visitor, which instead renewed attacks on the
study area has the highest known density ofterritorial pairs residentfemale. Thevisitorwassmallerthantheresidentmale,
and number ofSarus Cranes anywhere in the world. Pairs/ but largerthan the resident female. The resident female and
familieswererecognizedbycolour-bandingthejuvenileseach thevisitorsparredforalmostfiveminutes,peckingeach other
year, with individual physical marks on adult birds, or by and indulging in rapid, violent bouts ofjump-rakes. The
location. Pairs, particularlythosewith young, wereobserved residentfemalewasclearly losingthebattle;the largersizeof
one to seven times a week (average offour observations) to the visitor could have proved to be an advantage. At this
collect data on breeding success, feeding habits, territory point, the resident male, which was otherwise circling the
size, and activitybudgets. Mate change was observed in two fighting pair of cranes, walked in and pecked the resident
instances and is discussed in this note. “Divorce” or change female. The resident female began running away from the
ofpairmembership was actually observed in one pair, while visitor,givingalarm-calls, andthemaleresponded bycalling
mate change could be deduced in another. In addition, other synchronously, but did not come to the rescue. The visitor
relevant aspects of pair bonding, territoriality, and related became very aggressive and mounted a fresh attack on the
behaviours observed are described and discussed. The resident female by kicking, jump-raking, wing-thrashing,
behaviour terminology used throughout the text follows sittingonthe backofthe bird and peckingthe neck and head
Ellisetal. (1998). hard and rapidly, finally chasing the bird into a pond and
forcing it to swim to the opposite bank. The male was now
Matechangeobservation 1 chasing the resident female as well, and clearly supporting
Theterritory ofone pairwas very close to the town of the visitor, though he synchronouslyanswered thealarm and
Etawah, and consisted ofa large Typha-bordered marshland guard-callsofthe resident female.
and crop fields. The pair had successfully raised one chick On emerging from the lake, the resident female was
during the breeding season in 1999-2000, and was seen to pursued once again by the visitor. This time, the female
defend the territory from other Sarus pairs and groups deliberately, but cautiously, approached human observers
throughouttheobservation period. In earlyAugust, the adult standing on the side ofthe marshland and stood as close as
birdswereobservedtochasethesub-adultfromtheterritory, 5 m. Thisdissuadedthevisitorfromattackingfurtherand she
J. Bombay Nat. Hist. Soc., 102 (1), Jan-Apr 2005 109
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MISCELLANEOUS NOTES
resorted instead to a watchful preening session from beside natalterritory inJune2000. Thepairwasobservedtonest in
the male bird. The resident female, while drying her wings, August 2000, but children removed both eggs and the pair
gave continuous calls, all of which were answered by the did notrenest. In November2000, observations ofthe birds
male. Severaltimes,theresidentfemalemadeamovetowards afterthe harvestingofpaddy in the territory showedthatthe
the male, whichcausedthe visitorto stop preeningandwalk femalewasdifferent,asevidencedbythepresenceofalltoes
towardsher. Eachtime,the residentfemalewouldwalkback onthefeet. Themalewaspresumedtobethesame, sincethe
towards the humans, causing the visitor to back off. After territory being defended bythe pairwas exactly the same as
nearly an hour, the resident male and the visitor managed to that determined using colour-banded chicks the previous
chasetheresidentfemaleaway.Thewhole incidenttookplace breeding season. The new pair nested in August 2001,
overaperiodof55minutes(1655-1750hrs). villagersremovedtheeggsfromthenest,andthepairrenested
Themale,withthe visitor,commencedconstructionof 18 days later. The one egg from renesting hatched, but the
anestanhourlater.Thenestsitewasshiftedthenextmorning chick disappeared within a week due to unknown
dueto humandisturbance, and bothbirdsworkedvigorously circumstances. Thepairdidnotrenestfollowingthedeath of
attheconstruction.Noeggswere laidandthenestwasfound thechick.ThechangeofthefemaleoccurredbetweenAugust
abandoned a week later. The new pair was not observed andNovember2000. Inthispair,asinthepreviouscase,mate
duetting until the end of October, when they were also change resulted in a decrease in immediate productivity and
observed contact calling in synchrony forthe first time, and themaleretainedtheterritory. Thepairwasobservedcalling
were first observed dancing only in August 2001. Though in unison in November2000 and dancinga month later. The
the nestingseason forSarus Cranes in the study area is July- pairbonding afterre-pairing, thus, was faster in this pair.
October(pers. obs.),thepairconstructedanestinApril200
1
but no eggs were laid. The pair constructed a nest again in On matechangeincranes
September 2001, but disturbance by people and cattle MatelossanddivorcehavebeendocumentedinSandhill
dissuaded them from laying eggs. Cranes Gras canadensis. New pairs have been established in
Thereason forre-pairing bythe male was not entirely birds following separation or death ofa partner (Nesbitt and
apparent, though the larger size and more aggressive nature Wenner 1987), and divorce has been observed in as many as
ofthe visitor female may have caused the male to choose 67%of24colour-bandedpairsobservedfor3-1 years(Nesbitt
1
over the previous, smaller one. The incident fits into the 1989). Though successful reproduction was seen to enhance
“forced divorce hypothesis” wherein a third dominant the maintenance ofa new pair bond, unsuccessful breeding
individual isresponsibleforbreak-up;previousreproductive wasnotnecessarilyalwaysthecausefordivorce(Nesbitt 1989).
success cannot predict the divorce and the break-up does Also,asobserved intheSarusCranes,territorywasretainedby
notnecessarily improve reproductive fitness ofthe divorced malesofseparatingpairseightoutofninetimes(Nesbitt 1989).
members (Choudhury 1995). This is also the only recorded InanotherstudyonFloridaSandhillCranesG.c. tabida,Nesbitt
instance of“courtship-role reversal” in Sarus Cranes with andTacha(1997)recordedbreakingof44%ofpairbonds;32.3%
femalesbeingsexuallycompetitiveanddisplayingaggression ofthesewereduetodivorce. Inthisstudy, incidenceofdivorce
to choose a male. Recent reviews have shown that this was found to be related to failure to reproduce (Nesbitt and
phenomenon arises when parental investment is greater by Tacha 1997). Territory wasretainedbymales92.9% oftimes,
males (Gwynne 1991). This aspect of Sarus Crane biology and females 69.2% ofthe time. In Eurasian Cranes G. grits, a
hasnotbeenexploredandpromisestobeanexcitingsubject hand-reared bird was recorded to change matesthree times in
for study. Young cranes are sometimes thought to build nest seven years (Johnsgard 1983). Mate changing is known in
platforms immediatelyafterestablishingabreedingterritory almostallcranespeciesincaptivity,anddatafromcaptivebirds
(Archibald2000). Thebuildingofanest intheabovepairof suggeststhatmatechangingismostcommon intheearlyyears
cranes uncharacteristically inApril 2000 may be part ofthe and stabilizes afterbirds find compatible partners (Swengel et
behaviour seen in newly paired young cranes. al. 1996). InSandhi11Cranes,re-pairingoffemalesthatretained
theirterritorieswasusuallywithyoungermales,whilemalesre-
Matechangeobservation2 paired with females ofthe same age as themselves, or older
In anothercase, mate change could be deduced from a (Nesbitt 1989).
physical abnormality in the female bird-the mid-toe ofthe MatechangesintheSarusinEtawah,however,occurred
right leg ofthe female was missing. In 1999, the pair had after cranes had bonded and even bred successfully. In the
successfully hatched two chicks, both ofwhich were colour two breeding seasons after mate changing, the change of
bandedinDecember 1999andobservedtodispersefromtheir partner was observed to result in a decrease in productivity
110 J. Bombay Nat. Hist. Soc., 102 (1), Jan-Apr 2005
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MISCELLANEOUS NOTES
ofthe pair in both cases. It is possible that productivity may the species. It is, however, not necessary that similar trends
be enhanced in the long run. Large-scale colour-banding of hold good in other areas with Sarus Cranes that have a low
paired adults using individually colour-coded plastic bands numberofnon-breeding individuals.
and/or recording of duet-calls, which are known to be
‘signatures’foragivenpair(Wessling2000), should be used On aggression and cognition
to investigate mate changes in Sarus Cranes. Information on Although peckingandjump-rakeshavebeen observed
theseaspectsofbehaviourofSarusCranes isentirelyabsent. to be part ofthe agonistic behavioural repertoire in every
These observationsovertwo andahalfyears, ofavery large species ofcrane, the fights in Sarus Cranes usually do not
numberofbreeding,territorial pairs,clearly indicatethatnot escalate beyond jump-rakes (pers. obs.), and the risk of
allSaruspairsbondforlifeasismadeouttobeforthespecies. physical damage is minimised. The birds, instead, resort to
lower levels ofnon-physical aggression that include a wide
Onpairbondingandterritoriality range ofpostures and calls (described in Ellis et al. 1998).
A few other aspects ofpair bonding and territoriality Observations in Etawah show that Sarus Cranes are capable
were observed during the study period. The first involves ofterrific violence against conspecifics.
injury to the malejust priorto the breeding season. In three An interesting feature of the incident where divorce
pairs,themalewas injuredduetocollisionwithelectricwires, was observed was that of the resident female seeking
rendering one leg useless, preventing mating forthe season. protectionfromtheattackingvisitorbywalkingupveryclose
In one ofthese pairs, the nestingarea, a perennial pond, was to humans. That the bird did it repeatedly suggested an
usurped by an adjoiningpair, which didnot haveany natural understandingon itspartthatthe visitorwould not riskclose
wetlands in theirterritory. The nesting area was regained by approachtohumans.Though farmersoftenremoveeggsfrom
theoriginalownersafterthe legofthe injuredmalehealedthe nests to dissuade pairs from breeding in their fields, they
followingyear. Intheothertwopairs,theadjoiningpairshad rarelypersecuteadultbirds. Theobservationsuggestshigher
sufficient area to nest in and did not perhaps need to usurp cognitiveabilitiesinSarusCranesthanwaspreviouslyknown.
theterritoryofthepairswiththe injuredmale.All threepairs
had successfully weaned young the previous season, and ACKNOWLEDGEMENTS
observations of unison calls and absence ofegg laying by
females ofall three pairs indicated that the female did not The observations were made during fieldwork in the
desertthe males, and did not mate with other males. Sarus Crane projectofthe Wildlife InstituteofIndia. I thank
In another instance, the male was alone for two years the Director and B.C. Choudhury for facilities and
(gender recognized by posture during calls given while infrastructure. Work permits were kindly granted by Chief
defending territory). Both years, the adjoining pairs could WildlifeWarden,UttarPradesh. Librarysupportwasprovided
not appropriate any part ofthe territory. In February2002, a byB. DidricksonandM.S. Rana,andI gratefullyacknowledge
femalejoinedthemale. Inoneotherpair,themale’swingwas the same. D. Singh and A. Verma provided field assistance,
injured badly, but the pair could successfully defend their and R. Chauhan and familykindly provided accommodation
territoryfromotherpairs. Thepair,however,didnotbreed in andfacilitiesatEtawah. B.C.Choudhury, D. Mudappa,T.R.S.
thethreebreedingseasonsduringwhichtheywereobserved. Raman, andA. Sinha provided comments on previous drafts
The second aspect involves death ofthe male: in only ofthe note and I thank them for the same. I am especially
one pair the male was killed by electrocution after flying into indebted to S. Nesbitt who kindly provided many pertinent
liveelectricwires.Thefemale,withhertwofledgedyoung,was references and critical comments on a previous draft.
ousted from the territory, most ofwhich was appropriated by
twopairswithterritoriesadjacenttotheterritoryofthefemale. February24,2003 K.S.GOPI SUNDAR
These observations suggestthat itmay notbe possible Wildlife InstituteofIndia, P.B. 18,Chandrabani,
forafemaletodefendterritoryalone. However,femaleswith DehraDun248001 Uttaranchal, India.
,
injuredmalesseemtobeabletosuccessfullydefendterritories, Present address: c/o International Crane Foundation
as also single males. This is consistent with observations on E-l 1376-^ShadyLaneRoad,
SandhillCranes(Nesbitt 1989). Thepattern alsofitsinwitha PO.447,WI-53913-0447,USA.
male-dominatedresourcedefencesystem(Greenwood 1980) c/oWildlife Protection SocietyofIndia
where the male has a higher investment in securing and M-52,GreaterKailash Part
1
maintaining the resource (in this case, territory), and the NewDelhi 110048,India.
female’s mate choice is imposed upon the mating system of Email: [email protected]
J. Bombay Nat. Hist. Soc., 102 (1), Jan-Apr 2005 111
MISCELLANEOUS NOTES
REFERENCES
Ali, S. & S.D. Ripley (1989): A Handbook of Birds of India and Masatomi, H. (1994): Structure and function ofcrane dance. Pp. 146-
Pakistan. Volume 2. Megapodes to Crab Plovers. Oxford MS.In:TheFutureofCranesandWetlands(Eds: Higuchi,H. &
University Press, Bombay. J. Minton). Proceedings ofthe International Crane Symposium
Archibald, G.W. (1976): The unison call of cranes as a useful (ed.), Wild Bird SocietyofJapan,Tokyo,Japan.
taxonomic tool. Unpublished Ph. D. dissertation. Cornell Nesbitt,S.A.(1989):ThesignificanceofmatelossinFloridasandhill
University, Ithaca, New York. cranes. Wilson Bull. 101: 648-651.
Archibald, G.W. (2000): Michigan’s whooping cranes. ICF Bugle Nesbitt, S. & T.C. Tacha (1997): Monogamy and productivity in
26(4): 3. Sandhill cranes. Proc. NorthAm. Crane Workshop 7: 10-13.
Choudhury, S. (1995): Divorce in birds: a reviewofthe hypotheses. Nesbitt,S.A.&A.S.Wenner(1987):Pairformationandmatefidelity
Anim. Behav. 50: 413-429. insandhillcranes.Pp. 117-122.In:Lewis,J.C.(ed.)Proceedings
Ellis, D.H.,S.R. Swengel,G.W.Archibald&C.B. Kepler(1998):A ofthe 1985 Crane Workshop, Platte River Whooping Crane
sociogram forcranes ofthe world. Beh. Proc. 43: 125-151. MaintenanceTrust, Grand Island, NE, USA.
Greenwood, P.J. (1980): Matingsystems,philopatryanddispersal in Swengel, S.R., G.W. Archibald, D.H. Ellis & D.G Smith (1996):
birds and mammals. Anim. Beh. 28: 1140-1162. Behaviourmanagement. Pp. 31-43. In: Cranes: their biology,
Gwynne,D.T.(1991):Sexualcompetitionamongfemales:whatcauses husbandryandmanagement(Eds:Ellis,D.H.,GF.Gee&C.M.
courtship-role reversal? TREE 6: 118-121 Mirande). HancockHouse, Blaine, Washington.
Johnsgard, P.A. (1983): Cranes ofthe World. Croom Helm, London Wessling, B. (2000): Crane voiceprints. The ICF Bugle 26 (Aug):
& Canberra. 1-2.
DISTRIBUTION OF MASKED FINFOOT HELIOPAIS PERSONATA
13.
IN THE SUNDARBANS RESERVED FOREST OF BANGLADESH
Introduction pairs, standing at the shores ofthe small rivers and channels.
The Sundarbans Reserved Forest (SRF) ofBangladesh, These channels and small rivers are locally known as khals.
the home ofthe Bengal Tiger, is a unique habitat for wildlife, Sometimes the birds were found sitting on the trunk ofbaen
especially for avian biodiversity. It is the world’s largest trees(Avicenniaofficinalis)inclinedoverthekhals. Thehead,
contiguous block ofmangrove forest, with an area ofc. 6,017 neckandsomepartofthebackisvisiblewhileswimming.The
sq. km, managed by the Forest Department since 1884 Masked Finfoot is very shy, solitary, and sometimes tries to
(CannonizadoandHossain 1998).Ofthetotalarea,4,143sq.km hide in the grass if approached by people or boats. Khan
islandniass,while 1,874sq.kmiswaterbodies.TheSundarbans (2000)reported its breedingfrom July-Augustand nestsata
m
mangrove forest is situated in south-western Bangladesh, height of 1-3 on horizontal branches oftrees, built with
between21°39'00"-22°30' 15"Nand89°2'00"-89°54'07"E. twigs.
There are 32 species ofmammals, 8 species of amphibians,
14 species ofturtles, 30 species ofsnakes, 35 species ofother Distribution
reptiles, 186 species of birds (Hossain and Acharya 1994), A total of24 Masked Finfoot were sighted in the SRF
196 speciesoffishes(Bemacsek2000)and334speciesofplants from 1999 to2001. Theywere mostly seen in the freshwater
(Prain 1903)recorded.TheMaskedFinfootHeliopaispersonata zone that is in the eastern part of river Shipsa of the
(GR.Gray1849(1848))istheonlyspeciesoftheOrderGruiformes Sundarbansmangroves. Themaximumsightingwasrecorded
found in the Sub-Himalayan region, in northeast India and in whilecruisingintheTambulbuniakhal. Eightindividualswere
the Sundarbans ofBangladesh. This bird is also distributed in sighted in four different locations. This khalappeared to be
Myanmar,MalaysiaandThailand(Khan2000).Grimmettetal. relativelyundisturbed.Themaximumwesternlimitofsighting
(1998) reported that the Masked Finfoot is a rare resident or oftheMaskedFinfootistheSarbatkhalikhalofKhulnaRange
visitorinBangladesh.TheMaskedFinfootfoundinBangladesh ofthe SundarbansWestForestDivision,whichisalso located
Sundarbansisaresident.Notmuchliteratureisavailableonthe in the freshwater zone, east ofthe river Shipsa. This bird is
biology ofthe Masked Finfoot in this region. Khan (2000) normally seen in the Katka and Kachikhali khal of the
reported that it is endangered in Bangladesh and globally Sundarbans East Sanctuary and nearthe western entry point
vulnerable. ofthe Mara Bhola khal which is located in the moderately
,
The Masked Finfoot is a duck-like bird sparsely saltwater zone. Besides these sites, the Masked Finfoot was
distributed over a large forest area of the Bangladesh seen in the Bara Morogmari khal and Jongra khal of the
Sundarbans. It is locally known as Hans Pakhi. Khan (2000) Sundarbans East Forest Division. None wereeversighted in
reported the Bangla name Goilo Hansh. This bird is usually the saltwater zone (Fig. 1), though the area was extensively
found in tidal channels of dense swampy mangrove forest, searched and inquiries made. This bird was sighted over an
whicharerelativelyundisturbed. Itwasseenmostofthetimein area of2000sq. km. Each sitewas farfromtheothers, sothe
112 J. Bombay Nat. Hist. Soc., 102 (1), Jan-Apr 2005