Male combat in the black whip snake, Demansia vestigiata

1 Pages·1994·0.09 MB·

by  J A Covacevich

1
MEMOIRSOFTHEQUEENSLAND MUSEUM
52
MALE COMBAT IN THE BLACK WHIP SNAKE,
DEMANSIA VESTIGIATA. Memoirs ofthe Queensland
Museum37{/>.\521994:-MalecombatiswellknowninAustralian
elapkbandboids(Shine, l$£l).Uhasbeenn^ioiTedinnenyelapid
genera-Austrelaps.Cryptophis(nowRhinoptocephalus),Demon-
sia,Hemiaspis,Notechis,Oxyuranwi,PseuderhisandFseudanaja.
These genera are characterised by male size superiority. Male
combatisunknowningenerainwhichfemalesarelargerthanmales
&
e.g.Acanxhophis and Vermicella, (Shine Allen, 1980; Shine,
1991). Shine (1978) first reported this sexual dimorphism/male
combatcorrelationandhascommentedonitsadaptivesignificance
(Shine,1981, 1991).Hesummarisedthisasa ..malestrategyfor
(i)forcingrivalmatestofleefromthevicinityofareceptivefemale
...(ii)physically"carrying"rivalmalesawayfromafemale...(iii)
defendingagainsthomosexualcourtship..and(rv)gainingaccess
tofood...' (Shine,1981).
WereportrecentobservationsofmalecombatinDemansia
vestigiataandpresentphotographsofcombatinthisspecies.
OnJune 13. 1994twosnakes wereencountered 11km south
oftheStarckeR„NEQ(14u5rS, I45a02'E).inagrassyopen
forest dominated by Melaleuca viridifolia. (This is typical
habitatforD. vestigiataonCapeYork Peninsula). At about
4.00pm they were foundin theopen, in thewheel rutofthe
unsealedtrack fromCooktownto theStarcke R. They were
observed and photographed (Fig. 1 A-C), but were not ex-
aminedtocheck sex However,asmatinghasbeenobserved
byoneofus<JC)toberelativelypassiveinthisspecies;asthe
snakeswereobservedveryclosely(fromadistanceofabout
5m)andwerenotcopulating;astheywerelarge(withTLsof
approximately70cm);andtheirbehaviourwasverysimilarto
thatreportedformalecombat inotherelapidspecies,we are
confidentbothsnakesweremales.Wewatchedtheirritualfor
closeto45minutes.Theymoved,asapair,about20malong
the road - all the lime twisting, coiling, raising their
forebodiesbothtogetherandseparately,andthenfallingback
tobeginthesequenceanew.
Male combat in D. vestigiata has been recorded before,
briefly. Shine (1980) notedan observation by Neil Charles,
near Cooktown , 22 September(year not cited) '.., The two
males were plaited together in typical ritualised combat ...
were capturedand their sex confirmed ...*. It has also been
photographedbeforebyJ Stanisic,D.Potterand3.Chaseling,
21 September. 1988,neartheCaptainBillyLandingturn-off.
CapeYorkPeninsula.Theirphotograghshavebeenlodgedin
the Queensland Museum Photographic Index (NP119-21).
Demansia vestigiata isaspecies inwhich the males exceed
females in size. Our observations conform with several
strategiessuggestedbyShine(1981)toexplainthisbehaviour.
Theactivitycarriedbothsnakesfar from theirstartingpoint
intheshortperiodthey wereobservedclosely. Shine(1980)
observed *... no clear seasonal pattern (in reproduction) is
evidentinD atra (nowD.vestigiata)...'.OurWinterobser-
vation,considered withtheonlyothersknown(inSpring)is
consistentwiththis
LiteratureCited
FIG. 1. A-C, Demansia vestigiata, males in combat,Starcke
Shine,R. 1978. Sexualsizedimorphismandmalecombatin R.,NEQ.
snakes.Oecologica33: 269-278.
1980. Ecology or eastern Australian Whipsnakes of the Shine, R. & Allen, S. 1980. Ritualcombat in the Australian
genus Demansia. Journal of Herpetology 14(4): 381- Copperhead, Austrelaps superbus (Serpentes,
389. Elapidae) VictorianNaturalist97: 188-190.
198P1seMuadteicnhgisanpdomraplhyercioamcubsa.tiJnoAuursntarlalioafnBHlearcpkestnoalkoegsy. JB.rAi.sbCaonvea,ceQvuiecehn,slQauneden4s1l01a,ndAuMsutsraeluima,;LPORoBbeorxts3,30S0h,ipStoount'hs
15(1): 101-107. Flat, viaCooktown, Queensland4H7 ,Australia;I.McKirmu,
1991 'Australiansnakes.Anaturalhistory'.(ReedBooks James Cook Museum, Cooktown, Queensland 4871,
PiyLtd. Sydney). Australia; 10August 1994.