Branch, Shine. Harlow & w€bb 89 Or i gi naI con t r i bu t ions of UerpctologJ Sexualdimorphism, diet and aspects of reproductionof thewcstern keeledsnake, P1lft onodipsas carinal.r (Serpentes: Colubridae) W.R.BRANCH* Departthenlaf Herpetolog/,Part ElizahethNl|se nt, P.O. BoxI 3 117, Hune\rco.]601 3, LasternCapc, tbutll Atr icd R. SHINE, P.S ITARLOW and J.K. UBBB SchoolaIBialogi.ll Scienc.esACa, The Universiy ofsytlnev,N.S.|Y. 2aa6,Austmlio To rrlrod corespondcnccshould bc addrcss€d BRANCIT WR., R SHINE,P.S. HARLOW and lK WEBB. 1997.Se\1lal dimorplrisn. dicl ard aspe.tsof rcproductionof thc w€stemkeeled snakc, Plrr o adipsas.arinata (Seqle. es:Colubri&e). Afr. J. Herpelol.46(2): 89-97. Ewntaiiot atul dittectiM oI hnls.wt spcinas prc\,idal onginl data o" noryhalog', s.tul rlintaryllisn\ f.e.ln1!! IabiLt ah.l reptudrctiw biobgt of k. lare wskn k?e!.d s4ka elnonodjpsrs 6inalallo,, lla,ibid drd 4ngalq. lhis snrall, sle,t1l.r hake is ,@tut tal. FqaLs Mhre at a larAet size (47-51 m tuu|wit ldsth. SI/I-) tlnn nnl6 Q9-31 cht SrL), d1,1 dtbh c$idembly laryer winlnt sies (to 77 c SrL). /lt tJle M e bdt lensth. Mlc: Ituw siqnifi@r 1/ldger toik l@rfenales. Reldlite 10 St/L, Mlysis oJ cMtiance detect.d rc sianili@tt dillmcT betn@ the sM h h@d laStJt, h@d vidh, bd, \'i.Ih. or [email protected] shaPe 0..., widlh relativ. to lot811t, d ftlaht ete siz). Atl prcy irds wre tenebrtles. with liads conyisnts 67 dz aI nt diel. tujents 25 '/q bids 4 %q ar,l a/a) unidennf..l vnebtute bd14 4 %- Andta tih'd pfer, aak6 (39 % of o ptey) atd sknts (t8 ye.l@'vrated. Noctumt 86kas f/froedua Chondrodaclylus PahEtog€ko ard Pachldaclyl$) as NEll 4 diannl otps fa\opltopB url Naru.Lsia, wre cate". All skink prc.v wre Mdttya s7. ManMlian pfty wre qte,' pri"nnly by lar4er sndk s. nE ur1&lal fnsnlnted ltea.{ shieds ak.l a'la,Ead paldtirc leeh of\a\6dJjilr9s.eii?,ia na.y be adaplatias nt rymtit shepr\ dtu.sl ptq 10 be.fltact.rlIftnt ret@ls. Introduction Bmnch 1988:Broadley 1990) or rcSionalsuncys of hcrpc(ofaun(Bauer el al. I 99:l). llcrc arc lt\t rclcrencesto Thc \\'cslcmkc.lcd snake.I'rthono.lipsas cafi1ata, is a r,jre dnss?eci€s ir) tlle lilcrdhrrc. back-fangedsnak€ restricled 10 gmvcl plains and and Girnficr's (1868) 1]?e specimcn ot Plhonadip&s "found savainai ftom llrc Bctlunic Dislicl in southemNamibia lo cdrirdra $as allcgedly b] Mr J. Chapnan on drc extremesoudr-w€stem Angola (Broadlcy1990). Thc genus Zllnb€ze', but Boulenger(1888) noted a sccondspc.imen is nonotwic and of wcertain la-\onomicaflinities. It is llom Damandand. The sp€cies is nov kno$n to be unusualamong colubrids (serl.q! lato) in possessinggready rcnricted1o the *e(em arid regionof soudEm Alric4 ard fragment€dll€ad shiclds,a pcculiar na\illary dentition(3rd to bc absenlfrom ttrc Zmbezi drainage area (Bro.ldley to 6th la4es! posleriormostloodl large and gooved), a 1990). Ar Chapnan travelled fionl Wai\rs Bay on his reduced nMbcr of paladne tl-dl (including a gready joumev (o $e Zambezi.Broadley (l9ll) reslrictedthe 9p€ enlarged"fang"), and hFapophysesdeveloped throughoul localil) to Darnaraland.Lilltc is kno*n of tfie biolog/ of lhe venebralcolumn O4ani €t al. 1982;Sch:i(ti & Mccarthy Pythonodipsascarinatd exc€pl for anecdolrl obsefvatrons 1987). Thescfcatrnes have stimulatcd invesligations into irs (I-ankesl9l4: Falk l92l; Stuan1976). Perhapsconnlsed pos.rblcqaors as a prolo\ipcr"ti e. rc{mblng a putau\c by tlrc original q,pc loc2lry. and ir uencedby thc unusual transidorl]rlfonn betwsrn colubridsand e"?rryvip.6 Ma^ largc. up$ardl]drcclcd noshls of tltc s?ccics.Slcmleld cl al. 1982).Exccpl in phylog€nelicin\esligalions and i (19i0) rnistakenlysuggestcd dn1 d)e sp€cieslives relr natoml (e9., Mc(ens 1955, l97l; Fitzsimonsl%2: Alr. J. H.rpetol. 1997.46(2r:a9-9j 90 Previous souces of infonMtion on th€ habits of South A.fiican Musem (Capc Torur), Naftib Des€n Pytlnnodirys carinata ltave come prnnarily ftom Reserch Shtion (C,obabeb),Slale Muserun of Namibia obsenations ofcaprivos?ecinens. l$kes(1914) notedtlar (Windhock) and Glifomia Acadcmy of Scienccs(Sar) a capUvespecimen of,3,/r onodipsasc.vinata \\"d tocawffIat Fmncisco,USA). and that during daylight lDurs it often hid under bark or Prcservd sp€cimeNwerc nreasurcdand diss€.rcdas sloneson sandin rhe ter.fiunl Another caDti\c sra c $iA folloNs. We recordcdsnour-ven( lengrh (SVL). lait l€ngttl fed a srnall. lnparric skrnt- r6r|,ely Mab;ra otu abt^. hcadl€ng1h (from posicriormargin of th€ towcrjaw 10tllc which it bit two or ttrire times and shookbefore releasing tip of Ure snour), head ividth (at ttrc widesl point). cyc (FaI( l92lr. Ti'c prq \!"s subsequcny ingesle4tcrdrng dramct€r.body widlh (diamclcrar midbody)and bodYnrass Falk ly2ll I lo inlcr tlLlr ljle snaleposscss a \r€ak venorn tlle sp-lmcnsr\crc opcncd $rrh , ILidlcirrrdtrncrsron, ,Id Ho*ever, Marx er al. (1982) recordedihat l€se small any pr€y itcrns in ttle alimenrat, crnal (including drc snakesconslrict lizzrd prey, wtich continuesto struggtcfor hindgu0 ritrc rcmov€d lor later idcDtficarion ald sometimc after bcing sciTrd. Tlrcse obseNations$ggcsl measur€rned.Sizes of rclatively udigcslcd prey (tcnglh. Unl encnonution plays lirdc parr in prcy imnobilizarion. $idtl\ nuss) \€rc dclcnnincd direcdy, aod reconsliturc.l OllrcrobseNations(Branch pers.obs., Haackc p€rs.co m., s7ls of morc fully digcslcdprcy ilcn$ $€re dctcnnincdbI May 1996)on feeding in alplive specimcnscor irn thoseof comparisonwi(h snDilar-sizc4 inract specimensir thc Marx (1982). et al. The oniy rcccnl reponon lhe biolog/ of coll€ctionof the Pon Elizibe& Mus€ur Relalir€ prcy wild s?ecimens is dul of Sr an (1976), for l}ree snakes na-rs(RPM ofa gut ilcm \l"s calcutarcdby crpressinSjls from thc Namib park. Des€n Two of rhesecamc ftom nass as a percentaScof the snakc's mass (minus rhc prey spaisclyvegetate4 arid areas,whitst the third $€s found in riverinevegetalion nerr s€mi-pem)rncntpools in the Kuiset) S€x and rEproducrivc s1atus of the snakes $erc Rivcr T\ro sp€cimens had eare4 one containingan adutr determincdby visual ineection of tlre Ilblcs rl€re gs:ko (Pachydactylus : p. Sonads. bibronii taqigatus) and rhe mnsidercdnuture ifthq had enlarge4 turgid reslesand/or olh€rtwo unidcntified small rodenb rvhile. thickcmd effercnl duqs (ndicating lhe prcsenc€of Mar\ (1982) ct al. drcw allenlion Io drc slrikinS slrrm). Fcmalcsrverc classificd as Duturc iflhey tradthick- morphological convergcnce bctB€cn ttthonottipsas, musolar oviducls. vitellogenic ovariaJr folliclcs and/or Spalercsophis (a Nodr Afiican colubrid also luving oudrrc€l eggs. Somemature snakes \irh regresscdgonads fragmented llc€d shictds) and vip.rs. Th€se aurnors rnaybe misrakenlyctasscd as inunalure. Additjonal daraon conjecturd dlat lhc unusualfraginentalion of he.adshields diet and reproduction$€re oblainedfrom the lirenturc. and in vipen, boids and Ihe co|ubi'd g.nen Spdkrosaphisand from personalcomrnunication may promolc rykanodipsas rhe wide gapc tqlufto ro Slatislicalanzlsis follows ttut ouUincdfu Shineel al. engrnf hrge prey. 'Ihey also srr8gesteddral the edargcd (19%a- c), afld involvcdt$o-iailcd unpairedt-tesrs rc assess h^F;s in Wlaline Ptthonodipsasmigh fircrion to r€strain the signficancc of se-\ difiereocesin mejn trair \,ztu€s. geckosdlal are prone to escapecapture by rcaringrhcir skin. Mea$rements of mass werc loA-transfon€d prior to \,farx et al. (1982) made ptea a for more ecotogicrj analysisto aclieve nonnrlity of dislributioflsafld €quatilyof inloinatio on Pythonodipsasto addressthese problems. vanances. To cMrnine dillerences in body proponions Subs€4rndy,Scfiard & Mccadry (1987)denorEtiared dlar bcM€en drc se\eq we us€d aialysis of co\.ffiance and the va.rious morphological similaitics be$ccn helemgencityof slopcstes1s. Contingency-table (chi-square) Sllktosophis afi Ptrhonodipst reprcs€ntconvergence. aralyseslrere usedto test the signifcance of obseNedsa\ Wemer(1985) also proposed an alrernarivch!,pothesis for differencesin dietarycomposition. An atpha te\€l of 0.0j h€ad shield fragmenlation Sparercsophis and 11?sused dnoughout. Ptthonodipras, srggesnng $al, atons wirh dorMl colouration and ot]rcr fea(urEs.they fonned a su(c of aalapulion5for Balcs€rr n rtucD of y,rp3rn, \apc6 Results Resolutionot thescconnicUng h)polhescs is harnpc,€db) tle d€a(h of information on the specics,biotogy_ In this Scxual dimoqrhism: We c\arr{ned 55 sp€cimcnsof contexqwc pr€sen( pJ,thokadipsa, here biological data tot Pfthonodipsascainota l,l:,fiuseumcollections Ofdrcsq ll carinata d.nyeJ ffom del2iled aralysis of pres€n-ed r€re Ju\€niles too ffull or poorlv preseNeo ro sex accuratel). The remaindercomprised 15 adult mates,3 juvenilc males,15 adult felrr1lq ar)dgjuvenitc fcmales. nris spcci€sdisplays considemble sexual dinlorphism Materials and methods in bod), size and proportions. AduI( fcnules atain sig ficandylarg€r sizes tlun adult nratcs. For nlosrof thc Informadonon rhc disrnburion Inrphotos/, d,er and trails ir€ measured(snoul-venr lcngrb he"d lengl\ head Rproducf.r\€ brofos/ pr,thonadfsa, of was bascd o \vidrll body widdl body mars). rhe ditrcrcncc i mcan e\aiulrauon ofpre.scncd specimeltIin the co ectionsof the \alucs bcllve€r adult nr.llcs and adull fcrnales N,as Transvazl Mr$eum (prcloria). pon Etiabedr Museurn, slali9icallJ.,sigoifican{ di.lpir€ our relatively low samplc Bmnch, Shine, Harlow & Webb 9t Tabfe l. Body si?4sand so\1ralsize dirnorphisrn in adultPl,lro nodipsas carinatd. Meanvalues for €achtrail. with slandard deviation in brackels,are slrcwr. The tlro right columnsshow rcsultsof unpan€dflo-tailcd t-resls and slatislical significanceof lle direrencesbetivccn (he sexes. For mass.untransform€d dara sivcn in tablc. but t€sr are bascdor In-lnnsformedvalucs, TEit t (28dn t5 l5 Snout-venllerelir (on) 38.49(6 99) 54.5r(10.43) 160:l < 0.0001 29.0- 5l 5 3A5-7?\) Tail lererh (m) 6.60(0.99) 6.40(1.r5) 020 0.62 Rmge of lail lo€Irs 5.0-9.2 4.9-84 t8 ?A(2.51) 25.09(2 88) 625 <0000r Rarge of fi@d ldgdrs 15.0,230 19.6-294 FIod !$ddr (mn) r0.32(20t) t4 64(2.71) 412 < 0 0001 Range in hod lvidLirs 0- l0 0-5 Mars (s) 246(r93) 55 I (29r) 346 <0.003 8-65 19,t0 Bodywidlh (m) r0.25(2.80) 13.48(2 6l) 323 Rll.lqe in bodv wiClhs 0-i0 0-5 T^ble 2, Dier ln Pythonodipsas.drraad.