the science of man-eating among lions panthera leo with a reconstruction of the natural history of...

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The Science of Man-Eating Among Lions Panthera leo Witha Reconstruction of the Natural History of the Man-Eaters ofTsavoAuthor(s): Julian C. Kerbis Peterhans and Thomas Patrick GnoskeSource: Journal of East African Natural History, 90(1):1-40. 2001.Published By: Nature Kenya/East African Natural History SocietyDOI: http://dx.doi.org/10.2982/0012-8317(2001)90[1:TSOMAL]2.0.CO;2URL: http://www.bioone.org/doi/full/10.2982/0012-8317%282001%2990%5B1%3ATSOMAL%5D2.0.CO%3B2

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Journal of EastAfrican NaturalHistory90:1-40(2001)

THE SCIENCE OF 'MAN-EATING' AMONG LIONS PANTHERALEO WITH A RECONSTRUCTION OF THE NATURAL HISTORY OF

THE 'MAN-EATERS OF TSAYO'

Julian C. KerbisPeterhansUniversityCollege,RooseveltUniversity

430S. MichiganAve.Chicago,IL, 60605-1394,U.S.A. &Divisionof Mammals,FieldMuseumof NaturalHistory

Chicago,IL, 60605-2496,U.S.A.jkerbis~frrn]h.org

ThomasPatrickGnoskeBirdDivision,ZoologyDepartment,FieldMuseumof NaturalHistory

1400S. LakeShoreDrive,Chicago1160605-2496,U.S.A.tgnoske~frrn]h.org

ABSTRACT

Thestoryof the'Man-eatersof Tsavo'hasbeenretoldthroughscript,cinema,andoraltraditionin the 100+yearssincetheir infamous'reignof terror'.Despitetheirpredictablybroadpopularappeal,thedetailspertainingto thenaturalhistoryof theselionsPantheraleo haveneverbeenreviewed.Theskullsandskinsof theselionshaveresidedat theField Museumof NaturalHistory(Chicago)for over75 years.Ananalysisof theskullof theprimaryculpritdisplaysa traumaticinjurythatmayhavelimitedhispredatoryabilityinsubduing'normal'prey.A sampleofhairs,reflectingthedietofbothman-eaters,ispreservedinthebrokenandexposedcavitiesof theircanines.Variousadditionalcircumstanceslikelycontributedtotheirman-eatinghabit.TheTsavoincidentcloselyfollowedthedebutof rinderpeston thecontinent,whichdevastatedcattleandbuffalo,theprimarypreyof theTsavolion.TheTsavo'nyika'consistsof adensethornscrubthicketlimitingvisibilityandpassage,representinganidealhabitatforan 'ambushpredator'.Finally,historicalreviewof theliteraturerevealsthat'man-eating'wasnotanisolatedincidentatTsavo.Thisbehaviourwaswellestablishedin thevicinityof therailwaybridgewellbeforetheseinfamouslionsappeared,andcontinuedwellaftertheirdemise,suggestinga recurringopportunity,whichmayhaveevolvedintoa localbehaviouraltradition.In sum,virtuallyall of therecognisedpreconditionsforman-eatingoutbreakstooccurwereineffectatTsavointhe1890's.

INTRODUCTION

The'Man-eatersof Tsavo'firstgainedinfamyin theBritishpressin 1900(TheSpectator,March3)whentheywerereportedtohavecausedatemporaryhalttotheconstructionof the

Weusetheterm'man-eating'byconvention,asattacksarenotlimitedto 'men'anddonotalwaysconcludewithconsumption.

2 J. C. KerbisPeterhans& T. P. Gnoske

'Uganda'Railway.ThisrailwaywastorunfromtheIndianOceanportof Mombasa,Kenya,to theshoresof LakeVictoria,whichwasthenlocatedin Uganda.BritishengineerJ.H.Pattersondocumentedhisattemptstodispatchthetwoadultmalelionswithdetailedjournalentries(Patterson,1898-1899).Theseentriesbecamethebasisforhisfirst-handaccount,IntheField (London),firstpublishedattheturnof thecentury,andlaterasthebasisfor hisbook,TheMan-eatersof TsavoandotherEastAfricanAdventures(Patterson,1907).EveryKenyanschoolboyknowsthestoryof theTsavolions,firstthroughoraltraditionandlaterthroughthispopularreference.Two Hollywoodfilmshavefurtherpopularisedthestory:BwanaDevil (1953)andTheGhostandtheDarkness(1997).Despitethepopularappealofthisincident,no detailsconcerningthelionsthemselves,or thecircumstancessurroundingthisnotoriousman-eatingoutbreak,werepublishedbetweenPatterson's1907accountandthebriefreviewby KerbisPeterhansetal. (1998).Afterreviewinghistoricalaccounts,recentliterature,theoriginaljournalsof LH. Patterson,GameDepartmentrecords,andtheskullsandskinsof the'Man-eaters'themselves,wehaveidentifiedthesecircumstances.Thispaperaddressessomeof theconditionsthatleadto man-eatingin generalandhowtheserelatetotheincidentsatTsavoover100yearsago.

Severalcircumstanceshaveoftenbeenassociatedwith pantherid(big cat)attacksonhumans.Sickly, injured,agedor emaciatedpantherids,whichareunableto securetheirnormalprey,canoftenbecomeman-eaters(Corbett,1944,1948,1954).Predatorsmayalsofocuson abnormallybehavingprey,with certainhumanbehavioursprobablyqualifying.Amongsocialcarnivores(e.g. lions),thefavouringof particularpreyspecies(e.g. livestockorhumans)canbepassedfromonegenerationof predatorstothenext,withthepotentialtobecomea local socialtradition(Swayne,1895;Taylor, 1959;Rushby,1965).HistoricalrecordsfromTsavosuggestthatpredationuponhumanswasa long-standingphenomenon.Humanswereattackedandkilledby lionsin theTsavoareawellbeforeconstructionof therailwaybegan(1886,documentedin Jackson,1894)andcontinueatpresent,over100yearsaftertheinfamouspairwasdispatched(KenyaWildlifeService,1994-1998).Anotherfactor,anecdotallymentionedin theliterature,is theabsence,depletion,or removalof typicalprey,causingthepredatorstoseekalternativefoodsourcessuchaslivestock.Thisbringslionsintocontactwithhumans,sometimesresultingin theinclusionof humansin lions'diets.Lionsalsodevelopa tastefor humansafterbeing'provisioned'withdeadones.Environmentalvariablescan be importantsinceheavycover is essentialfor 'ambushpredators'tosuccessfullystalktheirprey(Schaller,1972;Funstonetai, 2001).Seasonalfactorsarealsothoughtto be importantasgamedispersesduringtherains,makingthemmoredifficulttolocateandsecure(Jackson,1894).In late19thcenturyTsavo,all of thesefactorswereinplayconcurrentlyandall mayhaveplayeda role in thedevelopmentof theworld'smostrenownedman-eatingoutbreak.Whatfollowstherefore,is acriticalreviewof thesedifferentscenariosandthelikelyroleeachof themmayhaveplayedin theeventsatTsavoover100yearsago.

NOTES ON THE NATURAL mSTORY OF THE 'MAN-EATERS OF TSAVO'

UnliketheTsavoof todaywithlargetractsof openexpanse,theTsavoof the1890'swascomposedof a nearlyimpenetrable,thornthicketknownas 'nyika'.The questfor ivoryduringthe19thcenturyhadeliminatedelephants(Loxodontaafricana)frommuchof easternKenya,includingmostof Tsavo(Thorbahn,1979).This is why manyof theporterstransportingivorythroughTsavoatthetime,originatedfarup-country,sometimesevenfrom

TheScienceof 'Man-Eating'amonglionsPantheraLeo 3

Uganda(Patterson,1907,Preston,n.d.).Elephantsareakeystonespeciesandhavea majorimpacton thevegetationandthelargemammalcommunity.The eliminationof elephantsfromTsavocauseda proliferationof densewoodyandthornyundergrowthandeliminatedherdsof grazingungulatesfromthevicinity.Preston(n.d.)describesthisthickhabitatindetail.Browsers,includingdik-dikMadoquasp.andblackrhinoDicerosbicomisincreased.A reviewof Patterson'sfield journals(1898-1899)quantifiesthe animalspeciesheencountered(table 1). There were no wildebeestConnochaetestaurinus.Hartebeest

.(hartebeest/hirola,Alcelaphusbuselaphus/hunteri)andzebraEquusburchelli/grevyiwerearoundbutnotcommon.PattersonneveroncereferstobuffaloSynceruscafferor cattleBostaurusssp.in hisjournal.Thiscanbetracedto thearrivalof rinderpestonthecontinentin1891,whichhada devastatingimpacton thebovinepopulations(Lugard,1893;Mettam,1937).Bythe1960's,theTsavoelephantpopulationhadrecoveredandTsavobecameknownas oneof the largestelephantsanctuariesin EastAfrica (Leuthold& Leuthold,1976).Therefore,thetwo largemammalspecies(elephantandbuffalo)comprisingmostof themammalianbiomassin Tsavotoday(ibid.),werevirtuallyabsentin the1890's.In sum,by1898,Tsavohadalreadybeenseverelyimpactedbyhumans,resultingin vastanthropogenicdifferencesbetweentheTsavoenvironmentof the1890'sandthatof today.

The 'Man-eatersof Tsavo'themselvesconsistof twoadultmalelionsthatarevirtuallydevoidof manesin theconventionalsense.Theydisplayaslightsagittalcrestof hairthatcanbetypicalof somemanelesslions.Thesecondlionkilled(FMNH 23969,figure1)hadslightcheektuftsas well as darkenedchestpatcheswhile the first lion was withouttheseadornments.They werephotographedby ColonelJ.R. Patterson(1907)aftertheyweredispatchedin 1898.Exceptfor theseverelybrokencanineandremodeledmandibleandcraniumof theprimaryculprit(FMNH 23970;figure2), theman-eatersof Tsavowereadultmalelions in theirprime(6.5-8.5yearsof age).Their squamoso-parietalsuturesareobliteratedmakingthemat least6.5 yearsold (Smutset al., 1978),but theirmaxillo-premaxillarysuturesarenotevenpartiallyclosed,makingthemunder9 yearsold. Theirteethalsobetraythisagerangeastheyareyellowingandthereis visiblewearonthecanine,incisor,p3 andP4(>5-6 yearsof age,ibid.).Althoughtheseindividualsmayhavebeensiblingsdueto theirassociationandsimilarsizeandmorphology,FMNH 23969displaysmoreapicalwearthanFMNH 23970.Wedoubtthattheirdifferencein ageextendsbeyondoneortwoyears.

BothanimalswerehugeindividualsasPatterson'spublishedphotos(1907)demonstrate.Pattersonusesthefollowingin describingthefirstlion: "enormousbrute","powerfulbeastin everyway", (Patterson,1898-1899).FMNH 23970was2.95m long(noseto tail)and1.12min heightattheshoulderwhileFMNH 23969was2.90m longand1.22m in heightattheshoulder(ibid.).EastAfricanmalelionsaverage0.96mheightatshoulderand2.67min lengthaccordingto Meinertzhagen(1938)whocollectedin theAthi-KapitiPlainsandintheSerengeti.Guggisberg(1975)providesanadditionalmeasurement:0.91m in heightattheshoulderand2.74mlong.

Patterson(1907)claimedthattheman-eaterswereprime-aged,healthymalesandwassocitedby subsequentauthors(e.g. Selous,1908;Akeley,1923;Bradley,1926;Guggisberg,1961;Cloudsley-Thompson,1967).Wecanonlyassumethatthisreferredtotheconditionoftheirlimbsandtorsoandthathedidnotinspecttheirdentition.Residingin thecollectionsoftheFieldMuseumof NaturalHistory(FMNH) for 75years,thetwoTsavolion skullshadnotbeendifferentiatedfromoneanotherin anyway.Oneof us (TPG) rediscoveredtheseskullsin thecollectionsof theField Museumin the 1980'sandsubsequentlydeducedwhichwasthefirstman-eatershotbyreferringtoPatterson'sdiscussionof thedeathsofeach


Figure 1. The second Tsavo man-eater slain (FMNH 23969).

Figure 2. The first Tsavo man-eater slain (FMNH 23970).


(Patterson,1907).Thefirstlion (FMNH 23970)waskilledby shotsto thebody,whilethesecondlion was shotwith severalbullets,includingoneto theheadthatshattereditszygomaticarch(FMNH 23969).AlthoughPattersonstatesthathemayhaveshotoff thetipof thecanineof thefirstman-eaterslain(Patterson1907,1925),bothlionsaremissingtheapicalendof theirlowerleftcaninesduetopre-existingtraumas.

Table 1.Fauna of Tsavo as represented in the fieldjoumal ofJ.H. Patterson, 189~1899

Group

Common nameNo. of times mentionedInvertebrates

tsetse fly 1mosquito

1total

2

Reptiles

crocodile 1total

1

Birds

long-billed 1waterfowl

1owl

1spur fowl

2sand grouse

3ostrich

4birds

5partridge

6guinea fowl

12total

35

Mammals

black panther 1baboon

1rabbit

1rat

1giraffe

1donkey

2monkey

2hippo

2waterbuck

2bushbuck

3leopard

3zebra

4wild cat

4hartebeest

4small deer

5goat

11rhino

14paa (dik dik)

16lion

70total

147

Oneof us(TPG) firstnoticedthattheskullandmandibleof FMNH 23970weremalformedduetoa severelybrokencaninewithexposedpulpvacuity.Thisobservationwasfirstnotedin KerbisPeterhansetai. (1998)withfurtherdetailsprovidedby NeiburgerandPatterson(2000).This injuryprobablyoccurredfairlyearlyin life asit ledtoobviousremodellingofthejaws(figures3,4).Inparticular,therootof thebrokenlowercaninehadbeenre-orientated

6 J. C. Kerbis Peterhans& T. P. Gnoske

Figure 3. Lateral view of FMNH 23970 depicting forward projection of right upper canine.Compare with vertical left upper canine visible in rear (courtesy of K. Keith).

Figure 4. Anterior view of FMNH 23970 depicting broken cavity of lower right canine. Noteasymmetry of upper incisors and canines due to broken and missing mandibular teeth (courtesyof K. Keith).


towardsthehorizontalplane,andthemandibleandassociateddentitionwerecompletelyasymmetricdueto mal-occlusion.This injury(perhapscausedby akickor a blowfromthehead/hornof a buffaloor zebra)couldhavepreventedthelion fromefficientlykillingitsnormalprey.

Thesecondman-eater(FMNH 23969)hadslightlydamagedteeth,specificallya brokenupperleftcarnassialandbrokenlowerrightcanine(photoin Patterson,1907).Thebreaktotheupperleft carnassial(p4) is fairlyfresh(severalmonthsin age)asreflectedin its stillsharpedges.Thebrokencaninetiphadbeenwornsmoothfrommonths,perhapsyears,ofwear.Despitethesebreaks,wedonotbelievetheseinjurieswereseriousenoughto affectthisanimal'spredatorybehaviour.

Their tenureas man-eatersmayhavebeenfirst mentionedby Ansorge(1899)whodiscussedlionattacksonacaravanin 1896attheverycrossingpointof theTsavoRiveroverwhichtherailwaybridgewassubsequentlyconstructed.At thistime,theTsavoman-eaterswouldhavebeenapproximately4.5to 6.5yearsold, full-grown'sub-adults'.R.O. PrestonfollowedAnsorgeattherivercrossingbutprecededPatterson.Prestonarrivedin TsavoinJanuaryof 1898(Miller, 1971)andpromptlyrecordedthedeathsof tworailheadworkersdueto lions(Preston,n.d.). J. H. Pattersonarrivedin Marchof 1898,andin lateApril1898,attackswereagainreported.By thetimethe 'reignof terror'wasover,Patterson(1907,p.l07) statedthatthelions"haddevouredbetweenthemno lessthantwenty-eightIndiancoolies". The figure of 28 was cited by subsequentauthors(Selous,1908;Guggisberg,1961;Miller, 1971).Thefirstman-eaterwaskilledon 9 December1898andthesecondon29December1898(Patterson,1898-1899).Despiteagapof 20daysbetweenthedeathsof thetwo lions,therewereno humansfromtherailwaycrewtakenby theremainingman-eater.This leadsustobelievethatthefirstindividualslain(FMNH 23970),withthelong-termdentaltrauma,wastheprimaryculprit.If weaddthetwodeathsrecordedbyPrestonpriorto Patterson'sarrivalandthedeathdiscussedby Ansorge,thedocumentedtotalcouldincreaseto31.

BetweenMarchandDecemberof 1898,a minimumof 28humanswastakenby thesenotoriouslions.Overtheyearshowever,thesefigureshavechangedandthelegendhasgrown.In his journalentries(1898-1899)Pattersononly discussesthe deathsof 14individuals.In his 1907book,hementions28deathsof theimportedandwell-paidIndianlabourers.Weassumethisfigureis accuratesincetheBritishmaintainedpreciseaccountingdetails(manyof whicharesummarisedin Hill, 1976).His only referenceto victimisedAfricanlabourersis summarisedas "scoresof unfortunateAfricannativesof whomnoofficialrecordwaskept"(Patterson,1907,p.107).In 1925however,Pattersonpublishedafollow-upaccountwherehe statesthat 107Africanswereamongthevictims,therebyincreasingthetotalkilledonhiswatchto "135IndianandAfricanartisansandlabourers"(p.1).NeiburgerandPatterson(2000)expandthedescriptionto "135armedmen".Caputo(2000)expandsthecarnageto 140people.The factis, thatthereis no publishedrecordindicatingthatanymorethan28wereofficiallyrecognisedasbeingvictims,althoughourreviewof thehistoricalliteraturecanpossiblyaddthreemore.

If wearetoassumehowever,thatthefigureof 135is accurate,andfurtherassumethat135peoplewouldprovideca.23kgof ediblemeatperindividual,thelionswouldhavebeenleftwith3060kg of meatoverthe10-monthperiod.Schaller(1972)hasestimatedanadultmalelion'sdailyintaketobeca.7 kg of meatperday,resultingin 2540kgperyear,perlion, or 5080kg for bothadultmaleTsavolionsfor the10-monthperiod.Althoughthesefiguresarewellwithinanorderof magnitude,thereis noconvincingevidencein Patterson's


journalsthatthismanypeoplewerekilledby lionsduringhistenurein Tsavo.Furthermore,it appearsthat'normal'preywerealsoconsumedoverthistimeperiod.

Althoughdepictedasdedicatedman-eaters,bothlionscametobaitandattackedlivestock.Thefirstlionslainapproacheda deaddonkeyusedasbait,whilethesecondcarriedoff sixtetheredgoatsovera two-dayperiod(17-18December,1898;Patterson1898-1899).Thesevereinjuryto FMNH 23970didnotpreventit fromfeedingon 'normal'preyafterwards.Studiesof theirdietarypreferencesarecurrentlybeingconductedthroughtheanalysisofseveralthousandanimalhairs, removedfrom the brokencaninesof the man-eaters.Preliminaryresultsprovidedby OgetoMwebi(personalcommunication)indicatethatthesehairsaremostlyfromthelionsthemselves,lodgedin thecaninevacuitiesduringboutsofgrooming.Mwebi (personalcommunication)hastentativelyidentifiedthefollowingpreyspecies:zebra,porcupine(Hystrix cristata), warthog(Phacochoerusaethiopicus),impala(Aepycerusmelampus),eland(Taurotragusoryx), andoryx(Oryx gazella).To date,thereisno evidenceof humanhair, whichsuggeststhatimmediatelyfollowingthebreakto thecanineof thefirstman-eater,humansdidnotsuddenlyappearon themenu.If wedo findevidenceof humans,wewill beableto distinguishAfricanfromIndianvictims.However,sincelionspreferhumanvisceraandlargefleshyparts,includingthebuttocks,thighsandarms(seefiguresof humanvictimsin Kingsley-Heath,1965;Beard,1988),hair-bearingareassuchasthecraniumandperhapsthepubismaynotbeconsumed.Thismayexplaintheabsenceof humanhairin oursamples.Whatis clearis thattheselionswerenotobligatoryman-eatersandthattheycontinuedtopursuepreyotherthanhumans.

FOSSIL RECORD AND MODERN mSTORY OF MAN-EATING

For aslongastheyhaveco-existed,primates,alongwithungulates,havebeentheprimarybaseof preyfor Africanpantherids(Brain,1981).For mostof theirhistory,extinctandlivinghominidshaverepresentedlittlemorethana vulnerable,slowmoving,bipedalsourceof proteinfor thebigcats.In thePlio/Pleistoceneof SouthAfrica,Australopithecusrobustuswasthesinglemostcommonpreyitemfor leopardsPantheraparduswithaminimumof 88individualsrepresentedatthesiteof Swartkrans(Brain,1981).ThenewlydiscoveredSouthAfricansiteof Drimolenpromisessimilarresults(Keyseretal., 2000).Theearliestreputedhominidfossilwasalsosaidto havebeenkilledanddismemberedby a carnivore(Fox,2000).While Homo sp. seemsto havebeenmoreeffectivein avoidingpredationthanAustralopithecus,basedon fewerremainsin fossillair sites(Brain,1981),earlyHomo,nevertheless,remainedon themenu.In fact,paleoanthropologicalmaterialfrom SouthAfrica, whichhasprovidedmostof the fossil evidencefor theearlystagesof humanevolution,appearsto havebeenprimarilyaccumulatedby largepredators,particularlypantheridsandhyaenids(Brain,1981;KerbisPeterhans,1990).

EuropeanPaleolithicrockartdepictscavelionsembeddedwitharrowsar spears(figure1in Frobenius,1933;BegouenandBreuil,1958;Ruspoli,1987).Oneof theearliesthistoricaldepictionsof man-eatingthatwehavefoundis thenearly5,000yearold 'BattlefieldPallette'depictinga lion eating,and/orkilling,deador woundedLibyansduringa clashwith theEgyptians(Aldred, 1980).Bushmenrock artistsillustratenumerousscenesof lionsdismemberinghumansaswellashumanretaliation(Tongue,1909).Stow(1905)writesthatlion feduponthefleshof Bushmenevenmorethantheirsheep.With theadventof thecolonialerain Africa andAsia, documentationof man-eatingbecamemoreregular.Thiscoincidedwiththeexplorationof continentalinteriorsin the19thcentury,thedebutof 'big


gametrophyhunting',andtheconstructionof inlandrailwaysin thelate19thandearly20thcenturies(Sowerby,1923;Hill, 1976).

Man-eatingis notunusual,nornecessarily'aberrant'.Fromthelate19thcenturyupuntilthepresent,man-eatingincidentsbypantheridsin AfricaandAsiahavecontinued.Duringafive yearperiodin the 1920's,7,000humandeathsdueto tigersPanthera tigris werereportedin India(McDougal,1987).The Sangaman-eaterskilledover161peoplein SWUgandain themidto late1920's(Temple-Perkins,1955).In the1930's,lionskilledaround1500peoplein a 150squaremileareaof southernTanzania(Rushby,1965).Between1978and1984,tigerskilleda minimumof 128peoplein Kheri,a smallIndianDistrictin UttarPradesh.Threehundredeighteenpeoplewerekilledbytigersin themangroveswampforestsof theSundarbansTigerReservebetween1975and1981(Sanyal,1987).A minimumof 193lion attacksresultingin 28 humandeaths,wererecordedfromareasadjacentto theGirForest(India)between1977and1991(Saberwaletai., 1994).In sum,humanandpantheridconflictshaveexistedthroughouttheircoexistence,withevidencefor sustainedandlocalisedoutbreaksof attacksonhumans.

ACCESS TO INJURED, SICK OR DEAD HUMANS

SlaveandTradeCaravanRoutesMostcarnivores,especiallylionsandhyaenasCrocutacrocuta,arefacultativepredatorsandscavengers,activelyhuntingor scavengingdependingonthecircumstances(Schaller,1972;Krouk,1972).Theslavetradein EastAfricapromotedtheconsumptionof humans,asdeadordyingslaveswereabandonedalongcaravanroutes.A slavetradertoldA.J. Swann(citedin New, 1874)thatanyslavetooweaktocarryhisloadwasabandonedor killedatonceinordertodiscourageothersfromrefusingtocarrytheirburdens.DuringLivingstone'stravelsalongcaravanroutesin centralAfrica,heoftenencounteredhumanremains.He estimatedthatonlyonein five slavesreachedthecoastalive(citedin Miller, 1971).With 20,000slavesimportedeachyearto Zanzibaralone,therewasprobablya minimumof 80,000humanslostannuallyalongthenortherncaravanroutes.This hugenumberof abandoned,sickly,dying,anddead,representeda regularbonanzato anycarnivorepreparedto takeadvantageof them.

The 'Ugandarailway'wasbuiltalonga Swahilicaravanroutethathadbeenusedfordecades.Thecaravanroutemapsof Wakefield(1870)arequitesimilartothoseof Johnston(1899)andtherailwayline is shownto closelyparalleltherouteusedby 'explorersandcaravans'(Hill, 1976).At theTsavoRiver, Patterson(1907)describeshis tentas beingpitchedcloseto theformercaravanrouteto 'Uganda'.He providesa photographof thecrossingpointof thecaravantrailovertheTsavoRiver(figure5). Preston(n.d.)discussesthissamecaravantrail,stretchingalongtheright(south)bankof theSabakiRiver.

Traderoutesalsogenerateextensive'debrisfields'andconditionthelocalcarnivorestoahighlypredictablefoodsource.Peopleandgoodsmovingalongthecaravanrouteincludedhumanslaves,porters,ivory, luggage,and foodstuffs.Coast-boundWakambatraderstransportedlivestockincludingsheep(Ovisaries), goats(Capra hircus)andcattle.In thelate19thcentury,Europeanexpeditionsjoinedthemix,travellingalongthesameroutesasthosepliedby ArabandAfricantraders.Firsthandaccountsof thesecaravansincludethosebyFrench-Sheldon(1892),Lugard(1893),Neumann(1898),Ansorge(1899),Patterson(1907),

. andPreston(n.d.).

10 J. C. Kerbis Peterhans& T. P. Gnoske

Figure 5. Caravan crossing the Tsavo River (Patterson, 1907).

Despiteproclamationsbanningthe internationaltradein slaves(1873, 1876), and thesimilaredictin 1890,an illicit slavetradecontinuedthroughtheTsavoregionduringthelate19thcentury;slaveownershipwasnot banneduntil 1907(Miller, 1971).One of the reasonsthe British claimedto haveconstructedthe railway was thatits developmentwould help toput an end to the illicit slave trade, which still flourished in the late 19th century:"After a railwayhasexistedfor sometimetherecannotbe.... anyotherkind of locomotiontocompetewith it.... If a railwaycouldexistfromthislaketo thecoast,caravanscouldno morebeemployedastheyareemployednow to carry ivory" (Lord Salisbury,1891quotedin Hill,1976,p. 54). It was reasonedthatanefficientandrapidalternativein thetransportof goodswould eliminatetheprofitabilityof all caravans.

However, even the end of the formalisedslave trade did not end the regular loss ofhumanlife alongthis route. Selous(1908)depictslions postedaroundcampfireswaiting foropportunities.Portershired to carry ivory andtradegoodswereabandonedin thebushafterdying from exposure(Portal, 1894)or sufferingi~uriesor disease(French-Sheldon,1892;Lugard, 1893).French-Sheldon'scaravancameacrossan abandoned'ill wretch' at Buru in1891, "dying from hungerand neglectwho was unableto proceedwith a caravan.... andturnedadrift,withoutadequatemeans,to reachthecoastasbesthecould or drop deadin thebush" (p. 203).At theendof a long daysmarch,portersoftenlimpedinto their campswithbrokenbonesandsevereinjuries(French-Sheldon,1892).Lugard(1893)describesliberatingslavesin a caravanheencounteredinTsavo in 1890,andspeaksof a paralysed'porter'beingabandonedto hyenas at the Voi River. He concludes, "I have never seen anythingapproachingthe carelessnessof humanlife and the callousnessto humansufferingwhichseemto characterisesomemethodsof African travel" (Vol II,p. 544).

The Scienceof 'Man-Eating' amonglions PantheraLeo 11

French-Sheldon(1892),Ansorge(1899)andPatterson(1907),passedwestwardalongtheTsavo caravanroute and criss-crossedwith caravansmoving east. In Patterson'schapter,entitled'The StrickenCaravan'(1907),he describesa caravanof 4,000porters(BasogaandBaganda)moving from Uganda to Mombasa in 1898. On their return to Uganda, theentourageagainpassedPatterson'scampon theAthi-Kapiti Plains. An epidemicof dysenteryhad sweptthroughthe contingent,perhapslinked to their drasticchangein diet along theway. After eachday's march,dozenswere left alongtheroute;thegroupcouldnot stopasfoodandwaterwerealwaysat a premium.Thirteendroppedout in thevicinity of Patterson'stentanddespitehis bestefforts,only sevenweresaved.Along thetrack, Pattersonestimatedfinding a swollen corpse every 100 m. When passing one of their abandonedcamps,Pattersonencounteredabout12freshgravesthathadalreadybeendisinterredby scavenginghyenas.

Burialpractises,epidemics,warfareLocal burial practisescan also encouragethe developmentof man-eatingbehaviourbyproviding easy accessto human corpses. The Masai simply abandonedtheir dead, andsometimesthe 'neardead',in thebushto hyenasandlionsasdid theKikuyu (Percival, 1925;Saitoti, 1980;Read, 1984).French-Sheldon(1892)describescomingacrossthecorpseof adeceasedMasai, weightedin armletsand leglets.Selous(1908)describesan incidentnearBulawayo,Zimbabwewherean elderlywomanwasdraggedalive andtied to a treefor thehyaenas.In the samevolume,Selousdepictshyenashoveringaroundan abandonedcorpse.Melliss (1895)describespickingup an elderlywomanwho couldnotkeepup with her clan,andwho was left to fendfor herselfalonga Somalicaravanroute.Gouldsbury(1916)writesof theSomali:

"Women generally, and more especiallywhen old and decrepit,are of very littleaccountamongthe Somali. If unableto keepup with the kafila (=caravan)on themarch,theyare oftenabandonedandleft exhaustedon thesideof theroad, eithertofollow asbesttheycanor to be devouredby a hungrylion, shouldonehappento passthatway" (p. 167).

In theTaita Hills, abovetheTsavo caravanroute,theWataitadig up theirdeadandthenplaceskulls in rock shelters,while thepeopleof Tavetadispersethebonesof thedeadin thebushand place the skulls in sacredtree hollows, rock shelters,or earthenpots (French-Sheldon,1892;Adamson, 1967).The Wakambapeoplesinhabitingthe Tsavo region weresaidto leavethe bodiesof 'peasantsandwomen' andeventhe mortally infirm in the bush'for thehyaenasto devour'(Hobley, 1910;Lindblom, 1920).

In India, Corbettdocumentsseveralinstancesof man-eatingoutbreaksby leopardsandtigers. These include the Rudrapryag Leopard, which killed 150 humans (1918-1926)followingan influenzaoutbreakthatkilled over onemillion people(Corbett,1948),andthePanarLeopardwhich killed 400 humans(1905-1907)following a severecholeraoutbreak(Corbett,1954).Many Hindu familiescannotaffordtheexpensivefuneralpyrenecessaryfora propercremation.Instead,thedeadareabandonedwith a red-hotcoal in theirmouth.It ispossible,butdoubtful,thatHindu railway workersdying in Tsavo were disposedof in thisfashion.There was no shortageof firewood; lions were kept at bay during the night withnon-stopfires. In any case,not all of the importswere Hindi, as Pattersonhimself (1907)speaksof therivalriesbetweenMuslim andHindi labourers.

Between1898and1899,an outbreakof smallpox andfaminein Kenyakilled thousandsof Wakikuyu. The deadand near dead were abandonedin the bush to be devouredby


carnivores(Percvial,1925).Oncethediseasesabatedandthesuppliesof corpsesranout,thelargenumbersof hyenasturnedtheirattentionstowardslivinghumans.Hyenasstartedtakingchildrenatduskandgrabbingadultsastheyslept(Percival,1925).Miller (1971)estimatesthat25,000Africanswerefelledby diseaseandstarvationduringthistime(1898-1900).Such inadvertentprovisioningof carnivoreshas oftenbeencorrelatedwith attacksonhumans.Eventoday,provisioningof hyenasbytouristoutfitterscanleadtohumanfatalities(Singer,2000).

Patterson(1907)andHill (1976)againprovideanalogiesfor thesituationin Tsavoin1897-1898.A severefamine,causedin partby a severedroughtcausedthousandsof localWakambato die of starvationduringthetimetherailwaywasbeingbuiltthroughTsavo(Miller, 1971).In theirdesperation,Wakambawouldattackandslaughterisolatedrailwaymaintenancegangsin ordertostealtheirfood(Patterson,1907).DeathamongtheWakambadueto a smallpoxoutbreakwasalsodevastatingatthistime.Despitemassivereliefefforts,therewasnotenoughtreatment(lymph)togoaround(Miller, 1971).ThehumantollamongtheIndiancooliesimportedtoworkontherailroadwasalsosubstantial:340of 7,131diedbetween1897and March of 1898.Deathwas mostlydue to malaria,diarrhoea,anddysentery;an additional705weredebilitated(Hill, 1976),with manybeingreturnedtoIndia.

Duringcivil unrestandconflict,largepantheridshavebeenknownto kill humansafterhavingregularaccesstohumancorpses.As discussedearlier,the5,OOO-year-old'BattlefieldPalette'depictslionsconsuminghumansfollowinga battlein Egypt(Aldred,1980).In theArakandistrictof Burma,tigershadnotpreviouslyclaimedmanyhumanvictimsbutduringWorldWar II, theysuddenlyturnedtheirattentionsto liveanddeadsoldiers(McDougal,1987).Caputo(personalcommunication)describesatleastthreeinstancesof tigerattacksonhumansduringhis timein Vietnam(1966-1969),an observationconfirmedby Jackson(1985).

A similarscenariowasdocumentedin TsavoduringWorldWarI (vonLettow-Vorbeck,1920).TheGermans,colonialpowersin Tanganyika,andtheBritish,whocolonisedKenya,hadmilitaryconflictsinthevicinityof TsavoNationalParkwithlionsalsotakingtheirshare.GeneralPhillips,basedin Voi for threemonthsin 1915,lostthreeIndiansoldiersto lion inthevicinityof theTsavoRiver(Trzebinski,1986).Whenthewarbegan,notedgamerangerA. B. PercivalwaschargedwithdefendingtherailwayagainstsabotagefromtheGermans.SentrieswerepostedandaccordingtoPercival(1928):

"Lionswereaveritablecurse;manaftermanonsentrydutywastaken,till it seemedsheercrueltyto puta manon suchdutyatall. Sentriesweredoubledandstillmenweretaken.It needslittleimaginationtorealisethecase:twomenattheirpost,bushallroundandcloseup-it wasinvitingattackbylions."(p.286).

DuringWW I, thewoundedanddeceasednotrecoveredbynightfall,wereassumedtobetakenbythiscarnivorousentourage(Percival,1928).

PREDATION ON LIVESTOCK: HUMAN-CARNIVORE CONFLICT

HistoricalsourcesTheinitialattractionof largecarnivorestohumanscanalsocenterona supplyof livestockandpackanimals.Herodotusmayhavebeenthefirsttodiscusslionskillingdomesticstock(baggagecamels,Camelusdromedarius),whentheywere describedattackingXerxes'caravansduringhistripthroughPaeonia(Rawlinson,1992).In Africa,thefirstlong-horned,

The Scienceof 'Man-Eating' amonglionsPantheraLeo 13

Nile valleycattle(Basprimigenius)weredomesticatedby 4,000BC (Rouse, 1972).The firstlong-horned,humpedcattle(Bastaurusindicus)arrivedin Africa about2,000 B.C., whentheycrossedfrom southernArabia into thehorn of Africa. The presenceof domesticstock,particularlycattle,contributedto futureassociationsof livestock,humansandlions.

After comingintocontactandconflictwith humanswhile killing domesticstock(Swayne,1895; Neumann, 1898; Borradaile, 1928), predatorseducatethemselveson the sights,sounds,andactivitypatternsof humans;theymayswitchto herdsmanandhumansin general(Layard, 1887; Caldwell, 1925; Percival, 1925, 1928; Pitman, 1931; Hunter, 1952;Guggisberg, 1975; McDougal, 1987). Four of the eight man-eatingtigers discussedbyCorbett(1944, 1948,1954)werealsonotoriouscattlekillers, confrontationsthatled to directconflictwith humans.For example,theChukaman-eater(Corbett,1954)attackedandkilledcattle.On one occasion, it was disturbedby, and subsequentlykilled, a young herdsmanlooking for his cattle, therebybeginninghis man-eatingcareer. The Chowgarhman-eateralternatedbetweenpreyinguponcattleandhumansandultimatelybecamemore focusedonhumansafterits largecubwaskilled. This cubhadassistedher in bringingdowncattle.

Swayne(1895)discusseda parasiticrelationshipbetweenhumansand lions in Somalia.This revolvedarounda detailedcalendarof caravanmovementswhich was influencedbyshippingschedulesandseasonalavailabilityof caravan-transportedgoods:

"The movementsof thenativeencampmentsseemchiefly to influencethechangesinthequartersof thelions, thelatterfollowing thekarias(=herds)astheymoveto freshpasture.When a family with its flocks and herds and its karias (sic),moves, itsattendantlions, if thereshouldbe any, accompanyit, beingsometimesman-eatersandmoreoftencattle-eaters.Last June my own caravan,while returningto thecoastfromOgaden,was followedby a pair of hungrylions. We discoveredthisby chance,whensomescoutsof mine,happenedto go backalongtheroad" (p. 293-294).

Pitman(1931)describesan incidentin SW Ugandain 1928when four lions claimed 15cattlein a few weeks. Little attentionwas paid to this incidentanddueto a communicationgap,nothingmorewasheardfor severalmonths.Within ninemonths,humanswereincludedamongthe victims. Before they were destroyed,theyhad claimedmore than250 headofcattleandno lessthan22 humans.

In historic Tsavo, at least three circumstancesbroughtabout massivemovementsofpeopleand their accompanyinglivestock: caravans,the building of the railway, and troopdeploymentsduringWorld War I. Whenmassmovementsoccur, infirm andinjuredlivestockandfood debrisare left to thecarnivores.The situationfor Tsavo wasparticularlyacute,astheregionis knownasthe 'nyika', a dry, thornyshrublandwith particularlylow preydensity(Leuthold& Leuthold, 1976).

French-Sheldon(1892), Lugard (1893), Ansorge (1899), and Patterson(1907)all statethat caravans,including thosepassingthrough Tsavo, were routinely stalkedby hyenasand/orlions, attractedby the food refuseas well as the livestock(sheep,goats,cattle,anddonkeysEquusasinus)that often accompaniedtheseexpeditions.French-Sheldon(1892)writes:

"Whenwe campedfor thenightwe wereobligedto form a hedgeof thorn-bushesandcircle theencampmentwithhugebonfiresto keepthewild beastsfrom attackingus. Itwas terrifyingto hearthecontinuousroar of lions resoundingon all sides..... andtoseetheglareof hyenaeyesin thedarknessof theumbrageoussurroundings.A senseof abjecthelplessnessmomentarilypossessedme...."(p. 162).


Bringinglargenumbersof domesticungulatesintoa naturallyprey-depauperateregionasTsavo,is anobviousattractiontothelocalcarnivorecommunity.

Duringthemid-1890's,advancerailwaycrewsin theTsavoareawerechargedwithclearingbushandtheconstructionof embankmentsaheadof theUgandaRailway.Hill(1976)writesthatin 1897-1898over90%of the1502camels,donkeysandcattleusedfortransporthaddied.Theseanimalswerevictimsof tsetseflies, lackof waterin theTarudesert(Patterson,1907;Hill, 1976),andotherailments.DuringWorldWar I, therewassubstantialmortalityamongthethousandsof transportanimalsfuellingthewareffortagainsttheGermansin theTsavoregion.TheBritishwereactuallygratefulthatcarcassesof deadanddyingtransportanimals(upto20perday)couldsimplybeabandonedin thebush,100mfromcamp.Lionsandhyenasfollowedin thewakeof troopmovementsand"wereassuredof a feasteverynight"(Percival1928,p. 295).Percivalstatesthat,withsuchinadvertentprovisioning,theboldnessof thelionsandhyenasaroundarmycampsgrew.Hecontinues:

"Whenon safariin thereservein 1919-1920,I wasstruckby theboldnessof thehyenas;theyhungroundthecampatnight,comingto suchclosequartersthattheykeptthedogsbarkingincessantly.I feltquitesurethatthisunusualtemerity,greaterthanI haveknownthebrutesto displayanywhereelse,maybe explainedby theirexperienceduringthewar"(p.295).

Percivalportrayedlionsof thecoastalregionasparticularlylargeandaggressive.Soldiersmountedonhorsebackcameacrosslionsthat:

"....learnedthatfood in theshapeof horsesabandonedon accountof injuriesorsicknessweretobehadwithoutexertionontheirpart,andtheydoggedthemountedmendayandnight.As thiswasneartheGermanlines,firingwasstrictlyforbidden;hencethelionsgrewboldandexceedinglytroublesome.Theywouldcomefearlesslyuptotheveryoutskirtsofacamp"(p.287).

Human-carnivoreconflictin Tsavo:speciesprofIles,sex,age,andseasonaldataIn Kenyatoday,pastoralpeoplescanbecompensatedfor thelossof domesticstock.KenyaWildlifeServicehasestablished'incidentreport'log-booksthatdocumentthecircumstancessurroundingconflictsbetweencarnivoresandhumans.Between1994and1998,a totalof121incidentsbetweenlargecarnivoresandhumansandtheirlivestockwereregisteredbyKWS officialsbasedin Voi (TsavoEastNationalPark,table2). Lionswereresponsiblefor93%of theseincidents.Collectively,cheetah,leopardandhyenasaccountedfor only7%oftheincidents;theyexclusivelyattackedsheepandgoats.In areaswheretheyco-occurwithlions,leopardstypicallyselectfor smallerprey(Kerbis Peterhans,1990;Fayetai., 1995;TrevesandNaughton-Treves,1999).Conversely,lionpredominatelyattackedcattle(63%),withsheepandgoatssecondary(27%).

Specificdatafor lions is detailedin table3. Male lions attackedcattlemoreoften(41/71=58%)thanfemalelions(30/71=42%),whilefemalespreferentiallyattackedsheepandgoats(18/30=60%vs. 12/30=40%).Multiplekillingswererelativelycommon.Femaleswithcubskilledmoreindividualsperattackthaneithermalelionsor femaleswithoutcubs,averaging4.8 sheep/goatsand2.5cowsperattack.Malelionsaveraged3.25goatsand1.6cowsperattack,whilesolitaryfemaleskilledanaverageof 1.4sheep/goatsand1.3cowsperattack.Femalelionswithyoungweremorepronetomultiplekills, takingatleastfourgoatsonsixoccasions(ononeoccasion20werekilled);3-6 cowswerekilledoneightoccasions.Onemalelionkilled18goats,whileindividualleopardskilledeightand10goatsonseparateoccasions,obviousexamplesof 'surpluskilling' (sensu Kruuk, 1972).Accordingto Kenya


WildlifeServicearchives,themostrecentincidentsof 'man-eating'atTsavoEastN.P. wererecordedin October1994andJuly 1998.

Table 2. Kenya Wildlife Service, Incident Log Books 1994-1998representing 121Incidents Voi,Tsavo East National Pari

the science of man-eating among lions panthera leo with a reconstruction of the natural history of...

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