Relative availability of natural prey versus livestock predicts landscape suitability for cheetahs

18 Pages·2015·1.87 MB·English

Relative availability of natural prey
versus livestock predicts landscape
suitability for cheetahs Acinonyx jubatus
in Botswana
HanlieE.K.Winterbach1,2,ChristiaanW.Winterbach1,2,
LorraineK.Boast3,RebeccaKlein3 andMichaelJ.Somers2,4
1TauConsultants(Pty)Ltd,Maun,Botswana
2CentreforWildlifeManagement,UniversityofPretoria,Pretoria,SouthAfrica
3CheetahConservationBotswana,Gaborone,Botswana
4CentreforInvasionBiology,UniversityofPretoria,Pretoria,SouthAfrica
ABSTRACT
Preyavailabilityandhuman-carnivoreconflictarestrongdeterminantsthatgovern
thespatialdistributionandabundanceoflargecarnivorespeciesanddeterminethe
suitabilityofareasfortheirconservation.Forwide-ranginglargecarnivoressuchas
cheetahs(Acinonyxjubatus),additionalconservationareasbeyondprotectedarea
boundariesarecrucialtoeffectivelyconservethembothinsideandoutsideprotected
areas.Althoughcheetahspreferpreyingonwildprey,theyalsocauseconflictwith
people by predating on especially small livestock. We investigated whether the
distributionofcheetahs’preferredpreyandsmalllivestockbiomasscouldbeusedto
explorethepotentialsuitabilityofagriculturalareasinBotswanaforthelong-term
persistenceofitscheetahpopulation.Wefounditgaveagoodpointofdeparture
for identifying priority areas for land management, the threat to connectivity
between cheetah populations, and areas where the reduction and mitigation of
human-cheetahconflictiscritical.Ouranalysisshowedtheexistenceofawideprey
baseforcheetahsacrosslargepartsofBotswana’sagriculturalareas,whichprovide
additionallargeareaswithhighconservationpotential.Twentypercentofwildprey
Submitted 5February2015
biomassappearstobethecriticalpointtodistinguishbetweenhighandlowprobable
Accepted 27May2015
Published 9July2015 levelsofhuman-cheetahconflict.Weidentifiedfocalareasintheagriculturalzones
whererestoringwildpreynumbersinconcurrencewitheffectivehuman-cheetah
Correspondingauthor
HanlieE.K.Winterbach, conflictmitigationeffortsarethemostimmediateconservationstrategiesneededto
[email protected]
maintainBotswana’sstilllargeandcontiguouscheetahpopulation.
Academiceditor
SaraVarela
Subjects ConservationBiology,Ecology,EnvironmentalSciences,CoupledNaturalandHuman
AdditionalInformationand
Systems
Declarationscanbefoundon
page14 Keywords Cheetah,Landscapesuitability,Preyavailability,Human-carnivoreconflict,Botswana
DOI10.7717/peerj.1033
Copyright INTRODUCTION
2015 Winterbachetal.
The cheetah is Africa’s most endangered felid (Marker et al., 2007) and is listed as
Distributedunder Vulnerable with a declining population trend in the IUCN Red List of Threatened
CreativeCommonsCC-BY4.0
Species(Durantetal.,2008).Botswanaisimportantfortheregionalandgloballong-term
OPENACCESS survivalofcheetahs.Ithasalargeandstillcontiguouscheetahpopulation,andhoststhe
HowtocitethisarticleWinterbachetal.(2015),Relativeavailabilityofnaturalpreyversuslivestockpredictslandscapesuitabilityfor
cheetahsAcinonyxjubatusinBotswana.PeerJ3:e1033;DOI10.7717/peerj.1033
secondlargestnationalpopulationwith±1,786animals(Klein,2007)afterNamibiawith
±3,138–5,775animals(Hanssen&Stander,2004;Markeretal.,2007).Italsoformsthe
majorconnectingrangeforthesouthernAfricancheetahpopulation,whichisthelargest
knownfree-rangingresidentpopulationcomprising±6,500animals(IUCN/SCC,2007).
Atleast75%ofthecheetah’sresidentrangeinsouthernAfricafallsoutsideprotected
areas (IUCN/SCC, 2007), mostly on farmlands where competition with other large
carnivoresislowandasufficientsmalltomedium-sizedwildpreybasestilloccurs(Marker
& Dickman, 2004; Klein, 2007; Lindsey & Davies-Mostert, 2009). Cheetahs are one of
themostwide-rangingterrestrialcarnivoresandneedextensiveareastosustainviable
populations(IUCN/SCC,2007;Belbachiretal.,2015).Interspecificcompetition,especially
fromlions(Pantheraleo)andspottedhyaenas(Crocutacrocuta),issuggestedasoneofthe
mainreasonforthiswide-rangingbehaviourasitcanstronglyinfluencetheirmovements,
behaviour and density (Durant, 2000; Broekhuis et al., 2013). Competition between
cheetahsandtheirdominantcompetitorsoccurspredominantlyinsideprotectedareas,
wheredensitiesoflionsandspottedhyaenastendtobehigh(Creel,Spong&Creel,2001).
Withfewprotectedareaslargeenoughtocontaintherangingbehaviourofcheetahs,the
provisionofadditionalareasbeyondprotectedareaboundariesisnecessarytoeffectively
conservethembothinsideandoutsideprotectedareas(Woodroffe&Ginsberg,1998).
Consequently,conservationeffortsinhuman-dominatedlandscapesarecriticalforthe
cheetah’slong-termsurvival.
Thetwoprimaryfactorsinfluencinglargecarnivoresurvivalispreyavailabilityand
conflict with humans (Winterbach et al., 2013). The strong linear relationships that
existbetweenthedensityofAfricanlargecarnivoresandthebiomassoftheirnatural
prey(Hayward,O’Brien&Kerley,2007)pointtopreyavailabilityastheprimarynatural
determinantthatgovernsthespatialdistributionandabundanceoflargecarnivorespecies,
andhencethesuitabilityofanareafortheirconservation(Gittleman&Harvey,1982;
Fuller&Sievert,2001;Hayward,O’Brien&Kerley,2007;Broekhuisetal.,2013).However,
althoughcheetahspreferwildprey(Markeretal.,2003),theyalsocauseconflictwith
peoplebypreyingonlivestock,usuallysmallstock(sheepandgoats)andoccasionally
calvesandfoals(Markeretal.,2003;Ogadaetal.,2003;Woodroffeetal.,2007;Selebatso,
Moe&Swenson,2008).Asaresult,inhuman-dominatedlandscapes,humanactivitiesand
conflictswithpredatorsoftenbecomeasstrongadeterminingfactoraspreyavailabilityin
theexistenceoflargecarnivores,includingcheetahs(Woodroffe&Ginsberg,1998;Markeret
al.,2003;Gussetetal.,2009;Schuette,Creel&Christianson,2013).
In2009,theBotswanaDepartmentofWildlifeandNationalParks(DWNP)drafted
anationalconservationactionplanforthecountry’scheetahsandAfricanwilddogs.
Oneoftheprimarytargetssetoutintheactionplanistoobtainquantitativeknowledge
regardingthemainthreatstosecuringaviablecheetahpopulationacrossitsrangein
Botswana.Scientificinformationoncheetahdistributionanddensityonacountry-wide
scale,however,isnearlyimpossibletoobtain,buttheurgentconservationstatusofthis
speciesmeanswecanill-affordtowaitfordetailedscientificinformationbeforepolicy
decisionsaremade.Therefore,anobjective,clearsystemofevaluation,basedonthebest
Winterbachetal.(2015),PeerJ,DOI10.7717/peerj.1033 2/18
availableandreliableinformationisneeded,thatcanbeusedasabasistosupportpolicy
setting(Theobaldetal.,2000).
InthisstudyweaimedtoassesspotentiallysuitablehabitatacrossBotswanaforthe
long-termpersistenceofcheetahsusingwildpreydistributionandaproxyforprobable
human-cheetahconflict.Suchanassessmentisespeciallyimportantintheextensiveagri-
culturalareasusedprimarilyforraisinglivestock,wherearoundhalfofBotswana’scheetah
populationoccurs(Winterbach&Winterbach,2003).Datafromcountry-wideaerialsur-
veycountsofbothwildpreyandlivestockwerethebestavailableinformationforthisas-
sessment.Wecalculatedcheetahpreybiomassfromtheaerialcountsofwildspecieslikely
tobeutilizedbycheetahsinBotswana.Asaproxyforprobablelevelsofhuman-cheetah
conflict,wecalculatedtheproportionofcheetahpreybiomassrelativetothecombined
biomassofwildpreyandsmalllivestock.Bycombiningthisinformationwithcountry-
widereportsofhuman-cheetahconflict,wecreatedapredictivemapoflandscapesuit-
abilityforcheetahs.Thisapproachtomakingalandscapeassessmentforaspecificspecies
onanationalscaleisunique,andgeneratedfundamentalknowledgethatcaninform
decisionsregardinglandmanagement,connectivitybetweencheetahsub-populations,
andhuman-cheetahconflictmitigation.Thepredictivemaphighlightedsomeimportant
implicationsfortheconservationofcheetahsinBotswana,whichwediscuss.
STUDY AREA
TheRepublicofBotswanaisca582,000km2insizeandislandlockedwithNamibia,South
Africa,Zimbabwe,andZambiaasitsneighbours.Roughly50%ofits2millionpeople(3.5
people/km2)liveinruralvillagesandsmallsettlements(CentralStatisticsOffice,2014).
Themeanaltitudeabovesealevelis1,000m(515–1,491ma.s.l.).Theclimateisarid
tosemi-aridwithhighlyvariablerainfallandseveredroughts.Meanannualrainfallvaries
from650mminthenorth-eastto250mminthesouth-west.Averagemaximumdailytem-
◦ ◦
peraturesrangefrom22 CinJulyto33 CinJanuaryandaverageminimumtemperatures
◦ ◦
from5 Cto19 C,respectively(DepartmentofSurveysandMapping,2001).Thecountry
hasonlytwoperennialrivers;theOkavangoRiverwhichfansoutintotheOkavangoDelta
andtheKwando/Linyanti/ChoberiversystemwhichformstheboundarywithNamibia
andZambia.TheMakgadikgadiPansisaseasonalwetlandwithnaturalperennialwater
holesintheephemeralBotetiRiverprovidingcriticaldryseasonwatersourcesforwildlife
inMakgadikgadiPansNationalPark.Acrosstherestofthecountry,scatteredpansand
ancientriverbedsperiodicallyholdwaterduringthewetseason.Considerableseasonal
variationsinthedensityanddistributionofungulatespeciesoccurandtheblockingof
migrationroutesbyveterinaryfenceshasledtoungulatedie-offsduringdroughtyears
(Verlinden,1998;Bergstro¨m&Skarpe,1999).SeasonalmigrationsofBurchell’szebraand
bluewildebeest(Connochaetestaurinus)stilloccurinsideMakgadikgadiPansNational
Park(Brooks,2005),andzebramigratebetweenMakgadikgadiPansNationalParkandthe
OkavangoDelta(Bartlam-Brooks,Bonyongo&Harris,2011).
Approximately38%ofthelanduseinBotswanaisdesignatedforwildlifeutilization;
17% as protected areas (national parks and game reserves) and 21% as Wildlife
Winterbachetal.(2015),PeerJ,DOI10.7717/peerj.1033 3/18
ManagementAreas.Thelatterareprimarilydesignedforwildlifeconservation,utilisation,
andmanagement(Hachileka,2003).TheNorthernConservationZoneconsistsofChobe,
NxiaPan,andMakgadikgadiPansNationalParks,MoremiGameReserveintheOkavango
Delta,andWildlifeManagementAreas.TheCentralKalahariGameReserveandKgalagadi
TransfrontierParkarelinkedwithWildlifeManagementAreastoformtheSouthernCon-
servationZone.ProtectedareasandWildlifeManagementAreasdonothave‘predator-
proof’fences,withtheexceptionofthewesternandsouthernboundaryofMakgadikgadi
PansNationalParkwhichprovidesonlyapartialbarrierduetolackofmaintenance.
Fivepercentofthecountryisurban,57%israngeland(ofwhichroughly70%istribal/
communalgrazingland),25%isstateland,and5%isfreeholdlandleasedforlarge-scale
commercialranching(DepartmentofSurveysandMapping,2001).IntheDraftNational
PredatorStrategy(Winterbach&Winterbach,2003),thecountrywassub-dividedintotwo
mainpredatormanagementzones:theConservationZonecomprisesnationalparks,forest
reserves,sanctuaries,andWildlifeManagementAreas;theAgriculturalZonecomprises
rangelands,residential,andminingareas(Fig.1).
Livestock(mainlycattle)rearingistheprimaryeconomicactivityover largeparts
of Botswana and constitutes 70–80% of the agricultural GDP (Botswana Ministry of
Agriculture,2011).Inthe2012householdsurvey,thelivestockpopulationinBotswana
wasestimatedas2.6millioncattle,1.8milliongoats,and300,000sheep,mostofwhich
werelocatedonthemorefertileeasternsideofthecountry.Approximately92%ofthese
livestockarefarmedtraditionallyusingthecattlepostsystemoncommunalgrazingland.
Botswana’s key environmental issuesinclude water scarcity and pollution, rangeland
degradation and desertification, loss of biodiversity, deforestation, and an increased
frequencyofperiodicdroughts(Wingqvist&Dahlberg,2008).
METHODS
Cheetahwildpreywererepresentedbythoseanimalspeciescountedinaerialsurveys
acrossBotswanathatarewithintheaccessiblepreyweightrange(bodymass14–135kg)
forcheetahsidentifiedbyClementsetal.(2014)(Table1), hereaftertermed‘cheetahprey’.
Forsmalllivestockweusedgoatsandsheep(hereafterreferredtoas‘smallstock’)asthe
mainlivestockwhosedepredationisasignificantpredictorofhuman-cheetahconflict
levels,asillustratedbyproblemanimalcontrol(PAC)reportsfromDWNP(DataS1).The
sourceoftheestimatednumberofeachpreyspeciesandsmallstockwastheBotswana
AerialSurveyInformationSystemdatabase(BotswanaGovernment,2000),whichholdsthe
annualdry-seasoncountry-widesurveydata.
′
We calculated the mean number per cheetah prey species for each 12 grid cell
(approximately21×22km)forthe2001to2005and2007surveys.Weexcludedthe
surveyconductedin2006,asitonlycoverednorthernBotswana,andthoseconducted
duringthedroughtyearsbefore2001andverywetyearsafter2007.Thiswasdonetoavoid
includingcountsfromextremeyearswhenlargevariationsinpopulationestimatesislikely.
ThemeannumberperspecieswerethenconvertedtospeciesbiomassinLargeStockUnits
(LSU),usingtheformulaLSU=numberofanimals×bodyweight0.75(Meissner,1982),
Winterbachetal.(2015),PeerJ,DOI10.7717/peerj.1033 4/18
Figure1 LandusecategoriesandpredatormanagementzonesinBotswana.Landusecategoriesand
predatormanagementzonesinBotswana.ThepredatormanagementzoneswereidentifiedinWinter-
bach, Winterbach & Somers (2014). The Conservation Zone (CZ) comprises protected areas (national
parks,gameandforestreserves,andsanctuaries)andWildlifeManagementAreas.TheAgriculturalZone
(AZ)comprisesrangeland,residential,andminingareas.
andsummedtoprovidethetotalcheetahpreyandsmallstockbiomass,respectively,per
gridcell.Wecalculatedthepercentagethatcheetahpreybiomasscontributedtothetotal
biomassconsistingofcheetahpreyandsmallstock(hereafterreferredtoas‘percentage
cheetahprey’biomass),wherealowpercentageindicatedhighprobablelevelsofconflict
(DataS2).
Cheetahbiomassstronglycorrelateswithdryseasonpreybiomass(Fuller&Sievert,
2001),andwefeltthecombineddatasetofthesixaerialsurveysusedinthisstudybest
representedthegeneraldistributionofpreyandsmallstockbiomassonacountry-wide
scale.Althoughaerialsurveystendtoundercountsmallmammalspeciessuchassteenbok
(Raphiceruscampestris)andduiker(Sylvicapragrimmia)(Jachmann,2002),itistheonly
feasiblemethodforwildlifemonitoringoversuchlargeareas.Weutilizedtheexisting
Winterbachetal.(2015),PeerJ,DOI10.7717/peerj.1033 5/18
Table 1 Cheetah prey species masses (kg) used in the conversion calculations from aerial survey
countstoLargeStockUnits(LSU)andthecorrespondingLSUvaluesusedtodeterminebiomass.
Species Scientificname Weight(kg)a LSUconversiona
Tsessebe Damaliscuslunatuslunatus 110 0.34764
Redlechwe Kobusleche 72 0.25298
Ostrich Struthiocamelus 68 0.24237
Warthog Phacochoerusafricanus 45 0.17783
Impala Aepycerosmelampus 45 0.17783
Reedbuck Reduncaarundinum 40 0.16279
Springbok Antidorcasmarsupialis 26 0.11785
Duiker Sylvicapragrimmia 15 0.07801
Steenbok Raphiceruscampestris 10 0.05756
Notes.
aSource:BotswanaAerialSurveyInformationSystemdatabase(BotswanaGovernment,2000).
broadlandscapesuitabilitystratificationforlargecarnivoresinBotswanafromWinterbach,
Winterbach&Somers(2014),andrefinedtheagriculturalzonestoidentifyhomogeneous
strata based on the distribution of cheetah prey biomass, small stock biomass, and
percentagecheetahpreybiomass.
Wetestedthehypothesisthatpercentagecheetahpreywascorrelatedwiththelevelof
conflict.Weuseddataonlivestockattacksbycheetahsbetween1995and2006consistingof
PACreports,andfarmsquestionnairesurveys(N =188)conductedduring2004and
2005 (Klein, 2007), to determine ifthe number of livestock attackschanged with the
percentagecheetahprey.Weusedthefollowingintervalsofpercentagecheetahprey:0,
>0to≤1,>1to≤2,>2to≤5,>5to≤10,>10to≤20,>20to≤80,and>80to≤100,and
determinedthenumberofgridcellsandthenumberofreportedattacksperinterval.Then
wecalculatedthenumberofattackspergridcellforeachintervalandtheoverallmean
numberofattackspergridcell.
Weusedachisquaretesttodetermineifthenumberofgridcells(expectedvalues)and
thenumberoflivestockattacks(observedvalues)differedsignificantlyforthefollowing
categoriesofpercentagecheetahprey:0,>0to≤20,>20to≤80,and>80to≤100.
Observationswereclassifiedintocategoriesindependentlyandallcategorieshadexpected
frequencies>5%.WeusedBonferroniintervals(Byers,Steinhorst&Krausman,1984)to
testforcategorieswithobservedfrequenciesthatdifferedsignificantlyfromtheexpected.
Basedontheresults,weidentifiedthethresholdofpercentagecheetahpreytodifferentiate
betweenlowandhighprobablelevelsofconflict.Onthepremisethatstratawithhigh
probablelevelsofconflictwillhavealowsuitabilityforthelong-termsurvivalofcheetahs,
wecalculatedforeachstratumthepercentagegridcellswith≤20%cheetahprey.We
thenusedtheNaturalBreaks(Jenks)functioninArcMap9.3.1toclassifythestratainto
fiveclassesofrelativelandscapesuitability.TheNaturalBreaks(Jenks)functiongrouped
similarvaluesandmaximizedthedifferencesbetweenclasses.
Weusedpresenceandabsencedataofcheetahstotestourlandscapeclassificationof
strataassuitable(veryhightolowsuitabilitycombined)orunsuitable.Gameranchers
Winterbachetal.(2015),PeerJ,DOI10.7717/peerj.1033 6/18
andcommerciallivestockfarmersinthegameranchingregionsoftheCentral,Ghanzi,
NgamilandandNorthEastregionaldistricts(Boast,2014)reportedthestatusofcheetahs
ontheirpropertiesinquestionnairesurveys(N =89),conductedduring2012and2013.
Cheetahswerereportedaspresent(visualsightingsortracksseenatleastquarterly),
transient(visualsightingsortracksseenlessfrequentlythanquarterly),orabsent(never
seen cheetahs or its tracks). We used a chi-square test with Bonferroni simultaneous
confidence intervals (Byers, Steinhorst & Krausman, 1984) to test the hypothesis that
farmersreportedcheetahsaspresentorabsentinsimilarproportionstothenumberof
gridcellspersuitableandunsuitablelandscapeclasses.
RESULTS
CheetahpreyoccurredwidelyacrossBotswana,withthehighestbiomassintheOkavango
DeltaandKwando/Linyanti/ChoberiversystemintheNorthernConservationZoneand
intheTuliConservationZoneineasternBotswana(Fig.2).Cheetahpreybiomasswas
lowacrossmostpartoftheNgamilandAgriculturalZoneinthenorth-west.Smallstock
occurredwidelyacrosstheagriculturalzones,butwasunevenlydistributed(Fig.3).The
percentagecheetahpreydifferedmarkedlybetweenthestrataidentifiedintheagricultural
zones(Fig.4).AlistofstratanamesandidentificationnumbersaresuppliedinDataS3.
IntheeasternpartsoftheCentralAgriculturalZone(stratum5.3),andintheKgalagadi
AgriculturalZone1(stratum8.3),theMakgadikgadiPansCommunitystratum(stratum
5.6),andthetwostratasurroundingtheOkavangoDelta(strata6.2and6.4),cheetahprey
contributedonly0–5%ofthetotalbiomass(cheetahpreyplussmallstock).Thisindicates
veryhighprobablelevelsofconflictintheseareas.
Livestockattacksrecordedpergridcellforthepercentagecheetahpreybiomassintervals
rangedfrom0.23to0.81attackspergridcellwithameanof0.49andstandarderrorof
0.25(N =8)(Table2).Thenumberofattackswasconsistentlybelowthemeanwhen
thepercentagecheetahpreybiomassexceeded20%.Theobservedfrequencyofattacks
betweenthecategoriesofpercentagecheetahpreydifferedsignificantlyfromtheexpected
values(χ2=52.42,df=1,P<0.001)(Table3).Livestockattacksweremorethanexpected
(P=0.05)ingridswith0%cheetahpreybiomass,andsignificantlylowerthanexpectedin
areaswith>20%(α=0.05,Z =2.4977).Wethereforetookgridswith≤20%cheetahprey
biomasstorepresentareaswithhighprobablelevelsofconflict,and>20%cheetahprey
biomasstorepresentareaswithlowprobablelevelsofconflict.
Basedonthepercentagegridcellsperstratumwith≤20%cheetahprey,weratedthe
fiveclassesoflandscapesuitabilityidentifiedinArcMapasveryhigh(0–6.7%grids),
high(6.8–25%grids),medium(25.1–50%grids),low(50.1–75%grids)orunsuitable
(75.1–100%grids)(Fig.5).DataS4summarisesthenumberofgridcellsperstratum,the
numberandpercentageofgridcellswith≤20%cheetahprey,andthesuitabilityclass.The
classificationofsomestrataasunsuitableforcheetahswassupportedbythequestionnaire
datawheretheproportionoffarmersthatreportedcheetahspresentorabsentdiffered
significantlybetweensuitableandunsuitableareas(χ2 = 129.11,df=3,P < 0.001)
(Table4).Farmersreportedcheetahsabsentintheunsuitableareas(n=10)significantly
Winterbachetal.(2015),PeerJ,DOI10.7717/peerj.1033 7/18
Figure2 ThedistributionofcheetahpreybiomassinLargeStockUnits(LSU)acrossBotswana.Chee-
tahpreyarerepresentedbythosewildanimalspeciescountedinsixaerialsurveysacrossBotswana(2001
to2005,and2007)thatarewithintheaccessiblepreyweightrange(bodymass14–135kg)forcheetahs,
identifiedbyClementsetal.(2014).ThestratificationoftheConservationandAgriculturalZonesinto
strataisidentifiedbynumber(DataS3).
morethanwouldbeexpectedbychance,andonly13.9%offarmersreportedcheetahs
absentwithinthesuitableareas(N =79)(α=0.05,Z=2.4977).
DISCUSSION
Ouranalysisandthepredictivesuitabilitymappresentedprovideameansforassessing
thelandscapesuitabilitywithinBotswanaforcheetahs.Weidentifiedthreeimportant
featuresofthepredictivemap:landmanagementintheagriculturalareastosupport
a sufficient prey base for cheetahs, maintaining connectivity between cheetah sub-
populationswithinBotswanaandacrossitsborders,andfocalareasforthereduction
ofhuman-cheetahconflict.
Theaerialsurveydatashowthatthereisagoodwildpreybaseforcheetahsacrosslarge
partsoftheagriculturalareas(Fig.2)despitetheextensivedistributionofsmallstock
Winterbachetal.(2015),PeerJ,DOI10.7717/peerj.1033 8/18
Figure3 ThedistributionofsmallstockbiomassinLargeStockUnits(LSU)acrossBotswana.Small
stockisrepresentedbygoatsandsheepasthemainlivestockwhosedepredationisasignificantpredictor
of human-cheetah conflict levels in Botswana. This was illustrated by problem animal control (PAC)
reports(DataS1).ThestratificationoftheConservationandAgriculturalZonesintostrataisidentified
bynumber(DataS3).
(Fig.3).Thehighdensityofsteenbokandduiker(range0.261–4.319animals/100km2)in
thetribalgrazinglandoftheGhanziCommunityStratum(stratum7.2)calculatedfrom
thesixaerialsurveyssuggeststhatlargeandsmalllivestockdonotnecessarilydisplace
smallungulatestotheextentthatlargeungulatesaredisplacedbycattle(Riginosetal.,
2012).Thisgreaterresourceavailabilitymaybecausaltotheconsiderablyhigherdensity,
smallerhomerangesizes,andgenerallylargerbodysizeofcheetahsinBotswanacompared
toNamibia(Boastetal.,2013).
Thesignificantreductioninlivestockattacksinareaswith>20%cheetahpreybiomass
showedthatpercentagecheetahpreybiomasscanbeusedtodistinguishbetweenhigh
andlowlevelsofprobableconflictonalandscapelevel.However,20%cheetahpreyasthe
likelycriticalpointtodistinguishbetweenhighandlowprobablelevelsofhuman-cheetah
Winterbachetal.(2015),PeerJ,DOI10.7717/peerj.1033 9/18
Figure4 ThedistributionofthepercentagecheetahpreybiomassinLargeStockUnits(LSU).Percent-
agecheetahpreybiomassistheproportionofcheetahpreybiomassrelativetothetotalbiomass(cheetah
preyandsmallstockbiomasscombined)andwasusedasaproxyforprobablelevelsofhuman-cheetah
conflict.Alowpercentageindicatedhighprobablelevelsofconflict.ThestratificationoftheConservation
andAgriculturalZonesintostrataisidentifiedbynumber(DataS3).
conflict is estimated for Botswana and not necessarily valid for other landscapes.
Furthermore,smaller-scalestudiesusingothermethodstocountwildlife(e.g.,transect
counts) should be conducted within Botswana, to test whether the critical point we
reporthereremainsvalidatfinerscalesofinvestigation.Thefactthatlivestockattacks
bycheetahsdecreasedsignificantlywithanincreaseinpercentagecheetahpreyconfirms
thefindingsinNamibiaandinBotswanathatcheetahscommonlypreferwildprey(Marker
etal.,2003;Boast,2014).Apreferenceforwildpreyhasalsobeenshownforotherlarge
carnivoresinareaswherelivestockispredominant(Hemson,2003;Woodroffeetal.,2005;
Ogaraetal.,2010).Thistrendwouldlikelybesupportedbyeffortstomaintainwildprey
populationswithinlivestockareastodecreaselivestockdepredation(Mizutani,1999;de
Azevedo&Murray,2007).Itis,however,importanttonotethattheactualoccurrenceof
conflictisnotuniformlyspreadacrossareas(Woodroffe,Thirgood&Rabinowitz,2005;
Winterbachetal.(2015),PeerJ,DOI10.7717/peerj.1033 10/18