ImpactsImpacts ofof RoadsRoads andand HuntingHunting onon CentralCentral--AfricanAfrican MammalsMammals

WilliamWilliam F.F. LauranceLaurance SmithsonianSmithsonian TropicalTropical ResearchResearch Institute,Institute, PanamaPanama ’sAfrica’s VanishingVanishing RainforestsRainforests

E.E. Africa:Africa: 8%8% remainingremaining

W.W. Africa:Africa: GabonGabon 12%12% remainingremaining

C.C. Africa:Africa: 60%60% remainingremaining

Imagery: University of Maryland Deforestation data: Weber et al. (2001) SlashSlash--andand-- BurnBurn FarmingFarming CommercialCommercial && SubsistenceSubsistence HuntingHunting

““TheThe mostmost intensivelyintensively huntedhunted tropicaltropical regionregion inin thethe world”world” FaFa etet alal.. (2002)(2002) RoadRoad andand InfrastructureInfrastructure ProjectsProjects IndustrialIndustrial LoggingLogging CameroonCameroon inin 19591959

Global Forest Watch CameroonCameroon inin 19711971

Global Forest Watch CameroonCameroon inin 19951995

Global Forest Watch LoggingLogging inin GabonGabon !! DoubledDoubled overover thethe lastlast decadedecade !! >75%>75% ofof forestsforests nownow slatedslated forfor logginglogging

LauranceLaurance etet al.al. (2006)(2006) FuturesFutures 3838:454:454--470470 StudyStudy ofof RoadRoad andand HuntingHunting ImpactsImpacts

Goal:Goal: ToTo assessassess impactsimpacts ofof roads,roads, hunting,hunting, andand theirtheir interactioninteraction onon anan entireentire communitycommunity ofof rainforestrainforest ,mammals, inin anan areaarea wherewhere thethe faunafauna isis stillstill largelylargely intactintact TheThe GambaGamba ComplexComplex

RabiRabi

L o a n g o N a Moukalaba-Doudou t io National Park Rabi:Rabi: highesthighest-- n a l P a producingproducing r k Gamba oilfieldoilfield inin 30 km SubSub--SaharanSaharan AreaArea == AfricaAfrica 11,00011,000 kmkm2 RabiRabi--areaarea RainforestsRainforests StudyStudy AreaArea

! 400400 kmkm2 total,total, withwith 130130 kmkm2 insideinside RabiRabi OilOil ConcessionConcession ! SparselySparsely populatedpopulated (<1(<1 inhabitantinhabitant kmkm-2)) ! BalancedBalanced factorialfactorial design:design: ! 66 sitessites insideinside ! 66 sitessites outsideoutside SamplingSampling DesignDesign FiveFive 11--kmkm transects,transects, eacheach markedmarked atat 5050--mm incrementsincrements 5050 mm 300300 mm 600600 mm 900900 mm 12001200 mm

RoadRoad RabiRabi hashas roadsroads andand smallsmall clearingsclearings butbut huntinghunting isis strictlystrictly prohibitedprohibited 3 OutsideOutside reserve,reserve, rs = -0.897, P = 0.00008 Outside reserve 2 huntinghunting isis lightlight toto Inside reserve moderate,moderate, peakspeaks nearnear villagesvillages andand 1

logginglogging campscamps intensity Hunting 0 0 5 10 15 20 Distance to village (km) GorillaGorilla DiurnalDiurnal surveys:surveys: SpeciesSpecies identifiedidentified LeopardLeopard usingusing acoustical,acoustical, visual,visual, andand odorodor cues,cues, andand viavia signssigns suchsuch asas footprints,footprints, diggings,diggings, dung,dung, rubbingrubbing posts,posts, disturbeddisturbed vegetation,vegetation, andand apeape nestsnests NocturnalNocturnal surveys:surveys: SpeciesSpecies identifiedidentified viavia spotlightingspotlighting censusescensuses DiverseDiverse MammalMammal CommunityCommunity 1) SMALL UNGULATES 4) APES 8) RODENTS Water Chimpanzee Brush-tailed porcupine Blue Western lowland gorilla Giant pouched rat Marsh cane-rat Black-fronted duiker 5) MONKEYS Beecroft’s anomalure Ogilby’s duiker Grey-cheeked mangabey Lesser anomalure Peter’s duiker Red-capped mangabey Lord Derby’s anomalure White-bellied duiker Crowned monkey Cameroon scaly-tail Yellow-backed duiker Moustached monkey Putty-nosed monkey 9) HYRAX 2) LARGE UNGULATES Tree hyrax 6) NOCTURNAL PRIMATES African forest buffalo Allen’s squirrel galago Demidoff’s galago African forest elephant Elegant needle-clawed galago Thomas’ galago 3) CARNIVORES Potto Marsh mongoose Servaline genet 7) PANGOLINS Central African linsang Giant pangolin Palm civet Long-tailed pangolin African civet Tree pangolin Leopard SmallerSmaller UngulatesUngulates

12 Inside reserve Outside reserve 10

8

6

4 Duikerabundance 2

0 0 200 400 600 800 1000 1200 Distance to road (m) Laurance et al. (2006) Conserv. Biology 20:1251-1261 ForestForest ElephantsElephants

16

14

12

10

8

6 Inside reserve 4 Outside reserve Elephant abundance Elephant 2 Laurance et al. (2006) Conserv. Biology 20:1251-1261 0 0 200 400 600 800 1000 1200 Distance to road (m) RedRed RiverRiver HogsHogs

6 Inside reserve Outside reserve 5

4

3

2

1 Red River Hog abundance Hog River Red

0 0 200 400 600 800 1000 1200 Distance to road (m) NocturnalNocturnal PrimatesPrimates (4(4 galagosgalagos && pottopotto))

5 Inside reserve Outside reserve 4

3

2

Species richness Species 1

0 Laurance et al. (In prep.) Road 50 m 300 m 600 m 1 ScansorialScansorial Inside reserve Outside reserve RodentsRodents 0.8

(Larger(Larger muridsmurids,, 0.6 porcupines,porcupines, giantgiant pouchedpouched rat)rat) 0.4

Abundance (no./hr) 0.2

0 Road 50 m 300 m 600 m MarkedMarked BehavioralBehavioral EffectsEffects ofof HuntingHunting MonkeysMonkeys ! FewerFewer alarmalarm callscalls ! NoNo approachapproach behaviorbehavior

CroesCroes,, LauranceLaurance etet al.al. (2007)(2007) BiotropicaBiotropica 3939:257:257--263263 DuikersDuikers

! LessLess “freezing”“freezing” behaviorbehavior

! MoreMore fleeingfleeing ElephantsElephants

! MoreMore secretivesecretive

! MoreMore nocturnalnocturnal ConclusionsConclusions •• ManyMany speciesspecies——,duikers, redred riverriver hogs,hogs, sitatungassitatungas,, bushbush buffalo,buffalo, elephants,elephants, gorillas,gorillas, galagosgalagos,, carnivorescarnivores——areare negativelynegatively affectedaffected byby roadsroads and/orand/or huntinghunting •• RoadRoad avoidanceavoidance increasesincreases withwith eveneven modestmodest huntinghunting pressurepressure •• ScansorialScansorial rodentsrodents increaseincrease inin huntedhunted forestsforests •• ManyMany speciesspecies showshow stronglystrongly alteredaltered behaviorbehavior whenwhen huntedhunted •• EvenEven lightlight toto moderatemoderate huntinghunting markedlymarkedly altersalters forestforest mammalmammal assemblagesassemblages ThankThank youyou