«««« ORANGUTAN…TAXONOMY…AND…NOMENCLATURE« « Craig«D em itros« « The«taxonom y«of«the«orangutan«has«been«confusing«and«is«still«the«subject«of« m uch«debate.«Q uestions«at«the«specific«and«subspecific«level«are«still«being« investigated«(Courtenay«et«al.«1988).«The«follow ing«taxonom ic«inform ation«is« taken«prim arily«from «G roves,«1971.« « H IG H ER«LEVEL«TAXO N O M Y:« O rder:«Prim ates« Suborder:«A nthropoidea« Superfam ily:«H om inoidea« Fam ily:«Pongidae«(Includes«extant«genera«Pan,…Gorilla…and…Pongo).« « H ISTO RICA L«TAXO N O M Y«AT«TH E«G EN U S«A N D «G EN U S«SPECIES«LEVEL:«« G enus« Pongo«Lacepede,«1799.« O urangus«Zim m erm an,«1777«(N am e«invalidated).« « G enus«species«(Pongo…pygm aeus«H oppius,«1763).« Sim ia…pygm aeus«H oppius,«1763.««Type«locality«Sum atra.« Sim ia…satyrus«Linnaeus,«1766.« O urangus…outangus«Zim m erm an,«1777.« Pongo…borneo«Lacepede,«1799.««Type«locality«Borneo.« Sim ia…Agrais«Schreber,«1779.««Type«locality«Borneo.« Pongo…W urm bii«Tiedem ann,«1808.««Type«locality«Borneo.« Pongo…Abelii«Lesson,«1827.««Type«locality«Sum atra.« Sim ia…M orio«O w en,«1836.««Type«locality«Borneo.« Pithecus…bicolor«I.«G eoffroy,«1841.««Type«locality«Sum atra.« Sim ia…Gargantica«Pearson,«1841.««Type«locality«Sum atra.« Pithecus…brookei«Blyth,«1853.««Type«locality«Saraw ak.« Pithecus…ow enii«Blyth,«1853.««Type«locality«Saraw ak.« Pithecus…curtus«Blyth,«1855.««Type«locality«Saraw ak.« Satyrus…Knekias«M eyer,«1856.««Type«locality«Borneo.« Pithecus…W allichii«G ray,«1870.««Type«locality«Borneo.« Pithecus…sum atranus«Selenka,«1896.««Type«locality«Sum atra.« Pongo…pygm aeus«Rothschild,«1904.««First«use«of«this«com bination.« Ptihecus…w allacei«Elliot,«1913.««Type«locality«Borneo.« « CURRENT…TAXONOMY« « The«current«and«m ost«accepted«taxonom y«of«the«G enus«Pongo«includes«one« species«Pongo…pygm aeus«and«tw o«subspecies«P.p.…pygm aeus«(the«Bornean« subspecies)«and«P.p.…abelii«(the«Sum atran«subspecies)«(Bem m el«1968;«Jones« 1969;«G roves«1971;«Jacobshagen«1979;«Seuarez«et«al.«1979«and«G roves«1993).«

5« « A lthough«hybrids«have«been«produced«in«captivity,«A ndrew s«(1984),«G roves« (1986)«and«Janczew ski,«G oldm an«and«O 'Brien«(1990)«have«suggested«that«the« degree«of«difference«betw een«the«tw o«subspecies«is«considerable«enough«that« the«tw o«form s«be«considered«separate«species.«Based«on«further«investigation« of«the«physical«appearance,«behavior,«m orphology«and«biochem ical«and« chrom osom al«characteristics«of«the«subspecies,«the«authors«concluded«that«the« range«of«variation«does«not«w arrant«separate«species«designation.««They«concur« on«the«subspecific«taxonom y«of«Pongo…pygm aeus…pygm aeus«and«Pongo… pygm aeus…abelii.… « Recent«m olecular«genetic«research«results«show «a«distinctive«difference« betw een«the«Bornean«and«Sum atran«populations«different«enough«from «one« another«to«w arrant«separate«species«classification«(See«O rangutan«G enetic« D iversity«Chapter,«this«volum e).««« « Rohrer¼Ertl«(1988)«suggests«an«alternative«taxonom y«for«the«orangutan:«G enus« Pongo«von«W urm b,«1784«and«species«satyrus«Linnaeus,«1758.« « H e«divides«the«species«Pongo…satyrus«into«three«subspecies:« Pongo…satyrus…satyrus,«the«recent«Sum atran«subspecies«and«Sum atran«and« Javan«fossil«and«subfossil«form s,«Pongo…satyrus…borneensis,«the«recent«and« subfossil«Bornean«subspecies«and« Pongo…satyrus…w eidenreichii,«fossil«and«subfossil«form s«from «China,«Loas«and« Vietnam .«««« « PH YSICAL…APPEARANCE…AND…DESCRIPTION…OF…TH E…TW O…ORANGUTAN… SUBSPECIES« « The«tw o«subspecies«of«orangutan«exhibit«a«broad«range«of«variation«in« phenotypic«characteristics«(Rohrer¼Ertl«1988).««The«physical«differences«are« m ost«apparent«in«adult«m ales.««Perkins«and«M aple«(1990)«state«that«the« determ ination«of«subspecies«based«on«physical«appearance«alone«is«im precise.«« Subspecies«identification«has«been«refined«by«karyotyping«and«genetic« analysis.««The«diverse«physical«characteristics«used«to«differentiate«the«tw o« subspecies«are«listed«below .« «

6« «« Table…1… … Physical…Characteristics…of…the…Tw o…Orangutan…Subspecies… … Pongo…pygm aeus…pygm aeus……… Pongo…pygm aeus…abelii… (Bornean«subspecies)«« (Sum atran«subspecies)«

« « hair…color… hair…color… darker,«alm ost«m aroon«(A)« lighter,«m ore«cinnam on«colored«(A)… vary«from «red«rust«to«dark«m aroon«or«blackish«brow n« light«rusty«red«or«reddish«cinnam on«(B,E)… (D ,E)« young«are«paler«orange«becom ing«cinnam on«w ith«age«(C)… young«have«bright«orange«hair«w hich«darkens«to« chocolate«or«m aroon«w ith«age«(C)« m ay«have«w hite«or«yellow «hair«on«face,«in«beard«or«groin« (C,«D )… never«have«w hite«hairs«(D )« pelage«a«m ixture«of«light«and«dark«hairs««(C)… m ore«uniform «dark«pelage«(C)« m ore«variation«in«color«(E)« less«variation«in«color«(E)« « « « hair…length… hair…length… less«hair«about«the«head«density«and«neck«(A)« m ore«hair«about«the«head«and«neck«(A)« young«thinly«haired«(A)« young«have«denser«hair««(A)« shorter«hair«overall«(C)« longer«hair,«infants«have«long«hair«on«top«of«head;«adult« m ales«have«long«hair«on«arm s,«sides«of«back«and«beard«(C)« « « « « hair…texture… hair…texture… hair«stiff,«shiny«and«brittle«(C)« hair«is«finer«and«fleecier«(C,D )« stiffer«and«shinier«(D )« dry«in«texture«(D )«

« « hair…pattern… hair…pattern… no«inform ation« short«hair«com es«on«head«forw ard«over«top«of«head«(D )«

… …

7« Pongo…pygm aeus…pygm aeus……… Pongo…pygm aeus…abelii… (Bornean«subspecies)«« (Sum atran«subspecies)«

« …

facial…hair……… facial…hair………

beard«is«less«noticeable«(A,«E)«« beard«is«alw ays«present«and«w ell«developed«(A,B,E)«

less«hair«about«the«face«(C)« beard«is«lush,«often«gives«a«m ustached«« appearance«(A,E)«««««« in«young«face«is«usually«bare«(A)«««««««««««««««««««««««« fem ales«also«have«long«beards«(A)« beard«is«darker,«from «orange«to«dark«red«(C)«« both«sexes«generally«hairier«about«the«face«(C)« facial«hair«has«rough«tousled«appearance«(C)««««««««« young«are«hairier«about«the«face«(A)« facial«hair«generally«short,«scruffy«and«less«noticeable«(D )«« m ales«m ay«have«long«pointed«or«double«pointed«yellow « « or«orange«beards«(C)«

« facial«hair«neater«in«appearance«(C)«

« both«sexes«have«longer«facial«hair«(D )«

« long«yellow «beard«grow s«out«of«upper«jaw «giving«a« « m ustached«appearance«(A,D ,E)«««««««««««««««

« …

shape…of…face…………………… shape…of…face……………………

broader«faced«w ith«prom inent«m uzzle«but«have«a«great« m ore«elongated«and«flat«w ith«a«definite«O ¼shape«(B)« deal«of«variation«(C)« jaw «is«less«pronounced«(A)« upper«and«low er«jaw s«are«pronounced««« (prognathous)««(A,D )« long«oval«face«w ith««m arked«cheek«hallow s«(C,D )« « figure«eight¼shaped«face«(D )«««« « « « facial…color… facial…color…

area«about«the«eyes«has«a«bluish«cast««(A,F)« face«grey«(F)«

… «

eye…color…………… eye…color……………

darker«eye«color«(A)« usually«clearer«and«(variable)«paler««(A,D )«

… «

8« … …

Pongo…pygm aeus…pygm aeus……… Pongo…pygm aeus…abelii… (Bornean«subspecies)«« (Sum atran«subspecies)«

« « look…or…appearance…………… look…or…appearance…………… in«adult«m ales«"unfriendly«glow er"«(D )««««««««««««««««« in«adult«m ales«"haughty«quizzical"«look«(D )«

« « eye/nose…angle……(i.e.…angle…betw een…center…of…eyes… eye/nose…angle……(i.e.…angle…betw een…center…of…eyes…and… and…center…of…nasal…septum )…(E)… center…of…nasal…septum )…(E)… in«adult«m ales«angle«is«48¼66«degrees,«« in«adult«m ales«angle«is«37¼51«degrees,«« m ean«57«degrees««(C)« m ean«45«degrees««(C)««

« « cheek…pad/flange…(the…one…character…in…w hich…a…very… cheek…pad/flange…(the…one…character…in…w hich…a…very… clear…difference…appears…to…exist…betw een…the…tw o… clear…difference…appears…to…exist…betw een…the…tw o… subspecies…(E)… subspecies…(E)… in«m ales«developm ent«starts«in«8th«year,fully«developed« in«m ales«developm ent,«sarts«in«10th«year,«ully«developed« by«15th«year«(A,E,F)« by«20th«ear«(A,D ,E,F)… naked«or«covered«w ith«short,«bristly«hairs,««is«quite«shiny« hair«on«pad«is«light«in«color,«very«noticeable«and«silky«(A)« (A)««««««««««« … skin«is«dark«brow n«or«black,«naked«or«has««sparse«red«hair« have«tufts«of«short«w hite«or«yellow «hair)«(plum ous)«(C)« (C))« … curve«outw ard«from «the«face«(A,E)« rest«flat«against«the«face«(A,E)« sw ing«forw ard«like«"blinkers",«appear«rounded«and« extend«laterally,«parallel«to«the«face,«gives«the«face«a« lum py«(C)« diam ond«shaped«appearance«(C)« heavier«and«less«rigid,«develop«laterally«from «both«top« … and«sides«of«face,«giving«a«square«appearance«(C)«« *Pad/flange…developm ent…in…a…subordinate…m ale…m ay…be… junction«of«the«pads«above«the«brow «results«in«a«deep« inhibited…by…the…presence…of…a…m ore…dom inant…m ale…(Kingsley… w rinkled«pad«(C)« 1982;…N acey₣M aggioncalda…and…Czekala…this…volum e).… throat/gular…pouch………………………… throat/gular…pouch………………………… large«and«pendulous««in«adult«m ales«(A,D ,E)«« less«noticeable«in«adult«m ales«(A,D ,E)« larger«and«generally«naked«(C)« sm aller«and«usually«hairy«(C,F)«

« «

… «

9« « «

Pongo…pygm aeus…pygm aeus……… Pongo…pygm aeus…abelii… (Bornean«subspecies)«« (Sum atran«subspecies)«

body…size/«build………………………… body…size/«build………………………«

tendency«to«becom e«obese«in«captivity«(A,E)«« larger«in«body«length,«appears«m ore«m uscular,«rarely« becom es«overw eight«(A,E)« robust,«often«obese«(C)… thinner,«lankier,«tend«to«be«m ore«m uscular«or«linear«in« … build«(C,F)«

Body…W eight… Body…W eight…

Inform ation«on«body«w eights«is«scarce«(E).« Inform ation«on«body«w eights«is«scarce«(E).«

« «

Presence…of…nail…………………………… Presence…of…nail……………………………

nail«m ay«be«m issing«from «hallux«(A)« see«inform ation«below «from «Rijksen«(1978)«

« «

foot…placem ent/locom otion… foot…placem ent/locom otion…

hooked«foot«cannot«be«placed«flat«on«ground«(C,D )« foot«m ore«plantigrade«(C,D )«

w alk«w ith«foot«curled«on«outside«edge«(C,D )«« w alk«w ith«feet«splayed,«but«flat«or«nearly«flat«(C,D )««

spend«less«tim e«bipedal«(C,D )« ¼in«captivity«spend«m ore«tim e«bipedal,«often«w alk«w ith« chest«out«(C,D )« « … A;«Jones«1969« « B;«Bem m el«1968« C;«M acKinnon«1975« D ;«M allinson«1978« E;«Courtenay«et«al.«1988« F;«G roves«1971« «

«

« «

10« Rijksen«(1978)«distinguishes«tw o«m orphological«types«of«Sum atran«orangutan,«Pongo… pygm aeus…abelii:… « … Table…2… … Morphological…Types…of…Sum atran…Orangutan,…Pongo…pyem aeus…abelii…(Rijksen…1978)… « … …

Dark₣haired,…long₣fingered…type… Light₣haired,…short₣fingered…type…

… … hair…color… hair…color… brow n«to«m aroon« reddish«cinnam on«to«rusty«red…

… … skin…and…facial…color««¼« skin…and…facial…color««¼«

dark«brow n«to«blackish« light«to«dark«grayish«brow n«

… …

body…build… body…build…

delicate«build,«slender«extrem ities,«long«fingers«and« m ore«heavily«built,«stouter«lim bs,«short,«thick«fingers« toes« and«toes«

« « w eight……………………… w eight……………………… sm aller«and«lighter«in«w eight«« larger«and«heavier«in«w eight…

… « digits…and…nails…… digits…and…nails……

w ell«developed«thum b«and«hallux;«both«have«nails« sm all/rudim entary«nails,«thum b«and«hallux;«nail«m ay«be« m issing«on«thum b«but«alw ays«absent«on«hallux« … «

«

A ccording«to«Rijksen,«the«light¼haired,«short¼fingered«type«m ay«show «considerable«variation« in«characteristics«such«as«finger«length.««The«dark¼haired«form «show s«great«consistency«in« characteristics«such«as«long,«slender«lim bs«and«nails«on«both«thum b«and«hallux.«

11« CONCLUDING…REMARK« « «A s«w ould«be«expected,«subspecific«hybrids«produced«in«captivity«show «interm ediate« characteristics«betw een«the«Bornean«and«Sum atran«subspecies.««Captive«anim als«should«be« karyotyped«(consult«the«species«coordinator«at«lori410@ m indspring.com «for«a«listing«of« qualified«laboratories)«before«being«identified«to«the«subspecific«level.« « « REFERENCES« « A ndrew s,«P.««1984.««Review «of«L.E.M .«de«Boer,«ed.,«The«O rang¼U tan.«Its«Biology«and« Conservation.««Prim ate…Eye,«23:34¼37.« Bem m el,«A .C.«van.««1968.««Contribution«to«the«know ledge«of«the«geographical««races«of«Pongo… pygm aeus«(H oppius).««Bijdragentot…de…D ierkunde,«38:13¼15.« Courtenay,«J.,«C.«G roves«and«P.«A ndrew s.««1988.««Inter¼«or«intra¼island««variation?«A n«assessm ent« of«the«differences«betw een«Bornean«and«Sum atran«orangutans.«In:«J.H .«Schw artz,«ed.«« O rangutan…Biology,«pps.19¼29.««N ew «York:«O xford«U niversity«Press.« G roves«,«C.P.«1971.««Pongo…pygm aeus.««M am m alian…species.««4:1¼6.« ______.««1986.««System atics«of«the«G reat«A pes.««In:«D .R.«Sw indler,«ed.«« «««««Com parative…Prim ate…Biology,«(1),«pp.187¼217.««N ew «York:«A lan«R.«Liss.« ______.««1993.««Speciation«in«living«hom inoid«prim ates.««In:«W .H .«Kim bel«and«L.B.«M artin,«eds.«« Species,…Species…Concepts,…and…Prim ate…Evolution,«pp.109¼121.«N ew «York:«Plenum «Press.« Jacobshagen,«B.«1979.««M orphom etric«studies«in«the«taxonom y«of«the«orangutan.«Folia… Prim atologica,«32:29¼34.« Jones,«M .L.««1969.««The«geographical«races«of«orangutan.««In:……Proceedings…of…the…2nd… International…Congress…of…Prim atology,«Volum e«2,«pp.217¼233.«Basel:«Karger.… Kingsley,«S.«1982.««Causes«of«non¼breeding«and«the«developm ent«of«secondary«sexual« characteristics«in«the«m ale«orangutan:«a«horm onal«study.««In:«L.E.M .«deBoer,«ed.««The… O rang…U tan:…Its…Biology…and…Conservation,«pp.215229.«The«H ague:«Junk.« Janczew ski,«D .N .,«D .«G oldm an«and«S.J.«O 'Brien.««1990.««M olecular«genetic«divergence«of«orang« utan«(Pongo…pygm aeus)«subspecies«based«on«isozym e«and«tw o¼dim ensional«gel« electrophoresis.««Journal…of…H eredity,«81:375¼387.« M acKinnon«J.R.««1975.««D istinguishing«characteristics«of«the«insular«form s«of«orangutan.«« International…Zoo…Yearbook,«15:195¼197.« M allinson,«J.C.««1978.««"Cocktail"«orangutans«and«the«need«to«preserve«purebred«stock.««D odo,« 15:69¼77.« Perkins,«L.A .,«and«T.L.«M aple.«1990.««N orth«A m erican«O rangutan«Species«Survival«Plan:«Current« status«and«progress«in«the«1980's.«Zoo…Biology,«9:135¼139.« Rijksen,«H .D .««1978.«A…field…study…of…Sum atran…orang…utans…Pongo…pygm aeus…abelii,…Lesson…1827).« The«N etherlands:«H .Veenm an«&«Zonen.« Rohrer¼Ertl,«O .«1988.««Research«history,«nom enclature«and«taxonom y«of«the«orangutan.««In:«J.H .« Schw artz,«ed.«O rangutan…Biology,«pp.7¼18.««N ew «York:«O xford«U niversity«Press.« Seuarez,«H .,«H .J.«Evans,«D .E.«M artin«and«J.«Fletcher.««1979.«A n«inversion«in«chrom osom e«2«that« distinguishes«betw een«Bornean«and«Sum atran«orangutan.«Cytogenetic…Cell…Genetics,« 23:137¼140.«

12«