Extinction of a West African Red Colobus Monkey

JOHN F. OATES,*†† MICHAEL ABEDI-LARTEY,† W. SCOTT McGRAW,‡ THOMAS T. STRUHSAKER,§ AND GEORGE H. WHITESIDES** *Department of Anthropology, Hunter College/City University of New York, 695 Park Avenue, New York, NY 10021, U.S.A. †Ghana Wildlife Department, Box M.239, Ministry Post Office, Accra, Ghana ‡Department of Anthropology, Ohio State University, Mansfield, OH 44906, U.S.A. §Department of Biological Anthropology and Anatomy, Duke University, Box 90383, Durham, NC 27708, U.S.A. **Department of Biology, Guilford Technical Community College, Box 309, Jamestown, NC 27282, U.S.A.

Abstract: We provide the first documented case of the extinction in the twentieth century of a widely recog- nized primate taxon. During surveys in Ghana and Côte d’Ivoire in 1993–1999, we were unable to find any surviving populations of Miss Waldron’s red colobus monkey ( Procolobus badius waldroni), a primate taxon endemic to the forests of this part of West Africa. We conclude that this monkey, which at least one authority considers worthy of species status, is probably extinct. Hunting by humans appears to be the ultimate cause of the extinction. Until our surveys began, little attention had been paid to the plight of this red colobus mon- key, despite its listing as endangered by the World Conservation Union. The extinction of other large animals in the Upper Guinea rainforest region is likely to follow soon unless more attention is paid to the full range of endangered forms and more resources are devoted to their rigorous protection.

Extinción del Mono Colobus Rojo en Africa Occidental Resumen: Proporcionamos el primer caso de extinción documentado en el siglo veinte de un taxón de pri- mates ampliamente reconocido. Durante los reconocimientos en Ghana y Costa de Marfil entre 1993 y 1999, no pudimos encontrar ninguna población viva del mono colobus rojo de Miss Waldron ( Procolobus badius waldroni), un taxón de primates endémico a los bosques de esta parte de Africa occidental. Concluimos que este mono, al cual por lo menos una autoridad considera como merecedor del estatus de especie, probable- mente se haya extinguido. La cacería por humanos parece ser la causa definitiva de la extinción. Antes de comenzar nuestros reconocimientos, se prestó poca atención a la difícil situación del mono colobus rojo, a pesar de haber sido incluido en la lista de especies amenazadas de la Unión Mundial de Conservación. Es probable que pronto ocurra la extinción de otros animales grandes en el bosque lluvioso de la región supe- rior de Guinea a menos que se preste más atención al rango total de formas amenazadas y se canalicen más recursos para su rigurosa protección.

Introduction cies and subspecies by the end of the twentieth century. For instance, Myers (1979) suggested that an extinction For more than 40 years, conservationists have expressed spasm in the last 25 years of the twentieth century would concern that the effects on wild animal and plant popula- eliminate 1 million species, and Mittermeier (1986) sug- tions from the growth of the global human population and gested that about one-seventh of primate species “could from economic development, especially in the tropics, will easily be extinct by the turn of the century.” Although My- produce marked increases in the rate of extinction of spe- ers noted that many threatened species are rare mammals and birds (especially large-bodied, slow-breeding species), MacPhee and Flemming (1999) have documented the ††email [email protected] Paper submitted May 3, 1999; revised manuscript accepted January probable extinction since 1500 A.D. of only six terrestrial 5, 2000. mammal species that did not live in Australia or on islands. 1526

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One might argue that vigorous action by conservation- tion, limited to the far west of southern Ghana and a ists, prompted by concern about an impending extinc- small area in the southeastern corner of Côte d’Ivoire tion wave, has postponed disaster. Primates have re- (Fig. 1). The only firm record we have located for Côte ceived much attention from conservationists, and they d’Ivoire is from Booth (1954), who reports seeing mixed are one of the few large orders of mammals that has not groups of P. b. badius and P. b. waldroni in March 1954 lost a taxon (species or subspecies) in the twentieth cen- in high forest on the east bank of the Nzi River, just tury (Mittermeier et al. 1997). MacPhee and Flemming north of its confluence with the Bandama River. Here, (1999) found evidence of only one extinction of an an- Booth collected one specimen of P. b. waldroni, a fe- thropoid primate species in the last 500 years, the Jamai- male, which is in the Natural History Museum, London. can Xenothrix mcgregori. We suggest that the lack of Booth reports that he did not observe hybrid individuals recent primate extinctions is fostering complacency, at this location. and that such complacency may allow taxa to become Even in the early 1950s, Miss Waldron’s red colobus extinct that could have been saved by more vigorous was a threatened animal as a result of habitat destruction and timely action. This danger is particularly acute in the and hunting, and Booth expressed the view that its ex- case of taxa that have received little popular attention tinction in Ghana “in the near future must be regarded and live in parts of the world that are not a major focus as a probability, unless effective legislation to protect of biologists and conservationists. both the animal and its environment is forthcoming” We present evidence of the probable extinction of a (Booth 1956). In a 1954 census, however, this monkey form of West African forest primate, Miss Waldron’s red was still relatively abundant in the Tano Nimiri Forest colobus monkey (Procolobus badius waldroni ), which Reserve, 130 km south of the Goaso type locality (Col- we were unable to find during recent surveys in the for- lins 1956). ests of western Ghana and eastern Côte d’Ivoire. In addi- More than a decade after Booth’s warning, Jeffrey tion, we discuss the factors that have led to its disap- (1970) noted that the forest wildlife of western Ghana pearance and caused its fate to be neglected. was being devastated by the spread of farming and the hunting of wild game for meat, processes accelerated by logging activities that had opened up remote forests to settlement by immigrants. By that time, only occasional Taxonomy, Distribution, and Historical Abundance red colobus were shot by hunters, presumably because of Miss Waldron’s Red Colobus they had become rare. Because of growing concern for the survival of the country’s forest wildlife, the govern- P. b. waldroni is one of more than a dozen forms of red ment of Ghana in the mid-1970s established the Bia and colobus monkey that occur allopatrically across the Afri- Nini-Suhien national parks, along with associated “game can tropical forest zone. These forms have been production reserves” (now known as “resource re- grouped into between one and eight different species serves”). The monkeys of Bia, including the red colobus, and 14–18 subspecies (Oates et al. 1994). Miss Wal- were the subject of a field research program between dron’s red colobus was unknown to science until De- 1975 and 1978 (Asibey 1978; Olson 1986). Nevertheless, cember 1933, when a series of eight specimens was col- we have not found any authenticated record of a sight- lected by Willoughby P. Lowe near Goaso (lat 6Њ49ЈN, ing of Miss Waldron’s red colobus monkey in Ghana or long 2Њ27ЈW) in the Ashanti Region of the Gold Coast Côte d’Ivoire since that time, although the monkey is (now Ghana). The monkey was named by Hayman still listed as part of the fauna of Ghana’s Bia and Nini- (1936) as a new subspecies after Miss F. Waldron, Suhien national parks on the basis of the earlier reports Lowe’s companion on his collecting trip. Since its first (Lee et al. 1988). description, three specimens collected before 1933 have been recognized as members of the same subspe- cies. P. b. waldroni differs from P. b. badius, which oc- Methods curs from Guinea to western Côte d’Ivoire, in having red rather than black outer thighs and a red rather than To investigate the present status of P. b. waldroni and black forehead. These differences, and a diagnosis that, other rainforest monkeys, we made surveys in southern unlike P. b. badius, its external nose is not raised on a Ghana and Côte d’Ivoire in 1993–1999. In deciding fleshy base led Dandelot (1971) to propose that wal- which areas to search most closely for red colobus mon- droni be considered a “potential” full species, but other- keys, we relied upon (1) museum records and publica- wise all review treatments of African monkeys have rec- tions indicating past distribution, (2) information about ognized waldroni as a subspecies of Procolobus badius the status of forests and their wildlife provided by gov- (e.g., Rahm 1970; Napier 1985; Kingdon 1997). ernment officials in the Departments of Forestry and Museum records and published accounts indicate that Wildlife in Ghana and consultants to the Societé de De- in this century P. b. waldroni had a restricted distribu- veloppement des Forêts in Côte d’Ivoire, and (3) LAND-

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Figure 1. Distribution records for Procolobus badius waldroni from 1900 to 1976, derived from museum records and the literature. Goaso is the type locality for the subspecies.

SAT imagery of forests in western Ghana and eastern Suhien) and made repeated walks along these at speeds Côte d’Ivoire shown to us by the Planning Branch of the of 1–1.5 km/hour, searching for signs of primates. Si- Forestry Department in Kumasi, Ghana. milar straight-line surveys were possible along existing After traveling by road to sites that seemed potential paths at Bia. Most foot surveys began early in the morn- red colobus habitats, we questioned local people about ing and lasted for at least 4 hours. their knowledge of primates, making a particular effort Nineteen different forest areas (national parks, re- to speak to hunters. We also made forest surveys on source reserves, forest reserves, and forêts classées) foot. Given the relatively large number of sites selected were surveyed during 187 days of field work by various for survey and the fact that in most cases multiple loca- combinations of the five authors and three research col- tions were examined at each site, cutting new paths laborators ( Table 1 and Fig. 2). At each site we were through the forest for every foot survey would have usually accompanied by a local guide, who was often a been impractical. Instead, we generally used existing hunter or former hunter. paths, boundary lines, or old logging roads and walked along these slowly and quietly, looking and listening for primates. In two areas that we subjected to particularly Results careful scrutiny, the Kakum and Nini-Suhien National Parks in Ghana, we cut 4-km transect lines through the In our surveys we neither saw nor heard any red colo- forest understory (two at Kakum and two at Nini- bus monkeys. Three of us ( W.S.M., J.F.O., and G.H.W.)

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Table 1. Survey sites in Ghana and Côte d’Ivoire and the anthropoid primate species seen and/or heard at these sites.

Site Sitea code no.b Survey dates Surveyorsc Species detectedd Ghana Kakum NP & Assin Attandanso RR 19, 20 26 Mar.–9 Apr. 1993 EO, JO, TS C. campbelli, C. petaurista, 11–12, 18–24 Aug. 1993 EO, JO Co. vellerosus, P. verus 17–22, Nov. 1993 EO, TS Pra Suhien FR 18 6 Apr. 1993 EO, JO none Ankasa RR & Nini-Suhien NP 15 13–16 Aug. 1993 JO Cb.atys, C. campbelli, C. diana, 3–7 Aug. 1995 GW, MA C. petaurista. P. verus 22 Dec. 1995–4 Jan. 1996 JO, MA 23–25 Mar., 27–29 Apr., MA 13–16 May 1997 5–6 Oct. 1998 MA 11 Feb., 23 Apr., 4 May 1999 MA Bia NP & Bia RR 6 11–15 Nov. 1993 EO, TS C. campbelli, C. petaurista, 23 Jul. 1993 GW, JO Pan troglodytes Ayum FR & Subim FR 9,7 17–19 Jul. 1995 BD, GW, JO C. campbelli, C. petaurista, P. verus Krokosua Hills FR 8 21–22 Jul. 1995 BD, GW, JO Cb. atys, C. campbelli, C. diana, 4–11 Apr., 12–13 Aug. 98 MA C. petaurista, Co. vellerosus, 10–27 Jan., 21–26 May 1999 MA P. verus, Pan troglodytes Yoyo FR 12 29–30 Jul. 1995 GW, MA C. campbelli, C. diana, C. 24–26 May 1997 MA petaurista, Co. vellerosus, 13 May, 29 Aug., P. verus 19–22 Nov. 1998 MA Boin River FR 11 31 Jul. 1995 GW, MA C. campbelli, C. diana 6–10 Nov. 1997 MA Black Volta River near Bamboi 1–7 Apr. 1997 MA C. aethiops, C. petaurista 29 Jun.–1 Jul. 1997 JO, MA Draw River FR 16 14–19 Apr. 1997 MA Cb. atys, C. campbelli, C. diana, C. petaurista Dadiaso FR 10 31 May–1 Jun. 1997 MA C. campbelli, C petaurista, P. verus Cape Three Points FR 17 4–6 Jul. 1997 JO, MA none Tano Nimiri FR 14 23–26 Nov. 1997 MA C. petaurista Boi Tano FR 13 26–28 Nov. 1997 MA Cb. atys, C. campbelli, P. verus 19 Sep., 9–12 Oct., MA 25 Nov. 1998 Côte d’Ivoire FC de Songan 4 9–10 Mar. 1997 IM, SM none FC de la Yaya 1 13–16 Mar. 1997 IM, SM C. campbelli, C. diana, Co. vellerosus, P. verus FC de la Bossématie 3 14–18, 20–22 Mar. 1997 IM, MA, SM C. campbelli, C. petaurista FC de la Mabi 2 23–25 Mar., 11 Apr. 1997 IM, SM C. campbelli, C. petaurista Swamp forest near Lagune Ehi 5 7–8 May 1997 MA nonee aNP, national park; RR resource reserve; FR, forest reserve; FC, forêt classée. bCode numbers correspond to site numbers in Fig. 2. cBD, B. Dickinson; EO, E. Owusu; GW, G. Whitesides; IM, I. Monah; JO, J. Oates; MA, M. Abedi-Lartey; SM, S. McGraw; TS, T. Struhsaker. dC., Cercopithecus; Cb., Cercocebus; Co., Colobus; P., Procolobus. eA captive C. diana was found in a village near the Lagune Ehi forest. have conducted several years of field studies in forests in tected them. The fifth author, M.A., has been working which red colobus monkeys are abundant, and T.T.S. on a forest conservation project in southwestern Ghana has made a special study of this species for over 25 since 1996 and has searched assiduously for red colobus years. Consequently, we are familiar with the distinctive without finding one definite sign of the monkeys. None vocalizations and physical appearance of this large, con- of us saw any carcasses in the possession of hunters or spicuous monkey, which typically lives in large social bushmeat traders, and we encountered only a few older groups (usually Ͼ20 individuals) that spend much of hunters who could accurately describe this monkey. their time in the upper part of the forest canopy and vo- Every forest we visited in Ghana, with the exception calize frequently. If red colobus were present near any of the Bia and Nini-Suhien national parks, had been sub- of our survey routes, it is likely that we would have de- ject to logging, and some were being logged at the time

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1530 Extinction of a Colobus Monkey Oates et al. of our visits. Parts or all of the forests we surveyed in Sierra Leone [Oates et al. 1990]). Hunting probably has Côte d’Ivoire had been degraded by both logging and been exacerbated by the improved access to forests re- farming. In an extreme case, the Forêt Classée de Son- sulting from logging activities and by the growth of hu- gan, virtually no forest remained in the reserve. At each man populations in the area formerly inhabited by the site we visited we found evidence of recent hunting in red colobus. the form of spent shotgun shells, spent carbide from The three monkeys encountered least frequently in hunters’ acetylene headlamps, recently used camps, our surveys—(the red colobus, the black-and-white colo- and/or traps and snares. At many sites we heard shots or bus, and the mangabey)—are the largest-bodied mon- encountered hunters directly. keys in the forests of this region; each species has an Other anthropoid species besides the red colobus adult female body mass of Ͼ6 kg (Oates et al. 1990). were uncommon at all the sites we visited, and the spe- Studies in other tropical forest regions have found that cies we saw or heard most often were small-bodied large-bodied primate species are more likely than forms known to flourish in secondary forest: Lowe’s gue- smaller species to be made locally rare or extinct as a re- non (Cercopithecus campbelli lowei ), the spot-nosed sult of hunting with guns (e.g., Peres 1990). guenon (Cercopithecus petaurista petaurista), and the Hunting has had a disastrous effect on P. b. waldroni, olive colobus monkey (Procolobus verus) ( Tables 1 & not only because it is a relatively large and conspicuous 2). Next most frequently encountered was the Roloway animal, but also because laws protecting colobus mon- guenon (Cercopithecus diana roloway). Only rarely keys have not been enforced, and forest areas set aside seen or heard were the white-thighed black-and-white specifically for wildlife protection (such as Ghana’s Bia colobus monkey (Colobus vellerosus) and the white- and Nini-Suhien national parks) have been poorly pro- naped mangabey (Cercocebus atys lunulatus). tected against the activities of poachers. Although plan- ning has been underway to improve the protection of the Bia and Nini-Suhien national parks and their associ- Discussion ated resource reserves since 1990, a park management project funded by the European Union ( EU ) was not Confirming the presence of an animal in an area is easier launched until 1997. This delay was caused in part by than proving its absence, and we cannot be absolutely the EU’s administrative arm, the European Commission, certain that a few Miss Waldron’s red colobus monkeys requesting that the project proposal be revised to de- do not linger in one of the forests we surveyed, or in vote more resources to the development of human com- some other area, but our observations have convinced munities around the “protected” areas; meanwhile, no us that no viable population of this subspecies remains. increased resources or efforts were given to protection If P. b. waldroni is extinct, this is the first recorded ex- of the forests and their wildlife (Oates 1999). tinction of a widely recognized primate taxon in the The Upper Guinea rainforest of West Africa, which ex- twentieth century, and human hunting rather than habi- tends from western Guinea to eastern Togo, is one of tat loss has almost certainly been the primary cause of the smallest discrete rainforest regions in the tropics, the monkey’s extinction. Many of the protected areas but it contains many endemic taxa of plants and animals we visited, especially in Ghana, still contained relatively ( Jenkins & Hamilton 1992). Most of the original forest large areas of habitat suitable for red colobus, which can cover of Upper Guinea has been lost to agriculture, yet live at high population densities (e.g., 100–300/km2 in deforestation continues at a high rate, and wildlife has parts of the Kibale Forest, Uganda [Struhsaker 1975, little real protection even in the majority of nominally 1997], 180/km2 in parts of the Taï Forest, Côte d’Ivoire protected areas (van Schaik et al. 1997 ). The extinction [Holenweg et al. 1996], and 49–70/km2 at Tiwai Island, of Miss Waldron’s red colobus may be the first obvious

Table 2. Encounter rates with anthropoid primates on fixed-line transects in Kakum, Bia, and Nini-Suhien.

c Distance Encounter rate Sitea Surveyorb surveyed (km) C. cam. C. pet. C. sp. Co. vel P. ver Total Kakum NP, Antikwaa JO 12 0.50 0.42 0.17 0 0.17 1.26 Kakum NP, Obuo River JO 16 0.25 0.31 0.25 0 0.19 1.00 Kakum NP, Obou River TS 16 0.19 0.50 — 0 0.06 0.75 Bia NP and Bia RR TS 22 0.07 0.14 0.05 0 0 0.26 Nini-Suhien NP JO 16 0 0 0 0 0 0 aNP, national park; RR, resource reserve. bJO, J. Oates; TS, T. Struhsaker. cC. cam., Cercopithecus campbelli; C. pet., C. petaurista; C. sp., unidentified Cercopithecus species (probably C. campbelli or C. petaurista); Co. vel., Colobus vellerosus; P. ver., Procolobus verus. Encounter rate is the number of sightings and/or distinct vocalizations from discrete clusters of each species within 50 m of the transect line per kilometer surveyed.

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Figure 2. Southwestern Ghana and southeastern Côte d’Ivoire, showing survey sites. Site names (corresponding to map code numbers) are given in Table 1. manifestation of an extinction spasm that will soon af- of this monkey. Although a great deal has been said and fect other large animals in this region unless more rigor- written about endangered primates for at least the last ous protection is applied immediately. Signs of this im- 20 years, this apparent concern rarely has been trans- pending crisis, beyond the extinction of the red colobus lated into action on the ground. A few species and popu- and the evident fragmentation of the region’s original lations, particularly of great apes, have been a focus of forest, are the low frequency with which we encoun- conservation action, whereas taxa such as the red colo- tered two other locally endemic primate subspecies, bus monkey have been relatively neglected. Cercocebus atys lunulatus and Cercopithecus diana Unless attitudes change and the warnings inherent in roloway, each of which originally had a geographic dis- IUCN listings are taken seriously, other forms of red tribution similar to that of P. b. waldroni. colobus monkey may soon follow P. b. waldroni into In 1988 Miss Waldron’s red colobus was listed as en- extinction. Five other subspecies have already been dangered both in an IUCN Red Data Book ( Lee et al. listed as severely threatened: P. b. bouvieri of the Congo 1988) and in the IUCN Red List ( IUCN Conservation Republic has not been recorded in the wild by a scien- Monitoring Centre 1988). Neither the existence of these tist for many years; P. b. epieni of the Niger Delta and P. widely read listings nor the warnings of scientists over a b. pennantii of Bioko Island occur in limited areas that 30-year period led to any special concern over the fate have no formal protection; P. b. preussi, which inhabits

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1532 Extinction of a Colobus Monkey Oates et al. a small area on the Cameroon–Nigeria border, is poorly Harcourt, and N. M. Collins, editors. The conservation atlas of trop- protected; and P. b. rufomitratus occurs in fragile and ical forests: Africa. Macmillan, London. diminishing patches of gallery forest along Kenya’s Tana Kingdon, J. 1997. The Kingdon field guide to African mammals. Aca- demic Press, San Diego, California. River. Because of the dire predicament facing many Lee, P. C., J. Thornback, and E. L. Bennett. 1988. Threatened primates forms of red colobus, the most recent IUCN African pri- of Africa: the IUCN red data book. World Conservation Union mate plan has called for a special conservation action ( IUCN ), Gland, Switzerland. plan to focus on red colobus monkeys (Oates 1996). MacPhee, R. D. E, and C. Flemming. 1999. Requiem aeternam: the last five hundred years of mammalian species extinctions. Pages 333– 371 in R. D. E. MacPhee, editor. Extinctions in near time. 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