Primates (2012) 53:337–344 DOI 10.1007/s10329-012-0303-9

ORIGINAL ARTICLE

Distribution and population estimate for the chacma baboon (Papio ursinus) in KwaZulu-Natal, South Africa

Olivia M. L. Stone • Shawn W. Laffan • Darren Curnoe • Ian Rushworth • Andy I. R. Herries

Received: 29 September 2011 / Accepted: 20 February 2012 / Published online: 8 March 2012 Ó Japan Monkey Centre and Springer 2012

Abstract We report the current species distribution and Introduction population estimate for the chacma baboon (Papio ursinus) in KwaZulu-Natal Province (KZN), South Africa, based on The chacma baboon (Papio ursinus) is categorised in both an analysis of estimated area of occupancy and estimated the most recent International Union for Conservation of home range size. This estimate suggests a total population Nature (IUCN) Red List and the South African Mammal size of approximately 11,000 individuals for KZN. Much Red List as a species of least concern (Friedmann and Daly of the province is uninhabited, with a density in occupied 2004; Hoffman and Hilton-Taylor 2008). These assess- areas of approximately 1.8 animals per km2. The current ments note that the species is abundant and widespread population size may be more than an order of magnitude across southern Africa, being found in numerous protected smaller than historical population size. Chacma baboons areas across its range, and has a stable population. Most now exhibit a highly fragmented and discontinuous distri- distribution maps are very generalised and/or broad, pre- bution in KZN, with 58% of the population residing within senting the species as resident continuously across southern protected areas, and more than half of these troops reside in Africa, save areas such as the Namibian coast and central areas [1,500 m above average sea level. The small popu- and southern parts of Botswana (Skinner and Chimimba lation and highly fragmented distribution of chacma 2005; Hoffman and Hilton-Taylor 2008). However, local baboons in KZN, combined with rapidly increasing human knowledge in the KwaZulu-Natal Province of South Africa population size and transformation of natural habitat, (KZN) indicates that baboons no longer occupy large areas suggest this species requires greater conservation attention. of the published distribution range, and that densities may be lower than previously reported. No recent attempts have Keywords Chacma baboon Á Papio ursinus Á Distribution Á been made to estimate population size or record contem- Population Á GIS Á KwaZulu-Natal Á South Africa porary population distribution at a subcontinental, national or provincial scale. The chacma baboon comprises a minimum of two widely accepted clades or subspecies, Papio ursinus ursi- & O. M. L. Stone ( ) Á S. W. Laffan Á D. Curnoe nus (cape chacma) and Papio ursinus griseipes (grey-foo- School of Biological Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia ted chacma) (Groves 2001; Grubb et al. 2003; Sithaldeen e-mail: [email protected] et al. 2009; Zinner et al. 2009). Although taxonomy is not discussed in this paper, information regarding population I. Rushworth statistics and distribution may well become essential for Ecological Advice Division, Ezemvelo KwaZulu-Natal Wildlife, Queen Elizabeth Park, 1 Peter Brown Drive, Pietermaritzburg, KZN conservation management as recent research suggests KZN 2302, South Africa KZN encompasses the border between two chacma baboon clades (Keller et al. 2010). A. I. R. Herries Contemporary estimates of population size and trends Archaeology Program, School of Historical and European Studies, Faculty of Humanities and Social Sciences, La Trobe will allow for more accurate reassessment of ‘Red List’ University, Bundoora, Melbourne, VIC 3086, Australia status as well as informing provincial and national 123 338 Primates (2012) 53:337–344 conservation priorities. Importantly, it will also assist in the area utilised was unknown. Polygon data were annotated implementation of the Norms and Standards for the Man- onto 1:50,000 scale topographical maps, as were some agement of Primates in KwaZulu-Natal (Ezemvelo KZN point data; all actual sightings made by us were recorded Wildlife 2008). This is the first policy addressing the with a handheld global positioning system (GPS) unit conservation management of primates to be adopted by a (Fig. 1). province in South Africa, but lack of detailed knowledge Data for lone males were not included in this analysis. relating to population size, population trends, distribution Males are the dispersing sex in the species, either dis- and genetic structuring is hampering effective implemen- persing individually or on occasions as groups of young tation of this policy. males (Bulger and Hamilton 1987; Clarke et al. 2008; The present study aims to address this gap in under- Hamilton and Tilson 1982). These data were excluded as standing of primate conservation and ecology by providing they do not form a stable self-sustaining population or a contemporary provincial-level species distribution and troop and their locations are transient. population estimate for chacma baboons in KZN. This is For the Drakensberg region, data on current baboon achieved using geographic information system (GIS) distribution was provided by EKZNW. All baboon sight- technology. ings by conservation field staff in the uKhahlamba Dra- kensberg Park World Heritage Site (which covers the majority of the KZN Drakensberg) are routinely recorded, Methods and we extracted all data for the period 2005–2010 at a 1km2 grid scale. The area of occupancy was determined An initial wide-ranging field survey to determine the by recording all 1 km2 grid cells in which there had been location of chacma populations across KZN was com- one or more observations. This was supplemented by data pleted in August 2009. KwaZulu-Natal occupies an area obtained during interviews with conservation managers, of 94,361 km2 (Lehohla 2010), and much of this has field staff and our own sightings. been significantly altered by human activity. The current These data were then entered into GIS software (Arc- rate of habitat transformation is 127,450 ha a-1, which GIS 9.3) in their initial form (either point or polygon). A has led to an increase from 26.8% of land being trans- buffer was added to each point observation to estimate the formed in 1994, to 36.2% in 2000 and 42.3% in 2005. area used by a troop. The size of the buffer was determined The dominant transformation land cover types are crop- by the distance (radius) required to form a circle equivalent ping (12.39%), plantations (7.34%) and urban develop- to the species’ average home range determined by us from ment (5.6%) (Goodman 2010). As a result of this published estimates (Table 1). KZN encompasses a diverse transformation, some areas are no longer suitable for range of habitat types from sub-tropical coastal regions to baboons, thus a survey of the entire province was not harsh Afro-alpine conditions (Fairbanks and Benn 2000). warranted. Rather, the survey targeted areas with known, As home range size varies in different environments and reported or suspected occurrences, as well as adjacent KZN contains an extensive variety of potential habitat regions. We travelled in excess of 9,000 km during the types, estimates from different habitat types/geographic survey, which systematically covered all administrative areas were combined and averaged to provide a generalised areas of the province. The survey was guided by infor- non-habitat-specific home range of 15.19 km2 (Table 1). mation on baboon distribution that was obtained from The use of this type of approach is a well-established GIS Ezemvelo KZN Wildlife (EKZNW) officers and dat- method (Zinner and Torkler 1996; Roger et al. 2007). abases prior to the field survey. During the field survey The polygon layer and the buffered point location layers we interviewed local people (including farmers, land were combined to calculate the total area currently occu- owners, shop owners, private wildlife ranch staff and pied, taking the union of the two areas in case of spatial local residents) in many areas, especially the more overlap. Buffered areas that extended over the provincial remote parts of the province, to confirm status or gather boundary were clipped to that boundary. The total number location data. We also recorded opportunistic sightings of animals within the province was estimated by dividing by us from motor vehicle and on foot surveys. Two the total area occupied by the mean home range of forms of location data were collected. Data were recor- 15.19 km2 (Table 1) to predict the number of troops. The ded as polygons if the information gathered was reliable number of troops was then multiplied by the median troop enough to determine discrete areas utilised by baboons. size of 28, also estimated by us from published reports Thus, the polygons represented the actual inhabited areas (Table 1). There is wide variation in published data for and in some cases represented more than one troop. The chacma baboon troop size in southern Africa (range of remainder of the data were collected as point locations 7–128; Table 1), and the data are skewed and have a where troops were observed but the full extent of the bimodal distribution. Thus, the median value (28) is 123 Primates (2012) 53:337–344 339

Fig. 1 Raw data collection. This includes locations of actual sighting made by the authors, data collected from interviews (park staff and locals) and data collected by Ezemvelo staff as part of their regular surveys for the conservancies in the Drakensberg Mountains

Table 1 Summary of published estimates of home range and troop considered more appropriate than the mean (36). Popula- size for chacma baboon tion estimates derived in the same manner from troop sizes Home range (km2) Troop size using different measures of central tendency were included (no. animals) (Table 2). To compare the population size with the potential his- Mean 15.19 28 toric population, the environmental envelope model (EEM) Range (Min.–max.) 19.89 (4.53–24.42) 121 (7–128) for chacma baboon habitat in southern Africa (Stone et al., Sample (n) 41 127 in preparation) was clipped to the provincial boundaries so Raw data from DeVore (1965), Gaynor (1994), Marais (2005), as to extract likely inhabited land for KZN. This provided a Stoltz and Saayman (1970), Whiten et al. (1987), Hall (1963), population estimate based solely on environmental vari- Noser and Byrne (2007), Henzi et al. (1992), Hamilton et al. ables, effectively disregarding anthropogenic alteration of (1976), Anderson (1981), Bulger and Hamilton (1987), Busse (1984), Byrne et al. (1989), Cowlishaw (1999), Engh et al. (2006), the landscape. The population estimate derived was also Stueckle and Zinner (2008), Johnson (2001), Hall (1962), and Hill produced using the mean home range and median troop (2003) size (Table 1).

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In addition we sought to assess how important EKZNW Results protected areas are in relation to the current distribution of chacma baboons. This was achieved by calculating the Figure 2 depicts the estimated current distribution of the proportion of the population occurring in or within 500 m chacma baboon in KZN to be highly fragmented and dis- of the boundaries of all protected areas. An arbitrary value continuous. The estimated total area inhabited within the of 500 m was chosen to take into account the movement province is approximately 5,965 km2 from the combined and natural spread of a typical foraging group into poten- 120 disjointed areas (represented as polygons). The total tially hostile habitat beyond the boundary of the relatively area of KZN is 94,361 km2. Therefore, approximately safe protected area. 6.3% of the province is currently inhabited by baboons. Clearly, protected areas are important, and 58% of inhabited land, and by inference 58% of the population, Table 2 Estimated total baboon population for KZN using different occurs in or within 500 m of government protected areas, values of typical troop size (as given in parentheses) which only make up 8.1% of the provincial land surface Mode 1 (14) Mode 2 (18) Median (28) Mean (36) (Goodman 2010). Much of the province has been subjected to anthropogenic alteration (Fig. 3) including destructive 5,502 7,074 11,004 14,148 activities such as urbanization and commercial activities

Fig. 2 Estimated current distribution of chacma baboon (Papio ursinus) in KwaZulu- Natal in geographical relation to protected areas of KwaZulu- Natal

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Fig. 3 Estimated current baboon distribution compared with areas of land disturbance in KwaZulu-Natal

including cropping and plantations. Currently, 40% of areas with significant disturbance (Figs. 3, 4a). Inhabited protected lands are utilised by baboons. areas with less land disturbance do occur (Fig. 4b); how- Table 2 presents estimates of population size (ranging ever, these tend to be fewer and smaller in size. It is likely from 5,502 to 14,148 animals) using different measures of that the baboons remaining outside of these conservation central tendency. We conclude that the total population size reserves are concentrated in areas of low human interac- is approximately 11,000 animals (predicted value 11,004) tion/persecution. KZN has a prominent privately owned for the whole of KZN. Further, we estimate a density in commercial industry focussed around wildlife and game occupied areas of approximately 1.8 animals per km2. parks. Interviews with local farmers and reserve owners Figure 4 provides magnified examples of land distur- confirmed that baboons were concentrated around the more bance within inhabited areas, as it is difficult to discern ‘‘baboon-friendly’’ farming and game reserve areas. details of disturbed land on provincial-level maps. An Unfortunately, a data layer of privately owned protected inhabited area with significant land disturbance (Fig. 4a) areas was not available, or we may have found a signifi- contrasts clearly with areas of less disturbed inhabited land cantly higher percentage of the total population dependent (Fig. 4b). Figure 4c gives an example of overestimation on protected lands. using our methodology. Figure 4c highlights an example of overestimation of home range using our GIS method. It results from the placement of each location datum within an area the size of Discussion the average home range for these baboons. The inclusion of point locations within a gorge resulted in areas of sur- Figure 2 clearly demonstrates that a number of troops are rounding sugar cane plantations being included within their residing outside of EKZNW protected areas, including in home range. However, it is known that these commercial

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Fig. 4 Examples of inhabited areas in KwaZulu-Natal with varying levels of anthropogenic land disturbance. a High-level disturbance, b an area of low-level disturbance and c land disturbance in geographical relation to a protected area (Oribi Gorge) farms are not inhabited by baboons, owing to human per- KZN was derived from the median troop size, as the secution including shooting and poisoning to prevent crop median is less sensitive to outliers than the mean. raiding. At the provincial level these overestimations will In comparison, Stoltz and Keith (1973) completed a be countered by similar underestimates within the model. survey and direct census of baboons near Musina (‘‘Mes- Overall we expect our results are likely to be sina’’) in Limpopo Province (‘‘Northern Transvaal’’). Their overestimates. methods included a combination of direct counts, spoor The estimates of population size (Table 2) use different counts and visual group size estimation. They surveyed an measures of central tendency for a sample of published area approximately one-fifth the size of KZN and estimated troop sizes (Table 1). Our conclusion of 11,000 animals for a population of 27,348 animals. Moreover, the potential

123 Primates (2012) 53:337–344 343 population formed from the EEM taken from Stone et al. The estimate of the total chacma baboon population in (in preparation) produced an estimated population of KZN is small. The findings indicate that baboons are likely 114,265 baboons for KZN. This is effectively an estimate to be experiencing a population decline. Comparisons are, prior to extensive land alteration deriving from European- however, confounded to some extent by differences in style land management practices. methodology between the present and previous studies, The small estimated population size (*11,000 animals) making the exact level of decline difficult to quantify. We combined with their suggested dependency on protected recommend that conservation authorities focus their efforts lands suggests the KZN baboon population may be expe- on managing chacma populations both within and outside riencing a substantial decline in size. of protected reserves. Henzi and Lycett (1995) estimated the total chacma population for the KwaZulu-Natal (‘‘Natal’’) Drakensberg Acknowledgments We wish to thank Ezemvelo KZN wildlife for conservation area extrapolated from counts in 61 troops to their support and assistance with various aspects of the research. We are grateful to many residents of KwaZulu-Natal who assisted through 7,540 animals. This was achieved by taking the density of local knowledge to locate baboon troops in many places across the baboons [calculated from a minimum convex polygon province. Our thanks to Dr Dietmar Zinner and one anonymous (MCP) containing their sightings] and multiplying this by reviewer, whose comments improved this manuscript. A.I.R.H. the total land area. This differs from our own model, which acknowledges the support of ARC Discovery Grant DP0877603, and partial funding for the research was provided to A.I.R.H. by the excludes areas within the parks known not to be utilised by University of New South Wales Faculty of Medicine. the baboons, and includes inhabited unprotected areas adjacent to the park. We did not rely on density, but rather based our estimate on the number of troops the currently References inhabited land could support. The troop size we used to estimate the population size (28) was larger than the Anderson C (1981) Subtrooping in a chacma baboon (Papio ursinus) average troop size reported by Henzi and Lycett (1995). population. Primates 22:445–458 Bulger J, Hamilton W (1987) Rank and density correlates of inclusive However, our estimate using this method provides a much fitness measures in a natural chacma baboon (Papio ursinus) lower estimated total population of 4,314 animals. Whilst it troop. Int J Primatol 8:635–650 is possible that there has been a decline in this population, Busse CD (1984) Spatial structure of chacma baboon groups. Int J it is not known to what extent the difference may be due to Primatol 5:247–261 Byrne RW, Whiten A, Henzi SP (1989) Social relationships of the use of different methodologies. mountain baboons: leadership and affiliation in a non-female- We estimated the density within the occupied habitat of bonded monkey. Am J Primatol 18:191–207 KZN to be approximately 1.8 animals per km2. Providing a Clarke PMR, Henzi SP, Barrett L, Rendall D (2008) On the road again: competitive effects and condition-dependent dispersal in density estimate for the entire province is unrealistic, as the male baboons. Anim Behav 76:55–63 majority of the province is presently uninhabited. The survey Cowlishaw G (1999) Ecological and social determinants of spacing by Stoltz and Keith (1973) provided an estimate of about 1.5 behaviour in desert baboon groups. Behav Ecol Sociobiol animals per km2, similar to our estimate. In contrast, Henzi 45:67–77 and Lycett (1995) estimated densities for the Natal Dra- DeVore I (ed) (1965) Primate behavior: field studies of monkeys and apes. Holt, Rinehart and Winston, New York kensberg conservation area to be much greater at about Engh AL, Beehner JC, Bergman TJ, Whitten PL, Hoffmeier RR, 2.5–2.9 animals per km2. Again, differences in methodolo- Seyfarth RM, Cheney DL (2006) Behavioural and hormonal gies make these densities difficult to equate. responses to predation in female chacma baboons (Papio hamadryas ursinus The contemporary population size of chacma baboons ). Proc R Soc B 273:707–712 Ezemvelo KZN Wildlife (2008) Norms and standards for the for the whole of KZN is estimated to be *11,000, which is management of primates in KwaZulu-Natal, vol file no. 3.2.6. 9.6% of the estimated historical population size in the Board of the KwaZulu-Natal Nature Conservation Service, region. 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