Higher than expected growth rate of the Endangered West African giraffe Giraffa camelopardalis peralta: a successful human–wildlife cohabitation J.-P. SURAUD,J.FENNESSY,E.BONNAUD,A.M.ISSA,H.FRITZ and J . - M . G AILLARD Abstract The West African giraffe is a genetically unique Introduction population represented only by the subspecies Giraffa 20 camelopardalis peralta, categorized as Endangered on the ince the beginning of the th century the density ff ff IUCN Red List. These giraffes live outside protected areas, Sand distribution of gira e Gira a camelopardalis 1965 without natural predators and share their habitat with local populations has decreased across Africa (Sidney, )toa 140 000 1990 1999 ff people and their livestock. This study provides demographic total of c. , by the late s (East, ). Gira es , 80 000 data on this poorly studied megaherbivore and documents are now thought to number , (unpubl. data from ff its recovery. We analysed the results of photo-identification the international gira e database). The population of the ff ff censuses from 1996 to 1999 (count data) and from 2005 to West African gira e Gira a camelopardalis peralta,a 2008 (count and demographic data). From 1996 to 1999 genetically unique subspecies represented only by this 2007 the annual growth rate was c. 19% because of an unbalanced population, has also decreased (Brown et al., ; Hassanin 2007 population structure after a period of severe poaching. et al., ). ff From 2005 to 2008 an annual growth rate of c. 12–13% During Palaeolithic times the gira e ranged across West was estimated from both count data and demographic and North Africa, including the Mediterranean coastline 1957 20 parameters. This value fits with the maximum growth rate (Mauny, ). In the early th century the West African ff calculated for a browser species based on the allometric gira e was found across the Sudano-Sahelian zone from relationship linking growth rate and body mass. During the Chad to Senegal. Poaching, habitat loss and fragmentation 1995 period 2005–2008 adult and subadult females had a constant were the main drivers of their decline (Ciofolo, ). survival rate of 0.94 and a constant recapture rate of 0.97. Despite the implementation of an anti-poaching pro- 1980 ff 1981 Annual calf survival rate was 1. Observed sex ratio at birth gramme in the early s (Pfe er, ), the number of ff 1996 was 0.57 and mean reproductive success was 0.257. West African gira es continued to decline. In the last 50 Generation time was estimated to be 9.66 years. This individuals of this population were concentrated close 1998 spectacular population growth was mostly attributed to the to Niamey, the capital of Niger (Ciofolo, ; Le Pendu & 1999 absence of predators and the ongoing monitoring to limit Ciofolo, ). The Government of Niger made concerted ff illegal hunting. e orts to enforce legislation preventing the illegal killing of giraffes, further supported by a community education and Keywords Capture–mark–recapture, demography, giraffe, awareness campaign coordinated by PURNKO (Projet Giraffa camelopardalis peralta, growth rate, population d’Utilisation des Ressources Naturelles de Kouré). Since dynamics, survival 2000, with the additional help of ASGN (Association for Saving the Giraffes of Niger) and AVEN (Association pour la Valorisation de l’Ecotourisme au Niger; the giraffe guide association), poaching has almost ceased. Only three cases of poaching of giraffes were reported between 2005 and 2009.In2008 the West African giraffe was categorized as Endangered on the IUCN Red List (Fennessy & Brown, 2008). 2009 ff 220 J.-P. SURAUD*, H. FRITZ and J.-M. GAILLARD (Corresponding author) Laboratoire In the West African gira e numbered c. de Biométrie et Biologie Evolutive (UMR 5558), CNRS, Université Lyon 1, 43 bd individuals (Suraud, in press), living outside protected 11 nov, F-69622 Villeurbanne Cedex, France. E-mail jean-michel.gaillard@ univ-lyon1.fr areas and without natural predators (i.e. lions Panthera leo), and thus sharing their habitat with local people and their J. FENNESSY Giraffe Conservation Foundation, Purley, UK livestock. This unique case of human–giraffe cohabitation E. BONNAUD Ecology Systematics and Evolution, Paris Sud University, ORSAY ff Cedex, France enables gira es to be individually monitored at close range with minimal flight response, and thus offers ideal A.M. ISSA Direction de la Faune, de la Chasse et des Aires Protégées, Ministère de l’Environnement et de la Lutte contre la Désertification, Niger conditions to study population dynamics and estimate *Also at: Association pour la Sauvegarde des Girafes du Niger, Niamey, Niger the maximum population growth rate (r-max sensu 1977 Received 23 November 2010. Revision requested 17 February 2011. Caughley, ) of this poorly studied megaherbivore Accepted 9 March 2011. (sensu Owen-Smith, 1988). © 2012 Fauna & Flora International, Oryx, 46(4), 577–583 doi:10.1017/S0030605311000639 Downloaded from https://www.cambridge.org/core. IP address: 170.106.202.226, on 30 Sep 2021 at 17:39:51, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605311000639 578 J.-P. Suraud et al. Prior to this research most studies of giraffe population Soudano Sahélienne) project, local foresters, Peace Corps dynamics have focused on decreasing (Leuthold, 1978)or volunteers, and international students (Suraud & Dovi, stable populations (Foster & Dagg, 1972; Ngog Nje, 1983) and 2006, 2007; Suraud, 2008, 2009). These latter censuses were the maximum annual growth rate of a giraffe population improved by photo-identification, which allowed correcting was reported to be 6%, in the Serengeti National Park for repeated observations of the same giraffes. (Pellew, 1983). The aims of our study were to (1) analyse the Censuses based on photo-identification were quasi- results of the various West African giraffe censuses from exhaustive for this small population. We attempted to 1996 to 1999 (count data from photo-identification) and count every individual, developing an individual identity from 2005 to 2008 (both count and demographic data), card, and determined the distribution of the population (2) assess the structure of this population, and (3) estimate by sex and age classes. Photo-identification facilitated the demographic parameters of this recovering population. the building of individual capture–recapture histories, and thereby reliable estimates of age-specific survival rates. Then, using field-based estimates of reproductive Study area parameters we used demographic models to estimate population growth independently from annual counts The study area lies in the Sahel, with a mean total annual (Caswell, 2001). rainfall of 400–500 mm. The Fakara Plateau (Kouré, Each census was conducted annually, during the rainy Fandou), the North Dallol Bosso, and the Intermediate season, because the giraffes aggregated during this period in Zone are the three major areas of the West African giraffe’s the Kouré and Fandou plateaus, 60 km east of Niamey. The core range. Giraffes move across all three of these areas, and plateaus were surveyed using a systematic sampling design: their presence appears to be predominantly associated with annually from 2005 to 2008 up to three teams in 4-wheel seasonal rainfall and availability of forage (Ciofolo, 1998; drive vehicles identified every giraffe present until no new Le Pendu & Ciofolo, 1999). The giraffes roam during the giraffes were detected. The teams involved up to 22 people rainy season (June–October) onto the Fakara Plateau, and for c. 45 cumulative days every year from July to September. during the dry season (November–May) they return to the The photo-identification album was regularly updated and North Dallol Bosso where the vegetation is sparser but used to assess whether a given giraffe had been previously where species such as Faidherbia albida provide essential recorded or was a new individual. seasonal forage in the form of new leaves and pods. The From three to six age classes have been used to determine Intermediate Zone, the area used between the rainy and dry a giraffe’s age (Foster & Dagg, 1972; Leuthold, 1978; seasons, is an important corridor for the seasonal migration Pellew, 1983; Fennessy, 2003). We used four age classes to of these giraffes (Le Pendu & Ciofolo, 1999). standardize data. Long-term survey data allowed us to have The plateau vegetation is composed of tiger bush and information about most of the calves born between and cultivated crops (e.g. millet, sorghum and beans). Tiger within the two census periods (1996–1999 and 2005–2008). bush is a patterned vegetation community consisting The first age-class included juveniles , 6 months of age of alternating bands of trees or shrubs separated by characterized by a height of c. 2 m. The second included bare ground. Because of its organization and structure, young from 6 (. 2 m tall) to 18 months (up to 3 m tall) of tiger bush uses surface run-off optimally and is age; by the age of 12–18 months young may be separated largely dominated by Combretaceae (Guiera senegalensis, from their mothers. Although it included the second half of Combretum micranthum, Combretum nigricans) mixed the juvenile period and the first half of the yearling period with Mimosaceae and Capparidaceae (Acacia ataxacantha, (sensu Gaillard et al., 2000), we called this class yearling. Acacia macrostachya, Dichrostachys cinerea, Boscia angusti- The third corresponded to subadults from 18 months to folia, Boscia senegalensis; Saadou, 1996). 4 years of age; secondary sexual traits such as the small central ossicone are characteristic features of subadult . 4 Methods males. The fourth included adults m tall; the central ossicone of the adult males is well developed. ff Data collection As the pelage pattern of a gira e does not change during its life the form of the spots along the neck has been used to We analysed the results of two series of censuses.