Reproductive biology of a pride of lions on Karongwe Game Reserve, South Africa Monika B. Lehmann 1 , Paul J. Funston 1 * , Cailey R. Owen 2,3 & Rob Slotow 3 1 Department of Nature Conservation, Tshwane University of Technology, Private Bag X680, Pretoria, 0001 South Africa 2 K.e.r.i. Research, Ecological Institute of Research, P.O. Box 17, Schagen, 1207 South Africa 3 School of Biological and Conservation Sciences, University of KwaZulu-Natal, Durban, 4041 South Africa Received 1 April 2008. Accepted 31 July 2008 The reproductive biology of a pride of lions (Panthera leo) was studied on the 8500 ha Karongwe Game Reserve from 1999 to 2005. Over this period, the pride consisted of between four and 11 lions with a paired coalition of adult males during the first three years and a single adult male for the next three years. We recorded shorter than normal interbirth intervals, high birth rates of 1.3 cubs/lioness/year, very high cub survival rates, and subadults leaving the pride at young ages. This translated into substantially faster growth rates than are typical in large lion populations in ecologically similar circumstances such as Kruger National Park, but are similar to those of lions in Serengeti National Park. These demographic characteristics were probably induced initially by a lack of intense intraspecific competition and high prey availability, but population stability was maintained through the removal of young subadults by management. Interestingly, variability in conception rates between lionesses resulted in lower growth rates than have been found in other similar reintroduced lion populations. These demographic traits characterize many of the small reintroduced lion populations, and call for appropriate management to avoid the consequences of high predator densities. Key words: birth rate, inter-birth interval, intraspecific competition, pride size, small enclosed reserves. INTRODUCTION As large, unspoilt natural areas are rapidly decreas- ing, conservationists and reserve managers have increasingly turned towards small (<1000 km 2 ), enclosed reserves to re-establish areas to their former state primarily as a tourist attraction. This includes reintroducing megafauna, including large predators, onto relatively small reserves (Hunter et al. 2007; Hayward et al. 2007a; Funston 2008). Fences, however, restrict the immigration and emigration of animals and unless these small reserves are monitored and managed effectively, isolation could have a negative effect on genetics and social structure (Packer 1996; Grubbich 2001; Björklund 2003), and the balance between predator and prey populations (Peel & Montagu 1999; Tambling & Du Toit 2005). It is, therefore, impera- tive to carefully monitor the reproductive biology of reintroduced predators, including lions (Panthera leo) (Druce et al. 2004; Killian & Bothma 2003). Relatively little is known on the practicalities of managing growth rates of reintroduced populations of predators (Funston 2008), with several methods being employed. These include removal of subadults (Druce et al. 2004; Hayward et al. 2007b), vasectomisation of males (G. van Dyk. pers. comm.), contraception of females (Bertschinger 2001a,b; Hayward et al. 2007b), social disruption to induce infanticide, and culling (Smuts 1978; Anderson 1980). However, before any of these management interventions are utilized a sound understanding of the species’ reproductive biol- ogy in small, reintroduced populations is funda- mental. In large populations, lionesses within a pride tend to come into oestrus together and thus give birth synchronously (Bertram 1975). Lionesses tend to have their first litter at four years of age (Smuts et al. 1978; Packer et al. 1988), with 2–4 cubs typifying most litters. These variables along with average inter-birth intervals are key determinants of fecundity. This study focused on a single pride in Karongwe Game Reserve to determine the reproductive rate in a reserve with only one pride of lions. Additionally, the influence of having either a paired coalition or a single male on reproductive rate was investigated. Our a priori hypotheses were that low intraspecific competition and high prey availability would result in high population *Author for correspondence. E-mail: funstonpj@tut.ac.za African Zoology 43(2): 230–236 (October 2008)