Introduction.

With increased human population pressures and continued fragmentation of the landscape, the remaining habitat of wide-ranging carnivores has become more and more critical. Biologists and managers are increasingly forced to adopt interventionist approaches to carnivore conservation, among them, species reintroduction. Large carnivores are frequent subjects for such projects. Their ecological demands and potential for conflict with humans make them among the first species to disappear from an area. However, ironically, large carnivores frequently symbolize wilderness to the general public who express great interest in their reintroduction. Despite this high profile with the public, high cost and logistical complexity of such projects, many efforts involving large carnivores have received little post-release monitoring and those that have record limited success (Linnell et al 1997).

In South Africa, recent dramatic political changes have given rise to an extensive reassessment of the historical use of land (Wells, 1996). Revenue from increased eco-tourism to South Africa is viewed as a potentially lucrative alternative to subsistence and intensive farming practices which are usually at odds with wildlife. As a result, government, private land owners and local rural communities are all attempting wildlife reintroduction projects on a scale that is not occurring anywhere else in Africa. For most such projects the ultimate objective is to re-establish the large carnivores, in particular the lion. The lion holds deep emotional appeal to the general public and is the single most sought-after species for tourists visiting reserves.

At the beginning of 1999, at least ten projects have attempted to re-establish a free-ranging lion population in areas from which they had been eradicated in South Africa. Such a large-scale effort represents an unique opportunity to study the process of restoring large carnivores to areas they formerly inhabited. Lions are easily observed, enabling detailed data to be gathered following reintroduction and thus present an opportunity for investigating felid reintroduction where it has been so poorly researched in the past (Linnell et al 1997). Additionally, as they have such a high profile with the general public, the information collected from these efforts may be applied to other carnivore restoration projects in different parts of the world (Hunter, 1998). Furthermore, as the human population continues to grow in Africa and place enormous pressure on wildlife populations, the opportunity for these exercises on such an extensive scale may not present itself again.

The Lion Project at the University of Natal was initiated in 1996 with one of its main aims being the unification of numerous efforts to re-introduce lions in South Africa. The project aims to gather data on lion reintroduction into a central database so that information and experience from different reserves is available to all practitioners of reintroduction. Presently, seven significant sites are involved in the project with data collection mostly complete from the first release of lions which began in 1992 (Table 1). These reserves represent a cross-section of all forms of conservation land management in South Africa, i.e. National Parks, Provincial parks, privately-owned reserves and cooperative reserves comprising private owners and rural communities.

Table 1. Reserves involved in the Lion Project.

Table 1 presents details of the seven reserves currently involved in the Lion Project. In most cases, intensive data collection has been ongoing since the first release of lions. The "founder stock' column refers to the original population from which lions were derived, though not necessarily directly: for example, Welgevonden and Entabeni lions were translocated from Pilanesberg and Madikwe which were stocked with Etosha-caught animals. Greater detail can be found in the Register in Section 3 of this report.

In addition to its focus on reintroduced lion populations, the project is collaborating with three significant long-term studies of lion populations in Africa, in Kruger National Park, South Africa, in the Hluhluwe-Umfolozi Game Reserve, South Africa and in the Serengeti/Ngorongoro Crater ecosystem in Tanzania. The Kruger Park and Hluhluwe-Umfolozi projects are using long-term sightings records combined with periods of intensive study to establish the first detailed analysis of lion socio-ecology in South Africa. Debbie Weldon, an MSc student in the project (University of Natal) has captured 50,000 lion sighting records from Kruger Park dating from 1951 to 1991, with current data still being collected. She will produce the GIS analysis of Kruger lion-spatio ecology during 1999 under supervision by Rob Slotow (Univ. Natal) and Gus Mills (KNP). Data from Hluhluwe-Umfolozi spans 1973 to 1997 and 4548 records have already been analysed by 4^th year Agricultural Science student Beth Tindall (Supervisors: Neil Ferguson, Pietermaritzburg and Rob Slotow, Durban). A more extensive analysis is currently being undertaken as a MSc project by Agricultural Science student Ryan Van Niekerk (Supervisors: Neil Ferguson, Pietermaritzburg and Rob Slotow, Durban). The Tanzanian project is one of the longest running field studies of large mammals anywhere in the world and provides a extensive dataset of the ecological requirements of lions. Craig Packer has been the head of the Serengeti Lion project since 1978 and is an active participant and collaborator in the University of Natal project. Grant Hopcroft, a former field assistant in the Serengeti Lion Project is working on his MSc at the University of British Columbia (supervisor: Tony Sinclair) to determine the spatio-ecology of lions in the Serengeti. Data from Kruger Park, Hluhluwe-Umfolozi and Tanzania represents a unique database with which we are able to compare ecological and behavioural process occurring in reintroduced populations. Concomitantly, the reintroduced populations allow testing of theories not possible in established populations such as the process by which lions 'choose' where to settle following re-introduction and the effects on prey species with the re-establishment of their large predators.

This preliminary document serves to provide a general overview of the lion project to all involved reserves and participants. It places the research on re-introduced lion populations within the context of the larger University of Natal Lion Project and presents the short and long term aims of the research. It is hoped this report will assist reserve managers in their decisions regarding management of their lion populations as well as aiding and guiding the specific research interests of field workers.

Questions. The section details some of the specific questions the project is investigating.

During historic times, the lion ranged throughout the continent of Africa as well through much of Europe and Asia. However, lions are now largely restricted to isolated populations in parks and reserves, and most of these are so small that their long-term future is uncertain. Yet lions are generally prolific reproducers so that in small conservation areas, excess subadults are forced to disperse into surrounding areas, creating conflicts between wildlife authorities and local people. If lion reintroduction is to be successful, therefore, it will be important to identify those sites which can best sustain large, viable populations. However, to minimise conflict with humans, care must also be taken to predict how the lions would distribute themselves within each reserve and whether they would be likely to disperse into surrounding areas.

Long-term research on the distribution and reproductive performance of the lions in Serengeti-Ngorongoro ecosystem provides an essential foundation for the research program in South Africa. The Tanzanian studies emphasize the great variability in lion reproductive rates both through time (Packer, et al. 1988, 1991) and across broad-scale habitats (open-grass plains, Acacia woodlands, and mesic savanna/marshlands: Packer, et al. 1988, Packer & Pusey 1995, Hanby, et al. 1995). While re-introduced lion populations in South Africa have the potential to expand until they reach the local carrying capacity, population densities in each reserve will vary to a considerable degree according both to prey biomass (Van Orsdol, et al. 1985) and to the detailed geography of each reserve. We will use thematic maps and Geographical Information Systems (GIS) to predict both the size of each lion population and the distribution of lion prides. With a thorough understanding of lion ranging patterns, it should be possible both to identify the landscape features necessary to sustain viable lion populations and to minimise conflict with human populations outside the parks by predicting the dispersal behaviour of young lions.

The long-term data from the Tanzanian field studies, and historical Kruger Park and Hluhluwe-Umfolozi records are currently being captured into a GIS format to explore the causes of local variation in lion ranging behaviour. This information will provide the foundation to make a geographical assessment of each South African reserve in order to predict future ranging and dispersal patterns. Among the aims of this section, we will employ GIS analyses of the South African reserves to predict the following:

(a) Where the first colonists in each reserve will centre their home ranges. The colonising lions will have first choice as to where to centre their home range within the reserve. They would be expected to seek out the set of features most similar to those that confer rapid reproductive rates in similar habitat in the Kruger Park or Serengeti ecosystems.

(b) Where each successive cohort of dispersing subadults will settle. As each new set of surviving offspring leave their mothers' pride, they will have to move to areas of lower quality and should establish a range that contains the best set of remaining geographic features.

(c) The likelihood that the population will persist. Coupled with data on prey biomass, the geographic study should permit a preliminary estimate of reproductive rates for each part of the reserve and thus whether the population would be likely to persist, and, if so, from which areas subadults would be most likely to disperse out of the reserve.

The South African reserves vary dramatically from each other in habitat type, topography, and size. Some of them also contain relatively more browsing ungulates than the East African sites, and many of these show dissimilar herding and ranging patterns. Reintroduced lions may therefore distribute themselves in quite a distinct manner since the landscape features that determine good hunting areas (such as river confluences or thickets) may be quite different. On the other hand, lions also require safe denning sites and continuous access to water. Thus we expect to obtain a more complete view of the lions' habitat requirements, both in terms of the common features across all reserves and the local variants arising from the habits and diet of local herbivores. The addition of lions to an area may cause herbivores to modify their ranging behaviour, possibly spending more time in areas that provide refuge from predation, which in turn may influence lion ranging patterns. Yet, there is evidence that, in small reserves, herbivores are unable to find refuges from lions (Hunter 1998) and lion predation may have significant impacts on herbivore populations (see below). The interaction of ranging patterns by predators and their prey will be further explored as lion populations increase.

Reintroduced lion populations in South Africa currently hail from either Kruger National Park and surrounding areas, or from Etosha National Park, Namibia. Kruger is wooded scrubland whereas Etosha is semi-arid. If skills acquired in the natal area are crucial to successful reproduction, initial breeding success of reintroduced lions might be expected to be highest when placed in comparable habitats. Reproductive patterns and success across different sites will be compared to determine the role site selection plays in lion restoration and if future translocations need to try to 'match' habitats.

Historically, South Africa has maintained a policy of manipulating carnivore populations specifically to increase herbivore numbers. For example, from 1903 to 1960, lions and other large predators were routinely culled in the Kruger National Park. Subsequently, specific lion- and hyena-cropping programs were undertaken to try to arrest the decline in wildebeest and zebra populations in the Park and to protect locally rare populations of sable antelope Hippotragus niger and tsessabe Damaliscus lunatus (Smuts 1978). These policies were undertaken with a specific ecological hypothesis in mind: that predators limit or reduce prey populations and may even decrease the local diversity of herbivore species. However there is little evidence that carnivores limit their prey species in open systems. Indeed, carnivore cropping was halted in Kruger park in 1980 because the policy had no discernible effect on wildebeest and zebra numbers. However, in small reserves, the opportunity for herds to temporally or spatially escape predation may be limited. In many cases, lions are easily able to traverse the reserve in a day or night and could therefore follow any movements made by prey animals Accordingly, prey animals might be unable to move to areas where predation by lions is reduced for substantial periods, as occurs in migratory herds such as in the Serengeti.

Thus it is by no means obvious how lion reintroduction will influence the abundance of each species in each reserve. This project is assessing the impact of lion predation on community structure by monitoring the size of herbivore populations in each reserve. In some of the reserves, there are large areas of the reserve where predators are excluded, thus we can make a direct comparison between predator-free and predator-present areas (see Hunter & Skinner, 1998). Given the closed nature of each reserve, the lions will almost certainly cause some sort of change in the composition of each prey community, causing some species to decrease in abundance compared to others, or causing an overall decline in prey abundance. Data from Phinda have already documented a decline in some 'preferred' prey species (Hunter 1998), as well as modified vigilance behaviour by herbivores following lion reintroduction (Hunter & Skinner 1998). Where conditions exist that predators can sustain their numbers on abundant prey species, species at low densities which experience high predation pressure may undergo a population decline. It remains to be seen whether such a scenario will lead to the extinction of a prey species in a small reserve but that possibility exists. An attempt to restore eland at Phinda in 1996 failed because only 20 animals were released. Lion pressure quickly fragmented the herd and the released animals were killed within six months. In response to such a possibility occurring with wildebeest and reedbuck populations, Phinda management has taken some radical and financially costly action. Since 1996, 30 lions have been captured at Phinda and translocated to other reserves, and supplemental translocations of wildebeest were resumed in 1998. A critical aim of this project is to assess the response of ungulate populations following introduction of lions. Monitoring of ungulate populations is being maintained at all reserves with reintroduced lions to assess the impact of lion predation and to implement appropriate management action if such effects are extreme.

Lions once ranged over vast areas, but the species is now restricted to a series of isolated populations that often show reduced genetic diversity. For example, lions in the floor of Ngorongoro Crater went through a bottleneck of only 12 individuals in 1963, and the number of breeding adults has never exceeded 40 in the past 33 years (Packer, et al. 1991). In contrast, the adjacent Serengeti ecosystem extends over 25,000 km2 and holds about 2,000-3,000 lions. In comparison to the Serengeti, the Crater lions show a marked reduction in isozyme, MHC, and minisatellite polymorphism. Even more extreme, the lions in the Gir Forest of India went through at least one bottleneck of less than 20 animals early this century and now show virtually no genetic variation. Consistent with these findings, the Serengeti lions show the fewest signs of sperm abnormality and the highest sperm counts whereas the Asian lions have the poorest quality sperm (Wildt, et al. 1987).

Although it is not yet clear if any of these effects pose a serious threat to the future of these animals, there is widespread concern about the long-term viability of any small population that suffers such extensive inbreeding. Reintroduced lion populations will all be subjected to an initial bottleneck (the largest number of colonists is less than 20 animals), the average population size is likely to remain small, and the effective population size (i.e. the number of individuals that breed and contribute to the next generation) may be considerably smaller. Both sexes show considerable variance in reproductive success: only a proportion of male coalition partners breed successfully (Packer et al. 1991b) and if certain prides control ranges that are more valuable than their neighbours'(Part I), some females will leave many more descendants than others. Finally, if the prey populations undergo serious fluctuations (Part II), lion population size may also cycle and thus be subject to recurrent bottlenecks. Thus even if most reserves can sustain lion populations in the short term, it is not clear whether they can be maintained in the long term without active management, including the managed movement of individuals between reserves so as to establish a meta-population (see Section 3).

It is essential to record the initial genetic composition of each population so as to provide a foundation for long-term research. The project is therefore collecting blood samples from every animal in every population to prepare for eventual analysis, and storage at the University of Natal. Because of widespread concern over the potential loss of genetic diversity in these small populations, plans are already being considered to increase their effective population size by translocating individuals from one park to another. The first of these exchanges will take place in early 1999 between Phinda and Makalali which have agreed to exchange a 2-male coalition each. Both reserves are presently faced with a populations based on a small number of founders and inbreeding occurring between resident males and their female offspring. This exchange will hopefully act as a model for similar transferrals between reserves with reintroduced lions.

Small populations are also subject to serious threat from infectious disease. For example, the threatened African wild dogs of the Serengeti have virtually disappeared over the past 30 years at least partly as a result of repeated infection with rabies and canine distemper virus (CDV) whereas the Serengeti lion population suffered a 35-40% drop in less than six months due to an outbreak of CDV in 1993/94 (Roelke-Parker 1996). In the latter case, the reservoir for the virus was the domestic dog population surrounding the Serengeti, which was probably also the case in the demise of the reintroduced wild dog population in Madikwe in 1998. After the Serengeti CDV outbreak, the timing of numerous other viral epidemics in these animals was retrospectively determined because blood samples had been taken and stored for many years prior to the epidemic. By regularly collecting blood samples from re-introduced lions (both for the genetic surveys and whenever attaching or changing a radio collar) we can monitor their exposure to serious feline pathogens, including CDV, calicivirus, coronavirus and parvovirus. In addition, these studies will permit perhaps the best opportunity to study the pathogenicity of feline immunodeficiency virus (FIV) which causes AIDS in domestic cats but appears to cause no disease in lions. Finally, this regime may also have benefits in tracking the emerging problem of tuberculosis in lions.

As one of the most intensively studied social mammals, the lion has provided substantial information on behaviours which mediate interactions between conspecifics. Loud vocalisations such as roaring is one prominent and easily observed behaviour used by lions to exchange information between individuals. Lions of both sexes roar to advertise territorial behaviour and to maintain contact between pride members. As pride members may spend much time alone or in sub-groups scattered across the pride territory (Packer et al. 1988), lions may roar in unison in mixed sex or same-sex groups, and also roar when alone. Roars are an effective means of communicating with distant companions, and lions roar frequently in contexts suggesting within-pride communication (McComb et al. 1994). However, lion roars clearly also function to regulate between-pride competition (McComb et al. 1994; Grinnell et al. 1995).

Elegant playback experiments conducted in the Serengeti have significantly contributed to our understanding of lion communication. These experiments have demonstrated that lions are able to identify known individuals from their roars and make numerical judgements when played a chorus of roars. (McComb et al. 1994; Grinnell et al. 1995). This information carries considerable survival value. Lions are highly territorial and are occasionally killed in intra-specific clashes over resources. Evidently, roars contain important information used by lions to assess when to approach another roarer.

Nonetheless, the role of roaring in lion society is clearly far more complex and many questions remain unanswered. Lions roar in some contexts where the function is difficult to elucidate. Similarly, lion responses to roars are highly variable and probably dependent on numerous variables which are not well understood. One such variable is likely to be the complexity of an animal's social 'neighbourhood'. Lions generally occupy exclusive pride territories surrounded by other prides and so would be expected to hear and be familiar with vocalisations from many other individuals. Lions would benefit from being able to distinguish between the roars of members from stable adjacent prides and those of unfamiliar, potentially dangerous newcomers. The influence of different neighbourhood complexities upon an individual's ability to make these sorts of decisions is still little known.

Reintroduced lion populations provide unique opportunities to investigate lion vocalisation. All the parks under study are less than 1000 km2 and the lion populations in each are correspondingly small (from one to several prides). The small size of both the lion populations and the parks in which they live will reduce the complexity of the lion social neighbourhood. Long-term monitoring of some populations has suggested that lions in small reserves may be in unusually close proximity to each other, and may experience a reduction in the total number of extra-pride lions an individual encounters (Hunter 1998). Additionally, intensive monitoring of reintroduced lion populations has furnished an extensive database of the genetic and social relationships between individuals, meaning that we are able to predict with accuracy all the individuals in a population which with each lion is familiar. In some cases, all individuals are familiar with all others, a situation which does not occur in established populations. The unique combination of geographic and social factors in small reintroduced populations may allow lions in small parks to have an unusually complete understanding of their neighbours and the social environment in which they live. This aspect of the project seeks to examine the effects of population size and geography on the social functions of vocal communication within and between groups of lions in small, reintroduced populations.

Specifically, this section of the research aims to address a number of questions:

1: What can listening lions learn about roarers by eavesdropping on lion vocal networks (McGregor 1993)?

2: How does the complexity of the social network affect the interpretation of the roars of strangers, neighbours, and kin (McGregor &Dabelsteen 1996)?

3: Do kin, group members or populations share recognisable vocal signatures (e.g. Gouzoules & Gouzoules 1990)?

Additionally, the project aims to establish if playbacks of lion roars can be applied as management techniques to manipulate lion populations. Many of the small reserves with reintroduced lion populations are in need of techniques to curtail lion activity in certain areas such as along vulnerable fence lines or alternatively may wish to encourage lion activity in high tourism areas. The project will investigate the potential of roar playbacks towards this aim.

This section includes a brief introduction to each reserve involved in the study, listed in chronological order (i.e. from the time of lion introduction). While it includes some summary information on each population, complete data can be found for each site in Section 3.