Register      Login
Wildlife Research Wildlife Research Society
Ecology, management and conservation in natural and modified habitats
RESEARCH ARTICLE

Estimating lion population variables: prey and disease effects in Kruger National Park, South Africa

Sam M. Ferreira A C and Paul J. Funston B
+ Author Affiliations
- Author Affiliations

A Scientific Services, SANParks, Skukuza, 1350, South Africa.

B Department of Nature Conservation, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.

C Corresponding author. Email: SamF@sanparks.org

Wildlife Research 37(3) 194-206 https://doi.org/10.1071/WR09030
Submitted: 12 March 2009  Accepted: 25 February 2010   Published: 18 May 2010

Abstract

Context. Lion (Panthera leo Linnaeus, 1758) populations experience a range of ecological and human influences that affect their demography. Few lion populations have reliable estimates of population size, trends in these, or demographic profiles. Threats such as those imposed by diseases are thus hard to evaluate and respond to.

Aims. To calibrate call-up stations and define survey effort required to achieve estimates with known precision, and extract age structures and estimate survival rates, to estimate lion numbers, sex and age structure and survival rates, and then to evaluate the effect of bovine tuberculosis (bTB) on estimates of lion density and survival.

Methods.By using call-up stations, we developed a statistically robust approach to estimate selected population variables and evaluated the perceived threat of bTB in landscapes of varying prey biomass in the Kruger National Park.

Key results. The size of the lion population was stable, although long intervals between present and historical estimates limit this conclusion. Density and survival rates associated positively with prey biomass, and a positive association was detected between the survival rate and bTB prevalence, with survival being higher in areas that had high prevalence of bTB. Male survival was lower than female survival, disregarding the effects of prey biomass or bTB prevalence. Body condition of lions was high, with scores lower at low to medium prey density.

Conclusions. The effect of an exotic disease on the Kruger lion population may be negligible at present. Intra-specific competition in areas where lions live at high densities affects survival rate. However, droughts could disrupt the hierarchical influences of prey biomass and bTB prevalence on lion densities and survival.

Implications. To evaluate the effect of an exotic disease on lion demography, population surveys should include age- and sex-structure assessments, complemented with focal studies of fecundity. This reflects the importance of understanding host–disease dynamics to inform management options.

Additional keywords: bovine tuberculosis, call-up surveys, demography, monitoring, Panthera leo, population size.


Acknowledgements

The South African National Parks are thanked for the opportunity to conduct this research in Kruger National Park. We are grateful to Professor Gus Mills and Miss Thembi Khoza for help in coordinating the study. For their eager support and participation, we thank all the section rangers and camp managers in Kruger who assisted us so willingly during the fieldwork. For collecting most of the field data, we thankfully acknowledge our research assistants Andrei Snyman and Hennie de Beer. Mrs Judith Kruger is gratefully acknowledged for providing the aerial census data. Dr Rachel Fewster commented and checked our statistical approaches. For financial assistance, we gratefully acknowledge Mr John Jackson from Conservation Force, and additional financial contributions from Mr Rodney Fuhr, and the Tshwane University of Technology (Department of Nature Conservation and Faculty Research Committee). The manuscript was improved by comments from three referees.


References

Aguirre A. A. (2009). Wild canids as sentinels of ecological health: a conservation medicine perspective. In ‘Parasites and Vectors (Supplement 1). Proceedings of the 4th Symposium on Canine Vector-borne Diseases’. (Seville, Spain.)

Alexander, K. A. , and Appel, M. J. G. (1994). African wild dogs (Lycaon pictus) endangered by a canine-distemper epizootic among domestic dogs near the Masai-Mara National Reserve, Kenya. Journal of Wildlife Diseases 30, 481–485.
CAS | PubMed | Bengis R. G. , Grant C. C. , and de Vos V. (2003). Wildlife diseases and veterinary controls. In ‘The Kruger Experience: Ecology and Management of Savanna Heterogeneity’. (Eds J. T. du Toit, H. C. Biggs and K. H. Rogers.) pp. 349–369. (Island Press: Washington, DC.)

Bengis, R. G. , Kriek, N. P. J. , Keet, D. F. , Raath, J. P. , de Vos, V. , and Huchzermeyer, H. F. K. A. (1996). An outbreak of bovine tuberculosis in a free-living African buffalo (Syncerus caffer – Sparrman) population in the Kruger National Park – A preliminary report. Onderstepoort Journal of Veterinary Research 63, 15–18.
CAS | PubMed | Chardonnet P. (2002). ‘Conservation of the African Lion: Contribution to a Status Survey.’ (International Foundation for the Conservation of Wildlife, France, and Conservation Force, USA.)

Cleaveland S. C. , Hess G. , Laurenson M. K. , Swinton J. , and Woodroffe R. M. (2001). ‘The Ecology of Wildlife Diseases.’ (Oxford University Press: Oxford, UK.)

Cleaveland, S. , Mlengeya, T. , Kazwala, R. R. , Michel, A. , Kaare, M. T. , Jones, L. , Eblate, E. , Shirima, G. M. , and Packer, C. (2005). Tuberculosis in Tanzanian wildlife. Journal of Wildlife Diseases 41, 446–453.
CAS | PubMed | Edwards A. W. F. (1972). ‘Likelihood.’ (Cambridge University Press: Cambridge, UK.)

Ferreira, S. M. , and van Aarde, R. J. (2008). A rapid method to estimate population variables for African elephants. Journal of Wildlife Management 72, 822–829.
Crossref | GoogleScholarGoogle Scholar | Gentle J. E. (1943). ‘Random number generation and Monte Carlo methods.’ (Springer-Verlag: New York.)

Gerrodette, T. (1987). A power analysis for detecting trends. Ecology 68, 1364–1372.
Crossref | GoogleScholarGoogle Scholar | Hanby J. P. , Bygott J. D. , and Packer C. (1995). Ecology, demography and behaviour of lions in two contrasting habitats: Ngorongoro Crater and the Serengeti Plains. In ‘Serengeti II: Dynamics, Management and Conservation of an Ecosystem’. (Eds A. R. E. Sinclair and P. Arcese.) pp. 315–331. (University of Chicago Press: Chicago, IL.)

Hayward, M. W. , and Hayward, G. J. (2007). Activity patterns of reintroduced lion Panthera leo and spotted hyaena Crocuta crocuta in Addo Elephant National Park, South Africa. African Journal of Ecology 45, 135–141.
Crossref | GoogleScholarGoogle Scholar | Hood G. M. (2005). ‘Poptools. Version 2.6.6.’ Available at http://www.cse.csiro.au/poptools [accessed 1 July 2005].

IUCN SSC Cat Specialist Group (2006). ‘Regional Conservation Strategy for the Lion Panthera leo in Eastern and Southern Africa.’ Available at www.felidae.org [accessed December 2006].

Keet, D. F. , Kriek, N. P. J. , Penrith, M. L. , Michel, A. , and Huchzermeyer, H. (1996). Tuberculosis in buffaloes (Syncerus caffer) in the Kruger National Park: spread of the disease to other species. Onderstepoort Journal of Veterinary Research 63, 239–244.
CAS | PubMed | Keet D. F. , Kriek N. P. J. , Penrith M. L. , and Michel A. (1997). Tuberculosis in lions and cheetahs. In ‘Proceedings of a Symposium on Lions and Leopards as Game Ranch Animals. Onderstepoort’. (Ed. J. van Heerden.) pp. 151–156. (Wildlife Group of the South African Veterinary Association: Onderstepoort, South Africa.)

Keet, D. F. , Kriek, N. P. J. , Bengis, R. G. , Grobler, D. G. , and Michel, A. (2000). The rise and fall of tuberculosis in a free-ranging chacma baboon troop in the Kruger National Park. Onderstepoort Journal of Veterinary Research 67, 115–122.
CAS | PubMed | Schaller G. B. (1972). ‘The Serengeti Lion.’ (University of Chicago Press: Chicago, IL.)

Schutte, I. C. (1986). The general geology of the Kruger National Park. Koedoe 29, 13–38.
Skinner J. D. , and Smithers R. H. N. (1990). ‘The Mammals of the Southern African Subregion.’ (University of Pretoria: Pretoria.)

Smuts, G. L. (1976). Population characteristics and recent history of lions in two parts of the Kruger National Park. Koedoe 19, 153–164.
Sokal R. R. , and Rohlf F. J. (1995). ‘Biometry: The Principles and Practice of Statistics in Biological Research.’ (W.H. Freeman & Co.: New York.)

Stander, P. E. (1991). Demographics of lions in the Etosha National Park. Madoqua 18, 1–9.
Viljoen P. C. (1989). ‘Ecological Aerial Survey in the Kruger National Park: Objectives and Methods.’ (South African National Parks: Skukuza, South Africa.)

Whyte I. J. (2001). ‘Information and Instructions to Pilots and Observers Participating in the Kruger National Park’s Aerial Line Transect Surveys (ALTs) in the Partenavia P-68 Observer.’ (South African National Parks: Skukuza, South Africa.)

Wilson, G. J. , and Delahay, R. J. (2001). A review of methods to estimate the abundance of terrestrial carnivores using field signs and observation. Wildlife Research 28, 151–164.
Crossref | GoogleScholarGoogle Scholar |

Woodford, M. H. (2009). Veterinary aspects of ecological monitoring: the natural history of emerging infectious diseases of humans, domestic animals and wildlife. Tropical Animal Health and Production 41, 1023–1033.
Crossref | GoogleScholarGoogle Scholar | PubMed |

Woodroffe, R. , and Frank, L. G. (2005). Lethal control of African lions (Panthera leo): local and regional population impacts. Animal Conservation 8, 91–98.
Crossref | GoogleScholarGoogle Scholar |