There is much concern about certain of Namibia’s carnivore species, notably lions, spotted hyaenas and wild dogs. Small populations of these animals inhabit vast areas, making them susceptible to reduced genetic variability and other environmental threats that could lead to their extinction. Dr Philip Stander, Carnivore Co-ordinator of the Division Specialist Support Services at the Ministry of Environment and Tourism, reports on the Namibia Carnivore Monitoring Programme.
Although large carnivores in sub-Saharan Africa have showed a marked decrease in numbers and distribution over the past five decades, their numbers appear to be stable in Namibia. The decline can be attributed to an increased conflict with human development. Today, in many parts of Africa, large carnivores are found only in protected areas.
Namibia is one of only a few African countries that support six large carnivore species. The distribution of lions, spotted hyaenas and wild dogs is restricted to protected areas and areas of low human density with sufficient numbers of suitable prey. Leopards, cheetahs and brown hyaenas are more adaptable and show a much broader distribution, including areas of intensive livestock farming. Although the populations of all six species appear to be stable, there is constant conflict between these predators and people, mainly because they prey on livestock.
However, due to their restricted distribution, there is concern especially over the long-term sustainability of Namibia’s lion and wild-dog populations. This is due mainly to a shortage of scientific data on the ecological factors that determine population regulation. Despite the immense size of the areas inhabited by large carnivores in Namibia, these animals occur in very low numbers. Their populations may, therefore, be susceptible to the threats that face small populations, such as reduced genetic variability and other environmental factors that could lead to social instability or extinction.
Lions, for example, are important to the ecology of the Etosha National Park and the Khorixas District. Previous studies have indicated that these lions exhibit unique behaviour, such as adaptations to surviving in harsh environments. However, there is generally little information available on their population dynamics and conservation status. Lions have both aesthetic appeal and financial value for tourism, a growing industry in the Southern African Region, and are one of the top attractions in Namibia’s parks and reserves. It is, therefore, important to obtain baseline data on their ecological and population characteristics to guide the long-term conservation of this species.
Importance of basic data
Baseline data on density, demography and ecology are needed for all large carnivore species in Namibia. This information is essential to assess the conservation status of the different species and to address their conservation. The objectives of current research are:
In 1998 the Ministry of Environment and Tourism (MET) initiated the Namibia Carnivore Monitoring Programme (NCMP). This programme is aimed at providing baseline data on large carnivore populations throughout Namibia, on the basis of which reliable monitoring programmes for facilitating long-term conservation and utilisation standards will be established. The objectives are, furthermore, to standardise the collection of data throughout Namibia, facilitate the collaboration between various research and conservation projects, and contribute to a collective understanding of the ecology and conservation of large carnivores on a national scale.
Current studies of large carnivores
Information on population demography is being collected in several study sites where radio-telemetry and individual marking of study animals will play an important role. Indirect measures of density and trends will then be coupled to each of these projects. The studies are:
The Large Carnivore ATLAS of Namibia
A summary of information on Namibia’s large carnivore species is being compiled for The Large Carnivore ATLAS. This programme depends on, in addition to organisations compiling data in the above focus areas, information on large carnivores collected by the tourism industry, conservancies, farmers, government employees, and other interested parties.
Attractive, icon-based data forms are distributed to all relevant parties. Completed forms are then returned to a central point in Windhoek. Observation data are then entered into a specially-developed database on a computer designated for NCMP data management. The information is analysed quarterly and presented in a report presenting a summary of the individuals who submitted observations; the age and sex structure of each species of carnivore; the habitats where the carnivores were observed; and a distribution map for each species. These reports are then distributed widely, especially to those individuals who submitted observations.
The Large Carnivore ATLAS of Namibia is aimed at establishing baseline biodiversity information that will aid all relevant conservation organisations and the Government of Namibia to develop and implement effective conservation strategies, and formulate appropriate policies. The baseline information will also be crucial to conservancies and farmers in developing tourism and sustainable trophy-hunting enterprises.
Cheetah ecology on commercial and communal farmland
This project will be initiated in 2001. It will be a joint venture between the MET, AfriCat Foundation, Okatumba Wildlife Research, and the farming communities.
Due to their behaviour patterns, cheetahs are difficult animals to study. They move over extensive areas and the population turnover appears to be high. Five intensive study sites of varied habitats and land-use practices have been selected, where data will be collected on fundamental parameters, such as density and population demography.
Studies will be directed on cheetahs only on two study sites – Hochveld and Omaruru commercial farms – because they are areas of high cheetah density. Other large carnivores, such as lions and spotted hyaenas, will be studied in central Etosha, western Etosha/Hobatere, and the Khorixas District. These are areas of lower density and communal farmland. Lions and leopards will also be studied in these areas. In each of the study sites the cheetah population size will be determined through radio tracking and the recognition of groups and individuals. The entire study area will be covered systematically to capture and radio collar all individuals that frequent the area.
Cheetahs are captured in box-traps, by tracking their spoor and by using sound play-backs to attract them to bait. They are then immobilised. Radio collars are fitted to all individuals and one or two members of a group. Radio-collared animals are located once a week with the use of a fixed-wing aircraft. Aerial locations are followed by ground observations to record group composition in relation to individuals and age/sex structure, and the ratio of marked to unmarked individuals. The structure and composition of groups are monitored through individual identification and record keeping.
During the study, special attention will be directed to movements, social interactions, breeding, predation and mortality. Much attention will be devoted to the design, testing and implementation of indices for future monitoring of population size and basic demography. Emphasis will be placed on the accuracy, reliability, repeatability, and cost-effectiveness of the methods used. The conflict between cheetahs and farmers will be monitored continuously.
Developing future monitoring techniques
Due to the high costs involved in direct assessments of population dynamics, several indirect measures emanating from other parts of the world have been proposed. These include individual recognition of the spoor of tigers, estimating population trends from spoor counts in cougars and estimating leopard densities from a relationship with rainfall and suitable habitat. Indirect methods of sampling large carnivore populations are often cost-effective, repeatable and objective, but are criticised for being inaccurate. Indices of density have the added advantage of precision and the measurement for trends. Indirect sampling occurs mostly in areas where direct methods are not possible due to financial or practical constraints.
The NCMP study sites will be essential in providing data to develop and calibrate monitoring techniques, such as indirect measures or indices, which will form the basis of future monitoring techniques. The correlation between spoor frequency and true population density will be investigated for lion, leopard and cheetah in seven key areas, as the main future monitoring technique. During research conducted in the Nyae Nyae conservancy area, spoor frequency has been shown to be a function of range utilisation, which increases under higher densities, and with sufficient sample sizes may be an index of true density.
This article appeared in the 2001 edition of Conservation and the Environment in Namibia.