Author: Debbie Weldon

School of Life and Environmental Sciences

University of Natal

Durban, 4001

South Africa

Masters thesis

Supervisor: Dr R.H. Slotow

University of Natal (Durban), School of Life and Environmental Sciences

Co-supervisor: Dr M.G.L. Mills

National Parks Board, Skukuza

During 1998 the capturing of the ranger returns (lion sightings forms) by volunteer UND students was initiated. This continued during the December student vacations and will be completed by mid January 1999. Data on the lions sighted by the Kruger National Park (KNP) rangers were captured from ranger diaries for the years dating 1962 to 1985, 1986 and 1988. Computerised diaries were obtained for the years dating 1987, 1989 - 1997. Lion sightings forms for completion by the night drive students were initially introduced to Skukuza in January 1998. After monitoring the success thereof, i.e. the response of the students as well as the number of sightings recorded, the forms were introduced to the remaining camps where students are based. Two private camps, Shimuwini and Sirheni, were also approached with regard to recording lion sightings as the managers of these camps are familiar with the lions in their respective areas. The data from these two camps will be used in conjunction with data from Gus Mills, Paul Funston and Ian Whyte for ground-truthing the results based on the historical and night drive data. Aerial prey census data has been obtained for the years 1980 to 1993.

To understand the ecological processes shaping lion spatial demography.

Ranger returns contained information on lions recorded by the natural and sometimes, the district rangers. The forms date from 1957 to 1985. These forms have been captured by volunteer undergraduate students, with a total of 40512 lines of data captured (Table 1). The division of data between the stations is detailed in table 1.

Table 1:

Lion sightings data has been captured from the ranger returns of 23 stations throughout the Kruger Park. The number of forms varies between stations as the stations were established at different times. The earliest returns date back to 1957 and they end in 1985.

The ranger stations were established at different times and some were closed or merged with others, e.g. Klipkoppies no longer exists as a separate station. The data obtained from these diaries varies between stations according to the ranger in charge. In certain cases, the lion sightings reported in the diary will also appear on the ranger returns. Data on lion sightings has been captured from the diaries for the years dating January 1963 until December 1985 for all the stations listed in table 2.

Table 2:

Lion sightings data has been captured from the ranger diaries for the years dating 1965 to 1988.

To determine the effect of habitat structure on lion spatial ecology.

1. I have divided the KNP into four habitat types. A map was created by resampling the Landscap map received from KNP to create Landrsmp. As Landscap, and hence Landrsmp, was based on Gertenbach's habitat map of KNP (1982), the 35 landscapes of Landrsmp were reclassed to create a habitat map with four habitat categories. These four habitat categories were chosen on the basis of vegetation/habitat structure, namely 1: Mountainous, 2: Woodland, 3: Thickets and 4: Open tree savanna.

Habitat 1, the Mountainous areas included landscapes 2, 29 and 31 from Gertenbach's classification (1982). Areas 29 and 31 represent the Lebombo south and north respectively, while area 2 represents the Malelane mountain bushveld area. These 3 habitats provide a similar habitat in that they are mountainous with stony soils and their vegetation is described as dense bush savanna to more open areas in the bottomlands.

The Woodland areas, habitat 2, are represented by landscapes 3, 6, 8,10,11, 14-16, 18, 22-24, 26-28, 30, 32-34. Woodland was used to define areas of relatively open to dense bush with moderate to dense field cover.

Habitat 3, the Thickets are represented by landscapes 4, 7, 10, 11, 13, 20, 21. Unlike woodlands that are more open, thickets are areas of extremely dense bush/trees. The field layer in these areas is generally quite sparse as a result of the dense woody component.

The Open tree savanna areas, habitat 4, are represented by landscapes 1, 9, 12, 17, 19, 22, 23, 25, 35. These areas can be described as open habitats with a few scattered trees. The field layer ranges in height from 1-2 m, however in landscape 35, the field layer is relatively sparse.

Differentiation was not made on a plant species level as this should be accounted for by the differences in prey densities in areas falling into the same category. Each grid cell (1 minē) was allocated a number (e.g. 1/2/3/4) according to the dominant habitat type.

Table 3:

The habitat map was created by reclassifying the 35 habitats defined by Gertenbach (1983) into 4 categories, namely 1) mountainous, 2) woody, 3) thickets and 4) open tree savanna.

Table 3 continued

Ninety-eight sightings of adult male lions were made from January until 6 October 1998. Once averaged, the resulting 76 sightings were compared using ANOVA. Although the results were not significant (ANOVA, F_3,72 = 0.764; P = 0.518), there was a greater range in group size in habitat one (figure 2). However, there were generally few sightings in this habitat type, therefore this could not be considered a significant result (four, figure 2).

Adult females were seen 144 times from January until 6 October 1998. The analysis of the data, the sightings averaged to 95, were not significant (ANOVA, F_3,91 = 0.212; P = 0.888). There is little variation in group size between the habitats. Although it is slightly greater in the mountainous areas (habitat 1), this is also the habitat in which the least sightings occurred (six, Figure 3).

Subadult males were reported for 50 drives. The averaged sightings (41) compared between habitats did not give a significant result (ANOVA, F_3,36 = 0.229; P = 0.875). However, most of the sightings occurred in the thicket areas (24 in habitat 3, Figure 4), while only 1 sighting was made in habitat 1 (mountainous, Figure 4) and 2 in habitat 2 (woody, Figure 4). There is slightly greater variation in group size in habitat 4 (open tree savanna, ten sightings) than in habitat 3 (thickets, 24 sightings, Figure 4).

Subadult females and large female cubs were seen on 40 occasions and averaged to 32. The results of this comparison were also not significant (ANOVA, F_3,28 = 0.827; P = 0.490). There was little variation between habitats three and four in which the majority of the sightings occurred (22 and 8, respectively, Figure 5).

Chapter 2

Aim

To determine the effect of prey availability or presence of major lion prey species on lion group dynamics.

1998:

Aerial census data on the major prey species (e.g. buffalo, wildebeest, zebra, waterbuck, warthog, impala and giraffe) of lions has been obtained from KNP for 1980-1993. Previous to 1985 the game was counted from the ground and recorded on census forms that varied in form from 1950 to 1984. Partial aerial surveys were carried out in the late 1970s and early 1980s in conjunction with the ground counts. However, the whereabouts of the information prior t 1980 is currently unknown.

1999:

Chapter 3

Aim

To determine the effect of rainfall on lion group dynamics through its influence on prey species' movement patterns and distribution.

1998:

Although rainfall measurements from 22 stations in KNP were recorded on a monthly basis in the ranger diaries, the data has been obtained from the CCWR. The data will be used to create a map of annual rainfall regions over which the lion variables will be overlaid for comparison between the rainfall regions.

1999:

The rainfall data has been obtained from the CCWR will be used to create rainfall maps. The variation in the rainfall will also be calculated.

Short term goals for 1999