Feeding ecology of the Kalahari springbok Antidorcas marsupialis in the Kgalagadi Transfrontier Park, South Africa

Abstract

Springbok Antidorcas marsupialis ecology was examined on the South African side of the Kgalagadi Transfrontier Park in the Kalahari, with the use of public questionnaires and field forms. Statistically significant differences were found between data that were collected by public respondents and the researcher when using the same questionnaire. Questionnaires are useful for gathering large amounts of data, but should be carefully structured to ensure the quality of the data. Feeding was the most common activity of springbok and the frequency thereof varied during the day and between seasons. Environmental conditions and seasonal changes affected the feeding behaviour of springbok in the southwestern Kalahari. Springbok fed in direct sunlight in the mornings and moved into the shade during the afternoon. More time was spent feeding in the shade during the warmer months than during the colder months, especially under northerly to northeasterly wind directions. Herd sizes were found to increase during the cold-dry season and decreased during the hot-wet season. Springbok and blue wildebeest Connochaetes taurinus taurinus displayed niche separation by competition avoidance. Springbok utilized natural licks. Night-time observations of springbok were made during different seasons and habitats on the South African side of the Kgalagadi Transfrontier Park in 2003. Nocturnal feeding behaviour was described in the context of other similar studies. Feeding times were highlighted, yet the role and importance of nocturnal feeding remains unclear. The nutritional content of some southwestern Kalahari food plant species were determined. The nutrients in the sampled plants showed a wider fluctuation range than plants in other regions. Phosphorus levels in the Kalahari were found to be low in general and calcium levels were higher than in other regions. Browse species contained higher crude protein levels than grass species. The nutritional value of the plants was lowest during the cold-dry season and highest during the hot-dry one. The nutritional status of springbok in the southwestern Kalahari was assessed by using faecal profiling. The faecal nutritional status for springbok populations in different habitats and seasons was examined. Faecal nutrient levels confirmed springbok as mixed feeders with a diet composition that was between that of true browsers and grazers. Faecal concentrations of phosphorus and nitrogen were similar to that of springbok in other areas, but phosphorus intake was shown to be low, particularly during the cold-dry season. Phosphorus appears to be a limiting nutrient and may cause nutritional stress in springbok in the southwestern Kalahari during dry periods.