R. T. F. Bernard

The diet and ecological role of giraffe (Giraffa camelopardalis) introduced to the Eastern Cape, South Africa

With an increase in the popularity of wildlife ranching in southern Africa has come the introduction of non-native (extralimital) mammalian herbivores. Financial gain has arguably been at the forefront of these introductions, with little or no assessment of the ecological consequences. The diet of three populations of introduced giraffe Giraffa camelopardalis was assessed by direct observation in the Eastern Cape Province, South Africa between January 2002 and October 2003, as the first step towards understanding the ecological role played by giraffe in the region. Similar to the diet of giraffe within their native range, a deciduous species from the genus Acacia (Acacia karroo) was the most important species in the diet. Giraffe in the Eastern Cape Province, however, consumed more evergreen species than those within their native range. The relative lack of deciduous species in the Eastern Cape Province provides a probable explanation for such a result. Seasonal variation in the consumption of the most important species in the diet was evident with members of the genus Rhus being more important in the winter months. This was attributed to the deciduous nature of A. karroo. The potential for giraffe to have a detrimental effect on the indigenous vegetation is discussed. We conclude that the study provides a much-needed list of plant species threatened by giraffe browsing in a region where the vegetation is thought to have evolved in the absence of such a browser.

Aardvark Burrows: A Potential Resource for Animals in Arid and Semi-Arid Environments

Arid and semi-arid environments are characterized by extreme fluctuations in temperature and low rainfall, which present significant challenges to the animals inhabiting these areas. However, the presence of burrows may allow animals to avoid climatic extremes and predators and may act as valuable foraging sites. We assessed the microhabitat conditions (maximum and minimum temperature, relative humidity and seed abundance) of aardvark (Orycteropus afer) burrows in relation to paired non-burrow areas at three sites in South Africa. We also describe the extent to which they are used as resources by other vertebrates. Maximum temperatures were significantly lower and minimum temperatures and relative humidity values were significantly higher inside the burrows than outside. The concentration of seeds inside the burrows and at the paired non-burrow sites was similar. Twenty-seven vertebrate species (21 mammals, two birds, three reptiles and one amphibian) were recorded making use of the burrows and it is likely that these species accrue benefits (e.g. a buffered microclimate) from burrow use. However, our sampling was biased towards mammals and nocturnal species. Consequently, we recommend further work to establish the overall reliance of vertebrate taxa on aardvark burrows in arid and semi-arid environments.

Bushclumps as refugia for small mammals in two Eastern Cape conservation areas

ABSTRACT Bushclumps are scattered islands of thicket-like vegetation within a matrix of more open vegetation. We investigated the role of bushclumps as refugia for small mammals, and examined the effect of a limited number of abiotic and biotic factors on their richness, diversity and abundance. Small mammals were surveyed using Sherman small mammal traps at two sites in the Eastern Cape Province, South Africa (Mountain Zebra National Park and Kwandwe Private Game Reserve). Soil hardness and seed abundance, inside and outside bushclumps, were determined. Trap success was significantly higher inside bushclumps than in areas outside, and species diversity and the abundance of small mammals were greater within bushclumps compared to outside. Bushclumps also had significantly softer soil and a higher concentration of seeds. We conclude that bushclumps provide a concentrated source of food and protection from predators for small mammals, and are thus used significantly more than adjacent open areas. The conservation of bushclumps is therefore important for the overall maintenance of ecosystem functioning.

A Comparison of Two Diet Analysis Techniques for a Browsing Megaherbivore

Abstract

Attitudes of Rural Communities Toward Dispersing African Wild Dogs in South Africa

Subsistence pastoralists often view large carnivores negatively given that any loss of livestock is likely to represent a significant economic cost. Consequently, large carnivore conservation initiatives in rural landscapes should incorporate appropriate human–carnivore conflict mitigation strategies. In this study, structured interviews with local residents (n = 247) were used for determining attitudes toward African wild dogs (Lycaon pictus) among rural communities neighboring two protected areas in KwaZulu-Natal, South Africa. Contrary to expectations, the majority of respondents (58%) were generally positive toward wild dogs. This was probably due to a lack of livestock depredation by wild dogs and relatively high levels of formal education among respondents. Respondents with greater knowledge of wild dogs and conflict mitigation had more positive attitudes, and most were aware of effective husbandry techniques. The positive attitudes observed in these rural communities may benefit wild dog dispersal from natal home ranges and the future conservation of this endangered carnivore.

Do elephants influence the organisation and function of a South African grassland

The impact of elephants (Loxodonta africana) on woody plants is well known. Elephants can be regarded as drivers of ecosystem functioning by, for example, decreasing woody plant litter accumulation through defoliation. However, their influence within grassland landscapes is, by comparison, very poorly understood. We assessed the influence of elephants on grassland functionality at three separate sites (1, high elephant density, long occupation time; 2, low elephant density, short occupation time; 3, no elephants) in the Addo Elephant National Park, Eastern Cape Province, South Africa. Using landscape function analysis (LFA) we described the landscape organisation of each site, and, using visual surrogates, calculated indices of landscape stability, infiltration and nutrient cycling. The number of vegetation patches/10 m of transects surveyed was higher at sites where elephant density was high (3 elephants/km2) and where elephants had been present for a long time (>70 years). However, patch size was significantly smaller when elephant density/time of occupation increased, and the proportion of bare soil was higher where elephant density and occupation time were highest. In addition, stability, infiltration and nutrient cycling indices at a site scale were significantly lower where elephants were present at high densities and after a long occupation time. However, bare soil stability was not greatly affected by elephant grazing pressure, implying that a ‘threshold of potential concern’ has not yet arisen. We conclude that the functioning of this grassland landscape is significantly altered when elephants are present. These conclusions highlight the importance of management factors such as containment and the provision of artificial water points which may be compromising the functionality of these landscapes. We recommend ongoing assessments to inform future management decisions.

Life history of the springhare ( Pedetes capensis ) from a strongly seasonal environment in the Eastern Cape Province of South Africa

The life history of the springhare (Pedetes capensis, Forster, 1778) at 33°S, in the Eastern Cape Province of South Africa, was characterized by continuous, aseasonal and asynchronous reproduction. Females were monotocous and consecutive pregnancies were separated by a non pregnant period (30–50 days) similar in length to the period of lactation. Young were relatively large at birth (8% of adult body weight) but were altricial and only emerged from the burrow at weaning. Towards the end of lactation, many females mated again (20% of all females were both lactating and in early pregnancy) and annual fecundity was probably two but never more than three. For a rodent, albeit a large one, this is a very slow rate of reproduction and we propose that the ricochetal locomotion (jumping on the hind legs) and semi-fossorial life style of the springhare will have resulted in decreased juvenile and adult mortality, and increased longevity, and that these factors have shaped the evolution of the life history of the springhare.

The use of acoustic detectors for assessing bat species richness and functional activity in a South African National Park

Abstract Insectivorous bats are a difficult group of mammals to survey because they are small, nocturnal, fly and often roost in hard to reach places during the day. However, bats should not be neglected from biodiversity assessments because they play pivotal roles in pest regulation and as biological indicators. We used acoustic detectors to sample bat species richness at three sites within the Mapungubwe National Park (MNP), South Africa during the austral winter and summer of 2013. A minimum of 11 species from six families were recorded, with the clutter-edge foraging bats (Miniopteridae and Vespertilionidae) and open-air foraging bats (Molossidae), dominating. Bat activity was significantly higher in summer compared to winter and this is likely linked to higher prey availability and reduced thermoregulatory costs at this time. Our results represent the first assessment of bat species richness in the MNP and our data compare favourably with historical records for the region. In addition, we provide evidence for the presence of at least one undescribed species. We advocate the use of acoustic detectors for future bat surveys as long as comprehensive reference call library data are available.