Academic literature on the topic 'Extralimital'

The giraffe at Nyaru were found to be browsers who made little use of graze during the study period. They utilized a diversity of 20 browse species. Two species, Acacia karroo and Acacia cyclops, formed the bulk of the giraffe diet throughout the year. A definite seasonal dietary shift was evident. A. karroo was favoured in summer and autumn and formed the main food species in spring, summer and autumn. A. cyclops was favoured throughout the study, but its contribution to the diet increased during winter when less A. karroo was consumed. This seasonal shift is related to the deciduous nature of Acacia karroo. Although a seasonal shift in species contribution to giraffe diet has been observed in many other giraffe feeding studies, no studies on giraffe feeding have been done in the Mosaic Thicket of the southern Cape. The ecological browsing capacity for giraffe in thicket was estimated to be between 0.020 BU/ha and 0.095 BU/ha. The browsing capacity for giraffe at Nyaru, based on the available phytomass 2–5 m above the ground, was estimated using those species that formed the bulk of the giraffe diet, and amounted to 0.063 BU/ha. A maximum of three giraffe could thus be stocked on the 157 ha of suitable giraffe habitat on Nyaru. This stocking rate recommendation lies within the range commonly recommended by local consultants for giraffe introductions into the southern Cape. Their recommendations are, however, not based on quantitative assessments such as performed in this study. The recommendation of this study should not be applied as a fixed ecological capacity for giraffe in thicket, but should be seen as a starting point in the adaptive management cycle. Ongoing monitoring of parameters, such as herbaceous composition and phytomass; as well as the condition of key browse species, is strongly advocated. A. karroo was browsed significantly more and carried significantly fewer pods per tree at a heavily used site compared to a lightly used site. Heavy browsing thus appears to affect the reproductive success of A. karroo significantly. Fewer pods are likely to lead to lower regeneration and thus reduced density of A. karroo. Whether A. karroo will maintain its dominance within the thicket vii community in the long run will be related to how individual plants survive and reproduce and if some can escape from herbivory. Fewer G. occidentalis were clumped with other species at the heavily used site compared to the lightly used site. This could possibly be attributed to the fact that intense browsing pressure at the heavily used site caused protective clumps to be eaten away, thus exposing G. occidentalis to higher ungulate browsing. Previous studies have found that nurse shrubs protect G. occidentalis against ungulate browsing. G. occidentalis was browsed significantly more at the heavily used site compared to the lightly used site. There was a general trend of fewer fruits at the heavily used site compared to the lightly used site, while fruits were absent on G. occidentalis growing alone at the heavily used site. This suggests a negative effect of heavy browsing on plant reproductive success and emphasizes the importance of nurse plants for the successful recruitment and hence long term prevalence of G. occidentalis in Mosaic Thicket.

The nyala on Buffelsdrift Private Game Reserve were found to be mainly browsers and made little use of grass during the study period. Browse contributed 87.8 percent to the annual diet, while grass contributed 12.2 percent. Only six species formed > 5 percent of the annual diet. Of these six only three species formed > 10 percent. They are the shrubs Acacia karroo, Pappea capensis and Grewia robusta. These were followed by the shrub Portulacaria afra, the dwarf shrub Zygophyllum lichtensteinianum and the grass Cynodon dactylon all contributing between 5 - 10 percent. There were definite seasonal dietary shifts with preference to different plant species. The shift takes place between the wet seasons (winter and spring) and the dry season (summer). Herbaceous species such as Cynodon dactylon and Erharta calycina were favoured in the winter/wet season. Shrubs such as P. capensis, P. afra and dwarf shrubs such as Limeum aethiopicum and Z. lichtensteinianum were favoured during the spring/wet and summer/dry seasons. Nyala habitat use in BPGR differed significantly from expected use when taking the relative area of habitats into consideration. However nyala did not display signififcantly different habitat preferences between seasons. Male and female nyala displayed differences in foraging behaviour at the plant form, plant species and habitat scale. Males preferred a greater proportion of shrubs and females a greater proportion of dwarf shrubs. Males preferred the shrubs Pappea capensis and Portulacaria afra the most and females preferred the dwarf shrubs Limeum aethiopicum and Zygophyllum lichtensteinianum the most. Plant species site availability varied significantly between the sexes, indicating that males and females selected different feeding paths. The difference in their feeding strategy appears to be related to the selection of plants that best satisfy the nutrient requirements of each sex. These findings are in agreement with the results from earlier studies on nyala sexual dimorphism. At the habitat scale females selected more for open dwarf shrubland and males more for densely vegetated habitats. This appears to be as a result of males attempting to maximize their foraging opportunities by selecting areas that offer food in greater quantities. Nyala in BPGR appear to co-exist with kudu and eland through spatial resource partitioning. This is suggested to be due to the influence of body size-gut size relationships on forage selectivity.

Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol)<br>Due to their popularity for tourism, giraffes are being introduced into Thicket areas within the Little Karoo region of the Western Cape. However, information regarding the activity budgets and diet selection of these giraffes is lacking. Therefore, this study aimed to achieve three objectives; to determine the diurnal activity budget, diet composition and browsing levels, and the estimated browsing capacities of extralimital giraffe. The study was conducted on two privately owned farms, namely Kareesbos Private Game Reserve and Tsumkwe Private Game Reserves. Observations were completed on both study sites using the interval scan method, whereby observations were conducted on all visible individuals from 6 am – 6 pm for four days every 3 months (winter, spring, summer and autumn). Observations found browsing to be the most dominant activity displayed by both populations, with walking and rumination being the second and third most dominant activity. Females browsed more than males in both study sites. Dietary observations showed four species (Pappea capensis, Portulacaria afra, Euclea undulata and Searsia longispina) and five species (Searsia longispina, Euclea undulata, Pappea capensis, Vachellia karroo and Grewia robusta) to comprise approximately 90% and 80% of their diet in Kareesbos and Tsumkwe respectively. The importance of flower bearing species (Lycium spp. and Rhigozhum obovatum) increased during the spring and summer seasons in both study sites. In addition to the diet selection, browsing by both giraffe populations was shown to occur mostly below 2 m. Estimated browsing capacities for Kareesbos and Tsumkwe were 25 and 21, and 107 and 88 ha per giraffe, respectively, for the respective browse height strata of less than two metres and five metres. It is suggested that browsing capacities of less than two metres be considered when stocking giraffe and the number of individuals adjusted accordingly on each farm, due to the continuous low browsing of giraffe at less than two metres. Furthermore, results indicate that these giraffes have adapted to take advantage of forage available in ecosystems outside their natural ranges. Low foraging heights suggests possible niche overlap with other browsers, which may result in increased competition for food when it becomes limited. Long term ecological monitoring of extralimital populations and appropriate management procedures are therefore required to avoid the displacement and degradation of indigenous fauna and flora within the Little Karoo, and possible mortalities amongst the giraffe populations.

En el siguiente artículo, los autores debaten sobre si el Tribunal Constitucional se extralimitó en sus facultades al declarar inconstitucionales una serie de resoluciones judiciales que contravienen su decisión, apesar de que algunas de dichas resoluciones fueron expedidas varios años antes de la Sentencia en cuestión. Así, los autores se enfrentan con el fin de concluir si los argumentos utilizados por el Tribunal son suficientes y correctos.

Giraffe are extralimital in the Eastern Cape Province, South Africa where recent local introductions have persisted despite limited research into their impact on the indigenous flora. The diet of 15 giraffe at the Shamwari Game Reserve was recorded by direct observation during summer (March/April) and winter (July/August) 2001, quantifying diet by frequency of occurrence (individual records scored and expressed as a percentage of the total). Preference indices were also calculated. Habitat use was measured by the number of hours giraffe fed in different habitats. The diet comprised of 14 plant species, the most important species being Rhus longispina (47.9%), Acacia karroo (25.7%) and Euclea undulata (17.6%). Importance of R. longispina, A. karroo and Tarchonanthus camphoratus fluctuated seasonally. Rhus longispina was more important in winter with a corresponding decrease in feeding on A. karroo. Tarchonanthus camphoratus was only consumed during summer. Acacia karroo thickets (previously disturbed areas) were utilized most (summer 12 h; winter 9 h), with alternative habitats utilized more often in winter than in summer. We suggest that the seasonal fluctuation in the importance of R. longispina & A. karroo reflects the deciduous nature of A. karroo.