Smit, G. N.Van der Waal, Cornelis2017-10-312017-10-312001-11http://hdl.handle.net/11660/7367English: A comparative study was conducted in order to investigate the relationship between forage availability and parameters of kudu populations thought to have a bearing on kudu carrying capacity in a semi-arid savanna. This involved eight game-fenced study units. The leaf production and standing crop of woody and forb species were determined. Woody species were classified according to rainfall season acceptance to browsers, the presence and absence of physical deterrents and foliage retention period into the dry season. Ungulate densities were determined during the late dry season of 1999 by helicopter census. The leaf dry mass production below a height of 2 m, the mean browsing height of kudu, ranged from 362 kg ha' to 695 kg ha' (mean = 516 kg ha') between study units. The forb standing crop (dry mass) ranged from 83 kg ha' to 376 kg ha' (mean = 214 kg ha') between study units. Large-scale kudu mortalities were reported in the dry season of 1998 in the study area. Below average rainfall received during the preceding rainfall season probably contributed to these mortalities, which were further aggravated by a prolonged cold spell experienced at the time. The lack of late dry season woody foliage was significantly related to mortalities. Relationships between kudu mortalities and kudu density or study unit size were insignificant. Kudu faecal nitrogen concentration was determined at regular time intervals during the dry season of 1999. This was preceded by a normal rainfall season. Kudu faecal nitrogen concentration declined during the dry season and reached a minimum during the dry hot season (August - October). Kudu faecal nitrogen concentration peaked during the month of November. Mortalities and poor physical condition of kudu populations were linked to low dry hot season kudu faecal nitrogen concentrations. Variation in kudu faecal nitrogen concentration was significantly explained by the availability of woody species' foliage, excluding the contribution of early deciduous species. It is hypothesised that kudu survival is largely dependent on the nutritional status of the animals. Animals with a low nutritional status are more susceptible to diseases and the effect of physical exposure during adverse weather. The nutritional status of kudu populations is apparently dependent on the availability of dry season foliage resources, which is again dependent on the preceding rainy season's rainfall. During droughts, forage resources available during the late dry season, the critical period, are important. During average rainfall years, kudu appear to be less dependent on critical resources, and the availability of dry season resources before the critical period is entered becomes increasingly important. Different strategies to optimise kudu production, given the variation in forage resources between years, are discussed. It is proposed that kudu carrying capacity in semi-arid savanna is based on the availability of forage resources during the dry season, taking into account the effect of rainfall on resource availability/quality.Afrikaans: 'n Vergelykende studie is uitgevoer met die doelom die verwantskap tussen voedsel beskikbaarheid en parameters van koedoebevolkings, wat moontlik betrekking op koedoedrakrag het, te ondersoek in 'n sernl-arlede savanna. Agt wildwerendomheinde studie-eenhede is betrokke by die studie. Die blaar en bogrondse produksie van onderskeidelik die houtagtige en kruid spesies is bepaal. Houtagtige plantsoorte is geklassifiseer volgens reënseisoen-aanvaarbaarheid deur blaarvreterwild, doringagtigheid en die bladhoudendheid tydens die droëseisoen. Hoefdierdigtheid is tydens die laat droëseisoen van 1999 met 'n helikoptersensus bepaal. Die droëmassa van blare onder 2 m hoogte, die gemiddelde weihoogte van koedoes, het van 362 kg ha' tot 695 kg ha:' (gemiddeld = 516 kg ha") tussen studie-eenhede gewissel. Kruid staande-oes (droëmassa) het van 83 kg ha' tot 376 kg ha" (gemiddeld = 214 kg ha' kg ha) tussen studie-eenhede gewissel. Grootskaalse koedoevrektes is gedurende die droë seisoen van 1998 in die studiegebied aangemeld. Onder-gemiddelde reënval wat gedurende die voorafgaande reënseisoen ontvang is, het moontlik tot die vrektes bygedrae wat verder vererger is deur 'n langdurige koue gedurende die tyd. Die tekort aan laat-droëseisoen blaarvoedsel was betekenisvol gekorreleer met vrektes. Verwanskappe tussen koedoevrektes en koedoedigtheid of studie-eenheid grootte was nie betekenisvol nie. Koedoe-misstikstof konsentrasie is op gereelde tye tydens die 1999 droë seisoen bepaal. Dit is voorafgegaan deur 'n normale reënseisoen. Koedoe-misstikstof konsentrasie daal gedurende die droë seisoen en bereik 'n laagtepunt gedurende die droë warm seisoen (Augustus - Oktober). 'n Hoogtepunt in misstikstof is tydens November gevind. Vrektes en swak liggaamstoestand in koedoepopulasies is verbind met lae misstikstof konsentrasies tydens die droë, warm seisoen. Variasie in misstikstof konsentrasie is betekenisvol verklaar deur die blaarbeskikbaarheid van houtagtige spesies wat die bydrae van vroegbladwisselende spesies uitsluit. Dit word hipoteties gestel dat koedoe-oorlewing grootliks afhang van diere se voedingstatus. Diere met 'n lae voedingstatus is meer vatbaar vir sekere siektes en die effek van blootstelling tydens ongure weer. Die voedingstatus van koedoebevolkings blyk afhanklik te wees van die beskikbaarheid van blaarvoedsel tydens die droëseisoen wat weer afhanklik is van die afgelope reënseisoen se reënval. Tydens droogtes is veral die beskikbaarheid van voedselhulpbronne tydens die laat droëseisoen, die kritieke periode, belangrik. Gedurende normale reënval jare blyk koedoes minder afhanklik van die beskikbaarheid van blare tydens die kritieke periode te wees en word die beskikbaarheid van droë-seisoen voedselhulpbronne voordat die kritieke periode binnegegaan word, toenemend belangrik. Verskillende strategieë om koedoeproduksie te optimiseer, gegewe die wisseling in voedselhulpbronne tussen jare, word bespreek. Dit word voorgestel dat koedoedrakrag gegrond word op die beskikbaarheid van voedselhulpbronne gedurende die droëseisoen met inagneming van die invloed van reënval op blaarvoedselbeskikbaarheid.enBrowserCritical resourcesDry seasonNutritional statusPhenologySpinescensStocking rateRainfallAcceptabilityAvailabilityWildlife managementAnimal feedingAnimals -- FoodDissertation (M.Sc.Agric. (Animal, Wildlife and Grassland Sciences))--University of the Free State, 2002DissertationUniversity of the Free State