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dc.contributor.advisorKok, O. B.
dc.contributor.authorDe Swardt, Dawid Herklaas
dc.date.accessioned2017-11-10T07:34:01Z
dc.date.available2017-11-10T07:34:01Z
dc.date.issued1998-11
dc.identifier.urihttp://hdl.handle.net/11660/7465
dc.description.abstractEnglish: Several aspects of the ecology of Gurney's Sugarbird were studied in the Lydenburg area (Mpumalanga) and at Sterkfontein Dam Nature Reserve and Qwaqwa National Park (Free State) during the period April1980 to June 1998. The distribution pattern of Gurney's Sugarbird is closely associated with that of Protea roupelliae along the Drakensberg escarpment in the Grassland Biome. Nectarivore densities at Protea clumps were affected by the size of clumps, flower availability and grasssland fires. Sugarbird densities were higher during winter, spring and early summer when sufficient flowers were available. Male sugarbirds were significantly larger than females in all body measurements, except tarsus length. Significant correlations were recorded between culmen/total head length and wing/tail length of the two sexes, and between maximum width of the bulged P6/wing length in males. Monthly variations in body mass were recorded in both sexes, and birds were heaviest during the November-March breeding season. Adults with long, fully-grown tail ornaments usually had longer wings, while males had wider bulged P6. Primary moult occurred between November to March, coinciding with the breeding season. Tail moult also occurred during this period and were replaced as soon as their condition worsened. The sugarbirds have a September-March breeding season, with a peak from November to December in the Lydenburg area. P. roupe/liae were usually selected for nesting sites, while P. caffra was also occasionally used. Nests were completed within five days by the female; mean nest height was 1,85 m. Nests were lined with the brown, fluffy seeds of P. roupelliae. Incubation period was 16-17 days, nestling period 21-23 days, and post-nestling period 20-30 days. Breeding success was 41,4%, higher than that of the Cape Sugarbird. Sugarbirds foraged mostly on the nectar of P. roupelliae, but during winter they fed on A/oe arborescens in nearby suburban areas and on mountain cliffs. Insect orders which predominated in the diet of Gurney's Sugarbird were Coleoptera and Hymenoptera. These insects also comprised the main arthropod fauna in P. roupelliae flowers. Bees and ants were recorded in both stomachs of sugarbirds and Protea flowers. Sugarbirds foraged on P. roupe/liae flowers by probing several times into a flower whilst moving clockwise on it. Beetles were taken from flowers and small flying insects hawked from the air. Movement and survival data for 93 individuals were obtained from 553 captured sugarbirds in the Lydenburg area. Recaptures showed fidelity to mountain sites, local movements between mountain sites, seasonal movements and individuals recaptured at the same suburban localities during winter. Peak in occurrence in suburban areas was from late May until early July, coinciding with the flowering season of Aloe arborescens. Sugarbird movements were after the peak flowering periods of P. roupelliae, birds leaving burnt Protea veld after fires and after seasons characterised by low annual rainfall. Annual survival in the Lydenburg area was estimated at 80,7%. Life expectancy was 4,6 years. Two individuals were recaptured after periods of 88 months and one after 74 months. Recapture data suggests a longevity of beyond seven years for this species. This longevity data represents the first of its kind for the species. The conservation of Gurney's Sugarbird and the' management of its Protea roupelliae habitat is a priority. Uncontrolled fires in grassland with P. roupe/liae trees, and logging of wood for fuel, have negative influences on bird and protea populations. The recommended fire regime for P. roupelliae woodland is during dry winter periods (June/July), rotated biennially, or as late winter-spring fires (August/September). The application of regular block burns or firebreaks in montane grassland will ensure less damage to tree canopies during accidental fires.en_ZA
dc.description.abstractAfrikaans: Verskeie aspekte rakende die ekologie van Rooiborssuikervoëls is gedurende die tydperk April 1980 tot Junie 1998 in die Lydenburg-omgewing (Mpumalanga), Sterkfonteindam Natuurreservaat en Qwaqwa Nasionale Park (Vrystaat) bestudeer. Die suikervoëls se verspreidingspartoon oorvleuel met dié van Protea roupefliae in die grasveldbioom langs die Drakensberg-eskarp. Bevolkingsgroottes van suikervoëls en ander nektarvoedende voëlsoorte word beïnvloed deur faktore soos die grootte van bosgroepe, beskikbaarheid van proteas in blom en die effek van grasveldbrande in Protea-veld. Bevolkingsdigthede van suikervoëls was hoër gedurende die winter, lente en vroeë somer wanneer volop blomme beskikbaar is. Suikervoëlmannetjies was betekenisvol groter as wyfies in alle liggaamsmates, behalwe in tarsus-lengte. Beduidende korrelasies het tussen snawel/totale kop-lengtes en vlerk/stert-lengtes tussen beide geslagte en tussen die maksimum breedte van uitranding in die sesde primêre veer (P6) en vlerklengte in mannetjies voorgekom. Maandlikse variasies in liggaamsmassa kom in beide geslagte voor en voëls was die swaarste gedurende die November-Maart broeiseisoen. Volwasse mannetjies met uitgegroeide ornamentele stertvere het ook meestal langer vlerke en breër uidrandings van P6 gehad. Ververing van die primêre vlerkvere vind tussen November-Maart plaas en oorvleuel met die broeiseisoen. Ververing van stertvere vind ook gedurende die tydperk plaas en word vervang sodra hulle verweer raak. Die broeiseisoen was hoofsaaklik tussen September-Maart, met 'n piek gedurende November-Desember in die Lydenburg omgewing. Voorkeur word aan Protea roupelliae-bome as neslokaiiteite gegee, alhoewel P. caffra ook benut word. Neste word binne vyf dae deur die wyfie gebou en die gemiddelde neshoogte was 1,85 m. Die saadpluime van P. roupelliae-blomme word in die neste uitgelê. Die inkubasieperiode is 16-17 dae, nestyd 21-23 dae en na-nesperiode 20-30 dae. Broeisukses is as 41,4% bereken en is hoër as dié van die Kaapse Suikervoël. Suikervoëls voed hoofsaaklik op nektar van P. roupe//iae-blomme en gedurende die winter op Aloe arborescens-nektar in bergklowe, asook in dorpsgebiede. Insekordes van veral Coleoptera en Hemiptera word deur die suikervoëls benut. Hierdie insekte kom ook in groot getalle in P. roupelliae-blomme voor. Bye en miere, wat in blomme voorkom, is ook in die maaginhoude van suikervoëls gevind. Voeding in Protea-blomme vind plaas deurdat die snawel herhaaldelik in die blom ingesteek word om nektar te verkry, terwyl die voël kloksgewys om die blom beweeg. Kewers word vanuit blomme opgepik en klein vlieënde insekte word uit die lug gevang. Seisoenale migrasie- en oorlewingsdata (553 individue gering) is vanaf 93 suikervoëls in die Lydenburgstudiegebied verkry. Hervangstes is hoofsaaklik in dieselfde berglokaliteite verkry, of as bewegings tussen berglokaliteite, seisoenale bewegings en hervangstes gedurende die winter in die dorp. Suikervoëls is tussen laat Mei en vroeg Julie in die dorp waargeneem, wanneer Aloe arborescens in blom is. Seisoenale migrasies was ná die piek blomtyd van P. roupelliae, voëls wat gebrande Protea-veld verlaat en ná seisoene met lae reënval. Oorlewing van die suikervoël-bevolking in Lydenburg was 80,7%, met 'n berekende lewensverwagting van 4,6 jaar. Twee individue is na periodes van 88 maande en een na 74 maande gevang. Hervangsdata dui daarop dat suikervoëls tot meer as sewe jaar kan leef en is die eerste van dié data vir Rooiborssuikervoëls. Die bewaring van Rooiborssuikervoëls en die bestuur van hul Protea roupelliae-habitat is 'n prioriteit. Onbeheerde vure in grasveld met P. roupelliae bome en die versamel van Protea-hout het negatiewe invloede op plant- en voëlbevolkings. Die aanbevole brandseisoen vir P. roupelliae is gedurende die droë winter (Junie/Julie), op 'n twee jaarlikse. rotasie, of as laat winter/lente-brande (Augustus/September). Die toepassing van gereelde blokbrande of voorbrande in berggrasveldgebiede sal dan tydens toevallige brande minder skade aan kroondakke van proteabome veroorsaak.af
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectBirds -- Behavioren_ZA
dc.subjectBirds -- South Africa -- Environmental aspectsen_ZA
dc.subjectDissertation (M.Sc. (Zoology and Entomology))--University of the Free State, 1998en_ZA
dc.titleAspects of the behaviour and ecology of Gurney's Sugarbird Promerops Gurneyi verreaux, 1871, in Protea Woodland, South Africaen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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