Ecology and habitat suitability of Cape mountain zebra (Equus zebra zebra) in the Western Cape, South Africa

Olivier, Adriaan Jacobus (2019-12)

Thesis (MScConsEcol)--Stellenbosch University, 2019.

Thesis

ENGLISH ABSTRACT: Endemic to South Africa, the Cape mountain zebra (Equus zebra zebra) historically occurred throughout the Western Cape, and parts of the Northern and Eastern Cape. However, due to human impacts fewer than 50 individuals remained by the 1950’s. Conservation efforts over the past 50 years have resulted in the population increasing to over 4700 individuals and having moved on the IUCN red list, from Critically Endangered to Least Concern. As there are still many isolated meta-populations, CapeNature established a Biodiversity Management Plan for the conservation of Cape mountain zebra in the Western Cape. In 2001, 15 (six males and nine females) Cape mountain zebra was reintroduced into Bakkrans Nature Reserve, situated in the Cederberg Wilderness Area of South Africa. More than 17 years after the initial reintroduction, the species have persisted in this arid environment. No long-term monitoring has been carried out on this population of Cape mountain zebra. In this study, the demographics, diet, artificial waterhole dependency and habitat suitability of Cape mountain zebra was investigated. Individual stripe pattern was used to determine Cape mountain zebra demographics. Driving transects and camera traps identified 21 unique individuals (100% of population) of which 19 were adults (90.4%) one was a yearling (4.8%) and one was a foal (4.8%). It was expected that the population would experience an initial lag in population growth where after it would rapidly increase; however, population growth is still very low. Adult Cape mountain zebra on the reserve currently exhibit an extremely male biased sex ratio of 1:0.27 (male:female). Population structure and organization does not display similarities to those of other well-established populations; however, a male biased population structure has been associated with other populations in the Western Cape. In addition, microhistology was used to determine the seasonal dietary preference of Cape mountain zebra. Results showed that Cape mountain zebra in Bakkrans Nature Reserve are mixed feeders as grass contributed to 41.5% of the annual diet, restios 16.4% and dicotyledons 29.3%. Leaf material was preferred annually, while stem, flower and inflorescence use increased during the wet season. Green grasses were preferred annually and were accepted >60% across all seasons. Tallest swards were accepted during the late dry season and shortest in the late wet season. Camera traps were used to study artificial waterhole dependency of Cape mountain zebra. Artificial watering points in the low lying areas were utilized more frequently due to more suitable habitat and higher zebra densities. Waterhole use was highest around dusk peaking at 19:00h and 20:00h. As seasons changed, Cape mountain zebra shifted their preference times to avoid intraspecific competition and accommodate for the earlier and later shifting of dusk. Finally, habitat suitability in Bakkrans Nature Reserve was analysed to determine how suitable the habitat is for a reintroduced population of Cape mountain zebra. Additionally, the suitability of three other reserves, Grootwinterhoek, Limietberg and Matjiesrivier Nature Reserves was tested for the potential reintroduction of Cape mountain zebra. Results confirmed that Bakkrans Nature Reserve has poor habitat suitability for Cape Mountain Zebra as scores were <10 and similar results were found for Matjiesrivier Nature Reserve. Furthermore, the Grootwinterhoek Nature Reserve is also of poor habitat for Cape mountain zebra. Of all the reserves, Limietberg Nature Reserve had the most suitable habitat. Results from this study, have identified issues facing Cape mountain zebra conservation in Bakkrans Nature Reserve as well as the Western Cape and management recommendations were presented.

AFRIKAANSE OPSOMMING: Histories, het die Kaapse berg sebra (Equus zebra zebra) regoor die Weskaap en dele van die noord en Ooskaap in Suid Afrika voorgekom. Alhoewel, as gevolg van impakte deur mense het hul nommers geval tot minder as 60 deur die 20ste eeu. Bewarings pogings oor die afgelope 50 jaar het teogelaat dat die populasie gegroei het tot meer as 4700 sebras en geskuif vanaf die IUCN rooi lys as Krities Bedreiged na Minste Bekommernis. Daar is steeds baie mata-populasies en as ‘n gevolg het CapeNature ‘n Biodiversitiet Bestuursplan opgestel vir die Bewaring van Kaapse bergsebras in die Weskaap. In 2001, was daar 15 (6 mannetjies, 9 wyfies) Kaapse bergsebras hervestig in Bakkrans Natuur Reservaat wat in die Sederberg Wildernes Area, Siud Afrika is. Meer as 17 jaar na die hervestiging, het die spesie sukksesvol voortduur in hierdie dorre omgewing. Voor hierdie studie, was daar geen lang termyn monitering gedoen op die Kaapse bergsebra populasie na die hervesiging. In die studie, kyk ons na die demografie, dieet, mensgemaakte watergat gebruik en habitat geskiktheid van die Kaapse bergsebra. Individuele streep pattroon was gebruik om Kaapse bergsebra demografie te bepaal. Ry transeksies en kamera lokvalle het 21 unieke sebras identifiseer (100% van populasie) waarvan 19 volwassenes was (90.4%), 1 ‘n jaaroud was (4.8%) en 1 ;n vul was (4.8%). Dit was verwag dat die populasie ‘n stadige groei sal ondervind na die hervestiging en daarna vinneg sal groei; alhoewel, populasie groei is nogsteeds stadig. Volwasse Kaapse bergsebras op die reservaat uitstallig ‘n manlike vooroordeling van 1:0.27 (manlike:vroulik). Populasie struktuur en organisasie wys nie ooreenkomste tussen ander sebra populasies nie; alhowel, daar is ander studies wat ook ‘n manlike vooroordeel beskryf in ander Weskaapse populasies. Daarbenewens, mikrohistologiese toetse was gebruik om die seisoenlike dieet van Kaapse bergsebras te bepaal. Resultate het gewys dat Kaapse bergsebras op Bakkrans Natuur Reservaat mengsel eters is. Gras het bygedra tot 41.5% van die jaarlikse dieet, restios 16.4% en kleiner bossies 29.3%. Blaar materiaal was verkies deur al die seisoene, terwyl stingel, blom en bloeisel gebruik vermeerder het gedurende die nat seisoen. Groen grasses was verkies reg deur die jaar en >60% in elke seisoen. Langste grasses was verkies in die laat droe seisoen en kortste in die laat nat seisoen. Kamera lokvalle was gebruik om die watergat afhanglkikheid van Kaapse bergsebras te bepaal. Watergate in die lealiggende areas was die meeste gebruik as gevolg van geskikte habitat ‘n hoer digtheid van sebras. Watergat geruik was hoogste rondom skemer, met spitstye om 19:00 en 20:00. Soos seisoene verander, het Kaapse bergsebras hulle voorkeur tye geskuif om intraspesifieke kompetisie te vermy en te akkommodeer vir die vooruit en agteruit skuif van skemer. Finaal, het ons gekyk na die habitat geskikbaarheir van Kaapse bergsebras in Bakkrans Natuur Reservaat. Daarbenewens, het ons ook die habitat geskiktheid getoets in drie ander reservate naamlik Grootwinterhoek, Limietberg and Matjiesrivier Natuur Reservaat vir die potensiele hervestiging van Kaapse bergsebras. Resultate het bevestig dat beide Bakkrans Natuur Reservaat en Matjiesrivier Natuur Reservaat swak habitat het vir Kaapse bergsebras as gevolg van die habitat geskiktheid indeks toetse wat <10 was. Van al die reservate, het Limietberg Natuur Reservaat die mees geskikte habitat vir die hervestiging van Kaapse bergsebras terwyl Grootwinterhoek Natuur Reservaat ook slegte habitat het. Gebasseer op die vindings van hierdie studie, is kwessies in die bewaring van Kaapse bergsebras in Bakkrans Natuur Reservaat en die Weskaap geidentifiseer en bestuursplanne was aanbeveel.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/107123
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