Performance, dispersal and demographics of Xenopus in the Cape
For my MSc I worked with two Xenopus species found in the South African Cape; the abundant (and invasive) Xenopus laevis (common platanna) and the IUCN Endangered X. gilli (cape platanna). Xenopus laevis is currently invading the native habitat of X. gilli at an alarming rate. My study aimed to compare the performance, as well as the distribution capabilities of both Xenopus gilli and X. laevis. The second aim of my study was to determine the population demographics for the two X. gilli populations. I also determined the demographics of X. laevis which are invading one of the X. gilli populations. This information will give some insight into the invasion capabilities of X. laevis and it will also help with the conservation efforts of X. gilli.
Graudated March 2016
Niche differentiation and feeding ecology of two sympatric species of Xenopus (Anura: Pipidae) from the Western Cape Province of South Africa
The endangered, endemic Cape Platanna (Xenopus gilli) and the invasive African-clawed Frog (Xenopus laevis) sympatrically inhabit a variety of freshwater habitats across the Western Cape Province in South Africa. In order to quantify the invasive species’ impact on sympatric populations of X. gilli, an assessment of the dietary requirements, patterns of interspecific competition and niche differentiation was conducted.
CIB & Zoologisches Forschungsmuseum Alexander Koenig
With Dennis Rodder
Chameleons on the Cruise: Seasonal differences in prey choice of two dwarf chameleon species (Chameleondae: Bradypodion)
Only chameleons are classified as cruise foragers (an intermediate foraging mode between sit-and-wait and active foraging) but it is not known whether cruise foraging changes seasonally. Seasonal changes were investigated by sampling stomach contents and available prey from two dwarf chameleon species: Bradypodion ventrale (thicket habitat; low altitude) and B. taeniabronchum (fynbos habitat; high altitude) during winter and summer.
Year completed: 2012
Completed at: Nelson Mandela Metropolitan University
Monitoring frog density through calls on Table Mountain
Traditional methods of monitoring frog populations involve estimating the numbers of calling males or marking and recapturing individuals. This project builds on an exciting new method which combines both techniques using an array of six microphones. The aim is to determine the changes in call density of a focal population of Arthroleptella lightfooti on Table Mountain. Our new method represents a way to monitor these and other frogs without the need to disturb them or their habitat. Call data were used to produce density interpolations of calling males, to determine the variation in seasonal call data and would provide insight into the calling ecology of this species.
Year completed: 2012
Completed at: University of Cape Town
Co-supervisors: Res Altwegg (SANBI-UCT)
DST-NRF Internship Position
Placed in the Zoology Department, NMMU
Internship duration: April 2013-March 2014
Mind the Gap: Investigating the current cause of the range disjunction of the common platanna
Xenopus gilli, the Endangered Cape platanna, has one of the most limited distributions of the known Xenopus species and is confined to acid blackwater pools within the Western Cape, South Africa. Xenopus gilli is one of the many organisms in the Western Cape with a disjunct distribution on either side of False Bay. The aim of this study was to investigate the timing and presumed cause of this disjusntion through morphometric and mtDNA analysis.
Year completed: 2011
University of Cape Town
The conservation genetics of a newly recognised Cape Peninsula ndemic: Rose's Mountain Toad (Capensibufo rosei)
Declines and losses of amphibian populations are a global problem involving a complexity of interacting causes and amphibians in Africa are among those predicted to be hit the hardest by anthropogenic global change. Capensibufo rosei, Rose's Mountain Toad, is a range restricted species that survives in a few small, isolated montane populations in the extreme south-western Cape of South Africa. A recent study revealed that C. rosei comprises several cryptic species, but it was uncertain as to whether the lineage on the mountainous Cape Peninsula is endemic. This project aimed to test the hypothesis that toads from the Peninsula are form a single genetic lineage, but are distinct at a population level due to limited dispersal abilities and little if any gene flow.
Year completed: 2011
Completed at: Percy FitzPatrick Institute of African Ornithology
Co-supervisors: Krystal Tolley (SANBI) and Peter Ryan (Percy FitzPatric Institute)
Seasonal and hormonal regulation of the female genital tract in oviparous and viviparous amphibians
Gymnophiona are elongated and burrowing amphibians living in tropical countries. Their reproductive biology is still poorly known and only a few species have been studied. Boulengerule taitanus lives in the cold forests of the Taita Hills, Kenya. This area undergoes two rainy seasons, a long season (March to May) and a shorter season (November to December) during which eggs and juveniles have been observed. In this work, the reproductive cycle of females is described for the first time.
Years: from 2009 to 2014
Universite Catholique de Lyon
Principle Supervisor: Jean-Marie Exbrayat