Carla du Toit

BSc (Hons) Cape Town
John Day 5.06

Carla was born and grew up in Johannesburg. Through visiting museums and several game reserves surrounding Gauteng, she developed a passion for dinosaurs which quickly evolved into a love of birds, the only living dinosaurs. She started bird watching on holidays at the age of six, and hasn’t looked down from the sky since. Since starting birding in the highveld, she has continued to pursue the passion across various continents. She spent many hours watching the garden birds in her father’s backyard in the south of England. She moved to the Cape for high school, and acquired her Bachelors degree in Genetics and Ecology and Evolution at UCT in 2015. Her research interests are in sensory ecology and linking morphology to behavioural ecology and palaeoecology.

Her love of all things feathered led her to study Sociable weavers, and their effect on the surrounding arid Kalahari environment for her Honours project in 2016 with Dr Robert Thomson (FitzPatrick Institute) and Prof Mike Cramer (Biological Sciences). The project showed how the small birds were creating “islands of fertility” around their giant communal nests, resulting in unique vegetation patterns.

Carla has finally achieved her childhood dream to combine her love for birds and palaeontology, as her current PhD project is looking at the sensory organs in the bills of African ibises in relation to their feeding ecology, and how these patterns can be used to study the fossil record. Ibises and several other families of probe-foraging birds (kiwi and scolopacid sandpipers) possess a specialised sensory organ in their beaks (a “bill-tip organ”) that allows them to detect high frequency acceleration components of mechanical vibrations in soil and water. The birds can use these signals to detect and locate their prey, which are often invisibly hidden in opaque substrates. Carla has described the organ for the first time in three species of common southern Aftican ibises. Her results have shown that there are clear relationships between the interspecific differences in both bone morphology and soft tissue histology of the bill-tip organ of ibises and each species foraging ecology. This includes links between the structure of the organ and foraging substrate use, foraging behaviour and foraging success using remote-touch. By testing the foraging success of captive Hadeda ibises under different substrate conditions, Carla showed that the species are able to use remote-touch to locate prey more successfully in wet soils compared to dry ones, a pattern that had previously only been hypothesised. Furthermore, this may in part be why the range expansion of hadedas in southern Africa has been so closely linked to increased irrigation of soils by human activity, as it is easier for them to locate prey in wetter soils. Finally, through studying specimens of lithornithid fossils from the Smithsonian Natural History Museum in the USA, Carla has shown that these ancient paleognathous birds (the earliest members of the clade including ratites – i.e., ostriches and kiwi – which evolved during the Cretaceous period over 65 million years ago), also possessed the bill-tip organ characteristic of remote-touch foraging in modern birds. Her results showed how the organ is plesiomorphic in all modern paleognathous birds, including the extinct elephant birds and moa, and is vestigial in all except kiwi.

This project is run through the FitzPatrick Institute and the Palaeobiology group at UCT, and is funded by the DST-NRF Centre of Excellence in Palaeosciences at Wits. Her supervisors are Dr Susie Cunningham and Prof Anusuya Chinsamy-Turan. Carla intends to remain in academia, in both research and teaching, and to continue to work on interdisciplinary studies.


Mechanosensory structures in the beaks of probe-foraging birds in relation to their foraging ecology (Graduated July 2022)


du Toit, C.J., Chinsamy-Turan, A., Cunningham, S.J.. 2020. Cretaceous origins of the vibrotactile bill-tip organ in birds. Proceedings of the Royal Society B: Biological Sciences. 287: 20202322.

Prayag, K.D., du Toit, C.J., Cramer, M.D., Thomson, R.L. 2020. Faunal input at host plants: Can camel thorn trees use nutrients imported by resident sociable weavers? Ecology and Evolution 10 (20): 11643-11656.

Notable popular articles regarding research:

This Unusual Bird Superpower Goes Back to the Dinosaur Extinction. The New York Times.

Bird beak extra sense evolved more than 70 million years ago. New Scientist.