About the Plenary Speakers

Professor Graham Alexander’s current interests are focused on the importance of snakes as predators. Snakes have an impressive factorial scope in their ingestion rates of prey, and this is likely to translate into a large and immediate functional response to changes in the abundance of their prey. Thus, snakes may be important and underappreciated ecosystem stabilisers in some environments, but this has not been investigated to any extent. Graham is currently conducting research to quantify these ideas and has worked on Southern African Python and Puff Adders for several years. He collaborates with Dr Bryan Maritz to study Cape Cobras and Boomslang, and their predatory impact on Sociable Weavers in the Kalahari. He also heads the Alexander Herp Lab, and carries a heavy undergraduate and postgraduate teaching load. He sits on the Viper Specialist Group, and on the Boa and Python Specialist Group for the Species Survival Commission of the IUCN. He sits on SANBI’s Alien Risk Analysis Review Panel and is a main member of the Steering Committee for the IUCN Southern African Regional Reptiles Specialist Group. He is also a taxon expert for SANBI redlisting initiatives and Threatened species work and consults for the Department of the Environmental Affairs in the formulation of AIS National Lists for NEMBA.

Website: https://www.wits.ac.za/apes/research/alexander-herp-lab/

Professor Hannes Van Wyk started his career as a Herpetologist at the National Museum in Bloemfontein. During this time he acted as Chairman of the HAA and finalized the constitution and HAA administration, as well as helped to organize the first HAA stand-alone conference held at Stellenbosch University. He relocated to Stellenbosch University during 1988 and has been an academic staff member in the Department of Botany and Zoology ever since. Although his early research centred around the ecophysiology (reproductive endocrinology, thermal biology, chemical communication) of lizards, much of his research since 1998 focused on the assessment of endocrine disrupting activity in freshwater systems. Initially, with the focus on estrogenicity, his group developed and validated a yolk precursor, vitellogenin (vtg), as a biomarker for estrogenicity using the African clawed frog (Xenopus laevis), Zebrafish (Danio rerio) and the Mozambique tilapia (Oreochromis mossambicus) as model animals. Although caged frogs were used in rivers and dams in the Western Cape agricultural region to study estrogenic activity (endocrine disruption potentially caused by agrichemical pollution, EDCs), the approach soon shifted to studies of disruption in the androgen and thyroid endocrine systems, mostly focussing on Xenopus laevis. Biomarkers employed evolved to include molecular, histological and physiological/biochemical endpoints used in in vitro and in vivo exposure designs. Prof van Wyk has served on several WRC project Steering Committees, but also on Amphibian expert EDC panels of the OECD and USA-EPA and he was a Co-Editor, and later Editor-in-Chief, of the journal, African Zoology for several years. Currently, his research activities relate to the understanding disrupted endocrine pathways associated to pesticides (including herbicides), crude oil (petroleum products), metals, and pharmaceuticals in fresh water systems. Although officially retiring at the end of 2019, his intention is to pick-up his herpetological research actively publish in this field.


Luke Verburgt is a general Zoologist (MSc. in Zoology), primarily specializing in the field of herpetology. He is co-Director of Enviro-Insight - a company specialising in Environmental Impact Assessments – and a research associate of the University of Pretoria (Department of Zoology & Entomology). Luke has worked throughout Africa and its islands (South Africa [including Marion Island], Lesotho, Zimbabwe, Malawi, Mozambique, Botswana, Madagascar, Uganda, Namibia, Angola, Mali, Guinea and Liberia), undertaking a variety of projects, including biodiversity assessments, critical habitat assessments preparation and implementation of management plans, and monitoring projects. He has published several scientific articles on African herpetofauna including some descriptions of newly discovered species.

Tribute to Bill Branch

Aaron Bauer is past-Chairman of the H.A.A. and a close friend and collaborator of Bill Branch since 1987. Aaron’s tribute traces Bill’s rise from amateur herpetologist to “elder statesman” of the herpetological community and his many achievements as a field naturalist, scholar, populariser, mentor and photographer. Bill contributed significantly to the H.A.A. and to almost every major herpetological initiative in South Africa, and his influence was felt continent-wide. His legacy includes not only the collections he built and his 600+ publications, but also the many lives he touched, both personally and professionally.

Additional plenary speakers to be announced!

Banner Photo: Bitis caudalis, Krystal Tolley