Last month we had a very brief visit, counted in minutes not hours, to Stellenbosch in South Africa. A few days later we were visiting Namibia for a couple of days and for a second time. The Namibian desert with its sand dunes is famous for the ways in which the various species of animals and plants that live there obtain water. The Namib is very different to what many think of as a desert because although it lacks rain it gets regular and small amounts of water delivered to it in the air. In short it is a land of fog and dew. The sea off Namibia is cold by virtue of the Benguela current running north. Thus fog banks form along the coast which are blown into the western part of the Namib. Water vapour condenses on surfaces during the cool night and penetrates the soil during the hot day. We have all seen on television the ways in which some beetles channel condensed water collected on their bodies into their mouths. Snakes lick condensed water collected on their scales. Dune lizards, which occur only in the fog belt of the Namib, by contrast, drink avidly from surfaces and sand but then store water in the expanded caecum for several months. The Hairy-footed Gerbil (Gerbillurus paeba), unlike some other desert rodents, cannot not survive on dried seed alone; it relies on water from the succulent plants that in turn rely on the fog and dew.
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| The only university building we had time to see in Stellenbosch housed the Faculty of Theology |
Namibia and Stellenbosch were connected in my mind because exactly 50 years ago we had a visiting worker in the department, the man who put the desert animals of Namibia on the map. Gideon Louw* spent January to June 1975 working on mammalian thermoregulation with John Bligh. Although the rest of the department did not see much of him, he did come along for a chat several times and we discussed all sorts of things about how all sorts of animals work in all sorts of environments. I remember the impression of a very nice man but deeply troubled by events in his own country. He was, I now learn, then shortly to move from his position as Professor of Zoology in Stellenbosch to the University of Cape Town. Biographers have recorded that Gideon Louw was a founder member of the Progressive Party which was utterly opposed to the apartheid policies being imposed by the government then in power. Stellenbosch was I have also learnt a stronghold of support for the National Party and an uncomfortable place for those opposed to its policies.
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| Gideon Louw |
In an appreciation of the work of Gideon Louw published in 2004, Joh Henschel and Mary Sealy wrote (references omitted):
In hyperarid areas such as the Namib Desert the occurrence of fog and dew plays an important role in the water economy of many desert organisms. This fact was known, particularly through the works of Walter (1936) and Koch (1961), by the time that Louw first visited the Gobabeb Training & Research Centre in the Namib Desert in 1966.
Louw soon recognised that ecophysiological mechanisms were a key towards understanding the relationship between atmospheric moisture and desert organisms. Extensive contributions of this doyen of desert ecophysiology range from water, energy, and salt balance, to thermal biology, conjunctively in terms of physiology, behaviour and ecology. He inspired a generation of students and colleagues to elucidate these mechanisms and their consequences, and later reviewed some of these insights.
Like a number of others working in his field, Louw did not have a first or even a higher degree in zoology. He had started on the animal science of agriculture and his first job was as an agricultural geneticist. Several spells in the USA, including a PhD in endocrinology at Cornell, followed before he returned to South Africa and a personal chair in zoology at Stellenbosch.
Louw’s work in Namibia became well known internationally when he was invited by Geoffrey Maloiy, the organiser, to a Zoological Society of London Symposium ‘Comparative Physiology of Desert Animals’ in July 1971, a meeting I had to miss because of a clash of dates. The published volume is still worth reading since all the major players in the field were contributors and showed the state of play after a major burst of activity that followed World War II.
Gideon Louw did much more than his research on the animals and environment of the Namib including writing several books, while his students have spread across the world and are well-established names in the biological sciences. From the reading I have done it appears that he was appalled by the political violence sweeping South Africa in the early 1990s and retired to Canada. He died on Vancouver Island on 22 March 2004, aged 73.
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| SJP spotted this lizard in the dunes at the deserted mining village of Kolmanskop near Luderitz in Namibia. It is the Common Rough-scaled Lizard(Meroles squamulosa) a psammophilous species closely related to the dune lizard (M. anchietae) studied by Gideon Louw (Noble Caledonia Expedition Team Photograph) |
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| This beetle was on the dunes at Kolmanskop |
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| Lichens on rocks in the desert get their water from the dew |
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| The reason this lichen is so green is that there had been rain sufficient for water from the Swakop River to empty into the Atlantic as in 2011 and 2022 |
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| A wide-angle view from the 'moonscape' viewpoint inland from Swakopmund |
*Gideon Nel Louw, born 24 December 1930 East London, South Africa; died 22 March 2004.
Anon. 2004. Tribute to world-renowned zoologist. University of Cape Town News HERE
Cherry M. 2005. Gideon Louw (1930-2004). South African Journal of Science 101, 399.
Henschel JR, Seely MK. 2004. First Approximation of the Ecophysiology of Fog and Dew – A Tribute to Gideon Louw. Proceedings of the Third International Conference on Fog, Fog Collection and Dew: Cape Town, South Africa, 11-15 October 2004 [no page numbers shown].
Louw GN. 1972. The role of advective fog in the water economy of certain Namib desert animals. Symposia of the Zoological Society of London 31, 297-314.
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