New investigations at Holly Shelter, KwaZulu-Natal, South Africa.

South Africa is considered to be a key area for the understanding of the history both of Hominins as a group and Modern Humans as a species. Despite this importance, only a limited number of sites attributed to the Middle Stone Age, an important developmental stage for Modern Humans, have been excavated within South Africa, and only six from KwaZulu Natal. The Holly Shelter site on Fountainhill Estate near Wartburg is one of only two such rockshelters in KwaZulu-Natal which are not located in coastal areas, the other being Border Cave, on the western scarp of the Lebombo Mountains. 

Holly Shelter was first investigated by archaeologist Gordon Cramb in the 1950s. The site produced both organic material and stone tools, a combination with the potential to yield a great deal of information about the period using modern techniques unavailable in Cramb's time. Recent re-examination of Cramb's material has suggested that it is similar to the assemblage recovered from Sibhudu Cave, about 40 km to the north of Durban, which would make the material likely to be 50-60 thousand years old, although the site itself has not been dated. 

In a paper published in the South African Journal of Science on 30 November 2022, Gregor Bader of the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen, and Manuel Will of the Department of Early Prehistory and  Quaternary Ecology, also at the University of Tübingen, present the preliminary results of a new investigation at Holly Shelter, which aimed to establish whether there are any intact archaeological deposits left at the site, whether the site features a discernible stratigraphic sequence which can be dated, is there any useful preservation of organic remains at the site, and whether distinct techno/typological units can be identified within the stratigraphic sequence.

(a) Location of Holley Shelter and other archaeological and palaeoenvironmental sites mentioned in the text.  (b) Three-dimensional model of the site produced with Agisoft Metashape Professional. Gregor Bader in Bader & Will (2022).

In the early 1950s Gordon Cramb excavated two areas close to the entrance of Holly Shelter, uncovering two distinct layers of occupation, the upper one producing a Later Stone Age technology, and the lower a Middle Stone Age technology, including bone tools. Bader and Will refrained from carrying out excavations close to this area, as there are now several large rock slabs lying on the surface here. Cramb's later investigations concentrated on an are further north, and deeper within the cave, an area which Bader and Will also concentrated on, as it was clear of large surface debris, and appeared more likely to yield a full stratigraphic sequence, excavating two new test trenches.

Excavation plan of Holley Shelter. Cramb Exc. 1 and 2 mark the areas of Cramb’s excavations in the 1950s. Exc. 1 was described by Cramb as the ‘Smaller habitable area’, Exc. 2 as the ‘Larger habitable area’. Green squares were excavated in 2022. Gregor Bader in Bader & Will (2022).

Both of Bader and Will's new trenches confirmed the existence of layered archaeological remains. The northern trench produced an upper layer of disturbed soil 5-10 cm thick, beneath which was a layer of orange-brown sandy silt, with charcoal inclusions. This layer contained several small hearths (former fire sites) as well as Middle Stone Age stone artefacts, predominantly made from hornfells, and a significant amount of faunal remains. Beneath this was a grey sandy silt layer. At the southern site this grey sandy silt produced a large hearth which covered most of the excavated area, as well as a large number of stone artefacts, including numerous splintered pieces similar to the ones identified in the Cramb collection, unifacial points, and frequent blades and points with faceted platforms. This layer also produced a lot of faunal remains, along with large charcoal fragments and Plant fossils. In both layers the finds were concentrated at the hearth sites, with little material in the surrounding area.

(a) West-profile of the northern section with layers redrawn, (b) west-profile of the northern section (original), and (c) three-dimensional model of the northern section at the end of the 2022 excavation season. Gregor Bader in Bader & Will (2022).

The lithic assemblage recovered by Cramb contained a high proportion of modified tools compared to debitage (flakes). This was previously assumed to be bias on the part of the mid-twentieth century archaeologist, who was operating at a time when the importance of small flakes was less well understood, and these were commonly overlooked. However, Bader and Will's assemblage contains a similarly high proportion of large tools, with  splintered pieces and unifacial points being the most common items in both collections. 

Artefacts from the lower layer in the northern section at Holley Shelter: (a)–(c) unifacial points, (d)–(f) splintered pieces, (g), (h), (k), (m), (n), (o) identifiable faunal remains, (i), (j) bone flakes, (l), (p) bones with cutmarks. Gregor Bader in Bader & Will (2022).

Bader and Will's excavations revealed a clear stratigraphic sequence at Holley Shelter, with archaeological evidence including material excellent organic preservation and clearly delineated anthropogenic hearth features. The sedimentology of the tool-bearing layers clearly matches Cramb's original description, as does that of the underlying layers, providing support for the accuracy of Cramb's descriptions.

The low proportion of debitage to finished tools, particularly when compared to assemblages from coastal sites in KwaZulu-Natal, suggests that the tools were not being manufactured on site, and the combination of these with the presence of multiple small hearth features, suggests that the site was repeatedly used as a location for short stays, while the coastal sites were likely to be more permanent settlements.

Bader and Will uncovered numerous pieces of charcoal from both artefact-producing layers at Holley Shelter, which opens the potential to establish a timeline for the site based upon radiocarbon dating. The excellent preservation of much of the organic material recovered from the site also has the potential to reveal much about the climate and ecology of the interior of KwaZulu-Natal during the Late Pleistocene, data which is at present not available. Furthermore, the archaeological evidence has much to tell us about the people living in this area at the time, and how they interacted with the wider environment.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.

Latimeria chalumnae: A live Coelocanth seen living off the KwaZulu-Natal South Coast, South Africa.

When a living coelacanth was trawled off East London, South Africa, at a depth between 72 m and 100 m on 22 December 1938, it caused an international sensation. The specimen was saved for science by the young curator of the East London Museum, Marjorie Courtenay-Latimer and identified by JLB Smith of Rhodes University College. Smith named it Latimeria chalumnae, after Courtenay-Latimer and the river off which it was caught. JLB Smith, who was a keen angler and had an excellent knowledge of Fish anatomy, behaviour and habitat preferences, predicted that the East London Fish was a stray from relatively shallow rocky reefs further north on the tropical east coast of Africa. Latimeria chalumnae has since been found in the Comoros (over 200 specimens), Mozambique (one specimen), Madagascar (over 13 specimens), Kenya (one specimen), and Tanzania (over 70 specimens), and a colony was discovered in the iSimangaliso Wetland Park in northern Zululand, South Africa, in 2000. Another species of living Coelacanth, Latimeria. menadoensis, was found on the other side of the Indian Ocean off North Sulawesi Island in Indonesia in 1997.this species is smaller than Latimeria chalumnae and its body, which is also covered with white spots, is brown rather than blue.

In a paper published in the South African Journal of Science on 26 March 2020, Michael Fraser of Pumula in KwaZulu-Natal, Bruce Henderson and Pieter Carstens of Somerset West in Western Cape Province, Alan Fraser, also of Pumula in KwaZulu-Natal, Benjamin Henderson and Marc Dukes, also of Somerset West in Western Cape Province, and Michael Bruton of the South African Institute for Aquatic Biodiversity, describe the sighting of a living Coelocanth, Latimeria chalumnae, off the KwaZulu-Natal South Coast Region, and present a review of Coelocanth sightings off the African coast and in the western Indian Ocean.

The first scientist to observe a living Coelacanth was Jacques Millot of France who briefly examined a dying immature female Fish (142 cm, 41 kg) in a flooded wooden boat at Mutsamudu on Anjouan Island in the Comoros in 1954. The Fish was captured at 8.00 pm on 12 November 1954 and was kept alive in the sunken boat from about 11.30 pm until 3.30 pm on 13 November 1954. The Fish was stressed and exhibited only feeble movements.

Several Coelacanths that were subsequently caught by traditional fishermen in the Comoros (mainly Grand Comoro), and brought to the attention of scientists, survived for periods of 1–42 hours, (usually less than 11 hours), near the water surface where they could be observed by divers.

Hans Fricke and his team from Germany were the first to study the living Coelacanth in detail from their research submersible Jago. They compiled an extraordinary data series on the living Coelacanth in the Comoros spanning 21 years and including 145 specimens that had been individually identified using the unique patterns of white spots on their bodies.

On 28 October 2000, mixed-gas divers Pieter Venter, Peter Timm and Etienne le Roux discovered Coelacanths living at a depth of 104 m in Jesser Canyon at Sodwana Bay in the newly proclaimed iSimangaliso Wetland Park in Maputaland; the shallowest sighting of Coelacanths at that time. On 27 November 2000 they filmed three coelacanths at a depth of 106 m in Jesser Canyon. These discoveries led to the establishment of the African Coelacanth Ecosystem Programme in April 2002 which aimed to initiate and promote a new phase of multidisciplinary research on the coelacanth and its habitats.

The South African Institute for Aquatic Biodiversity in Makhanda (previously Grahamstown) was appointed as the lead organisation for African Coelacanth Ecosystem Programme, which has been carried out in three phases: 2001–2006, 2007–2011 and 2012–2015. From 2002 to 2004, Professor Hans Fricke and his team returned to South Africa with the Jago submersible to study Coelacanths in the iSimangaliso Wetland Park from the FRS Algoa as part of African Coelacanth Ecosystem Programme. They carried out 47 survey dives with a total bottom time of 166 hours at depths ranging from 46 m to 359 m. Initially, 24 Coelacanths were identified in three submarine canyons at depths from 96 m to 133 m along a 48 km stretch of coast in the iSimangaliso Wetland Park. This number was later increased to 32 individuals. Over time the African Coelacanth Ecosystem Programme extended its research programme further north into other countries in East Africa and the Western Indian Ocean Islands using the FRS Algoa and other motherships, the Jago submersible and a Sea-Eye Falcon underwater remotely operated vehicle.

On 15 February 2004, mixed-gas diver Christo van Jaarsveld observed a coelacanth at a depth of about 54 m in Diepgat Canyon south of Sodwana Bay in the iSimangaliso Wetland Park. This sighting is the shallowest on record for a healthy adult Coelacanth and was the 19th specimen known from the iSimangaliso Wetland Park, but it has not been seen again. Christo van Jaarsveld has subsequently seen and filmed another specimen on 7 August 2018 in the iSimangaliso Wetland Park; this Fish has also not been seen since.

At about 9.00 am on 22 November 2019, a team of divers observed and filmed a single Coelacanth at a depth of 69 m off the village of Umzumbe (between Hibberdene and Pumula) on the South Coast of KwaZulu-Natal. This site is about 325 km south of the iSimangaliso Wetland Park. The divers, Mike Fraser and Alan Fraser from Pumula and Bruce Henderson and Pieter Carstens from Somerset West, launched from the Injambili launch site at Pumula, with Benjamin Henderson and Marc Dukes acting as surface support in the boat. Bruce Henderson and Pieter Carstens used open circuit trimix and Mike and Alan Fraser used rebreathers with trimix diluent.

Coelacanth off Pumula on the KwaZulu-Natal South Coast, South Africa, on 22 November 2019. Bruce Henderson in Fraser et al. (2020).

Mike and Alan Fraser are keen anglers and have fished the reef on which the Coelacanth was found for many years. They are also avid scuba divers who have been using AP diving rebreathers for the past 9 years and are familiar with the underwater terrain on this coast. Mike and Alan Fraser had previously speculated that the Umzumbe River Canyon would be an ideal place to spot a Coelacanth, because the caves and cracks seen on the sonar would offer good shelter from predators.

The reef on which the dive took place (the longitude and latitude coordinates for the discovery site are known but are being kept confidential in order to safeguard the Coelacanth) is about 1 km from the continental shelf edge and is washed by strong currents. The Coelacanth was first found by Alan Fraser who was swimming ahead of the other divers. On the video recorded during the dive he can be heard shouting for Bruce Henderson, who had the GoPro 7 video camera with a 150 m underwater housing. The maximum depth of the dive was 72 m and the total bottom time 15 minutes, of which about half was spent with the Coelacanth. Bruce Henderson filmed the Coelacanth at a depth of 69 m.

This is the original footage of the Coelacanth discovered off the coast of Pumula at 70m on 22 November 2019. It was filmed by Bruce Henderson and discovered by Alan Fraser. They were accompanied by Mike Fraser and Pieter Carstens. Ben Henderson and Marc Dukes were the top men for the dive. Wreckless Divers/YouTube.

The single Coelacanth that was sighted remained relatively motionless under an overhang despite the attentions of the four divers and their strobe lights. It maintained a head-down position, slowly moving its paired fins. Although the epicaudal ridge along the middle of the tail was prominent, the fin rays on the epicaudal lobe of the tail fin did not extend beyond the curve of the rays on the dorsal and ventral portions of the fin, as in the second Coelacanth, which JLB Smith initially thought was a separate species.

The size of the Coelacanth was estimated to be 180–200 cm and about 100 kg by comparing its dimensions with those of the divers, although it is difficult to estimate a Fish’s size accurately under water. It would almost certainly have been a female individual as male Coelacanths rarely exceed 150 cm in length.

This estimated size is comparable to the largest Coelacanths on record which include a 179 cm, 98 kg female caught off Pebane in Mozambique, a 183 cm female caught off Mutsamudu, Anjouan, a 187 cm, 85 kg individual caught off Toliara in Madagascar, and a 190 cm female caught off Chiconi, Anjouan.

What is the significance of the Pumula coelacanth discovery? It indicates that Coelacanths live along our coast further south than the iSimangaliso Wetland Park in Maputaland and raises the possibility that they may live elsewhere along the KwaZulu-Natal coast and even further south along the Transkei coast into the Eastern Cape. If this is the case, then the first Coelacanth that was caught off East London over 80 years ago may not have been a stray but a member of a resident population. Instead of being washed southwards from the tropics by the south-flowing Mozambique current, as JLB Smith had suggested; Coelacanths may have moved purposefully over time into suitable habitats further south than their optimal range in the tropics.

Dives conducted using the research submersible Jago off the Eastern Cape coast near East London and Port Elizabeth in 1991 by Hans Fricke, Jurgen Schaüer, Mike Bruton and others revealed that underwater habitats there were suboptimal, with only small overhangs and no deep caves. On these dives large ambush predators, such as the Wreckfish, Polyprion americanus, seemed to fill the Coelacanth’s niche.More suitable habitats for Coelacanths along the Eastern Cape coast have since been found in the Chalumna Canyon by Kerry Sink of the African Coelacanth Ecosystem Programme using remotely operated vehicles near the capture site of the first specimen in December 1938.

The depth preferences of Coelacanths throughout their range extends from about 54 m to over 800 m, shallow by marine standards as the average depth of the ocean is 3688 m. The Pumula Coelacanth record is therefore the second shallowest yet recorded for a healthy, non-pregnant adult Coelacanth. Coelacanth specimens, and the data associated with their capture, are well documented; the latest edition of the Coelacanth inventory compiled by Rik Nulens for the Coelacanth Conservation Council lists 323 specimens caught to date.

Dead or dying Coelacanths, some with their guts full of plastic, one with a Tetradon Blaasop Pufferfish stuck in its mouth, have been found floating at the water surface off Tanzania. A large Coelacanth (179 cm, 98 kg) pregnant with 26 pups, was caught between 40 m and 44 m on the continental shelf off Pebane in northern Mozambique in August 1991.

The discovery of a Coelacanth at a depth of only 69 m off Pumula (and at 54 m in the Diepgat Canyon) suggests that they may live shallower than previously thought, at least at the southern end of their range, which means that they may be more accessible to mixed-gas divers, as well as to shallow-water remotely operated vehicles and research submersibles, for study. Many aspects of Coelacanth biology and behaviour have not been documented, including whether they guard their young after birth and the diet and habitat preferences of the young.

The shallower depths at which Coelacanths appear to live off South Africa, compared to the Comoros, Tanzania or Madagascar, may be a consequence of their relatively low tolerance of high water temperatures and low oxygen saturations. As oxygen saturations are lower in warmer water, they may tend to live deeper in the warmer waters of the tropics and shallower in the cooler subtemperate waters off South Africa’s east coast. Mike Fraser has reported that, although the surface water temperature on the day of the discovery (22 November 2019) was about 25 °C, there was a marked thermocline at about 15 m from the bottom where the recorded temperature fell to 17 °C.

The discovery of a living Coelacanth off the South Coast of KwaZulu-Natal also reveals how little we know about marine life off our coast, despite intensive research, increasingly intense deep diving ventures and longterm commercial and recreational fishing pressure. That Coelacanths have been living undiscovered off the heavily fished south coast of KwaZulu-Natal, despite the high profile of the Fish over the past 80 years, suggests that many remarkable discoveries remain to be made in our oceans.

The African Coelacanth Ecosystem Programme and other programmes that promote and facilitate multi-disciplinary research in our marine environment should therefore continue to receive priority financial and logistical support, and recreational divers should be encouraged to collaborate with scientists so that their valuable observations can be included in the scientific dialogue. More effort should also be made to create organised platforms that make it possible for ‘citizen scientists’, especially deep divers, to participate meaningfully in scientific research. The possibility of creating an offshore Marine Protected Area off Pumula, without unduly impacting on the activities of recreational anglers, also needs to be considered.

See also...

Follow Sciency Thoughts on Facebook.

South African Police arrest five suspected Rhinocerous poachers.

Five suspected Rhinoceros poachers have been arrested by the South African Police Service in a raid on a property in the town of Hazyview in Mpumalanga Province  on Friday, 4 October 2019. The five men, reported to be between 29 and 52 years old, were wanted in connection with a number of incidents around Ntambanana and Esikhaleni in KwaZulu-Natal during 2018 in which a number of Rhinoceros were killed and their horns removed. Two hunting riffles were also seized during the raid. The men have been remanded in custody till Friday 11 October when they will appear before magistrates for a bail application.

Two riffles seized by South African Police during a raid on a property in Hazyview, Mpumalanga Province in which five suspected Rhinoceros poachers were arrested on 4 October 2019. South African Police Service.

Park authorities and private game reserves across Africa and Asia have been struggling with the problem of Rhino poaching for decades, but the problem has become more acute in recent years, with over a thousand killed in South Africa alone in 2017, and over 5500 in the past five years. The country is home to about 20 000 Rhinos, about 80% of the entire African population. The crime is extremely profitable, and widely believed to be controlled by organised crime syndicates, which are thought to have considerable influence over police and court officials in many areas, which results in suspected poachers often being released before they are brought to trial, often with only nominal bail payments.

South Africa is home to two Rhinoceros species, the Black Rhinoceros, Diceros bicornos, and the Southern White Rhinoceros, Ceratotherium simum simum.

The Black Rhinoceros is considered to be Critically Endangered under the terms of the  International Union for the Conservation of Nature's Red List of Threatened Species, almost entirely on the basis of the threat presented by poachers. The species formerly roamed across much of Central, East and Southern Africa, but has been wiped out in many areas. The total population is thought to have been about 850 000 in 1900, but to have dropped to about 2410 by 1995. Since then the population has benefited from careful management and protection from poachers, and reaches 4880 in 2010, though this means that many populations are living in carefully managed environments rather than being truly wild and free-ranging.

The Southern White Rhinoceros is currently the most common and widespread type of Rhinoceros, with a population estimated at between 17 212 and 18 915 individuals by the conservation organisation Save the Rhino. The species is also found in Botswana, Kenya, Namibia, Swaziland, Zambia, Zimbabwe, and Uganda, but around 90% of the population  is located in South Africa, making efforts to protect the species there critical to its long term survival. The Southern White Rhinoceros is currently classified as Near Threatened on the Red List of Threatened Species.

See also...

Follow Sciency Thoughts on Facebook.

Investigating Crocodile attacks in South Africa and eSwatini.

Conflicts between Humans and animals present a major challenge in conservation work, particularly where animals are prone to attacking Humans or livestock. The most common perpetrators of such attacks in Africa are Crocodiles, with two species, the Nile Crocodile, Crocodylus niloticus, and the West African Crocodile, Crocodylus suchus, together coming the overwhelming majority of wildlife attacks on the continent. Nile Crocodiles are particularly dangerous, with the largest males reaching around five metres in length, and a diet that includes animals such as Wildebeest, Connochaetes spp., and Buffalo, Syncerus caffer, species which it requires considerable strength to subdue. Crocodiles are extremely versatile in their environmental tolerances; they are semi-aquatic, but dwell in a range of habitats from large, fast flowing rivers to small ponds, and have quickly colonised Human-made environments such as canals, dam lakes and even irrigation ditches, creating extra opportunities for conflict with Humans. Despite the obvious hazards presented by Crocodiles, there have been very few organised studies of their behaviour and conflict with Humans.

In a paper published in the journal Orynx on 11 July 2019, Simon Pooley of the Department of Geography at Birkbeck University of London, the School of Life Sciences at the University of KwaZulu-Natal, and WildCRU at the University of Oxford, Hannes Botha of Scientific Services at the Mpumalanga Tourism and Parks Agency, and the Department of Biodiversity at the University of Limpopo, Xander Combrink of the Department of Conservation Science at the Tshwane University of Technology, and George Powell of the Department of Life Sciences at Imperial College London, present the results of a study of reported attacks on people by Nile crocodiles in South Africa and eSwatini (Swaziland) during the period 1949-2016.

Nile Crocodiles, Crocodylus niloticus. AFP/Getty Images.

The study area included north-eastern South Africa, including the warmer, low-lying (lowveld) region of the interior confined mainly to Limpopo and Mpumalanga Provinces, and northern KwaZulu-Natal Province, and the lower-lying warmer areas of eSwatini. Nile crocodile distribution in the region is limited to the warmer, summer rainfall regions of these countries, with the hot and wet season (with minimum temperatures above 15°C) during October–March (November–March in the interior of South Africa). Most of the rivers flow eastwards, from the central plateau and eastern escarpment to the Indian Ocean.

North-eastern South Africa and eSwatini (Swaziland), with the provinces of South Africa, key protected areas, rivers in which Crocodile attacks have occurred, and the locations of fatal and non-fatal attacks. Dams shown on the map are: (1) Makuleke Dam, (2) Middle Letaba Dam, (3) Flag Boshielo Dam, (4) Rust de Winter Dam, (5) Loskop Dam, (6) Driekoppies Dam, (7) Pongolapoort Dam, and (8) Goedertrouw Dam. Pooley et al. (2019).

The political landscape, and therefore land use, in South Africa changed radically over the period of the study. From 1949–1992 South Africa’s black African majority was persecuted under the system of Apartheid, with resettlement in remote rural homelands with poor land and few jobs, and men working in cities as migrant labourers. This system kept two-thirds of the population rural (some of them more likely to encounter crocodiles) until the early 1980s, when Apartheid began to fail. Apartheid influx laws were defied, and urbanisation accelerated, especially after an African National Congress-led government came to power in 1994. Employment in the agricultural sector is now low (5.6%) and declining, with unemployment much higher in rural areas. Census data from the Apartheid era are considered to be highly questionable, and the borders of magisterial districts varied
across the study period, and estimates of human population density exist only at a coarse scale.

eSwatini is a small, stable absolute monarchy with a largely rural population. The population increased sixfold during the study period. eSwatini is categorised as a lower middle income country, and the majority of Swazis are poor, with an estimated 70% of the population employed in subsistence farming. Many Swazis depend on rivers for water, for drinking, cooking and washing.

There are naturally occurring wild Nile crocodiles as far south as the Zinkwazi River in South Africa but the major viable populations are restricted to three disjunct protected areas: the eight large seasonal and perennial rivers traversing Kruger National Park in Limpopo and Mpumalanga provinces; and in KwaZulu-Natal Province, in Ndumo Game Reserve and the Lake St Lucia estuarine system.

A Nile Crocodile in the Kruger National Park. Trover.

Crocodile abundance in Kruger National Park peaked in the early 1990s and then declined during 1993-2000, but has since increased to an estimated 4300 individuals more than a metre in length. This is despite die-offs since 2008, caused by the nutritional disease Pansteatitis (Yellow Fat Disease). In Limpopo and Mpumalanga provinces, outside the Park just over 600 individual Ceocodiles were counted in the 1980s, most under three metres in length, with breeding populations in the Olifants, Limpopo, Luvuvhu, Komati and Blyde rivers. By the end of the study period only the 12.8 km² Flag Boshielo Dam on the Olifants River retained a viable Crocodile population outside Kruger National Park in Mpumalanga Province, and this population declined by 27% following the raising of the dam wall by5 m in 2006.

In northern KwaZulu-Natal Province, populations declined after World War II as a result of hunting and snaring, as well as habitat destruction and water shortages caused by the expanding agriculture and forestry sectors. A Crocodile restocking program was started in 1966 by naturalist and conservationist Tony Pooley, and legal protection for Crocodiles introduced in1969, resulting in a significant population recovery by the 1990s. However, the Ndumo Game Reserve population decreased by 38% during 1993-2000, possibly because of an increase in illegal killings and disturbance facilitated by the removal of the eastern boundary fence in May 2008, and in 2009 the population stood at 536 Crocodiles.

Lake St Lucia estuarine system in northern KwaZulu-Natal was restocked with juvenile Crocodiles during the period 1967-1976. The first aerial survey of Crocodiles in the lake in 1976 found a population of 356 animals more than a metre in length, and by 1993 this had risen to 975. The population remained stable until 2008 but has since declined, possibly as a result of prolonged drought.

A Nile Crocodile on the shore of Lake St Lucia. iSimangaliso Wetland Park.

With the exception of the 132 km² Pongolapoort Dam in KwaZulu-Natal declines have been reported for all major crocodile populations in South Africa. As a result, Nile crocodiles are categorised as Vulnerable in the country.

In eSwatini, extensive habitat has been converted for agriculture, and illegal hunting remained rife into the 1980s. In 1992 King Mswati III ordered a new draft of the Game Act, which introduced the
first legal protection for Crocodiles outside protected areas. No Crocodile population data are available for eSwatini, but the species is considered to be Vulnerable there.

Ezemvelo KZN Wildlife is the responsible authority in KwaZulu-Natal, South Africa. They remove rather than kill Crocodiles whenever possible, and do not erect or maintain protective structures, or pay compensation for attacks outside protected areas. The Mpumalanga Tourism and Parks Agency and Limpopo Province’s Department of Economic Development, Environment and Tourism deal with attacks in the interior. Crocodiles are protected under provincial conservation legislation.

In Mpumalanga problem crocodiles are trapped and released in either the Loskop Dam or Flag Boshielo Dam, or sold to commercial farms. The Limpopo authorities have issued tenders licensing trophy hunters to control damage-causing Crocodiles but few have been destroyed in this way. Fences have been built at some dams.

Ezemvelo KZN Wildlife Conservation Manager Mpume Ngcobo, of the St Lucia Crocodile Education Centre, releasing hatchlings into the protected kuNkazana Stream within the Eastern Shores section of the iSimangaliso Wetland Park. iSimangaliso Wetland Park.

In eSwatini, Big Game Parks is mandated by the office of the King to manage wildlife in the royal parks and outside protected areas. Their policy is to capture and remove confirmed problem crocodiles. No protective structures are built, and compensation is not paid.

Information on attacks by Nile crocodiles was obtained from the personal archives of conservationists Tony Pooley and Ian Player, the St Lucia Crocodile Centre, and the Times of Swaziland archive in Mbabane, eSwatini. Pooley et al. newspaper reports (print and online), journals and popular magazines, using the search term ‘crocodile’ paired with ‘attack’, ‘bite’ or ‘victim’, in English and Afrikaans.

Only details of attacks by wild crocodiles that resulted in injury or death were included. Alleged attacks that were not witnessed or that lacked forensic proof were excluded. Fatal attacks include attacks from which victims died later as a result of injuries sustained. Demographic categories for age
were child (under 16 years) and adult (16 years or older); sometimes exact age data were missing but victims were described as children or adults, and five year age categories were used for cases for which exact age data were available.

Crocodile attacks prior to 1949 were excluded because of a paucity of reliable data. It is likely that during the study period some attacks involving minor injuries went unreported. In remote regions, particularly areas to which people were relocated by Apartheid authorities, some serious attacks may have gone unreported.

A Nile Crocodile in eSwatini. Günther Eichhorn/Mlilwane Wildlife Sanctuary.

The literature searches returned 132 print newspaper stories and six magazine features for South Africa, and fifteen print newspaper stories of attacks in eSwatini. Sixteen online stories were retrieved through Google searches and searches of digital archives of five South African newspapers (in English and Afrikaans), and nine stories from the digital archives of two Swazi newspapers. Tony Pooley’s archive included personal records of 73 attacks in the study region, and Ian Player’s archive included 15 newspaper reports of attacks.

Overall the dataset comprises 214 crocodile attacks for the period 1949-2016: 185 attacks in South Africa and 29 in eSwatini. In South Africa, attacks have been recorded in 13 district municipalities but only five districts have more than five attacks recorded.  The majority of crocodile attacks occurred in natural water bodies with 50% of attacks in rivers or streams, 15% in lakes or pans, 3% in the St Lucia estuary, and 1% in wetlands, while 8% of attacks occurred in in dam lakes of various sizes, and 2% in canals or drains. The location of one attack was not given in the reports.

Crocodile attacks seemed to be closely related to season, with attacks far more common in the warm wet summer than in the cool dry winter. Three possible explanations for the seasonality of Crocodile attacks have been previously proposed: (1) increased Crocodile dispersal and encounter rates resulting from high rainfall and water levels, (2) Crocodiles are ectothermic and thus more active when it is warmer, and (3) increased aggression during the breeding season, Pooley et al. found that Crocodile attack incidence tracks high mean water levels (where data exist) and high monthly mean rainfall (particularly in the interior of South Africa), but that there is no significant relationship between individual attacks in the study region and high rainfall and water-level conditions recorded for dates of attacks only. They also note that previous studies have suggested that Crocodile attacks are more common in the dry season in neighbouring Mozambique.

A Crocodile in the Kruger National Park. flowcom/Flikr/Wikimedia Commons.

Monthly mean daily temperature is the strongest environmental predictor, with most attacks occurring at temperatures of at least 16°C. This effect of temperature could be explained by Crocodiles’ decreased physiological maintenance costs under cooler conditions and, conversely, increased activity levels and food requirements under warmer conditions.

The seasonality of crocodile attacks cannot be explained based on biophysical variables and Crocodile behaviour alone because of the overlap between Human and Crocodile activity (e.g. the seasonality of aquatic activity of both Crocodiles and people). Nearly half of attacks in the study region occurred on weekends and holidays, suggesting Human activity patterns are influential. Although the climate varies slightly between the interior and the coastal regions where crocodiles occur, the peak attack season is the same, December to March.

More data on local behaviour patterns of Crocodiles and people in hotspots for Crocodile attacks would contribute to more effective mitigation measures. For instance, it is known that Crocodiles congregate in lakes in Ndumo Game Reserve and on the eastern shores of Lake St Lucia in winter. Larger individuals disperse outside the protected areas or around the lake system in the summer. Thus in recreational areas around the Lake St Lucia system, notably the estuary, there are seasonal overlaps between the distributions of larger Crocodiles and people.

Nesting Crocodiles on the cliffs at Pongolapoort Dam, Northern KwaZulu-Natal. Champion (2010).

One hundred and ninety records include the activity the victim was engaged in when the attack occurred. Of these, most victims (29%) were attacked while swimming or bathing, followed by fishing (22%), doing domestic chores at the water’s edge (18%), crossing the water (16%), or other (13%). 65% of the victims of Crocodile attacks were male, and 45% female. Of the 139 reports including exact age information, 68% attacks (49%) were on adults (aged 16 years or older), and 71 attacks (51%) were on children (under 16 years). A greater proportion of the attacks on children were fatal (54%), compared with adults (35%).

The finding that it is mostly males that have been attacked in this region contradicts the assumption that in Africa women and girls are disproportionately at risk because of their domestic tasks at the water’s edge. The numerous attacks on females, most performing domestic chores, along the Pongola floodplain system in the 1960s and 1970s are atypical. Census data reveal a higher proportion of women than men resident in this region in this period, with men away working as migrant labourers. Pooley et al.s data show that domestic chores have been a less important factor in the wider region since around 2000, reflecting both the Crocodile’s contracting range and improved water provision in some rural areas.

A key finding is that 51% of victims were aged 0-15 years. That 62% of victims were aged 0-20 and the largest adult category was 21-30 (19%) may simply reflect the demography of the country (median age 26). Nevertheless, the high proportion of children, especially aged 11-15 years, 72.5% of whom were boys, suggests this should be a focus for concern and education.

The overall fatality rate from attacks was 49%, however, 57% of attacks on children (0-15 years) were fatal and 54% of victims aged 0-20 years were killed, in comparison with 40% of attacks on those aged at least 21 years. Fatality rates were influenced by whether the victim was accompanied or alone, and the size (length) of crocodile involved, as well as the size of the victim. Smaller victims (children) are more vulnerable to fatal attacks. Pooley et al. found that, of those adults who escaped death, 43% (22) escaped without help and 43% (22) were rescued, whereas only 35% (11) of children escaped unaided and 65% (20) were rescued.

Only 15 crocodiles involved in attacks were measured accurately, and therefore size data could not be used as an accurate variable. Furthermore, most Crocodile counts have been made from fixed-wing aircraft, so there are no general data on the size of Crocodiles to facilitate comparison of the number of fatal attacks with the proportion of large Crocodiles in wild populations. Comparing the length of crocodiles with fatality/non-fatality outcomes is complicated by age and size of victim, and whether there were rescuers present. Better data would be required to assess the relationship between size and deliberate attacks on people by Crocodiles in this region, although data from Alligators and Saltwater Crocodiles suggest that individuals measuring more than 1.8 m can inflict serious injuries, and individuals measuring at least 2.4 m carry out fatal attacks.

Overall, most victims were swimming, bathing or fishing, but desegregating data on activity of victim when attacked by age and gender reveals distinct profiles. Pooley et al.'s data show that until the 1980s most victims were performing domestic chores or crossing water when attacked, but since then these activities have been superseded by swimming and fishing.

Pooley et al. make several recommendations on how the risks associated with living with Crocodiles in South Africa and eSwatini could be mitigated in the future. For high risk areas there are a number of mostly low-cost actions that can be taken. Local authorities could facilitate safe water crossings, and safe access to water for swimming (particularly near rural schools) or domestic needs, including alternatives such as water tanks, piped water and protective enclosures. Provincial conservation authorities and district municipalities could create, equip and train teams to capture and remove problem Crocodiles. Where such teams already exist, it would be helpful to make them known to the public. If departmental resources are limited, a system of licensing private individuals (as in the USA) could be trialled. Some commercial Crocodile farmers already provide this service on an ad hoc basis. Removing Crocodiles requires the creation of clear protocols for disposing of captured Crocodiles.

Educating children should be a priority, particularly in identified high-risk areas. Outreach activities could be supported with existing materials that provide information on crocodile biology and behaviour, their ecological and conservation importance, as well as advice on avoiding and responding to attacks.

Provincial conservation authorities should appoint knowledgeable spokespersons to brief the public in the event of a Crocodile attack (or alleged attack). The accuracy of reporting would be improved by keeping detailed records of attacks, and building better communication between police, coroners and conservation authorities to ensure accurate information on causes of death are reported. In South Africa,where Crocodiles are farmed but not ranched (i.e. captive bred but not sourced from the wild) and there is no link between farming and the country’s wild populations of Crocodiles, and in a region where taboos against the eating of Crocodiles have recently been overturned, tolerance for wild Crocodiles should not be taken for granted.

See also...

Follow Sciency Thoughts on Facebook.

Poacher killed in shootout with specialist Anti-Poaching Unit in KwaZulu Natal, South Africa.

A poacher was killed and another injured in a shootout with a specialist Anti-Poaching Unit on the Thula Thula Private Game Reserve at Ntambana in KwaZulu Natal, South Africa, on Saturday 21 July 2018. The men were part of a group of eight confronted by the unit after shots were herd near a herd of Elephants on the reserve, which are thought to have been the intended targets of the poachers, with the remaining men fleeing the conflict. Five more members of the gang were later apprehended on the reserve, with one remaining at large. The injured man has been arrested and is being held in a hospital while he receives treatment for his wounds.

Patroling vehicles from the Thula Thula Private Game Reserve's specialist Anti-Poaching Unit on 21 July 2018. Zululand Observer.

In a separate incident a poacher was also arrested in the Kruger National Park on Sunday 22 July, after apparently being chased and trampled by a herd of Elephants. The man became separated from his group and approached a group of tourists, who held him until the police arrived. It is unclear what happened to the rest of his group. This incident came three days after a ranger on the reserve was shot dead by poachers.

Elephants are considered to be threatened across Africa, due to a combination of hunting, principally for the value of their tusks, and habitat loss, with the population across the continent thought to have dropped from 3-5 million in 1900 to about 415 000 today, and about 50% of Elephant-suitable land having disappeared since 1970. In South Africa the population trend has run the other way, with the population having fallen to a low of about 120 individuals in 1920, then risen to about 10 000 today through careful conservation management. However, while the country's extensive system of game reserves and national parks means that Elephants in South Africa face no immediate threat from habitat loss, the high black market value of Elephant ivory, combined with the high number of people living in poverty in the nation, means that Elephants are very much at risk from illegal hunting (poaching),

Elephants and Rhinoceros on the Thula Thula Private Game Reserve in KwaZulu Natal. Thula Thula Private Game Reserve.

The crime is extremely profitable, and widely believed to be controlled by organised crime syndicates, which are believed to have considerable influence over police and court officials in many areas, which results in suspected poachers often being released before they are brought to trial, often with only nominal bail payments. This has in turn prompted many reserves to develop their own security measures, hiring and training specialist rangers to keep poachers off reserves, occasionally in violent confrontations.

See also...

Follow Sciency Thoughts on Facebook.

Rabies outbreak kills at least five in South Africa.

An outbreak of Rabies has killed at least five people in South Africa since December 2017, with two more deaths thought likely to have been caused by the disease. The confirmed cases of the disease occurred in Limpopo, Mpumalanga, Eastern Cape and KwaZulu-Natal provinces, with two further possible cases in Free State and Eastern Cape provinces, where it was not possible to obtain tissue samples for testing. Rabies can in theory be caught from the bite of any infected Mammal, but almost all cases in Humans are caused by Dog bites. Of the recent South African cases all are thought to have been transmitted following attacks by infected Dogs, with the exception of the Free State infection, where the patient was bitten by a Cat. Most provinces of South Africa are usually considered to be free of the disease, but it is endemic to wild Dog populations in KwaZulu Natal and Eastern Cape Provinces, with the infection sometimes spreading to domestic animals, which can in turn be transported to other parts of the country. South Africa aims to be completely free of Rabies by 2030, and the vaccination of all domestic Dogs and Cats in the country is, at least in theory, compulsory.

A pet Dog being vaccinated against Rabies in Soweto, South Africa, following an outbreak of Rabies in 2010 which prompted the introduction of compulsory vaccinations against the disease across the country. Daniel Born/Gallo Images/Times.

Rabies is caused by Viruses of the genus Lyssavirus, a member of the Rhabdoviridae Family of negative-sense single-stranded RNA Viruses, which also includes pathogens attacking Fish, Insects and Plants. Rabies is spread through the saliva of infected animals, and causes hydrophobia (fear of water),  anxiety, insomnia, confusion, agitation, abnormal behaviour, paranoia, terror, and hallucinations, followed by paralysis, coma and death in Humans. Many animals (notably Dogs) become extremely aggressive at this stage and will bite anything that comes near them, helping to spread the disease. In Humans, the disease typically has a gestation period of about three months, during which time the disease can be treated by repeated vaccination and doses of human rabies immunoglobulin, though if treatment is not begun within ten days of infection it is less likely to be successful, and once the patient starts to develop symptoms the disease is almost invariably fatal. Any wound thought to have been caused by an infected animal should be washed thoroughly under running water for at least five minutes, before being treated with alcohol or iodine, and immediate medical attention sought.

Transmission electron microscope image with numerous rabies virions (small, dark grey, rodlike particles) and Negri bodies (the larger pathognomonic cellular inclusions of rabies infection). Centers for Disease Control and Prevention/Wikimedia Commons.

See also...

Follow Sciency Thoughts on Facebook.