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The Common Girdled Lizard (Cordylus vittifer) is a rock-dwelling reptile found in the South African provinces of Free State, North West, Gauteng, Limpopo, Mpumalanga and KwaZulu-Natal, as well as in Eswatini and peripherally in Botswana and Mozambique. These lizards are characterised by a ‘girdle’ of thick protective scales, and the first row of scales behind the head forms a distinctive collar. Amongst girdled lizards (genus Cordylus), such a collar is found in only three other species (C. machadoi, C. namakuiyus and C. phonolithos) that are restricted to south-western Angola and adjacent northern Namibia.

Colour pattern and certain scalation characteristics of the Common Girdled Lizard vary between populations in different geographical regions. Lizards may be pale to dark brown, sometimes with dark or light speckles and a dark or pale vertebral, dorsolateral and/or lateral stripe. This is a moderate-sized lizard, which in some populations grows to 95 cm from snout to vent, with a slightly longer tail. These lizards inhabit rocky outcrops, living in crevices between rocks and retreating at the first sign of danger. They feed on, inter alia, beetles, bugs and grasshoppers which they rush out to grab before retreating back to the safety of their crevices. Females give birth to 1–4 babies in November or December.

An assessment of morphological variation in this species was conducted by Schalk de Waal, an employee at the National Museum in the 1970s and early 1980s. His study focussed on populations in the Free State, but included large samples from elsewhere in the species’ range. De Waal concluded that there were three morphologically distinct forms (morphotypes), which he named varieties A, B and C. In the Free State these forms were easily distinguishable and did not overlap in distribution. Variety A was found in the northern Free State, variety B in the north-eastern Free State, while variety C was restricted to the Harrismith area. Variety A also occurred in Gauteng, North West and adjacent parts of Mpumalanga province, whereas variety B also occurred in Limpopo, Mpumalanga and KwaZulu-Natal provinces. However, several specimens, especially from Limpopo, Mpumalanga, and Eswatini, were considered ‘intermediate’ and could not be unambiguously assigned to either variety A or B. The three morphotypes were distinguished by differences in the size of adults, colour pattern, number of femoral pores and glandular femoral scales, separation (or not) of the anterior parietal scales, and number of longitudinal rows of ventral scales. In the 1980s, Niels Jacobsen collected many samples of Common Girdled Lizards in the former Transvaal Province, and examined these and others of this species from that area in museum collections. Similarly to what De Waal reported, he found that although most specimens could be assigned to varieties A and B using the characters proposed by De Waal, there was overlap in some characters. Jacobsen’s study concluded that variety A occurred in the North West Province, Gauteng and western Mpumalanga, while variety B was found in Limpopo, eastern Mpumalanga, Eswatini and KwaZulu-Natal.

We are trying to determine whether the Common Girdled Lizard is one highly variable species, or perhaps represents a species complex. We are considering the possibility that the three morphological varieties (A, B and C) discussed above, and perhaps also other populations, represent separate species. To investigate this in a modern taxonomic framework, we need to generate a phylogeny (‘family tree’) using information provided by the gene sequences of the lizards, to allow us to examine the relationships between populations, i.e. to determine which populations are closely or distantly related. We will then try to find a correlation between the genetically unique lineages or clades, and morphologically distinct populations. But before any of this could be achieved, we needed to collect new material throughout much of the range of the species to complement the samples we already had, so as to assemble a fully representative set of samples. Therefore, we had to conduct expeditions to KwaZulu-Natal, Free State, Mpumalanga and Gauteng provinces with the aim of collecting small samples of lizards at various localities.

Our first field trip was to KwaZulu-Natal. For two weeks we drove across the province to a variety of nature reserves where this species had been recorded previously. Although we did not find ideal habitat in all these areas, we discovered two specimens on our first day, in rocky grassland near Paulpietersburg. We then located suitable habitat near Bivane Dam close to the town of Louwsburg, where we found a large specimen just as a storm started. Travelling further south we discovered a healthy population on windswept rocky slopes between Nkandla and Isandlwana. At the southern limit of the range we struggled to find suitable habitat, but were eventually successful in locating specimens between Mpumalanga town and Cato Ridge, and again a little further north at Midmar Dam. On our return journey northwards we investigated both Spioenkop Nature Reserve and Weenen Game Reserve where this lizard had been reported many decades ago, but we could not locate suitable habitat at either reserve. We concluded the trip by exploring the Mooi River and Winterton areas, but found only a large Drakensberg Crag Lizard (Pseudocordylus melanotus subviridis).

Our next field trip was to Mpumalanga Province, targeting nature reserves mostly in areas where this species had not been recorded previously, in an attempt to find a specimen from as close to the supposed type locality (Bethal) as possible. Although we surveyed four nature reserves – S.S. Skosana, Loskop Dam, Mabusa and Nooitgedacht, and found lizards of several species, we failed to spot any Common Girdled Lizards.

We then travelled to the northern and eastern Free State Province, again focussing primarily on nature reserves and a few farms where the species had been collected before. Although variety A of this species had been recorded from the northern Free State in the 1970s, we were unable to locate any population in the Savannah Africa Nature Reserve or at several other farms in the area, including a farm where the species had been recorded in 1974. It appeared that much of this region underwent agricultural transformation. However, in the east of the province our luck changed and we encountered two specimens of variety B in rocky grassland habitat at Seekoeivlei Nature Reserve near Memel. On our last stop in the Free State we were successful in finding three specimens of variety C which is known only from the Harrismith area.

Our final field trip was to Gauteng Province where we were joined by well-known environmentalist Warren Schmidt. We hoped to collect typical variety A lizards there as we had been unsuccessful in finding any in the adjacent northern Free State. Starting in the south we had no luck at Alice Glöckner Nature Reserve, but then discovered a population of plain brown, unstriped lizards (typical of variety A) in the rolling hills of Boksburg. The next day was even better as we found two suitable sites in Suikerbosrand Nature Reserve where four mostly-plain brown lizards, some with black speckles, were found. We later located another four lizards near the town of Magaliesburg. After driving further north to Bapsfontein, we came across the mummified remains of a specimen and, after much searching, noticed a live brown-speckled lizard. In the final days of our journey we tried to locate suitable habitats around Pretoria, and eventually found two specimens on the slopes of the Magaliesberg range in the north of the city.

The new specimens have been sequenced for two mitochondrial and two nuclear genes, and are being examined for 22 morphological features (e.g. measurements and scale counts). Using a combination of the genetic and morphological data we hope to determine how different the various populations are and whether or not they represent one or more species. On all our trips we also collected valuable distribution records for a variety of other reptiles and amphibians. We look forward to publishing our findings for this project within the next year or two.

Lastly, we wish to thank the four nature conservation authorities—Ezemvelo KZN Wildlife; Mpumalanga Tourism and Parks Agency; Free State Department of Economic, Small Business Development, Tourism and Environmental Affairs; and Gauteng Department of Agriculture, Rural Development and Environment—for issuing collecting permits and allowing us access to their reserves. In some cases we were also offered assistance in the field. We also thank all land owners, conservation officials and local experts who assisted us with this project.

References

Bates, M.F., Branch, W.R., Bauer, A.M., Burger, M., Marais, J., Alexander, G.J., De Villiers, M.S. (Eds). 2014. Atlas and Red List of the Reptiles of South Africa, Lesotho and Swaziland. Suricata 1. Pretoria: South African National Biodiversity Institute.

Branch, W.R. 1998. Field Guide to Snakes and other Reptiles of Southern Africa. 3rd edition. Cape Town: Struik.

De Waal, S.W.P. 1978. The Squamata (Reptilia) of the Orange Free State, South Africa. Memoires van die Nasionale Museum, Bloemfontein 11, 1–160.

Jacobsen, N.H.G. 1989. A herpetological survey of the Transvaal. PhD thesis. Durban: University of Natal, South Africa. http://hdl.handle.net/10413/8461

Figure 1: Distribution of the Common Girdled Lizard (Cordylus vittifer). Yellow circles indicate known records (mainly museum records); pink circles with blue edges indicate localities where the authors collected specimens as part of their ongoing research project, and blue circles indicate areas where the authors searched unsuccessfully for this species. The yellow diamond with a green border indicates the type locality for this species (Bethal, Mpumalanga Province).
Figure 2: The first Common Girdled Lizard (Cordylus vittifer) collected during the recent field excursions near Paulpietersburg, KwaZulu-Natal. Note the fragmented pale ‘stripe’ down the middle of the back, a marking often found in specimens of this species. (Photo: Cora S. Stobie)
Figure 3: Habitat of the Common Girdled Lizard at Midmar Dam near Howick, KwaZulu-Natal. (Photo: Michael F. Bates)
Figure 4: Dr Cora Stobie and Mr Edgar Mohapi collecting a Common Girdled Lizard in Seekoeivlei Nature Reserve near Memel, Free State. (Photo: Michael F. Bates)
Figure 5: Common Girdled Lizard found in Seekoeivlei Nature Reserve near Memel, Free State. This specimen is referable to variety B and has a similar colour pattern to the lizards found in Paulpietersburg and Mpumalanga town, KwaZulu-Natal. (Photo: Michael F. Bates)
Figure 6: A ridge on the north-eastern slope of Platberg mountain, Free State, where Common Girdled Lizards were found. Common Crag Lizards (Pseudocordylus melanotus melanotus) were also found in the rock outcrops here. (Photo: Cora S. Stobie)
Figure 7: A Common Girdled Lizard from near Platberg, Free State. This specimen has dark lateral bands which is typical of variety C. These lateral bands are also seen in some lizards of this species from KwaZulu-Natal. (Photo: Michael F. Bates)
Figure 8: The locality in Boksburg, Gauteng, where a Common Girdled Lizard was found. Dr Stobie records details of the habitat (e.g. co-ordinates, elevation, habitat), while Dr Bates examines the specimen. (Photo: Warren R. Schmidt)
Figure 9: Common Girdled Lizard from Boksburg, Gauteng. Note the plain brown colouration of this specimen which lacks the speckles or stripes of others from KwaZulu-Natal and Free State. This colour pattern is typical of a form of Cordylus vittifer described as variety A. (Photo: Warren R. Schmidt)

 

 

 

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