Herpetofauna of the Rooi Cederberg Karoo Park
Photo 1: Defensive posture of the Armadillo lizard (Ouroborus cataphractus)
Herpetology is the branch of Zoology concerned with the study of amphibians and reptiles. In a South African context it refers to the study of frogs (including toads), lizards, amphisbaenids, snakes, chelonians (tortoises, terrapins and turtles), and crocodiles. These tetrapod groups are all ectothermic, meaning all use external heat sources in regulating their body temperatures. The other two extant tetrapod groups, birds and mammals, are endothermic and produce heat through their own metabolism. The word "herpetology" comes from the Greek word herpeton meaning "creeping animal" and -logia meaning knowledge. "Herp" is a vernacular term for reptiles and amphibians.
There are over 6700 species of amphibians and over 9000 species of reptiles in the World. South Africa is home to 118 frog species and more than 350 reptile species. In addition, at least two sea turtle species visit the country's shores to breed. South Africa has the richest reptile diversity in Africa and is globally ranked as having the third richest lizard fauna after Australia and Mexico.
Amphibians are the most threatened class of vertebrates with more than 30% of the species globally listed as threatened (Stuart et al. 2008). Reasons advanced for the worldwide decline of amphibian numbers include the presence of a larval stage in the life cycle of most amphibians, which may expose them to a wider range of pollutants; their permeable skin, which may make them more vulnerable than other tetrapods to pollutants; novel diseases and in particular exposure to the chytrid fungus; increased ultraviolet radiation; climate change; land-use changes and combinations of all of the above (Lips et al. 2008; Collins 2010).
The Western Cape Province has 54 described frog species, but at least three new species await formal description (Turner & De Villiers 2012). Twenty-eight species are endemic to the province and because of their small distributions, in conjunction with the extensive and ongoing transformation of the province, many are of conservation concern. Three species are listed as Critically Endangered, four as Endangered, one as Vulnerable, and six as Near Threatened (Measey et al. 2011). Frog diversity of the Western Cape Province is comparable or higher than Mediterranean climate countries (Spain 36, Portugal 22, Italy 47, France 40 species, Chile 55). Western Australia has more species (77), but over a much larger area (Turner & De Villiers 2012).
Of the 153 reptile species and subspecies that have been recorded in the Western Cape Province, 22 are endemic to the province and eight species are alien to the province (Turner et al. 2012). Of the indigenous species, one is classified as Critically Endangered, one as Endangered, nine as Vulnerable, 15 as Near Threatened and at least seven remain to be described as new species (Turner et al. 2012). South Africa has a wealth of reptiles (Branch 2006) and the Western Cape Province makes a substantial contribution (37%) to the national reptile diversity. This is due to a number of endemic species in the Western Cape Province, particularly those that are restricted to the fynbos biome.
The Rooi Cederberg Karoo Park
At least five frog, 25 lizard, 25 snake, two tortoise and one terrapin species are expected to be present in the Rooi Cederberg Karoo Park. Only one of these species is listed as threatened, the Speckled Padloper tortoise (Homopus signatus), which is listed as Vulnerable (Turner et al. 2012). Meyer et al. (2010) demonstrated that the eastern Cederberg area (including the Rooi Cederberg Karoo Park) encompasses a herpetological transition zone, with high species turnover from north to south as well as from east to west. The Rooi Cederberg Karoo Park accordingly forms an integral part of the Greater Cederberg Biodiversity Corridor and the fact that the park spans the divide between the Cape Floristic Region and the Succulent Karoo Biomes, two of the 25 biodiversity hotspots of the world, highlights the important role the Park will play as biodiversity corridor during global climate change and associated forced species range expansions and contractions.
Meyer (2008) identified a distinct Greater Cederberg reptile assemblage, which is mainly comprised of rock-dwelling species with restricted ranges. These species may represent the evolutionary leftovers of cycles of contraction and expansion of the northern arid and southern mesic faunas in response to global climate change. The greater Cederberg area, because of its high topographic heterogeneity, apparently has distinct refugial qualities in this regard. The Rooi Cederberg Karoo Park includes the eastern distribution boundaries of most of these species (Australolacerta australis, Cordylus mclachlani, Hemicordylus capensis, Goggia hexapora, Goggia microlepidota, Pachydactylus formosus, Leptotyphlops gracilior).
Several lizard species of considerable scientific interest are present within the Rooi Cederberg Karoo Park. Scientists from Stellenbosch University are presently studying the resident population of the group-living Armadillo Lizard (Ouroborus cataphractus). They are comparing this inland population with a coastal population in terms of general ecology and behaviour and have already identified important differences related to group-living. Likewise, the Cederberg population of the Graceful Crag Lizard (Hemicordylus capensis) is also being studied intensively. Bibron's Gecko (Chondrodactylus bibronii) recently received considerable attention.
The Cederberg area is one of the most popular ecotourism destinations in the Western Cape, and a wide spectrum of activities is on offer from both the private and state sector. Since amphibians and reptiles form very visible and attractive wildlife components along the many hiking routes and at other tourist destinations in the mountains, these animals have considerable value-adding potential to a wide range of ecotourism activities. At present, most corporate and private tourism facilities do not make use of the opportunity to provide environmental education and/or information on amphibians and reptiles to their visitors. The Rooi Cederberg Karoo Park is an exception in this regard and considerable effort is made to disseminate environmental information to the tourist. The provision of information on herpetofauna will increase environmental awareness of visitors to this Park and will thus contribute to the conservation of this important biodiversity component in general.
The Frogs of the Rooi Cederberg Karoo Park
Due to the relatively low rainfall of the region, not many frog species are expected to occur in the Rooi Cederberg Karoo Park. Distribution maps for SA frogs (e.g. Minter et al. 2004) indicate that 10 species could potentially be present in the park, but the range modelling analysis of Cunningham (2011) showed that only five, possibly six species, could be expected to occur in the Park: the Cape River Frog (Amietia fuscigula), the Clicking Stream Frog (Strongylopus grayii), Delalande's Sand Frog (Tomopterna delandii), the Karoo Toad (Vandijkophrynus gariepensis), the African Clawed Toad (Xenopus laevis), and possibly also the Common Caco (Cacosternum boettgeri). In recent conservation reports, all six species are listed as Least concern, i.e. that they are not considered threatened (Minter et al. 2004; Measey et al. 2011; Turner & De Villiers 2012). All six species potentially occurring in the Park have extensive distributions in South Africa, indicating that they are generalist species with wide tolerance limits.
Photo 2: The Common Platanna (Xenopus laevis)
From an ecotourism point of view, the Red Cederberg Karoo Park is home to at least one very interesting frog species. The African Clawed Toad or Common Platanna (Xenopus laevis) is a unique frog species because it is one of the few that became secondarily almost completely aquatic. It will only come onto land when it needs to move from one water body to another. After the human species, the Common Platanna is probably the best-researched animal on earth. For many years now it has been a popular laboratory animal and is especially used as experimental animals in medical research. It has been and still is an important export product of South Africa. Exported frogs are bred in captivity and not taken from the wild. History was made on 10 September 1933 when it was shown that platannas could be used in human pregnancy tests. Two physiologists of the University of Cape Town, H.A. Shapiro and H. Zwarenstein, discovered that female platannas will start spawning within hours after being injected with the urine of a pregnant woman. When a woman falls pregnant, the placenta starts producing a hormone, human chorionic gonodatropin. An excess of this hormone is excreted in the urine. It is this hormone that stimulates female platannas to ovulate and to lay eggs. Their findings was published in 1934 in Nature, as well as in the South African Medical Journal of which Dr C. Louis Leipoldt, famous South African writer-doctor and inhabitant of the Cederberg, was editor at that stage. The Shapiro-Zwarenstein Xenopus pregnancy test was used until the late sixties.
It is feared that the export of platannas from South Africa, especially between 1930 and 1960, when platannas were commonly used in pregnancy tests, led to the worldwide distribution of the fungus Batrachochytrium dendrobatidis. This fungus causes the skin disease chytridiomicosis in amphibians and is believed to be one of the great causes of the worldwide decline in amphibian numbers that is currently being experienced. The platanna itself seems to be immune to this disease.
Lizards of the Rooi Cederberg Karoo Park
Seven of the nine lizard families present in South Africa are represented in the Rooi Cederberg Karoo Park, only varanids and amphisbaenids being absent. The Park is expected to be home to two agamid species (family Agamidae), one chameleon species (family Chamaeleonidae), at least seven gecko species (family Gekkonidae), four skink species (Family Scincidae), four lacertid species (Family Lacertidae), four girdled lizard species (Family Cordylidae), and three gerrhosaurid or plated lizard species (family Gerrhosauridae).
Agamids (Family Agamidae)
Agamas are short-bodied lizards with thin tails and triangular heads and the bodies are covered with small scales. Many people believe that agamids are poisonous, but although they belong to a clade that includes poisonous forms, they themselves are not poisonous. It is, however, true that most agamas can inflict a painful bite, drawing blood, because they have two fang-like teeth in the upper jaw. Agamas are closely related to chameleons, as is obvious from their ability to change their body colour and from the way they use the tongue in feeding. The tongue is, however, much shorter than in chameleons.
Photo 3: Male of the Southern Rock Agama (Agama atra)
The Southern Rock Agama (Agama atra), one of the two species occurring in the Park, is probably the best-known lizard in South Africa. This is because of its extensive range and the conspicuousness of the brightly coloured males perching on rocks and fence poles along roads where they do a characteristic pushup display and head nodding when intruders come too close. The Southern Spiny Agama (Agama hispida), the second agamid present in the Park, is a medium-sized, terrestrial species preferring semi-desert areas. Males are beautifully coloured during the breeding season and can be green, olive or brown above, more or less uniform or with indistinct darker and lighter variegations. All South-African agamids are oviparous and females lay their eggs during early summer.
Photo 4: The Southern Spiny Agama (Agama hispida)
Chameleons (Family Chameleonidae)
Chameleons are not abundant in the Cederberg area. In the far south, the Cape Dwarf Chameleon (Bradypodion pumilum) may be found in some areas, in the far western parts, west of the Olifants River Valley, the Namaqua Dwarf Chameleon (Bradypodion occidentale) occurs, and in the east, all along the Swartruggens, the Little Karoo Dwarf Chameleon (Bradypodion gutturale) is found. The latter is, however, not common and only a few records exist, amongst others from Keurbosfontein, Grootrivier and Kagga Kamma. The Swartruggens apparently forms the western limit of the distribution range of this species, which has its stronghold in the Little Karoo. Although not abundant in the Rooi Cederberg Karoo Park, the single chameleon species present is certainly an ecotourism asset. Chameleons are renowned for their range of adaptations to an arboreal lifestyle and are usually high on the list of South African animals that international eco-tourists would like to see.
Photo 5: The Little Karoo Dwarf Chameleon (Bradypodion gutturale)
The ability to change body colour is a character shared with the agamids, the sister family of chameleons. Other shared characters include the small protruding eyes, granular scaling and lingual prey prehension. Despite several anti-predatory mechanisms, predators have a huge impact on chameleons. During veld fires there are also considerable losses. It is therefore not uncommon for chameleons to produce many offspring each year, in other words, to have high fecundity. The Cape Dwarf Chameleon, for example, can produce up to four clutches of 12 young per year (Jackson 2007).
In Africa, several chameleon species have become secondarily ground-living. These chameleons retained the binocular vision and opposing toes of their arboreal ancestors, but their tails are much shorter because they do not have a prehensile function anymore. As expected, the ground-living chameleons are mainly, but not exclusively, restricted to arid areas where vegetation is sparse. A good example is the Namaqua Chameleon (Chamaeleo namaquensis) that occurs in the dry western parts of South Africa and Namibia. This giant chameleon (up to 25 cm in total length) has not officially been documented in the Cederberg area, but chances are good that it may be found in the dry eastern areas of the Swartruggens and Tankwa Karoo.
Geckos (Family Gekkonidae)
Geckos are in general more abundant in arid regions than in high rainfall areas and it is not surprising that geckos make up the biggest portion of the lizards of the Rooi Cederberg Karoo Park. The gecko fauna of the Park includes one of the largest South African gecko species (Bibrons's gecko, Chondrodactylus bibronii: adult snout-vent length up to 100 mm) as well as two of the smallest species (the Striped Dwarf Leaf-toed Gecko Goggia lineata: adult snout-vent length up to 30 mm, and the Cederberg Dwarf Leaf-toed Gecko Goggia hexapora: adult snout-vent length up to 35 mm). The latter, together with the Small-scaled Leaf-toed Gecko (Goggia microlepidota), which could marginally occur in the western regions of the Park, are members of the unique Cederberg reptile assemblage identified by Meyer (2007).
Photo 6: Bibron's Gecko (Chondrodactylus bibronii)
All the gecko species occurring in the Rooi Cederberg Karoo Park are nocturnal and are consequently not as often encountered as diurnal lizards. Several species may, however, frequent buildings. Bibron’s gecko, for example, is well known to farmers, as it finds farmhouses and outbuildings particularly attractive to live in. It is, however, often regarded a nuisance as its faecies and urine sticking to the walls may become an eyesore. Bibron’s gecko is gregarious and often lives in large groups of up to 15 individuals. Buildings, especially those with a metal roof, apparently form ideal microhabitats for this gecko, in that the inside is safe from predators and provides a range of microclimates, from hot against the roof during daytime to cooler lower down.
Photo 7: The Cederberg Dwarf Leaf-toad Gecko (Goggia hexapora)
Aggregation behaviour in Bibron's Gecko has been intensively studied in recent years (Meyer & Mouton 2007; Broeckhoven 2011). There are several reasons why C. bibronii may aggregate, for example a shortage of shelter sites conveniently positioned relative to food sources such as termite nests, a shortage of shelter sites with optimal thermoregulation qualities, or a shortage of crevices with optimal qualities for protection against predators. There may also be social reasons why individuals may want to aggregate, for example for improved thermoregulation, as has been suggested for several other gecko species, or the dilution effect. Geckos do not have any armour for protection against terrestrial predators and the dilution effect of individuals sheltering communally may be an important benefit. It is possible that all of these, in combination or singly, may be applicable to C. bibronii, depending on the specific environmental circumstances.
Lacertids (Family Lacertidae)
Of the eight Old World Lizard or lacertid genera occurring in South Africa, four are represented in the park: Rock Lizards (Australolacerta), Desert Lizards (Meroles), Sandveld lizards (Nucras) and Sand Lizards (Pedioplanis). Lacertids are typically small to medium-sized lizards with a slender body, a long tail and well-developed limbs. They are all exceptionally fast runners, a necessity in the open habitats where they occur. All the South African forms are oviparous and the eggs are deposited in spring.
Photo 8: The Southern Rock Lizard (Australolacerta australis)
The Southern Rock Lizard (Australolacerta australis) is a greater Cederberg endemic and is a member of the Cederberg reptile assemblage (Meyer 2007). It is the most basal species in its clade and is therefore a good example illustrating the refugial qualities of the Cederberg area over evolutionary time. This beautifully coloured lizard is very secretive and is nowhere common. It may be marginally present in the western parts of the Park. The Western Sandveld Lizard (Nucras tessellata) is one of the most beautiful lizards in South Africa. It has the typical slender body, well-developed limbs and long tail of lacertids. The head, front limbs and front part of the body are black dorsally with brilliant white zebra-like bars on the sides and four thin cream stripes on the back. The rear part of the body, the hind legs and the tail are rich red-brown. The exceptionally long tail probably plays a role in defense in that it increases the chances that the predator will go for the tail rather than the body, giving the lizard a chance to escape. Knox's Desert Lizard (Meroles knoxii) and the Spotted Sand Lizard (Pedioplanis lineoocellata) are very similar in general appearance, but occur in different habitats. The former frequents sandy areas while the latter is restricted to rocky areas (Du Plessis & Mouton 2010).
Photo 9: The Western Sandveld Lizard (Nucras tessellata)
Photo 10: The Spotted Sand Lizard (Pedioplanis lineoocellata)
Skinks (Family Scincidae)
Three typical skink species and one legless skink are expected to occur in the Park. The three typical skink species have wide distributions in southern Africa. The Western Rock Skink (Trachylepis sulcata)is a rock-dwelling species while the Cape Skink (Trachylepis capensis) and the Variegated Skink (Trachylepis variegata) are ground-dwelling. Rock-dwelling species are typically dorso-ventrally flattened, with relatively long limbs and tails, while ground-dwelling skinks typically have long, tubular bodies and relatively short limbs. All three skink species have longitudinal lines of some sort on the body, indicating that they are active hunters. Among lizards, a striped pattern serves to confuse predators when the lizards are on the move. The Western Rock Skink displays distinct colour dimorphism. In juveniles and adult females the body is chocolate- to olive-brown with six dirty-gold, longitudinal stripes. Sexually mature males do not have the longitudinal stripes and are infused with black. In certain areas, the males may be completely black. The function of male coloration in a social context is probably more important than its role in camouflaging.
The Cape skink is probably the best-known lizard in South Africa as it is common in gardens and has an extensive range in South Africa. It tames easily, and will eventually eat from one’s hand. Such tame individuals may become very fat. In the wild, it is fairly secretive and will more often be heard than seen. The Variegated Skink is the smallest of the Trachylepis species that occur in South Africa. It is common within its range and is usually confined to rocky areas. Although associated with rocks, it is not a typical rock-dweller in that it seldom shelters in rock crevices, and in that it spends most of its activity time foraging at ground level among vegetation at the base of rocks. All three skink species are viviparous (live bearing) giving birth during late summer.
Photo 11: A male of the Western Rock Skink (Trachylepis sulcata)
Photo 12: A female of the Western Rock Skink (Trachylepis sulcata)
The Striped Legless Skink (Microacontias lineatus) is a small, legless skink with adult snout-vent length in the region of 130-150 mm. It is a burrower and is normally found in the loose soil at the base of scrubs in arid regions. It is viviparous and females possibly only have a single baby per season.
Photo 13: The Striped Legless Skink (Microacontias lineatus)
Girdled lizards (Family Cordylidae)
The Cordylidae is a family of lizards endemic to southern and eastern Africa. There are 80 named taxa in the family, the majority of which follows a rock-dwelling lifestyle and all of which are sit-and-wait foragers. Traditionally divided into four nominal genera, the family is now partitioned into 10 genera, placed in two subfamilies (Stanley et al. 2011). The Platysaurinae contains a single genus of oviparous species, while all species in the subfamily Cordylinae, partitioned into nine genera, are viviparous.
Four of the 10 girdled lizard genera are represented in the Rooi Cederberg Karoo Park and a fifth may possibly be present in the south-western regions of the Park. At least two of the four species have been extensively researched during recent years, the Armadillo Lizard (Ouroborus cataphractus) for its unique group-living behaviour, and the Graceful Crag Lizard (Hemicordylus capensis), a melanistic (black) species, for its adaptations to survive in warm environments. The third species, McLachlan's Girdled Lizard (Cordylus mclachlani) is a greater Cederberg endemic and a member of the Cederberg reptile assemblage identified by Meyer (2007). The fourth species, the Karoo Girdled lizard (Karusasaurus polyzonus) is closely related to the Armadillo lizard and is well known for its extra-ordinary cranial kinesis.
The Armadillo Lizard (Ouroborus cataphractus) is a heavily armoured, group-living lizard, restricted to the winter rainfall region of South Africa. When threatened, it will grab its tail in its mouth and roll into a tight ball. Normally this lizard lives in groups of up to six individuals, but in certain coastal areas groups of up to 60 individuals can be found. Research has shown that the group-living behaviour of this species is the indirect result of relying on the Southern Harvester Termite (Microhodotermes viator) as a food source. Individuals in groups sporadically visit the foraging ports of termite nests some distance away from the crevice shelter of the group where they gorge themselves on termites. Harvesting termites away from the crevice at the termite foraging ports and predation pressure associated with these foraging excursions is seen as the primary driving force in the evolution of heavy armour and the tail-biting anti-predatory behaviour displayed by O. cataphractus (Mouton 2011). The heavy armour compromises agility in this species, and the armadillo lizard is accordingly more prone to aerial predation during general maintenance behaviour (basking and social behaviour) at the rock shelter than other more lightly-armoured cordylids would be. Hayward (2007) demonstrated that the impact of aerial predation on the armadillo lizard is offset by living in groups as individuals in groups benefit from enhanced vigilance (many eyes effect). The Armadillo lizard displays numerous adaptations to group-living, amongst others, an extremely low metabolic rate and very low fecundity (only one offspring per season).
Photo 14: The group-living Armadillo Lizard (Ouroborus cataphractus)
A comparison of coastal and inland populations of the Armadillo lizard highlighted several distinct morphological and behavioural differences. It is believed that these differences stem from differences in lizard population densities and differences in overall predation pressure. In this comparison, the Armadillo Lizard population of the Rooi Cederberg Karoo Park is presently being used as inland representative population.
The Gracefull Crag Lizard (Hemicordylus capensis) is one of several melanistic (black) cordylids that occur in the southwestern corner of the subcontinent (Janse van Rensburg et al. 2009). It is believed that melanism in cordylids is an adaptation to conditions of limited sunshine, in that it increases the rate of radiation absorption under such conditions. The concentration of melanistic species in the southwestern corner of South Africa suggests that adverse climatic conditions prevailed here some time in the distant past. Today, most melanistic species survive as small relic populations in very specific microhabitats, either high up in the mountains, or in insular or peninsular situations along the coast. The Gracefull Crag Lizard is somewhat of an enigma in this regard in that it is not restricted to mountain tops, but also occur in hot environments where overheating as a result of its black body colour is a constraint. Research showed that this species uses significantly higher rock formations, and has relatively longer limbs than other melanistic species. Having a morphology that allows for flexibility in habitat use may enable species such as H. capensis to overcome the constraints of melanism in warm environments. The Graceful Crag Lizard displays much greater movement rates during activity than other cordylids. A less sedentary foraging strategy may be a prerequisite for life on large, barren rock surfaces where food availability may be low or not uniformly distributed. Both males and females of this species also have large home ranges, a unique phenomenon for cordylids (Janse van Rensburg & Mouton (2009). Due to the constraining effect of climate on the distribution of most melanistic populations, melanistic cordylids should be considered as priority species for conservation. While P. capensis is apparently adapted for survival in warm climates, it is dependent on the availability of suitable habitats. The Rooi Cederberg Karoo Park could thus play an important role in the conservation of this species’ habitat.
Photo 15: The Graceful Crag Lizard (Hemicordylus capensis)
The Karoo Girdled Lizard (Karusasaurus polyzonus) is the dominant lizard species in the Rooi Cederberg Karoo Park and is present wherever rocky habitat is available. It is probably the most common lizard species in the arid western and central parts of South Africa. It can typically be seen basking on rocks with the head and foreparts well raised off the rock face. Unlike most other girdled lizards, it seems to prefer the warmer lowland areas and is usually absent from the top sections of the koppies and mountains within its range. Typical of most girdled lizards when inside a crevice, the tail will be curled sideways to the front to shield the head and body from predators. Cranial kinesis is well developed and allows the lizard to press hard with the head against the roof of the crevice to prevent from being pulled out by a predator.
Photo 16: The Karoo Girdled Lizard (Karasasaurus polyzonus)
McLachlan's Girdled Lizard (Cordylus mclachlani) is a relatively small cordylid, and little is known about this relatively recently discovered species. It is a fairly secretive lizard and stays close to shelter while basking and foraging. Its small size and dull coloration makes it difficult to spot. Its extremely flattened body indicates that it is a rock-dwelling species and that it can use narrow crevices to shelter in. The tail of this species is exceptionally fragile when compared to that of other cordylids and is easily discarded when handled. This is a predator escape strategy. When the lizard is sheltering in its crevice, the tail is folded over the body, blocking the entrance of the crevice. When the lizard is hiding in shallow cracks or crevices, predators may, however, get hold of the tail, which will then easily break off.
Photo 17: McLachlan's Girdled LIzard (Cordylus maclachlani)
Gerrhosaurids (Family Gerrhosauridae)
The gerrhosaurids or plated lizards form the sister group of the cordylids. This family of lizards is endemic to Africa and Madagascar. All the species in the family are oviparous, all are active foragers and all are ground-dwelling. In all plated lizards, the body has a prominent lateral fold on each side. All three South African genera of plated lizards are represented in the Park. The Dwarf Plated Lizard (Cordylosaurus subtessellatus) is a small, slender lizard with an adult snout-vent length of 45-55 mm. Its fluorescent blue tail and black and yellow striped pattern on the body, renders it very conspicuous when active. Like many lizards living in arid environments, the lower eyelid is transparent, helping the lizards to see with the eyes closed and thereby preventing drying out of the eyes. This fascinating little lizard frequents rocky areas in karroid areas where it actively searches for its prey. It is a secretive lizard, its bright body colours probably preventing it from spending too much time in the open where it will be easily spotted by predators.
Photo 18: The Dwarf Plated Lizard (Cordylosaurus subtessellatus)
Photo 19: The Common Long-tailed Seps (Tetradactylus tetradactylus)
The Common Long-tailed Seps (Tetradactylus tetradactylus) has a thin and elongated body, the limbs much reduced, and the tail about three times body length, giving the lizard a snake-like appearance. Its elongate body and reduced limbs indicate that it frequents grass and restio habitats and that it can be classified as arboreal. Arboreal, grass-living lizards are generally heavily impacted on by veld fires. The common long-tailed seps is probably too small to be able to effectively flee from fire. In captivity individuals have been noted to burrow into loose sand, perhaps an indication that at least some individuals will be able to escape from fire by burrowing into sand or underneath rocks, or entering rodent burrows. It is still expected that direct mortality during fire will be high. This slender lizard is very agile and extremely difficult to catch.
The Namaqua Plated Lizard (Gerrhosaurus typicus) is a medium-sized, round-bodied lizard with prominent lateral folds. It is very secretive and is seldom seen. It has the habit of wriggling into loose sand so that only the tip of the snout sticks out. It is active in the early morning and late afternoon. An active forager, it preys on a wide range of insects, including termites.
Snakes of the Rooi Cederberg Karoo Park
More than 20 families of snakes are currently recognized in the world, comprising about 500 genera and about 3 400 species. Living species range in size from less than 10 cm to close to 9 m in length, with the fossil species Titanoboa cerrejonensis having reached lengths of up to 15 m long. Snakes are thought to have evolved from either burrowing or aquatic lizards around 112 million years ago during the mid-Cretaceous period. Snakes are often secretive and rely on scent rather than vision in their predatory and social behaviour. As a result, snakes are usually a less conspicuous part of the fauna than lizards. Nonetheless, snakes are important components of ecosystems in many parts of the world and display a broad range of specializations. Snakes are considered as important as birds of prey in controlling rodent pests in farmlands. The vast majority of local snakes are completely harmless or clinically unimportant and a greater tolerance and understanding of these efficient and unique predators is called for.
At least 25 snake species potentially occur in the Red Cederberg Karoo Park, including two cobra species and no less than four, possibly five adder species. The Black Spitting Cobra (Naja nigricollis woodi) is a long, slender, pitch-black snake found in some of the harshest areas of the Northern and Western Cape provinces. If escape is hindered, it will spit venom profusely at its attacker and take advantage of any hesitation this may cause to affect its escape. The Cape Cobra (Naja nivea) is responsible for the majority of fatal snakebites in the Western and Northern Cape provinces. Other elapids that are expected to be present in the Park include the Spotted Harlequin Snake (Homoroselaps lacteus) and the Coral Snake (Aspidelaps lubricus). Besides the Puff Adder (Bitis arietans), which is responsible for more than 60% of the serious snakebites in southern Africa, the ranges of three dwarf adder species may meet within the boundaries of the Park. The Red Adder (Bitis rubida) is common in the Cederberg area, the Horned Adder (Bitis caudalis) may enter from the East, while the Many-horned Adder (Bitis cornuta) may marginally enter the Park from the North-west. It would be interesting to know whether the three species occur in sympatry anywhere in the Park, and if so, how competition is avoided. A fifth adder species, the Berg Adder (Bitis atropos) may be present in the southern parts of the Park. The Karoo Sand Snake (Psammophis notostictus) and the Spotted House Snake (Lamprophis guttatus) are probably the commonest snakes in the area.
Photo 20: The Black Spitting Cobra (Naja nigricollis woodi; photo by James Gradwell)
Photo 21: The Coral Snake (Aspidelaps lubricus)
Photo 22: The Red Adder (Bitis rubida)
Photo 23: The Karoo Sand Snake (Psammophis notostictus)
Photo 24: The Spotted House Snake (Lamprophis guttatus)
Chelonians of the Rooi Cederberg Karoo Park
There are some 273 living chelonian species in the world. All lay eggs, those of aquatic forms normally being soft-shelled and those of terrestrial forms, hard-shelled. The common names tortoise, turtle, and terrapin, have no scientific connotation and are normally only used to differentiate between those species that live on land (tortoises), in the sea (turtles), and in fresh water (terrapins). Terrestrial chelonians usually have high domed shells and stout limbs, while aquatic ones usually have webbed feet and relatively flat shells to offer less resistance to movement in water. The southern African subregion has a rich chelonian fauna, with five sea turtles in coastal waters, nine terapins in freshwater rivers and vleis, and 14 land tortoises (Branch 2008). Two of the five tortoise genera and one of the two terrapin genera present in South Africa are expected to be represented in the Rooi Cederberg Karoo Park.
The Speckled Padloper (Homopus signatus) is the world's smallest tortoise averaging only 80-90 mm. It is the only herpetofaunal species of conservation concern possibly occurring in the Rooi Cederberg Karoo Park (Turner et al. 2012). A recent molecular study has showed that selection for crypsis on either granites or sedimentary rocks has resulted in different morphotypes within the range of this species (Daniels et al. 2010). Translocation should be avoided to retain current genetic diversity and to limit vulnerability of morphotypes on substrates where they do not blend in (Turner et al. 2012). Recent surveys indicated increased levels of habitat destruction for crop production (mainly rooibos tea) and habitat degradation by overgrazing (mainly by goats), which have resulted in local population declines and extinctions (Turner et al. 2012). Climate change is considered to be a real threat to the Speckled Padloper as research has shown that the species is very sensitive to extended droughts which have a negative impact on egg production and reduce growth rates (Loehr et al. 2007; Loehr et al. 2011). These physiological responses to alterations in climate necessitate east-west habitat corridors to enable movements to regions with sufficient rainfall (Loehr et al. 2009).
Photo 25: The Speckled Padloper (Homopus signatus)
Photo 26: The Angulate Tortoise (Chersina angulata)
The Angulate Tortoise (Chersina angulata) occurs in a variety of natural habitats and it is therefore unlikely that it has specialised habits. Relatively dense populations are found in coastal regions. The species occurs in a broad coastal region from North of Alexander Bay (into Namibia), southwards along the West Coast to the southwestern Cape or Boland, and eastwards through the southern Cape to East London. Inland, populations extend into the Cederberg, Tankwa Karoo, the Little Karoo and the eastern Great Karoo. It probably occurs throughout the Rooi Cederberg Karoo Park. Every year thousands of hatchlings fall prey to the ever-increasing pied crow population in the West Coast regions. Domestic dogs and motorists who deliberately run over tortoises on roads may be added to the list.
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