Sungazers are endemic to South Africa and are synonymous with the gently sloping Themeda sp. grassland of the Highveld plateau. Scattered populations can still be found where suitable habitat exists throughout the North Eastern Free State and South Eastern Mpumalanga. Individuals were previously recorded in West Kwazulu-Natal, recent research would suggest however that they are now void from this area.
Coming from South Africa, these lizards would be subjected to high temperatures throughout the year right? Wrong – South Africa has four distinct seasons. During the months of June, July and August, temperatures can drop to as low as -8 degrees centigrade (17.6 degrees Fahrenheit) with the possibility of snow being high. Conditions are such that Sungazers rarely wake from their winter brumation and rely totally on their fat reserves to see them through to the Spring. During the summer months temperatures can reach as high as 38 degrees centigrade (100 degrees Fahrenheit) with relatively high levels of precipitation. Humidity during this time however, would appear to be relatively low in comparison to the amount of rainfall. This suggests that the topography of the land promotes ample air movement thus suppressing the build up of humidity. During the summer months daylight lasts around 14 hours, decreasing to around 10 hours during the colder, winter months.
As we can see from this graph, any animal sharing this habitat would experience both high and low temperatures during any given 12 month period. Each species has its own way of dealing with these fluctuations, Sungazers do this by excavating a burrow. Temperatures underground will, most likely, remain far more stable during these extremes of temperature and allows these lizards to live at elevations which would otherwise be too inhospitable for them. Typical Sungazer habitat can be as high as 1,500-1,600 metres (4,920 – 5,250 feet) above sea level with the average burrow about 1.8 metres (5.9 feet) long, 30 – 45 centimeters (11.8 – 17.7 inches) wide and approximately 1 metre (3.2 feet) below ground.
These burrows usually face a North or North-westerly direction. This orientation towards the prevailing sun allows for maximum exposure to the beneficial ultra-violet rays. Sungazers are more than capable of digging their own burrow, to do so however can leave the ‘digger’ vulnerable to predation. Reptiles are masters at conserving energy and it is far easier, and less risky, to take over a rabbit burrow and modify it to suit than to build your own. Alterations usually take place after heavy rainfall when the ground is easier to ‘work with’. Sungazers will often use their spines to rasp away at the sides of the burrow during this modification process. The entrance of a Sungazer burrow is very distinct in that it is oval in shape and often has a trough, inadvertently, cut into the centre, this is created by the Sungazers tail as it enters and exits. The fact that there is no mound at the entrance to these burrows, suggests that excavation takes place little by little, over many years. Contrary to some reports, there is no enlarged chamber at the terminus of these burrows and burrows do not interconnect by choice. This incorrect data most likely came about after a lizard was found in an old rabbit burrow which do have these enlarged chambers and may connect with neighboring burrows. Although Sungazers will use the same burrow for many generations, low lying burrows may become flooded during the rainy season. Determined not to disrupt the daily ritual of ‘sun gazing’ these stubborn lizards will sit at the entrance of a flooded burrow. Only when disturbed will the lizard dive down, under the water only to emerging again once the danger has passed. Although these lizards can hold their breath for several minutes, it is thought that some burrows, by there design, may taper towards the surface thus creating a small air pocket in which the lizard can utilise if required. It is not known for sure if Sungazers have a pre-dug burrow on higher, drier, ground in the event that the primary burrow becomes flooded.
Sungazers live in colonies consisting of multiple males and females. Through choice, burrows are usually roughly 10 metres (32.8 feet) apart. Males may hold sway over a micro territory or group (harem) of females within the confides of the larger colony. Fights between males are rare once a hierarchy has been established. If anything, research would suggest that it is the females who are more quarrelsome as they seek out the best burrows – these fights are also rare and brief. Usually animals will have a ‘favourite’ burrow but when danger threatens multiple animals may use the same burrow, even animals of the same sex. Juvenile animals will remain with their mothers for the first year or two before being evicted and forced to excavate or find their own bolt hole. Several species of anurans (frogs and toads) have been found in active Sungazer burrows. These amphibians, which include Dainty Frogs – Cacosternum boettgeri, Running Frogs – Kassina wealii, Caco Frogs – Caco sp. and Guttural Toads – Bufo gutturalis, are not eaten by the lizards and appear to be of no benefit to the lizard.
Sungazers rarely venture far from the safety of their burrow. Being part of a colony has its advantages in the fact that there are many pairs of eyes on the look out for danger. Badgers, jackals and birds of prey pose the greatest, natural threat to an adult Sungazer. The tall grass of the Themeda, in relation to the size of a Sungazer, makes it difficult for the lizard to detect approaching danger. Rocks or termite mounds may be used to gain a better vantage point. When danger threatens, several animals may bolt for and enter the same burrow. Should a predator try to extract the lizard from its underground refuge, the first line of defence is to huff and puff loudly. This is similar to the sound of a Common Puff Adder – Bitis arietans. Unsurprisingly very few animals will risk sticking their noses into a burrow occupied by a Puff Adder!! If this fails to deter an attacker, the lizard will anchor itself within the burrow by thrusting its occipital (back of the head) spines into the roof of the tunnel. The Sungazer will also flail its ‘club like’ tail in the face of its adversary. This is usually sufficient to deter all but the most determined of predators. Sungazers have extremely strong tails but should they be broken or bitten off, they do not have the ability to regenerate them.
The diet of a wild Sungazer is made up primarily of insects, particularly those of the Coleoptera taxa – aka winged beetles. Ever the opportunist, these lizards will not pass up the opportunity to add a small vertebrate, such as a mouse to their diet should one venture too close. Someone once reported that they observed wild Sungazers feeding on carrion. Personally I would question the validity of this observation – not the integrity of the person providing the information but the fact that movement seems to be the prelude to a feeding response. I would suggest that it is far more likely that the Sungazers were attracted to the insects that were in turn attracted to the carrion. From a distance, it may look like the Sungazers were feeding on the carrion directly. The fertile soil of the Highveld plateau is prime agricultural land and large areas are set aside for cattle and other grazing ungulates. An inevitable by product of these animals is dung and in an effort to conserve energy, Sungazers will often sit beside this dung and pick off the insects that are attracted to it. These animals pose no direct threat to the Sungazers and are allowed to move freely within the colony.