Grysbok Environmental Education Trail
A number of reptiles and amphibians occur on the reserve. Clicking stream frogs (Strongylopus grayii) and painted reed frogs (Hyperolius marmoratus) call in large numbers at water bodies in the late afternoon and early evening. Tortoises are often seen, in the summer months – the angulate tortoise (Chersina angulata) is abundant. Few venomous snakes occur, but one of them, the puff adder (Bitis arietans), is common. The spotted gecko (Pachydactylus maculates) is also widespread, sheltering in old giant land-snail shells. Listed below are some of the species found on the trail.
This little frog breeds well in any puddle of water that is well supplied with vegetation. They can even breed in brackish pools near the sea! As the name indicates, their call is a wooden tapping sound, which is repeated monotonously.
This animal seldom exceeds 30 cm in length. It is a very common species in freshwater pans, even in arid areas such as the Karoo. It is omnivorous, and may even take birds, such as doves, when they come to the waters' edge to drink.
This is the largest tortoise in southern Africa, and it can achieve lengths of 72 cm and weigh 40 kg. It feeds on grass, shrubs and succulents, but may gnaw on bones to obtain sufficient calcium for its shell. They have a large home range (1-2 square km) and will defend it vigorously.
This is a small gecko, here seen hiding in the shell of a Giant African Snail (Achatina fulica max. 15-20 cm). The geckos reach a maximum length of 11cm and several of them may crowd into a big snail shell during winter. They feed at night on small insects and spiders. They live for 3 to 4 years.
This is a common snake, known to occur throughout southern Africa. It is, however, seldom seen. Egg eating snakes have several adaptations of the head and jaws which make it possible for them to eat eggs of up to three time the diameter of their heads! Special teeth in the gullet saw through the shell as it is being swallowed, allowing the liquid part of the egg to be extracted. The collapsed shell is spat out. Only fresh eggs are eaten.
This is a large (max. length 210 cm), thick snake. Mole Snakes are harmless constrictors which can be very useful in controlling the populations of mice and rats.
The Olive House Snake reaches a maximum length of 130 cm. It prefers slightly more moist habits than the Brown House Snake. It eats rodents and may also eat other smaller snakes.
This is the largest of the House Snakes (max. length 150 cm). It is quite a handsome snake with two pale yellow streaks down the sides of the head. Like Mole Snakes, House Snakes will attack when provoked or handled, but are easy to tame once they calm down. As the name suggests they were kept in, or encouraged near houses and granaries to eat rats and mice.
This is a very active species of snake that will pursue its prey instead of just waiting in ambush. Its diet includes lizards, frogs, rodents and even other snakes. The females stay with the eggs and guard them by coiling around them. They are called Skaapstekers (sheep biters) because of the old belief that they bit sheep.
The common name of this snake is derived from the newspaper (The Eastern Province Herald) that first noted its presence. The upper lip is reddish or orange in animals in the southern part of its range. It will rear up and flatten its neck when provoked, which causes it to be confused with cobras or vipers. Although its bite will bleed profusely, the venom has little effect on humans. Its normal prey, mainly frogs, are not so lucky and will succumb quickly once bitten.
"Boomslang" means Tree Snake, and these beautiful, shy snakes are almost always found in trees. This is one of the few snakes which has been recorded to cause a human death in southern Africa. It is one of the back-fanged snakes. It doesn't have the impressive fangs of adders and has to "chew" the prey with fangs found at the back of the mouth. Most cases of human poisoning were reported by careless snake handlers! Generally this snake will only bite under severe provocation. It hunts during the day and its huge eyes aid vision in the shaded treetops. The male is shown here. Females are usually light brown or olive with white to brown bellies. They become quite long (max. 200 cm) but remain slender.
This is one of the smaller cobras in the region (max. 170 cm). There are several colour phases, but usually it is dark yellow or copper coloured. The photo shows the speckled form, which is also found here. The venom is highly neurotoxic and the snake is not as shy as the Boomslang. It will readily rear up and attack when disturbed. Death usually occurs from the rapid onset of paralysis. Large amounts of antivenom is required.
As the name indicates, this is a nocturnal snake, which rests up under logs and in termitaria during the day. It has poor eyesight and hunts mainly by smell. Although this snake is poisonous, it's venom is not very potent and causes mainly pain and swelling.
This is a thick, heavily built snake, reaching a maximum length of 120 cm. Females give live birth and can have between 20 to 40 young. A Puffadder hunts by ambush, and is less likely to move out of the way than most other snakes. It hisses ominously when disturbed, hence the name "puff" adder. This is one of the front-fanged snakes. When it strikes, the fangs fold forward and inject venom into the prey on impact. The venom is cytotoxic and is usually deeply injected. About 60% of serious bites in Southern Africa are caused by Puffadders, and it is also responsible for most of the fatalities. It is found throughout Southern Africa.
Tel: +27 (0) 41 504 1111
Fax: +27 (0) 41 504 2574 / 2731
PO Box 77000, Nelson Mandela Metropolitan University
Port Elizabeth, 6031, South Africa
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