Geometric Tortoise
Encyclopedia
The geometric tortoise is an endangered species
of tortoise
and one of three members of the genus
, Psammobates
. It is found in a very small section in the South-Western Cape of South Africa
.
Province, South Africa
. It used to also occur within what is now the city of Cape Town
, but the last Cape Town population (at the tiny Harmony Flats Reserve) died out. It was believed to be extinct in the 1960s but a surviving population was discovered in 1972 and it now occurs in three isolated pockets where it is conserved. A population in the Ceres valley
, one in the Tulbagh
-Worcester
valley, and a group surviving on the coastal lowlands to the southwest.
These colourful tortoises live only in lowland fynbos
and renosterveld
vegetation, meaning that their populations are easily isolated by mountains which they cannot cross.
It is one of the rarest tortoise species in the world
and Renosterveld
plants and grasses. Its very specific diet of local plant species means that it usually dies when kept in captivity.
. Little is known about their reproductive behavior. When the female is ready to lay eggs
, she digs a hole in the ground and covers it with grass or other vegetation.
, and only 2000 to 3000 individuals exist today. It is threatened for a number of reasons, but mainly due to loss of habitat. Restricted as it is to fertile lowlands and valleys, the vast majority of its tiny natural range has been covered with farms and housing.
In addition, its eggs are a source of food for the African people and traders capture the adults for their shells which are used to make many different decorative items. This species is also preyed upon by other mammals, particularly introduced mammals such as pigs and dogs.
The South African government has set aside restricted park lands for this unique tortoise, and there are laws that prohibit the capture and the taking of its eggs.
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
of tortoise
Tortoise
Tortoises are a family of land-dwelling reptiles of the order of turtles . Like their marine cousins, the sea turtles, tortoises are shielded from predators by a shell. The top part of the shell is the carapace, the underside is the plastron, and the two are connected by the bridge. The tortoise...
and one of three members of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, Psammobates
Psammobates
Psammobates is a genus of tortoise. This genus contains three member species, all of which are indigenous to Southern Africa.-Species:*Geometric Tortoise, Psammobates geometricus*Serrated Star Tortoise, Psammobates oculifer...
. It is found in a very small section in the South-Western Cape of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.
Identification
It has a very strong, black and yellow patternered carapace used for defense against predators. The patterns are arranged in ray-like markings and help the tortoise blend in with its environment. This tortoise is very small, and a full grown turtle can only reach about 5 to 6 inches in diameter.Habitat
The geometric tortoise is naturally restricted to the far south-western corner of the Western CapeWestern Cape
The Western Cape is a province in the south west of South Africa. The capital is Cape Town. Prior to 1994, the region that now forms the Western Cape was part of the much larger Cape Province...
Province, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
. It used to also occur within what is now the city of Cape Town
Cape Town
Cape Town is the second-most populous city in South Africa, and the provincial capital and primate city of the Western Cape. As the seat of the National Parliament, it is also the legislative capital of the country. It forms part of the City of Cape Town metropolitan municipality...
, but the last Cape Town population (at the tiny Harmony Flats Reserve) died out. It was believed to be extinct in the 1960s but a surviving population was discovered in 1972 and it now occurs in three isolated pockets where it is conserved. A population in the Ceres valley
Ceres, Western Cape
Ceres is a town with 46,251 inhabitants in the Western Cape Province of South Africa. It is the administrative centre and largest town of the Witzenberg Local Municipality. Ceres serves as a regional centre for the surrounding towns of Wolseley, Tulbagh, Op-die-Berg and Prince Alfred Hamlet...
, one in the Tulbagh
Tulbagh
Tulbagh is a town in the Tulbagh valley and is situated in the Witzenberg Local Municipality, with the valley called "Die Land van Waveren" locally. Closest towns are Wolseley, Prince Alfred's Hamlet, Gouda and Ceres in the Boland district of the Western Cape Province, South Africa.The valley has...
-Worcester
Worcester, Western Cape
Worcester is a town in the Western Cape, South Africa. It is located 120 km north-east of Cape Town on the N1 highway north to Johannesburg....
valley, and a group surviving on the coastal lowlands to the southwest.
These colourful tortoises live only in lowland fynbos
Fynbos
Fynbos is the natural shrubland or heathland vegetation occurring in a small belt of the Western Cape of South Africa, mainly in winter rainfall coastal and mountainous areas with a Mediterranean climate...
and renosterveld
Renosterveld
Renosterveld is a term used for one of the major plant communities and vegetation types of the Cape Floristic Region which is located in southwestern and southeastern South Africa, in southernmost Africa...
vegetation, meaning that their populations are easily isolated by mountains which they cannot cross.
It is one of the rarest tortoise species in the world
Diet
The geometric tortoise's diet consists mainly of the leaves, flowers, and shoots of a wide range of indigenous FynbosFynbos
Fynbos is the natural shrubland or heathland vegetation occurring in a small belt of the Western Cape of South Africa, mainly in winter rainfall coastal and mountainous areas with a Mediterranean climate...
and Renosterveld
Renosterveld
Renosterveld is a term used for one of the major plant communities and vegetation types of the Cape Floristic Region which is located in southwestern and southeastern South Africa, in southernmost Africa...
plants and grasses. Its very specific diet of local plant species means that it usually dies when kept in captivity.
Behaviour
They are said to hibernate in the months of June through September, or when their natural environment is not normal, or when in captivityCaptivity (animal)
Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals or wild animals. This may include for example farms, private homes and zoos...
. Little is known about their reproductive behavior. When the female is ready to lay eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
, she digs a hole in the ground and covers it with grass or other vegetation.
Threats and Conservation
The geometric tortoise has lost 97% of its habitatHabitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
, and only 2000 to 3000 individuals exist today. It is threatened for a number of reasons, but mainly due to loss of habitat. Restricted as it is to fertile lowlands and valleys, the vast majority of its tiny natural range has been covered with farms and housing.
In addition, its eggs are a source of food for the African people and traders capture the adults for their shells which are used to make many different decorative items. This species is also preyed upon by other mammals, particularly introduced mammals such as pigs and dogs.
The South African government has set aside restricted park lands for this unique tortoise, and there are laws that prohibit the capture and the taking of its eggs.