Angulate tortoise (Chersina angulata)

Description

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Angulate tortoise fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Angulate tortoise description

A distinguishing feature of the angulate tortoise is its greatly enlarged ‘gular scute’, the frontmost part of its lower shell, under the head, which is used by the male as a weapon to ram and overturn other males when fighting for dominance ^{(3) (4) (5)}. A small to medium-sized ⁽³⁾ and rather colourful tortoise ⁽⁶⁾, the angulate tortoise has an elongated, domed carapace (upper shell), which is yellowish brown to olive in colour. Wide dark borders and dark centres mark the scutes on the top of the carapace, and dark triangles decorate the seams of the scutes around its lower edge. The plastron, or lower shell, is yellow to reddish, with a wide black mark down the centre. The head is usually dark, often with yellow on top, the jaws are weakly serrated, and the upper jaw is hooked. The limbs are yellowish or brown and the toes bear strong claws ⁽⁴⁾. Male angulate tortoises are distinguished from females by being larger, and having a longer gular scute, longer tail, and concave plastron ^{(3) (4) (6)}.

Also known as

angulated tortoise, Bowsprit tortoise, South African bowsprit tortoise.

Synonyms

Testudo angulata.

Size

Male carapace length: up to 27.2 cm ⁽²⁾

Female carapace length: up to 21.6 cm ⁽²⁾

Male weight: up to 2.1 kg ⁽²⁾

Female weight: up to 1.8 kg ⁽²⁾

Angulate tortoise biology

The angulate tortoise feeds on a variety of angiosperms (flowering plants), as well as mosses, mushrooms, insects, snail shells and animal faeces ⁽¹¹⁾. Activity patterns depend largely on temperature: on cool or wet days and in winter, the angulate tortoise is most active during the middle of the day, while in spring and summer it is less active during this hottest part of the day ⁽¹²⁾. Mating is most common between September and April. The male may pursue and bite at the legs and tail of the female during courtship ^{(3) (4)}, as well as engaging in combat with rival males ^{(3) (4) (5)}. When the time comes to nest, the female digs a hole, up to ten centimetres deep, into which usually only a single, oval-shaped egg is laid ^{(3) (4) (13)}. Each female may potentially lay up to six times a year ⁽¹³⁾. The egg hatches after 4 to 14 months ^{(4) (8)}, the new hatchling having a flattened shell a mere 4 centimetres long ^{(3) (4)}. Reproductive maturity is not reached until about ten years of age ⁽⁵⁾.

Angulate tortoise range

The angulate tortoise is endemic to South Africa and southwestern Namibia. It is particularly abundant in parts of the Cape Floristic Region, and occurs at elevations of up to 900 metres or more ^{(4) (7) (8)}. The species has also been introduced to Dassen Island, off the coast of South Africa ⁽⁹⁾, and further north at Swakopmund and Walvis Bay in Namibia ⁽¹⁰⁾.

Angulate tortoise habitat

The angulate tortoise inhabits a wide range of habitats, including Fynbos, Succulent Karoo, Nama Karoo, and Albany Thicket ^{(2) (3) (4)}.

Angulate tortoise status

Listed on Appendix II of CITES ⁽¹⁾.

Angulate tortoise threats

The Cape Floristic Region is seriously threatened by a range of human activities which have greatly reduced the habitat of the angulate tortoise. Many areas have been extensively cultivated, forcing the angulate tortoise to survive in marginal areas of habitat which are often small and fragmented ^{(7) (14)}. Even in upland areas where soils are less fertile, farming based on native crops, such as rooibos tea and cut flowers, is rapidly reducing the angulate tortoise’s natural habitat, while dense stands of alien plants provide a further threat ⁽⁷⁾. Although the angulate tortoise is commonly kept as a pet ⁽⁶⁾, little information is available on wild trade in this species.

Angulate tortoise conservation

The angulate tortoise is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that international trade in angulate tortoises should be carefully monitored and controlled ⁽¹⁾. Tortoises in South Africa and Namibia are protected wildlife, and permits are required for their collection or exportation ⁽⁸⁾. A number of conservation measures are being undertaken in the Cape Floristic Region, including the removal of alien plants and the expansion of protected areas ⁽⁷⁾. However, although around 14 percent of this unique region has some level of protection, these protected areas are not thought to be entirely representative of the region’s biodiversity ⁽⁷⁾, and improved protection of the angulate tortoise’s habitat may be required if the species is not to suffer declines in the future.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

For more information on tortoises and turtles and their conservation, see:

• World Chelonian Trust:
  http://www.chelonia.org
• Turtle Conservation Fund:
  http://www.turtleconservationfund.org/
• Turtle Survival Alliance:
  http://www.turtlesurvival.org/
• Turtles of the World (CD-ROM), by Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W.:
  http://nlbif.eti.uva.nl/bis/turtles.php?menuentry=inleiding

Authentication

Authenticated (30/05/09) by Professor Margaretha D. Hofmeyr, University of the Western Cape, South Africa.
http://www.bcb.uwc.ac.za/staff/rhofmeyr.asp

Glossary

Albany Thicket

A biome (major regional biological community) in the Eastern Cape of South Africa, characterised by dense, spiny shrubland dominated by succulents (plants with thick, fleshy, water-storing stems and leaves).

Cape Floristic Region

An area occupying about 90,000 square kilometres in South Africa that contains an incredibly high diversity of plant species (around 8,700 species), of which 68 percent are found no where else.

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Fynbos

The natural shrubland vegetation occurring in the southwestern and southern Cape of South Africa, holding the greatest diversity of plant species in the world. Fynbos is characterised by tall shrubs with large leaves, heath-like shrubs, wiry reed-like plants, and bulbous herbs.

Nama Karoo

An open, arid biome (major regional biological community) on the central plateau of the Cape Province in South Africa, and extending into Namibia. The Nama Karoo is dominated by dwarf shrubland.

Scutes

Horny scales of keratin that cover the bony shell of a turtle or tortoise.

Succulent Karoo

An arid biome (major regional biological community) extending down the Atlantic coast of Namibia and South Africa, and characterised primarily by the presence of low winter rainfall and extreme summer aridity. The vegetation is dominated by dwarf, succulent shrubs (shrubs with thick, fleshy, water-storing stems and leaves), and the region has the richest succulent flora in the world.

References

1. CITES (November, 2008)
   http://www.cites.org
2. Boycott, R.C. and Bourquin, O. (2000) The South African Tortoise Book: A Guide to Southern African Tortoises, Terrapins and Turtles. Privately printed, Hilton, South Africa.
3. Branch, W.R. (1984) Preliminary observations on the ecology of the angulate tortoise (Chersina angulata) in the Eastern Cape Province, South Africa. Amphibia-Reptilia, 5(1): 43 - 55.
4. Turtles of the World (CD-ROM), by Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W. (November, 2008)
   http://nlbif.eti.uva.nl/bis/turtles.php?selected=beschrijving&menuentry=soorten&id=358
5. Mann, G.K.H., O’Riain, M.J. and Hofmeyr, M.D. (2006) Shaping up to fight: sexual selection influences body shape and size in the fighting tortoise (Chersina angulata). Journal of Zoology, 269: 373 - 379.
6. World Chelonian Trust (November, 2008)
   http://www.chelonia.org/
7. Mittermeier, R.A., Gil, P.R., Hoffmann, M., Pilgrim, J., Brooks, T., Mittermeier, C.G., Lamoreux, J. and Da Fonseca, G.A.B. (2004) Hotspots Revisited. CEMEX, Mexico City.
8. Hofmeyr, M.D. (2009) Pers. comm.
9. Van Heezik, Y.M., Cooper, J. and Seddon, P.J. (1994) Population characteristics and morphometrics of angulate tortoises on Dassen Island, South Africa. Journal of Herpetology, 28(4): 447 - 453.
10. Griffin, M. (2003) Annotated Checklist and Provisional National Conservation Status of Namibian Reptiles. Namibia Wissenschlaftliche Gesellschaft, Windhoek, Namibia.
11. Joshua, Q.I. (2008) Seasonal effects on the feeding ecology and habitat of Chersina angulata in the southwestern Cape. PhD Dissertation, University of the Western Cape, Bellville, South Africa.
12. Ramsay, S.L., Hofmeyr, M.D. and Joshua, Q.I. (2002) Activity patterns of the angulate tortoise (Chersina angulata) on Dassen Island, South Africa. Journal of Herpetology, 36(2): 161 - 169.
13. Hofmeyr, M.D. (2004) Egg production in Chersina angulata: an unusual pattern in a Mediterranean climate. Journal of Herpetology, 38(2): 172 - 179.
14. Ferri, V. (2002) Turtles and Tortoises. Firefly Books Limited, Ontario.