Bolyeria multocarinata


Kingdom Animalia

No Image

Do you have one? Send it!

Phylum Chordata
Class Reptilia
Order Squamata
Family Bolyeriidae
Genus Bolyeria
Species Bolyeria multocarinata
Authority (Boie, 1827)
English Name Round Island Burrowing Boa, Smooth-scaled Splitjaw Snake
Dutch Name Round eiland-boa
Finnish Name Koloboa, Roundsaarenboa
French Name Boa Fouisseur de l'Île Ronde, Boa Fouisseur de l'Île Maurice, Bolyeride
German Name Mauritiusboa
Japanese Name ボリエリアボア
Portuguese Name Jibóia-da-ilha-round
Spanish Name Boa Excavadora de Round Island
Synonyms Eryx Multocarinata F. Boie, 1827; Tortrix Pseudo-Eryx Schlegel, 1837; Bolyeria Pseudo-Eryx Gray, 1842; Platygaster multicarinatus A.M.C. Duméril & Bibron, 1844; Bolyeria multicarinata Gray, 1849; Bolyeria multicarinata Boulenger, 1893; Bolyeria multocarinata Stimson, 1969
Taxonomy These snakes were formerly placed in the Boidae (Boas), but are now classed as a separate family, the Bolyeriidae (Splitjaw snakes) Bolyeriidae was formerly considered a subfamily of Boidae. It now is recognized that the Bolyeriidae is an unique lineage not closely allied with the Boidae. Currently, two monotypic genera (Bolyeria and Casarea) are recognized. (Barker and Barker 2007)
Characteristics The Round Island Burrowing Boa reached a length of about 1 m (39 in). Preserved specimens have reported total lengths of 54-140 cm (Boullenger 1893; Vinson 1949; Vinson 1975; Bullock 1977). Vinson (1949) even claimed that its maximum size was 1,8 m. The colour in life has been described as light brown with small blackish spots dorsally and pink marbled with blackish ventrally (Pike 1873; Vinson 1975) It was characterized by a pointed snout and by a cylinder-shaped body and head. (Day 1981; Bauer and Günther 2004; Wikipedia contributors 2007)
Lifestyle Little is known about the lifestyle of this snake. Its general body form suggests that the Round Island Burrowing Boa had fossorial tendencies, while its relative the Round Island keel-scaled Boa Casarea dussumieri seems more inclined towards surface dwelling or even toward an arboreal existence. Vinson (1953) notes that on an expedition to Round Island in 1952, "a member of the party reported the presence of a brownish snake quickly burrowing in holes on the ground". (Frazzetta 1970)
Range & Habitat In the past, Bolyeria was found in Mauritius on Gunner's Quoin, Flat Island, Mauritius, Round Island and Ile de la Passe (McDiarmid 1999). Later this snake species was restricted only to Round Island, a 151 ha volcanic islet approximately 0.25 ha north-northeast of Mauritius. This snake was found in the palm groves of mid-altitude top-soil layers on volcanic slopes. (Madagascar Reptile & Amphibian Specialist Group 1996)

Image: map showing the location of the island of Mauritius, the larger island close to the islands on which the Round Island Burrowing Boa once ranged. Created by Peter Maas for The Extinction Website. This image has been released under the Creative Commons Attribution Non-commercial No Derivatives 3.0 Licence. This applies worldwide.

Food The natural diet of the Round Island Burrowing Boa is unknown, although it is assumed to eat lizards, as does its relative the Round Island keel-scaled Boa Casarea dussumieri. (Bauer and Günther 2004)
History & Population After having disappeared from the islands of Mauritius, Gunner's Quoin, Flat Island, and Ile de la Passe. The last stronghold of this species was Round Island where it was once reasonably common. The Round Island Burrowing Boa was already rare by 1949. One individual and believed to be the last survivor of the species, was found in surveys of Round Island in the 1960s and early 1970s. It was last seen in 1975 despite intensive searches in between 1975 and 2001. (Day 1981; McDiarmid 1999; Bauer and Günther 2004; Barker and Barker 2007)
Extinction Causes The introduction of rabbits and goats to the island in 1840 resulted in damage to the vegetation, consequently causing soil erosion on the volcanic slopes and deterioration of palm forest habitat. This decline in habitat quality is thought to have been the main reason for the extinction of the Round Island Burrowing Boa. (Madagascar Reptile & Amphibian Specialist Group 1996)
Conservation Attempts Round Island is a nature reserve under the jurisdiction of the Mauritian Ministry of Agriculture and Natural Resources.
Museum Specimens The holotype of Bolyeria multocarinata can be found in the collection of Muséum National d'Histoire Naturelle in Paris, France. Five additional specimens have been reported in literature: three in The Natural History Museum in London, United Kingdom. One other in the Mauritius Institute (Korsós and Trócsányi 2002) and a stuffed specimen of which its current whereabouts are unknown (Vinson 1975). In 2004 it was reported that an additional specimen of this extinct snake, a male, can be found in the collection of the Museum für Naturkunde in Berlin, Germany. (Bauer and Günther 2004)

This species' closest living relative is Round Island keel-scaled Boa or Keel-scaled Splitjaw Snake Casarea dussumieri (Schlegel, 1837). This snake is endemic to Round Island. It is the only surviving member of the family Bolyeriidae. (Bauer and Günther 2004; Barker and Barker 2007)

Photo: head of an adult Round Island keel-scaled Boa (Casarea dussumieri). Photographed by Jean-Jacques Argoud in May 1986. This image has been released under the Creative Commons Attribution ShareAlike 3.0 Licence.


IUCN Red List of Threatened Species: Bolyeria multocarinata

Bolyeria - Wikipedia, the free encyclopedia



(Complete website)

Barker, D.G., Barker, T.M. (2007). Splitjaw Snakes (Bolyeriidae). Downloaded on 26 December 2007 from

Bauer, A. & R. Günther (2004): On a newly identified specimen of the extinct bolyeriid snake Bolyeria multocarinata (Boie, 1827).- Herpetozoa 17 (3/4): 179-181.

Boie, F. (1827). Bemerkungen über Merrem's Versuch eines Systems der Amphibien. Marburg. 1820. Isis von Oken, Jena; 20: columns 508-566.

Boulenger, G.A. (1893): Catalogue of the snakes in the British Museum (Natural History). Volume 1. London (Trustees of the British Museum (Natural History)), 448 pp.

Bullock, D.J. (1977). Round Island - a tale of destruction. Oryx, London; 14: 51-58.

Day, D., 1981, The Doomsday Book of Animals, Ebury Press, London. ISBN 0 85223 183 0.

Korsós, Z. and Trócsányi, B. (2002). Herpetofauna of Round Island, Mauritius. Biota, Race. 3: 77-84.

Frazzetta, T.H. (1970). From Hopeful Monsters to Bolyerine Snakes? he American Naturalist, Vol. 104, No. 935 (Jan. - Feb., 1970), pp. 55-72

Madagascar Reptile & Amphibian Specialist Group (1996). Bolyeria multocarinata. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <>. Downloaded on 26 December 2007.

McDiarmid, R.W., Campbell, J.A., Touré, T. (1999). Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).

Pike, N. (1873). Subtropical rambles in the land of the Aphanapteryx. New York (Harper and Brothers), XVIII + 509 pp.

Vinson, J.M. (1949). L'île Ronde et l'île aux Serpents. Proc. Roy. Soc. Arts. Sci Mauritius, Port Louis. 1: 32-52.

Vinson, J.M. (1953). Some recent data on the fauna of Round and Serpent Islands. Proc. Roy. Soc. Arts. Sci. Mauritius Inst. Bull. Port Louis. 1: 253-257.

Vinson, J.M. (1975). Notes on the reptiles of Round Island. Mauritius Inst. Bull. Port Louis. 8: 49-67.

Wikipedia contributors (2007), "Bolyeria," Wikipedia, The Free Encyclopedia, (accessed December 26, 2007).

Last updated: 6th September 2008.

This page is a part of The Extinction Website. © 2000-2009.