dcsimg

Biology ( Inglês )

fornecido por Arkive
Little is known about the natural ecology and behaviour of this elusive snake. Primarily nocturnal, juveniles and adult males in particular are partially arboreal. Their diet is composed exclusively of lizards, some of which are also endangered species endemic to Round Island (7). The breeding season is thought to begin in April although young have been observed at practically all times of the year. A clutch of up to 12 soft-shelled eggs is laid, perhaps amongst leaf litter or in a hollow palm trunk, and may be attended by the female (7). The incubation period is about 90 days, unusually long for a snake; young are born weighing less than 5 grams and are bright orange in colour (6).
licença
cc-by-nc-sa-3.0
direitos autorais
Wildscreen
original
visite a fonte
site do parceiro
Arkive

Conservation ( Inglês )

fornecido por Arkive
Round Island is a protected area and visitors to the island are restricted to scientists and conservationists (4). Rabbits and goats have been eradicated and the native vegetation of the island, much of which is itself endemic and endangered, is beginning to recover. The Government of Mauritius and the Mauritian Wildlife Foundation are also running an intensive habitat restoration programme (7). International trade is prohibited by the listing of this snake on Appendix I of the Convention on International Trade in Endangered Species (3). A captive breeding programme has been established with the aim of safeguarding the future of this rare snake and learning more about its complex biology (2). The Round Island keel-scaled boa is one of two snakes to be found only on this island, belonging to an ancient line that dates back over 60 million years (5). Its relative Bolyeria multocarinata however, has not been seen in the wild since 1975 and is feared to be extinct (2).
licença
cc-by-nc-sa-3.0
direitos autorais
Wildscreen
original
visite a fonte
site do parceiro
Arkive

Description ( Inglês )

fornecido por Arkive
The Round Island keel-scaled boa is one of the world's rarest snakes (2). This slender snake may reach up to 1.5 metres in length, the upper surface is generally dark brown whilst the underside is lighter with very dark spots. The body is covered in small, keeled scales that give rise to the species' common name (2).
licença
cc-by-nc-sa-3.0
direitos autorais
Wildscreen
original
visite a fonte
site do parceiro
Arkive

Habitat ( Inglês )

fornecido por Arkive
Historically inhabited tropical hardwood forest and palm savannah, but since the introduction of goats and rabbits to the island much of this habitat has been destroyed. As a result of habitat degradation the boa currently persists in degraded palm savannah and shrub layer vegetation (7).
licença
cc-by-nc-sa-3.0
direitos autorais
Wildscreen
original
visite a fonte
site do parceiro
Arkive

Range ( Inglês )

fornecido por Arkive
Found only on Round Island off the north coast of Mauritius in the Indian Ocean (4).
licença
cc-by-nc-sa-3.0
direitos autorais
Wildscreen
original
visite a fonte
site do parceiro
Arkive

Status ( Inglês )

fornecido por Arkive
Classified as Endangered (EN - D) on the IUCN Red List 2002 (1), and listed on Appendix I of CITES (3).
licença
cc-by-nc-sa-3.0
direitos autorais
Wildscreen
original
visite a fonte
site do parceiro
Arkive

Threats ( Inglês )

fornecido por Arkive
Habitat loss has been rife throughout the Mascarene Islands. Vast tracts of native forest (over 90%) have been cleared to make way for agriculture and on Round Island the introduction of rabbits and goats has further damaged native flora (5); however, these were removed during the 1980's. Perhaps 500 adults remain (with a total population of approximately 1000 individuals) on the 159-hectare Round Island (7).
licença
cc-by-nc-sa-3.0
direitos autorais
Wildscreen
original
visite a fonte
site do parceiro
Arkive

Distribution ( Inglês )

fornecido por ReptileDB
Continent: Indian-Ocean
Distribution: Round Island (off the coast of Mauritius)
Type locality: Round Island
licença
cc-by-nc-sa-3.0
direitos autorais
Peter Uetz
original
visite a fonte
site do parceiro
ReptileDB

Round Island boa ( Inglês )

fornecido por wikipedia EN

The Round Island boa (Casarea dussumieri),[4] also known commonly as the Round Island keel-scaled boa[1] and the Round Island ground boa,[1] is a species of nonvenomous snake in the monotypic genus Casarea in the family Bolyeriidae.[5][6] The species is endemic to Round Island, Mauritius. No subspecies are currently recognized.[4][6]

Etymology

The specific name, dussumieri, is in honor of Jean-Jacques Dussumier, a French merchant, ship owner, and collector of zoological specimens.[7]

Description

Adult female

Adults of C. dussumieri are slender and reach a maximum total length (including tail) of 150 cm (5 ft). The males have slimmer, more pointed heads and have shorter bodies than the females. The body is covered in small keeled scales that give the species one of its common names. The genus is unique among extant vertebrates as it has a split jaw (intramaxilliary joint that separates anterior and posterior bones), an adaptation that may be advantageous in catching its main prey of geckos and skinks.

The colour pattern is dark brown dorsally, the belly being lighter with dark spots. Over a 24-hour period the boa has a shift in colour, changing from "dark" during its relatively inactive day time period to "light" in the early evening through to dawn when it is most active. This effect is created through polychromatic skin cells.

Geographic range

C. dussumieri is known to survive on Round Island, but has been recorded on the islands of Gunner's Quoin, Flat Island, Ile de la Pas, and on mainland Mauritius (as subfossil remains).[3]

The type locality is "I'île ronde, près de Maurice " (Round Island, Mauritius).[3]

Between 11 and 31 October 2012 the boa was reintroduced into Gunner's Quoin as part of a joint collaborative project involving the Durrell Wildlife Conservation Trust, the Mauritian Wildlife Foundation, and the National Parks and Conservation Service of Mauritius.[8]

Conservation status

The species C. dussumieri is classified as Endangered (E) on the IUCN Red List for the following criteria: D (v2.3, 1994).[1] This means that, although it is not critically endangered, for some time it has faced a very high risk of extinction in the wild. In 1996 the population was estimated to number less than 250 mature individuals.[9]

Recent conservation efforts have seen an increase in the number of adult Round Island boas to around 1,000. This has been achieved by eradicating goats and rabbits from the island and restoring natural habitat, which has led to an increase of the Round Island boas’ natural prey, lizards. In recent breeding efforts, Round Island boas in captivity have been fed by scenting small mice with chicken thigh meat.

Reproduction

In C. dussumieri, breeding begins during April, although young have been observed throughout the year. A clutch of up to 12 soft-shelled eggs may be laid amongst leaf litter or in hollow palm trunks, and is sometimes attended by the female. Incubation is unusually long for a snake, lasting about 90 days. The young are bright orange at birth and weigh less than 5 grams.

References

  1. ^ a b c d Cole, N.; Hector, A.; Roopa, P.; Mootoocurpen, R.; Goder, M. (2018). "Casarea dussumieri". IUCN Red List of Threatened Species. 2018: e.T3989A152276140. doi:10.2305/IUCN.UK.2018-2.RLTS.T3989A152276140.en. Retrieved 17 November 2021.
  2. ^ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. ^ a b c d McDiarmid RW, Campbell JA, Touré TA (1999). Snake Species of the World: A Taxonomic and Geographic Reference, Volume 1. Washington, District of Columbia: Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).
  4. ^ a b "Casarea dussumieri ". Integrated Taxonomic Information System. Retrieved 16 August 2007.
  5. ^ "Casarea Gray, 1842". Integrated Taxonomic Information System. Retrieved 25 March 2015.
  6. ^ a b Casarea dussumieri at the Reptarium.cz Reptile Database. Accessed 25 March 2015.
  7. ^ Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN 978-1-4214-0135-5. (Casarea dussumieri, p. 78).
  8. ^ "Blog | Durrell Wildlife Conservation Trust".
  9. ^ 1994 Categories & Criteria (version 2.3)IUCN Red List. Accessed 16 August 2007.
licença
cc-by-sa-3.0
direitos autorais
Wikipedia authors and editors
original
visite a fonte
site do parceiro
wikipedia EN

Round Island boa: Brief Summary ( Inglês )

fornecido por wikipedia EN

The Round Island boa (Casarea dussumieri), also known commonly as the Round Island keel-scaled boa and the Round Island ground boa, is a species of nonvenomous snake in the monotypic genus Casarea in the family Bolyeriidae. The species is endemic to Round Island, Mauritius. No subspecies are currently recognized.

licença
cc-by-sa-3.0
direitos autorais
Wikipedia authors and editors
original
visite a fonte
site do parceiro
wikipedia EN