Island Racer

 



Galapagos racer

Near Threatened (IUCN 3.1)[1]
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Reptilia
Order:Squamata
Suborder:Serpentes
Family:Colubridae
Genus:Pseudalsophis
Species:
Binomial name
Pseudalsophis biserialis
(Günther, 1860)
  1. Island Racer
  2. Island Racer Hawaii
  3. Island Racer Hawaii

The Galápagos racer (Pseudalsophis biserialis or Philodryas biserialis) is a colubrid snake in the genus Pseudalsophis that is endemic to the Galápagos Islands. It is a mildly venomous constrictor but it is not considered aggressive or harmful to humans. The two subspecies are the eastern and western racers, the latter being larger, longer, and darker than the former. The western subspecies specializes in hunting fish, while both subspecies eat small reptiles, eggs, rodents, and bird hatchlings. The Galapagos racer is near threatened due to recently introduced species that feed on snake eggs, including pigs, rats, mice, and cats.[1][2][3] It is one of only three species of snakes on the Galápagos Islands, and it was first described in 1860.[4][5] In November 2016, a video clip from the BBC series Planet Earth II showing a group of Galápagos racers hunting marine iguana hatchlings became a viral trend.[6]

Taxonomy and etymology[edit]

Originally classified as Herpetodryas biserialis by Albert Günther in 1860,[7] this species has been renamed numerous times since then.[8][9] The generic names have included Dromicus, Orpheomorphus, and Oraphis.[10]

References[edit]

  1. ^ abMárquez, C.; Cisneros-Heredia, D.F. & Yánez-Muñoz, M. (2017). 'Pseudalsophis biserialis'. IUCN Red List of Threatened Species. 2017: e.T190541A56253872. doi:10.2305/IUCN.UK.2017-2.RLTS.T190541A56253872.en.
  2. ^'Pseudalsophis biserialis'.
  3. ^'Galapagos racer - Galapagos Conservation Trust'.
  4. ^Günther,A. 1860. On a new snake from the Galapagos islands. Ann. Mag. Nat. Hist. (3) 6: 78-79
  5. ^Thomas, Robert A 1997. Galapagos terrestrial snakes: biogeography and systematics. Herpetological Natural History 5 (1): 19-40
  6. ^Conversation, Rhys Jones, The. 'In Defence of Racer Snakes - The 'Bad Guys' of Snake vs Iguana'.
  7. ^Günther, A. 1860. On a new snake from the Galapagos Islands Herpetodryas biserialis. Proceedings of the Zoological Society of London 1860: 97-98.
  8. ^George R. Zug (28 June 2013). Reptiles and Amphibians of the Pacific Islands: A Comprehensive Guide. Univ of California Press. p. 222. ISBN978-0-520-27495-2.
  9. ^Julian Fitter; Daniel Fitter; David Hosking (5 January 2016). Wildlife of the Galápagos: Second Edition. Princeton, New Jersey: Princeton University Press. p. 96. ISBN978-0-691-17042-8.
  10. ^Van Denburgh, John (1912). The Snakes of the Galapagos Islands. California Academy of Science. pp. 325–327.

External links[edit]

Retrieved from 'https://en.wikipedia.org/w/index.php?title=Galapagos_racer&oldid=1014847571'

Trusted Windows (PC) download Island Racer 3.1.0.0. Virus-free and 100% clean download. Get Island Racer alternative downloads. Island Dragway, Great Meadows, NJ. 19,254 likes 361 talking about this 20,549 were here. Feel free to add your own photos and video to our page!

(Redirected from Antiguan Racer)
Antiguan racer

Critically Endangered (IUCN 3.1)
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Reptilia
Order:Squamata
Suborder:Serpentes
Family:Colubridae
Genus:Alsophis
Species:
Binomial name
Alsophis antiguae
Parker, 1933[1]

The Antiguan racer (Alsophis antiguae) is a harmless rear-fanged (opisthoglyphous) grey-brown snake that was until recently found only on Great Bird Island off the coast of Antigua, in the eastern Caribbean. It is among the rarest snakes in the world. However, in the last 20 years, conservation efforts have boosted numbers from an estimated 50 to over 1,100 individuals by eradicating non-native predators and reintroducing the snake to other Antiguan islands in its original range. In addition to Great Bird Island, the Antiguan racer has successfully recolonised the nearby Rabbit Island, Green Island, and York Island.

Taxonomy[edit]

Island

The Antiguan racer is a snake that belongs to the family Dipsadinae, which includes about half of the world's known snake species. It belongs to the genus Alsophis, which contains several species of West Indian racers. Many West Indian racers are threatened or extinct.[2]

Description[edit]

This racer exhibits sexual dimorphism.[2] The adult racer is typically about 1 m long, with females being larger than the males.[2] Young adult males are usually dark brown with light creamy markings, while young females are silvery-gray with pale brown patches and markings.[2] Females also have larger heads than the males.[3] However, older individuals of both sexes can be highly variable in colour hue and pattern, and are frequently heavily speckled or blotched in a range of hues, including white, taupe, reddish brown, brown, and black.

Distribution and habitat[edit]

The Antiguan racer originally inhabited Antigua and Barbuda and probably all of the islands on the Antigua Bank. By 1995, the species was found only on Great Bird Island, a small island 2.5 km off of the northeast coast of Antigua.[4] The island is extremely small at only 8.4 hectares.[4] It prefers to live in shady woodlands with dense undergrowth, although it is also found on sandy beaches and rocky outcrops.[2]

Ecology and behavior[edit]

The Antiguan racer is harmless to humans and has a gentle temperament.[2] It is diurnal, being active from dawn to dusk.[2] At night, it rests in a hidden shelter.[2] The Antiguan racer appears to have poor resistance to common snake mites, which are not naturally found in Antigua, which has ended some attempts at captive breeding.[5]

The racer primarily eats a diet of lizards, including the local Antiguan ground lizard.[2] While the species sometimes hunts for its food, it is typically an ambush predator, waiting for prey with most of its body buried beneath leaves.[2]

Relationship with humans[edit]

Island Racer

In the centuries before the Europeans arrived in Antigua, the Antiguan racers were numerous and widespread. The thick forest that covered the islands teemed with lizards, the snakes' favored prey, and the racer had no natural predators to threaten it.[6]

In the late 15th century, European settlers began to colonize and develop Antigua and Barbuda for huge plantations of sugarcane. The ships that brought slaves to the island (and those that also or instead carried away rum or other tropical products) also brought rats. Feasting on the sugarcane and, among other things, the eggs of the Antiguan racer, the rat population rocketed.[6]

The plantation owners, desperate to rid themselves of the rats, introduced Asian mongooses to kill the rats. However, they failed to realize that black rats (Rattus rattus) are mainly nocturnal, while the mongooses prefer to hunt during the day. The mongooses preyed heavily on the native ground-nesting birds, frogs, lizards, and Antiguan racers. Within 60 years, the snake had vanished completely from Antigua and most of its offshore islands, and many believed that it had become extinct.[6]

However, a few Antiguan racers survived on a tiny mongoose-free island known as Great Bird Island. A 3-month survey by conservation biologists from Fauna & Flora International found only 50 individuals alive in 1995.[7]

Conservation work quickly got under way with the eradication of rats, which threatened the racers on Great Bird Island.[8] The effort succeeded. In 1996, five adult racers were collected and sent to the Jersey Zoo for the first attempt at captive breeding.[5] The female racers laid 11 eggs with five hatching, but proved to be difficult to keep in captivity due to their feeding habits and low resistance to diseases. Nine of the 10 captive racers died because of the common snake mite.[5]

However, the eradication of rats and mongooses on Great Bird Island led to a population increase, with the number of racers on the island doubling in two years.[9] However, 20% of the racers were underweight because of the lack of prey lizards to maintain the population levels.[9] Efforts began to clear other offshore islands of Antigua of rats and mongooses to reintroduce the snake so the population could continue to grow.[9] Antiguan racers have been successfully reintroduced to Rabbit Island (1999), Green Island (2001), and York Island (2008), and their total population has increased to more than 1,000.[10]

The Antiguan racer was recently threatened by hurricanes, such as Hurricane Luis, Hurricane Georges, and Hurricane Irma, and now by deliberate killing by humans (despite being protected by law), flooding, drought, and inbreeding due to low genetic diversity.[11]

References[edit]

  1. ^Day, M. (2007). 'Alsophis antiguae'. 2007 IUCN Red List of Threatened Species. IUCN. Archived from the original on 19 December 2007. Retrieved 2007-12-15.CS1 maint: discouraged parameter (link)
  2. ^ abcdefghij'The S Files'. The Antiguan Racer Conservation Project. 2001. Archived from the original on 31 December 2007. Retrieved 2007-12-15.CS1 maint: discouraged parameter (link)
  3. ^'Antiguan Racer'. ARKive. Archived from the original on 2007-12-19. Retrieved 2007-12-15.CS1 maint: discouraged parameter (link)
  4. ^ ab'The Last Resort'. The Antiguan Racer Conservation Project. 2001. Archived from the original on 14 November 2007. Retrieved 2007-12-15.CS1 maint: discouraged parameter (link)
  5. ^ abc'Safety Net'. Antiguan Racer Conservation Project. 2001. Archived from the original on 2002-02-05. Retrieved 2007-12-21.CS1 maint: discouraged parameter (link)
  6. ^ abc'Hiss-tory'. Antiguan Racer Conservation Project. 2001. Archived from the original on 31 December 2007. Retrieved 2007-12-15.CS1 maint: discouraged parameter (link)
  7. ^'The Project: Mission Impossible?'. The Antiguan Racer Conservation Project. 2001. Archived from the original on 17 December 2007. Retrieved 2007-12-15.CS1 maint: discouraged parameter (link)
  8. ^'Removal Service'. Antiguan Racer Conservation Project. 2001. Archived from the original on 2002-04-29. Retrieved 2007-12-21.CS1 maint: discouraged parameter (link)
  9. ^ abc'Safety Net'. Antiguan Racer Conservation Project. 2001. Archived from the original on 2002-01-28. Retrieved 2007-12-21.CS1 maint: discouraged parameter (link)
  10. ^Fauna & Flora International. 'Antiguan racer'. Retrieved 17 May 2015.CS1 maint: discouraged parameter (link)
  11. ^'Problems'. Antiguan Racer Conservation Project. 2001. Archived from the original on 25 December 2007. Retrieved 2007-12-21.CS1 maint: discouraged parameter (link)

Island Racer Hawaii

External links[edit]

Island Racer Hawaii

Retrieved from 'https://en.wikipedia.org/w/index.php?title=Antiguan_racer&oldid=1010386244'