El Hierro giant lizard
- Gallotia simonyi redirects here. This page deals mostly with the extant subspecies Gallotia simonyi machadoi. For the extinct nominate subspecies, see here.
|Hierro giant lizard|
|Gallotia simonyi machadoi
Gallotia simonyi is a species of lacertid (wall lizard) that can be found on the island of El Hierro, one of the Canary Islands. The species was once present throughout much of the island and on the small offshore Roque Chico de Salmor, but is now confined to a few small areas of cliff with sparse vegetation. It is currently restricted to the southern end of the Risco de Tibataje in la Fuga de Gorreta, located between Guinea and the so-called Paso del Pino (an area of about four hectares). The species was also successfully reintroduced to the Roque Chico de Salmor in 1999, and subsequent reintroductions have taken place at Julan and at la Dehesa.(Miras & Pérez-Mellado 2005b)
About 60 centimetres (2.0 ft) long, the Hierro giant lizard is a thickset reptile with a broad head. Adults are dark grey to brown in colour, with two rows of pale orange patches running along its sides. Its belly is mostly brown, but has an orange to red colouration towards the middle. Older El Hierro giant lizards are mainly black with some grey. Males are larger than females.
The Hierro giant lizard is omnivorous. It eats plants - notably verode and Lavandula abrotanoides - as well as insects (ARKive 2006). Mating begins in May and 5 to 13 eggs are laid from June until the end of August. Their eggs hatch after 61 days.
Two subspecies are recognised:
- Roque Chico de Salmor giant lizard, Gallotia simonyi simonyi - extinct (c.1930s)
- El Hierro giant lizard or Hierro giant lizard (Spanish: Lagarto Gigante de El Hierro), Gallotia simonyi machadoi
Previously, Gallotia simonyi included the La Palma giant lizard and the La Gomera giant lizard as subspecies too (Miras 2005, Miras & Pérez-Mellado 2005a); the latter is known to be very closely related to the extant population (Maca-Meyer et al. 2003) and its specific distinctness is not universally accepted (e.g. Bischoff 2000). Subfossil remains from El Hierro that were assigned to the prehistorically extinct Gallotia goliath apparently belong to the present species (Barahona et al. 2000), but the population referred to G. goliath from Tenerife was distinct (Maca-Meyer et al. 2003).
Status and conservation
The nominate subspecies Gallotia simonyi simonyi was only known from the Roque Chico de Salmor, a small islet off northwestern Valverde municipality. It disappeared around the 1930s through unsustainable collecting of animals for scientific institutions and commercial interests, as well as predation by feral cats and possibly herring gulls (Diaz & Bischoff 1994, Miras & Pérez-Mellado 2005b). Following this population's disappearance, the species was believed to be entirely extinct.
In 1974, the German amateur herpetologist Werner Bings discovered a surviving population of this species on El Hierros mainland (Böhme & Bings 1975). This was subsequently determined to be a distinct subspecies, 100 years after the species was first described (López-Jurado 1989).
The population of this species is about 300 to 400 animals in the wild (including re-introduced populations), and it is classified as critically endangered by the 2006 IUCN Red List. This giant lizard's major threat is predation by feral cats, and possibly also by dogs and rats.
A recovery plan for the Hierro giant lizard has been developed and the United Nations and the Canary Islands Autonomous Government funded a program for the captive breeding and re-introduction of the Hierro giant lizard to its original natural habitat, including the Roque Chico de Salmor. Control of feral cats has been stopped in 2002, but according to the IUCN continued control of feral cats should be resumed to allow population recovery.
- ARKive (2006): Hierro giant lizard (Gallotia simonyi). Downloaded on 18 May 2006.
- Barahona, F.; Evans, S. E.; Mateo, J.A.; García-Márquez, M. & López-Jurado, L.F. (2000): Endemism, gigantism and extinction in island lizards: the genus Gallotia on the Canary Islands. J. Zool. 250(3): 373-388. doi:10.1017/S0952836900003101 (HTML abstract)
- Bischoff, Wolfgang (2000): DGHT-AG Lacertiden aktuell: Rieseneidechsen auf La Gomera. Version of 2000-MAY-23. Retrieved 2007-FEB-25.
- Böhme, W. & Bings, Werner (1975): Zur Frage des Überlebens von Lacerta s. simonyi Steindachner. Salamandra 11(1): 39-46. [Article in German]
- Diaz, Carlos Naeslund & Bischoff, Wolfgang (1994): Studien am Roque Chico de Salmor bei El Hierro (Kanaren): 1. Mögliche Ursachen für das Aussterben von Gallotia simonyi, 2. Die Artzugehörigkeit seiner Geckos (Tarentola). Salamandra 30(4): 246-253. [Article in German] HTML abstract
- European Commission (EC) (2003): Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora. Annex IV - Animal and plant species of community interest in need of strict protection. Treaty of Accession 2003. PDF fulltext
- European Environment Agency (2006a): European Nature Information System (EUNIS): Species Factsheet: Gallotia simonyi. Downloaded on 24 Feb 2007.
- European Environment Agency (2006b): European Nature Information System (EUNIS): Species Factsheet: Gallotia simonyi machadoi. Downloaded on 24 Feb 2007.
- López-Jurado, L.F. (1989): A new Canarian lizard subspecies from Hierro island (Canarian Archipelago). Bonner Zoologische Beiträge 40: 265-272.
- Maas, Peter H.J. (2006): The Extinction Website: Extinctions in Europe. Downloaded on 18 May 2006.
- Maca-Meyer, N.; Carranza, S.; Rando, J.C.; Arnold, E.N. & Cabrera, V.M. (2003): Status and relationships of the extinct giant Canary Island lizard Gallotia goliath (Reptilia: Lacertidae), assessed using ancient mtDNA from its mummified remains. Biol. J. Linn. Soc. 80(4): 659–670. doi:10.1111/j.1095-8312.2003.00265.x (HTML abstract)
- Miras, J.A.M. (2005). Gallotia auaritae. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Database entry includes a range map and a brief justification of why this species is listed as extinct
- Miras, J.A.M. & Pérez-Mellado, V. (2005a). Gallotia bravoana. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Database entry includes a range map and justification for why this species is critically endangered
- Miras, J.A.M. & Pérez-Mellado, V. (2005b). Gallotia simonyi. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Database entry includes a range map and justification for why this species is critically endangered
|Wikimedia Commons has media related to Gallotia simonyi.|
- lacerta.de: Gallotia simonyi machadoi image gallery. Retrieved 2007-FEB-25.