Hierro giant lizard  (Gallotia simonyi)

The Hierro giant lizard is classified as Critically Endangered (CR B1 + 2e, C2b) on the IUCN Red List 2003 (1) and is listed on Appendix I of CITES (3). It is also listed on Annex IV of the European Species Directive (4).

The Hierro giant lizard is a stocky reptile with a broad head and pronounced jowls (flesh under the lower jaw). It is dark grey to brown in colour, with two rows of pale orange patches running along its sides. The belly is mostly brown with orange to red colouration towards the centre. Female sub-adults have grey backs with four rows of blackish patches and two rows of orange-green marks on the side. Older individuals are mainly black with some grey (2). Males are larger (5).

The Hierro giant lizard is restricted to the Canary Islands, Spain (1).

This is a terrestrial lizard, living on a small, young volcanic island in rocky habitats (1) (6).

The Hierro giant lizard is an omnivorous lacertid which feeds voraciously on two main plant species, Kleinia neriifolia and Lavandula abrotanoides as well as insects (2). Courtship begins in May and involves males bobbing their heads with their throats inflated. Clutches of between 5 and 13 eggs are laid from June until the end of August. The eggs hatch after 61 days of incubation at 28 – 29 ºC (5).

Feral rats and cats pose the most serious threat to this lizard. Poisons used for pest control seem to be inadvertently affecting the lizard population (7).

Plans for conservation of this species are not extensive. 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. This management plan began in late 1997 and ran until early 2000 (7) (8). Juveniles are more suitable for re-introduction as the sprint escape performance of the adult lizard is diminished by prolonged captivity (9).

For further information on lizard species see:

Halliday, T. and Alder, K. (2002) The New Encyclopedia of Reptiles and Amphibians. Oxford University Press, Oxford.

• Lacertid: Old World terrestrial lizard.
• Re-introduction: putting an animal or plant into an area where the species or sub-species previously lived but from which they are locally extinct - usually referring to projects aiming to re-establish self-perpetuating populations.

1. IUCN Red List (October, 2004)
   http://www.redlist.org
2. Herpetology (October, 2004)
   http://www.nafcon.dircon.co.uk/gallotia.html
3. CITES (October, 2004)
   https://www.cites.org
4. Societas Europaea Herpetologica (October, 2004)
   http://www.gli.cas.cz/SEH/
5. Rodriguez-Dominguez, M.A. and Molina-Borja, M. (1998) Reproduction of the endangered Hierro giant lizard Gallotia simonyi machadoi. Journal of Herpetology, 32 (4): 498 - 504.
6. UNESCO (October, 2004)
   http://www.unesco.org/mab/br/focus/April01/spain.htm
7. The Giant Lizard of La Gomera (October, 2004)
   http://www.gobiernodecanarias.org/medioambiente/lagartodelagomera/vinglesa.html
8. Canary Islands Department of the Environment (October, 2004)
   http://www.gobcan.es/medioambiente/eng/biodiversidad/ceplam/vidasilvestre/life7.html
9. Cejudo, D. and Marquez, R. (2001) Sprint performance in the lizards Gallotia simonyi and Gallotia stehlini: Implications for species management. Herpetologica, 57 (1): 87 - 98.