Aran rock lizard (Iberolacerta aranica)

Spanish: Lagartija Aranesa
GenusIberolacerta (1)
SizeSnout-vent length: up to 6 cm (2)

The Aran rock lizard is classified as Endangered (EN) on the IUCN Red List (1).

Described to science as recently as 1993 (1), the Aran rock lizard (Iberolacerta aranica) is known only from a tiny area on the border of France and Spain. The greyish-brown skin is patterned with two rows of dark spots running down each side of the back. These spots are bordered by a lighter area, which contrasts with the darker colour of the lizard’s sides (2).

Endemic to the Mauberme massif, between the Arán and Ariége valleys, in the Central Pyrenean Mountains of France and Spain. The Aran rock lizard is currently known from an area of just 26 square kilometres (2).

The Aran rock lizard occurs in rocky alpine habitats between 1,900 and 2,500 metres above sea level. It often occurs on rocky areas at the edges of alpine meadows which are, except for in summer, blanketed in snow (1) (2).

During the harsh, cold winter months in the Pyrenees, the Aran rock lizard hibernates, and is only active for four months of the year, from mid-May to late September or the beginning of October. This leaves little time for the lizard to reproduce, and as a result only one clutch of eggs is produced each year. An average of three to four eggs are laid and incubated for a period of 30 to 36 days. The young Aran rock lizards develop slowly, and sexual maturity is reached relatively late, at the age of four years in males and between four and five years in females (3).

Like the closely related Pyrenean rock lizard, (Iberolacerta bonnali), the Aran rock lizard may reduce its activity in the middle of the day during its active months, perhaps to avoid the strong ultraviolet radiation that is present at such high altitudes (2)

The rocky alpine habitat of the Aran rock lizard is currently threatened by overgrazing by cattle and may face further pressure in the future from the development of ski resorts and the associated building of roads and tracks (1). The IUCN, who assessed the conservation status of this lizard, also state the possible development of hydroelectric projects and mining as a future threat to this species (1). The low reproductive potential of the Aran rock lizard and its restricted distribution only act to enhance the devastating effects that such threats may have on the population (3).

The Aran rock lizard is listed on Appendix III of the Bern Convention, a convention which aims to conserve wild flora and fauna and their natural habitats and to promote European co-operation in that field (4). Wild animal species on Appendix III are protected, but can be exploited if regulated in accordance with the convention (4). It is yet to be seen whether this level of protection is sufficient to ensure the survival of this Endangered reptile.

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:

  1. IUCN Red List (April, 2011)
  2. Arnold, N. and Ovenden, D. (2002) A Field Guide to the Reptiles and Amphibians of Britain and Europe. HarperCollins Publishers, London.
  3. Arribas, O.J. and Galán, P. (2005) Reproductive characteristics of the Pyrenean high-mountain lizards: Iberolacerta aranica (Arribas, 1993), I. aurelioi (Arribas, 1994) and I. bonnali (Lantz, 1927). Animal Biology, 55(2): 163 - 190.
  4. Council of Europe: Bern Convention (March, 2008)