Ibiza wall lizard  (Podarcis pityusensis)

The Ibiza wall lizard is classified as Near Threatened (NT) on the IUCN Red List (1) and is listed on Appendix II of CITES (3).

A ground-dwelling species, the Ibiza wall lizard (Podarcis pityusensis) is endemic to the Balearic Islands of the coast of Spain (4). Belonging to the Lacertidae family, a group of species which includes the sand and wall lizards (5), the Ibiza wall lizard is considered to be an excellent example of small-scale island evolution, with many different subspecies scattered on a number of isolated islands (6). 

Like other species in the Lacertidae family, the Ibiza wall lizard has a conical-shaped head and a pointed snout (5) (7). The neck is usually slightly wider than the head (7). The body is long and fairly robust, with well-developed limbs and a long, fragile tail. The eyes are large and have moveable eyelids. The tongue of the Ibiza wall lizard is long and narrow, with a prominent forked tip covered in small projections or folds. The scales of lacertid lizards tend to be enlarged and arranged symmetrically on the head, with small, often granular scales on the back and large, rectangular scales on the body. The scales on the tail are keeled (7), and are usually arranged in spirals (5).

The male Ibiza wall lizard is typically larger and longer than the female. Additionally, the male tends to have slightly different colouration to the female (7).

As many as 35 subspecies of the Ibiza wall lizard have been described, but the taxonomy of this species remains unclear and the actual number is probably far fewer (6) (8). There is a great deal of variation between the different subspecies, ranging from smaller forms with short legs and heads, to large, robust forms with wide-set legs. Similarly, colour is highly variable between subspecies, with the upperparts ranging from green-brown to black, grey, bright green, yellowish-green or blue. The underparts, sides, legs and tail also differ greatly in colouration. Melanistic individuals have also been recorded (7). 

The Ibiza wall lizard is endemic to the Balearic Islands of Ibiza and Formentera, as well as a number of nearby small, offshore rocky islands and islets (1) (6) (8) (9).

This small lizard has also been introduced to parts of Mallorca (1) (6), as well as two towns in Spain. It was previously introduced to Barcelona but is now extinct there (1).

The Ibiza wall lizard is found in almost all habitats on the larger islands of Ibiza and Formentera, including vegetated areas, cultivated land, parks and gardens, as well as close to and around human habitation. It also occurs in rocky areas, especially around the coast (1) (7) (10).

On smaller islands and islets, the Ibiza wall lizard will readily inhabit more open areas (10). The Ibiza wall lizard is found up to elevations of 475 metres (1).

Although active Ibiza wall lizards may be seen all year round, most individuals will spend the colder months hidden among dry stones and other recesses in a state of torpor (7).

The breeding season usually begins around April and continues until August (7). The female Ibiza wall lizard lays between one and four eggs (1) (7), which hatch around mid-August to September. It is thought that the Ibiza wall lizard becomes sexually mature after two years (7). 

The Ibiza wall lizard feeds primarily on invertebrates, particularly ants and beetles (11). Other food items include spiders and possibly small crustaceans (6) (7). This species also frequently consumes plant matter, especially fruits (11), as well as nectar, pollen, flowers, leaves and seeds (6) (7). 

This species is preyed on by a range of birds, snakes and mammals. The Ibiza wall lizard exhibits a number of anti-predator behaviours when caught, including squirming, biting, and defecating. The lizard is also reported to feign death, becoming limp, relaxing the limbs, head and tail, and curling the toes. In some cases, this species may also arch its head back and leave its mouth open when captured. Such behaviour has been suggested as being an adaptation intended to confuse predators so that the lizard can escape. The Ibiza wall lizard also exhibits striking colour variation between different populations, with some being conspicuously coloured and others having cryptic colouration. This variability in colour may be an adaptation to allow populations inhabiting different islands to avoid different types of predators (5).

Although there are not considered to be any major threats to the Ibiza wall lizard (1), there tends to be an elevated risk for species in the genus Podarcis which are endemic to small islands (12). A number of small islet populations in particular are threatened by disturbance, habitat loss and habitat alteration by visitors, as well as by the introduction of non-native species such as cats and rats (1) (7) (10).

Accidental poisoning by bait left for seagulls may also impact the Ibiza wall lizard on some islands (1). Over-collection for the pet trade has posed a threat to this species in the past, but the risk of this has declined somewhat and trade in this species is now governed by the Convention on International Trade in Endangered Species (CITES) (3) (6) (10).

The Ibiza wall lizard is included on Annex II of the Bern Convention (13) and on Appendix II of the Convention on International Trade in Endangered Species (CITES) (3), meaning that all international trade in this species should be carefully monitored (1). It also occurs in some protected areas (1).

Posters have been placed on several of the islands where the Ibiza wall lizard occurs, as part of a public education programme to raise awareness and encourage lizard protection (1) (7). Other recommended conservation measures for the Ibiza wall lizard include increasing habitat protection and considering captive breeding programmes if circumstances change on the islands this species inhabits (10).

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more about the Ibiza wall lizard:

• Salvador, A. (2009) Lagartija de las Pitiusas - Podarcis pityusensis. In: Salvador, A. and Marco, A. (Eds.) Enciclopedia Virtual de los Vertebrados Españoles. Museo Nacional de Ciencias Naturales, Madrid. Available at:
  http://www.vertebradosibericos.org/