Gran Canaria skink

The Gran Canaria skink, scientifically known as Chalcides sexlineatus, is a distinct lizard species endemic to the island of Gran Canaria in Spain's Canary Islands archipelago. This skink is recognizable by its flattened body, broad head, and robust legs, with variations in size and morphology observed between its two recognized subspecies: C. sexlineatus sexlineatus and C. sexlineatus bistriatus. The specific name "sexlineatus" refers to the characteristic striping pattern found on the species.

Habitat and Distribution

This species thrives across a wide altitudinal range on Gran Canaria, from coastal regions up to 1,850 meters above sea level. It inhabits nearly all environments, including temperate forests, grasslands, rocky peaks, and agricultural areas, though it is less common in dense pine forests and drier southern zones. The Gran Canaria skink has also been introduced to the island of La Palma and is found on the small islet Roque de Gando.

Physical Characteristics and Subspecies Variation

The average total body length of the Gran Canaria skink is approximately 15 centimeters, including its tail, with females tending to be slightly longer. Notable differences exist between the subspecies and geographic populations. The northeastern subspecies, C. s. sexlineatus, is often characterized by a bright blue tail, a light bluish belly, a black dorsolateral band, and four yellowish-brown lines on its back. In contrast, the southwestern subspecies, C. s. bistriatus, typically possesses a brown tail and a white to yellowish belly, with a brown back marked by white spots in a linear arrangement. Intermediate populations may display a green tail.

Diet and Behavior

The Gran Canaria skink is primarily an insectivore, feeding on insect larvae and other small invertebrates. These skinks are known for their elusive nature, making them challenging to observe.

Reproduction

The species is ovoviviparous, meaning they give birth to live young. Breeding occurs during July and August, with litters of 2 to 7 offspring typically born starting in September.

Conservation Status

Alarmingly, the Gran Canaria skink has been classified as Endangered by the IUCN Red List. The primary driver of this declining status is the introduction of the invasive California kingsnake, which preys heavily on the skink. The kingsnake has spread significantly across the island, leading to substantial decreases in skink populations in affected areas. Feral cats and the pet trade also contribute to the threats faced by this species. The Gran Canaria skink is afforded protection under various European and Spanish regulations, including the EU Habitats Directive and the Bern Convention.