Sunday, November 4, 2012

The lizard on the wall

Podarcis filfolensis laurentimulleri
The Maltese wall lizard is an endemic species. It is found only in the Maltese islands and two Pelagian islands. It is closely related to another lizard found on Sicily. Fossil records indicate that the two species are derived from a common ancestor which is now extinct and which reached the Maltese islands probably sometime when these were connected to Sicily.

When the land connection between the Maltese islands and Sicily disappeared the local lizards were separated from those in Sicily and started to evolve into a separate species – the Maltese wall lizard which is known to scientists and naturalists as Podacis filfolensis.

The Maltese wall lizard now consists of five subspecies that live isolated from each other each of which over a period of several thousand years could evolve into a separate species unless, that is, they become extinct or come into contact again with any of the subspecies.

What is known as the nominate subspecies is found on Filfla islet. Scientists refer to this subspecies as Podarcis filfolensis filfolensis. Podarcis filfolensis maltensis is found on Malta, Gozo and Comino. Podarcis filfolensis kieselbachi is endemic to St Paul’s Island. It is believed that this subspecies became extinct a few years ago. Another race, known as Podarcis filfolensis generalensis, is found on Fungus Rock (Il-Ħaġra tal-Ġeneral), off the west coast of Gozo.

This summer I had the opportunity to see and photograph the fifth subspecies of this interesting lizard, Podarcis filfolensis laurentimulleri. This subspecies lives only on Linosa and Lampione, two small Italian islands which together with the larger island of Lampedusa are known as the Pelagian Archipelago. The archipelago is found about 150 km south west of Malta. Being another subspecies of the Maltese wall lizard points at the fact that the Linosa/Lampione lizard arrived on these islands from Malta although it is not known how and when. It is possible that these lizards were transported by humans although, if this happened, it must have been thousands of years ago.

This subspecies is very dark with light-green spots all over the body and light blue spots on the lower sides. On Linosa the lizards are common everywhere and although grape growers kill them because they believe that they eat their grapes this subspecies seems to be doing very well and did not seem to be endangered or in risk of extinction. 

This article was published in The Times on 03.10.2012

1 comment:

  1. nice article. most populations that were regonised as a different subspecies are now being reconsidered as mere separate populations. in fact we have 17 recorded populations. lampione specimens are much morphologically different than those of lampione.

    see :