Geckos found in Hajar Mountains reveal more than initially thought
Scientist call to protect range for abundant diversity
The Hajar Mountains should be a priority for wildlife conservation, according to scientists, after finding what was originally classed as a single subspecies of gecko that could now be as many as 10.
The researchers carried out genetic analysis of hundreds of specimens of a gecko subspecies called Pristurus rupestris rupestris, sampling individuals in the mountain range that traverses eastern UAE in Ras Al Khaimah and north-east Oman.
They found that there were 14 genetic types, described as candidate species, among the reptiles they analysed, many of which have very limited distribution. The small habitat size of some of the candidate species may make them vulnerable.
In a recently published paper, researchers said that their results and previous studies indicated that the Hajar Mountains were “a biological hot spot and an important reservoir of diversity”.
“We therefore suggest that these mountains should be a priority focal point for conservation in Arabia,” they wrote.
One of the paper’s four authors, Prof Salvador Carranza, of the Institute of Evolutionary Biology, Barcelona, said that there was a lot of hidden diversi- ty in the Hajar Mountains, conservation of which he described as being very important.
“With these 14 lineages, you have some with very restricted areas. These areas are very important for conservation. They can help us to delineate the protected areas better so the distribution of these endemics – species found only in this area – is included. When you do the protected areas, endemics should be first.”
Prof Carranza said that the UAE made considerable efforts to protect wildlife, including geckos, but that an understanding of the exact distribution of individual species was needed if conservation efforts were to be effective. “For future protected areas all this information should be taken into account.”
Candidate species tend to look similar to one another in terms of their morphology, or appearance and structure. However, some exist in the same location as one another but do not interbreed, indicating that they are, in fact, separate species.
Behavioural factors, such as signalling between individuals, are likely to help populations become isolated from one another. Pristurus species are known for communicating by signalling instead of using calls.
“They have a complex behaviour of waving, communication is a very important part of their lives. They’re called semaphore geckos. They do all sorts of signalling,” said Prof Carranza.
“When you have these kinds of animals, as soon as populations become separated, signals become dialects. When the populations are in contact again they’re isolated. The isolation mechanisms are stronger when you have these complex behaviours.”
To have as many as 14 candidate species, as was found with this creature, is extreme, said Prof Carranza. In their paper, the scientists described it as an “unparalleled degree of species-level diversification in an Arabian vertebrate”.
The diversity of habitats found at different altitudes – the lizards can be found everywhere from sea level to 3,000 metres – along with physical barriers such as mountains and valleys, helps to explain why so many species have evolved, because populations become separated from one another and diverge.
When further analysed using genetic markers, the 14 candidate species are likely to turn out to be about 10 actual species, said Prof Carranza. There are, he said, at least half a dozen. The species are likely to have begun diverging from each other as much as 15 million years ago.
Pristurus has a body only 2.5 centimetres long. The reptile is found in towns and villages, including in homes, as well as in the countryside.
The other authors of the paper are senior author Dr Joan Garcia-Porta and Marc Simo-Riudalbas, both of the Institute of Evolutionary Biology, and Dr Michael Robinson of Sultan Qaboos University, Muscat.