Sunday, November 7, 2010

The Cypriot Grass Snake, Already Extinct?

A story carried by the Cypress Mail, written by Patrick Dewhurst (November 6, 2010) suggests the Cypriot Grass Snake (Natrix natrix cypriaca) will soon be extinct if it is not already. In an open letter to environmental Commissioner Charalambous Theopemptou, Hans George-Wiedl, a Cypress herpetologist and environmental activist, said he has not been able to find any signs of the snake in their last known habitat, the area around Paralimni Lake. Wiedl returned to the snake’s habitat for the first time in three years. He said, “I could see no sign of them, or any tracks left by them. The whole environment around the lake has changed for the worst. I would not be surprised if the grass snake at Paralimni has disappeared altogether… If there are a small number of grass snakes there, it is only a question of time until they disappear forever.”

The European Commission has required the Cyprus government ban real estate development in the area and designate the Paralimni a site of community importance (SCI).  While the government has made promises to do this, developments continued unabated. The Commission said it considered that “the Cypriot Authorities had not taken the necessary measures to protect the Cypriot Grass Snake, contrary to the requirements of directives on the conservation and habitats of flora and fauna.

A Reuters story from February 9, 2010, published in the Kathimerini, The International Herald Tribune in Greece and Cyprus reported that fishermen were being encouraged to once again fish the Xyialtos Reservoir, an area that had been off limits to them because they trampled the banks used by the Cyprus Grass Snake. This was an effort to reduce the introduced population of Largemouth Bass and trout. The invasive bass feeds in shallow waters near the banks of reservoirs; the same habitat used by Natrix natrix cypriaca  and . Both fish probably act as snake predators as well as competitors for food. The Cypriot Grass Snake rarely feeds on fish; most of its diet is composed of  Bedriaga's Frog, Pelophylax bedriagae (formerly Rana levantina).

Snakes of the genus Natrix on Cyprus have had a very confused history despite the fact that remains of Natrix natrix cypriaca were discovered at Aetokremmos, the oldest prehistoric site on Cyprus that dates to 12,000 YBP. The Grass Snake (Natrix natrix) was first reported from Cypress by botanist John Sibthorp when he visited the island in 1787, and the snake's presence was reaffirmed in 1865 when Unger and Koyschy noted its presence. Other reports of its presence were noted by Günther (1879) and by a variety of other authors and researchers. The flow of information about Cypriot Grass snakes stopped about 1913, although Hetch named the Cypriot population N. n. cypriaca in 1930 denoting its unique status as a Cypress endemic. By 1960 it was thought extinct but was rediscovered by Wield and  Böhme (1992).

Baier and Wield (2010) surveyed the population of N. n. cypriaca in the Troodos Mountains in 2008. Their results suggest that only two streams continue to be inhabited by the snake. The total number of Cypriot Grass Snakes in the Troodos area was estimated at 90–100 specimens. Suggesting there was a severe decline in the percentage of juveniles in both populations in comparison to studies in 2002 and 2005. 

A second species of natracid , the Dice Snake, Natrix tessellata, was also recorded from Cyprus by Unger and Kotschy (1865) and was also listed as part of the Cypriot fauna by other authors. Two subadult specimens of the Dice Snake (Natrix tessellata), collected in 1960 at Gönyeli-Nicosia, northern Cyprus, were discovered in the Zoological Collection of the Aegean University at Bornova-Izmir, Turkey by Göçmen, and Böhme. They challenged the view that the only existing voucher specimen of this species from Cyprus could have wrong locality data or was introduced to the island by humans. Thus, it seems the populations of both species of Natrix on Cypress are most likely near extinction.

Literature
Baier, F. and H.-J. Wiedl. 2010. The re-evaluated conservation status of the mountain populations of the highly endangered Cyprus Grass Snake, Natrix natrix cypriaca (Hetch, 1930), with miscellaneous natural history notes. Salamandra 46:1623.

Göçmen, B. and W. Böhme. 2002. New evidence for the occurrence of the Dice Snake, Natrix tessellata (Laurent, 1768) on Cyprus. Zoology in the Middle East 27:29–34.

Gunther, A. 1879. Notice of a collection of mammals and reptiles from Cyprus. Proceedings of the Zoological Society of London 1879:741.

Hecht, C. 1930. Systematik, Ausbreitungsgeschichte und Ökologie der europäischen Arten der Gattung Tropidonotus (Kuhl) H. Boie. – Mitteilungen aus dem Zoologischen Museum Berlin 16:244-393.
Wieldl, H. and W. Böhme. 1992. Wiederentdeckung der Ringelnatter (Natrix natrix ssp.?) auf Zypern, vorläufiger Bericht.  Herpetofauna 14:6-10.


3 comments:

  1. This is a very interesting article, I have just been googling for images of a snake I saw today whilst walking my dogs. It was identical to the images I have found of The Cypriot Grass Snake (normal pattern).

    I only saw it at the last minute because I nearly stepped on it, I had the chance to get a good look as it lay in the sun, it did not try to flee, but simply arched its head as if shocked. I moved by quickly because I had my dogs with me.

    Mathaios Malekos
    m2mcyprus@yahoo.co.uk

    ReplyDelete
  2. This is a very interesting article, I have just been googling for images of a snake I saw today whilst walking my dogs. It was identical to the images I have found of The Cypriot Grass Snake (normal pattern).

    I only saw it at the last minute because I nearly stepped on it, I had the chance to get a good look as it lay in the sun, it did not try to flee, but simply arched its head as if shocked. I moved by quickly because I had my dogs with me.

    Mathaios Malekos
    m2mcyprus@yahoo.co.uk

    ReplyDelete