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Disease Testing of Poole Cliff lizards.: |
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David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515  View other posts by David Bird |
Posted: 03 May 2010 The Institute of Zoology (N.E. funded)project concerning the disappearance of the Sand Lizard on the Poole Cliffs where Wall Lizards have appeared has finally begun. A team of 3 samplers came down just over a week ago to take swabs of the known extant population of Sand Lizards, 3 local herpetologists collected 29 Sand Lizards of the 30 required for a statistical analysis for testing although more were seen and were too active to catch. The nuber was greater than we had expected to find from surveys in the previous weeks but this does happen when one removes animals allowing other animals to come out of hiding when the dominant ones are removed. Unfortunately 2 juvenile Wall Lizards were found on the western end of the site, one was captured but the other specimen avoided capture. Another visit is planned for the capture and testing of a similar number of Wall Lizards in the next few weeks. The Sand Lizards were also sampled for D.N.A. for another project that is in its second year as a Ph.D. project to compare the relationship of the various populations that may be separated by various barriers such as rivers and in this case by urban sprawl which may give more of an insight on the cliff population and possible vulnarability. I am at present carrying out a survey of the Poole Bay Cliffs SSSIs for Sand Lizards and other reptiles for N.E. which is fitting in nicely with the other projects and may help to shed more light on the status of the species and reason for their decline. So far I have found 2 areas where Wall Lizards are now found in numbers and where I found some Sand Lizards in 2003 but Wall Lizards were not seen. I shall be in the Boscombe area, not on Portman Ravine for the N.E. survey as it is not SSSI but am sure I will spend some time there being in the area, so keep an eye open for me. David British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
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Ray999 Senior Member Joined: 07 Mar 2006 No. of posts: 101  View other posts by Ray999 |
Posted: 03 May 2010 Hi Dave Are there still sand Lizards on the site last seen in 2003 where the wall lizards are now present. Ray
ray999 |
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David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts by David Bird |
Posted: 04 May 2010 Ray, Sorry about that didn't really make it clear. I have seen no Sand Lizards in the 2 areas where I found them in 2003 where there were no Wall lizards at the time, although they were close by. One area was nice heathland with Heather, Dwarf Gorse and sand but had a fire on one section a few years back, the heather is coming back slowly but now has a quantity of breeding Wall lizards. David British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
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herpetologic2 Senior Member Joined: 15 Jun 2004 No. of posts: 1369  View other posts by herpetologic2 |
Posted: 07 May 2010 Hi David So was it the fire and the changes in habitat that caused the apparent decline in sandies before the wall's colonised the area? That's quite hard to prove isn't it? Jon Vice Chair of ARG UK - self employed consultant - visit ARG UK & Alresford Wildlife |
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David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts by David Bird |
Posted: 07 May 2010 I do not think one can prove anything on the cliffs, just record changes in the presence and distribution of animals and any habitat changes. Of course in the next few months we may have information on a few bacteria and viruses that are being tested for in these animals. I personally think that any change in the status quo i.e habitat change or in this case fire favours an alien introduced species such as the Wall Lizard which quickly spreads and in this case to the detriment of the local native Sand Lizard. The research being carried out at the moment will hopefully answer the question about a Pathogen and what effect it is having. David British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
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will Senior Member Joined: 27 Feb 2007 No. of posts: 330 View other posts by will |
Posted: 07 May 2010 hi David do you know if sand lizards are still immediately to the west of the green and wall lizard area at Boscombe, ie to the west of Sea Road? I saw one sand lizard here in 2005, and the walls and greens seemed not to have got past the road/bus terminus barrier. If I have time, I'll try to have a look this year, but I wondered if you (or anyone else) has surveyed here more recently? Also, have they spread to Hengistbury yet (does Hengistbury still have sand lizards?), and possibly (by illegal introduction) across the bay to Barton-on-Sea, which also has the same sort of vegetation and habitats as Boscombe ? Cheers Will |
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David Bird Forum Specialist Joined: 17 Feb 2003 No. of posts: 515 View other posts by David Bird |
Posted: 07 May 2010 Will I am afraid that I have always left the Boscombe cliffs to HCT in the past and most of my direct knowledge from surveys over the last 20 years has been on the Poole cliffs mostly at Canford Cliffs. I have made visits to see the Green Lizards and Wall Lizards at the main Portman Ravine but only a handful of visits in the past. I have variuos pieces of information that people have told me in the past which may help. in the Deichsel, Gleed-Owen & Mayer 2007 paper there is mention of the spread of Lacerta bilineata occuring from Portman Ravine reaching from 500 m West which is roughly the Manor Zig-Zag to 1050 m East which is the Southborne Zig-Zag with a single specimen found 3.2 km to the west which is roughly below the Russell Coates museum close to Bournemouth Pier. It is not clear whether the sighting of animals in these positions is due to they are easy places to view the cliffs from , or they were actual end of the ranges after dispersion from Portman Ravine or that they were other places where animals were originally released. A colony of Wall Lizards were also found in 2008 by David Wareham just to the west of Bournemouth Pier which is close to the Russell Coates museum, this seems to be unconnected with other populations. There were Sand Lizards recorded to the west of Sea Road Boscombe Pier when mitigation work was carried out a while back which I think was about 5 or 6 years ago. I am not sure if Wall Lizards or Green Lizards have definitley been seen there but I do have something in the back of my mind that some Wall Lizards had been seen just to the west of Sea Road a couple of years back. I had been told once that Sand Lizards had been found in the past close to the zig-zag to the west of Portman Ravine but on later enquiry the chap that told me about them denied that he had ever seen them there. This is one of the areas that I have to survey and it appears that it is a SSSI for the reason that Sand Lizards had been recorded there in the past. I do not think Sand Lizards have been seen at Hengistbury head for many years and I think it was put down as a possible release area by H.C.T. but this may have been put on hold until more information is forthcoming about the Wall Lizards and the new paramyxovirus like virus that has been found. I know nothing at all about Barton on Sea and its herpetofauna. British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker. |
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will Senior Member Joined: 27 Feb 2007 No. of posts: 330 View other posts by will |
Posted: 08 May 2010 Hi David Thanks for the very comprehensive reply - I'll see if I can add anything to the sand lizard records for the immediate vicinity of Boscombe this summer Will |
- Disease Testing of Poole Cliff lizards. |