Amphibian and Reptile Groups of the UK

Amphibians were swabbed in the numbers required to provide meaningful results from 102 locations across the country during the first swabbing session and from 75 during the second swabbing period.  Enough amphibians were swabbed from a total of 70 populations across both time periods.  Amphibians were swabbed across England and in Wales and Scotland.  In addition, amphibians were swabbed in Jersey.

Across the country, 5,998 amphibians were swabbed: 

1,426 Common toad

1,402 Palmate newt

1,813 Smooth newt

594 Great crested newt

393 Common frog

152 Natterjack toad

135 Alpine newt

64 Marsh frog

19 Pool frog

This has been a magnificent achievement.

The relatively large numbers of introduced species and natterjack toads tested is because there was an element of targeting sites with these species as part of the overall sampling strategy.  The relatively small number of common frogs is because we started swabbing after their breeding season and then they became scarce in ponds over the summer, possibly dispersing due to the wet weather.

Almost all of the sites tested have been shown to be clear and definite negatives for the presence of the chytrid infection.  However, there are some samples from some sites which did not come up as being clearly negative after two rounds of analyses.  We need to carry out some more confirmatory tests on the samples from these sites before we can sign them off as definitely positive or definitely negative. 

These samples are problematic because they have not come out clearly as positive, or clearly as negative.  There are a number of possible reasons for this, including (1) they are negative, but there was a problem with the PCR reaction (such as binding of the primers used to test the samples) preventing the reading of a clear negative result, (2) there is a substance within some of the samples from these sites which is interfering with the PCR test; (3) these samples really are positive, but with extremely low levels of infection.

It will take a little more time to further analyse these samples before we are able to give final results.

In the meantime, we would like to map out each of the sites tested.  To do this, we will need Ordnance Survey map references, grid references or post codes for each site.  Some of you have already provided these.  If you haven’t done so, but know these details, then please send them through to me (please put “UK chytrid survey” in the subject line).  If not, please look these up for your sites and Andres will be in touch with you shortly.

Until then, thank you so much for all your help with this important project.

With many thanks and best wishes.

Andrew

P.S. Please do not give up on biosecurity in the light of the results so far.  Even if chytrid infection has not yet been detected in your area, there are other diseases (and invasives) that can be carried around – and chytrid might be around but not yet detected!  It looks like this nasty pathogen might be localised in a few sites in the UK at the moment – let’s keep it that way.

Andrew A. Cunningham BVMS PhD MRCVS

Reader & Head of Wildlife Epidemiology

Institute of Zoology

Zoological Society of London

Regent's Park

London NW1 4RY