11/4/10: Herpetological heaven: Marsh Frog, Great Crested Newt and Adder

I've been into reptiles and amphibians ever since I can remember, but still haven't seen most of the less common species found in the UK, partly because I haven't lived that near to where any of them occur. Some of those omissions were rectified this past week, two by design and one by accident.

On a sunny 8th April I headed to the Thames Rd Wetland site on an indirect route to Mottingham.

Quite unexpectedly around 18 frogs were seen jumping into the water from around a foot back from the 'lake' margin. This they did whilst I was still some distance away, as I walked along the south-facing side of the site. Basking, coupled with this sort of avoidance behaviour, is characteristic of the 'Green Frog' complex (Marsh/Edible/Pool - which interbreed) and not the native Common Frog. Only one re-surfaced in a reasonable amount of time, confirming it wasn't a Common Frog, and a brief but fair view of another that at first landed on some algae provided further evidence. There was no prominent dorsal stripe. A definitive ID will depend on catching and measuring some - which looks like it won't be easy.

Mottingham station was the meeting point for a Froglife Great Crested Newt survey by torchlight.

I was one of 6 people who joined Sivi Sivanesen (employed by Froglife, now part of the Reptile and Amphibian Conservation) to help in her work of surveying more than a hundred ponds across London for the presence (or not) and population sizes of Great Crested Newt colonies.

The Great Crested Newt is the biggest and least common of the three species of newts found in the British Isles and is one of only three amphibians which are protected by the UK Biodiversity Action Plan. It is the subject of much research and monitoring in an effort to reverse the decline in its numbers.


Going out after dark and shining powerful torches into ponds is one of the three main ways of monitoring newts, and this is what we were doing on this occasion. We found GCNs at all three sites I was 'on board' for, and in three out of four ponds looked at before I had to head for home.

One, in a fairly open location, the margins of which comprised flooded grass, was swarming with Smooth Newts (our commonest species), and more than 60 Great Crested Newts were seen. Phenomenal. Rather gruesomely, two GCNs were fighting over a dead Smooth Newt for supper.

On the following weekend I was priveleged to see a number of Adders at the best of the four known sites for them in Greater London, in the company of an expert in their conservation.


This female Adder - being handled with care for educational purposes - was soon released.


Male Adder - at home in London!

It was somewhat surreal seeing these fabulous animals so close to busy main roads and with big buildings on the skyline. They aren't at all threatening, and are far smaller than I suspect most people think they are.