The marsh frog (Pelophylax ridibundus) and its relatives (edible frog Pelophylax kl. esculentus, Iberian water frog Pelophylax perezi, pool frog Pelophylax lessonae etc.) are fairly easy to recognise as a group, although it is difficult to distinguish between the different species.  Collectively they are referred to as 'green frogs', or 'water frogs'.

The background colour can be green, brown or grey.  Green coloration can be vivid.  Some have a light stripe running along the back.

In spite of the variability in coloration, there are several characteristics these frogs share. 

• They are noisy, calling during late spring and sporadically through the summer. 

• When calling, they inflate vocal sacs on either side of the head. 

• Note also the dorsolateral ridge running from behind the eye towards the hind end of the frog - useful in distinguishing large water frogs from the North American bullfrog. 

These frogs are more aquatic than our native common frog, remaining in and around the water all year (most common frogs spend a good proportion of the year on land).  They like to sunbathe and can be seen basking by the side of ponds.

*Note that a particular form of the pool frog is now believed to be native to England and is subject to a reintroduction programme.