The Marsh Frog is a water-dwelling, generally green-colored frog species. It can reach a maximum length of 17 centimetres, but males remain smaller (around 12 cm). The head is proportionally large and the hind legs are long, which gives them excellent jumping abilities.
There is a large variation in colour and pattern, ranging from dark green to brown or grey, sometimes with some lighter green lines; a lighter line on the back is generally present. The Western European populations are generally dark green to black with dark spot on the back and sides and three clear green lines on the back.
The Marsh Frog usually breeds in more brackish (salt and freshwater mixed) ditches, ponds etc or larger ponds and lakes near the coastline.
Oare Marshes and Elmley Marshes are strongholds for these frogs in North Kent. Interestingly, despite having freshwater ponds at the site, there have been few/none recorded Common Frogs or Toads at the site. Many are concerned that they are affecting our native amphibian populations by creating competition for food although it is not proven.