The Lizard has many examples of temporary ponds – sometimes called ephemeral pools – that are inundated with water in the winter but dry out in the summer. Some of these ‘ponds’ are not much more than muddy puddles associated with the trackways that criss-cross the heaths, but there are also larger pools, such as Hayle Kimbro and Croft Pascoe Pool. The Lizard is the only site in the UK to have been given a special European habitat designation – Mediterranean Temporary Ponds.

This freshwater habitat is important for a range of rare annual plant species – for example, Yellow Centaury, Pygmy Rush and Three-lobed Water Crowfoot – that do not cope well with competition from the more vigorous perennials and grasses that would otherwise be dominant. Amphibians also make effective use of the pools to spawn: the drying out of the pools in summer means they do not support predator fish.