Wetlands are essential habitats, playing crucial roles in our environment. They protect our shores from waves, reduce the impacts of floods by soaking up water like a sponge, filtering and purifying it so water quality improves, and they absorb pollutants too. Wetlands also provide a habitat for a huge diversity of animals and plants, many of which are found nowhere else. In fact, species diversity in wetlands is so great, there are a fair few species that many people have never heard of. Here are five examples of under-the-radar critters often found in Britain’s wetlands.
Desmoulin’s Whorl Snail
This land snail is named after the early 19th Century French naturalist Charles des Moulins. It lives in marshes and swamps in calcerous wetlands amongst tall plants such as pond sedges. The snail spends the winter down on the ground in the plant litter, but climbs up the growing plant leaves in spring and spends the summer living on the plants’ leaves eating micro-flora (fungi, algae and bacteria) found on the greens’ surface.
It can be found across Europe but within Western Europe, only the populations in England and Ireland are considered viable. In the UK, it is listed as endangered and is a priority species on the UK Biodiversity Action Plan. However, there is a possibility that it has been under-reported due to its small size—its 4-whorled shell is only 3mm long. But 20 years ago, this tiny snail hit the headlines as its presence on a site of the planned Newbury bypass caused the building work to be postponed. The work only continued once the snails had been moved to a new habitat nearby, although sadly they subsequently became extinct in that area.
Ten-spotted Pot Beetle
Another priority species on the UK Biodiversity Action Plan is the ten-spotted pot beetle. Pot beetles are a group of petal and leaf-eating beetles. There are 19 species in the UK but, like the ten-spotted pot beetle, many have suffered declines in distribution and are quite rare. They get their name from the protective ‘pot’ that larvae live in, created from their own droppings. After laying each egg, the female holds it in her back legs and covers it with a waxy coating and droppings. This covering is known to deter predators such as lacewings and ladybirds.
When the larvae hatch, they stay within the protective pot, enlarging its neck as they grow. The pot acts like a snail-shell and provides camouflage and protection. The ten-spotted pot beetle occurs on protected wetland sites, where their numbers continue to be monitored. The future of this species is linked to the protection of lowland raised bogs, its favoured habitat, and enhancing willow as a food source.
This dragonfly prefers still water sites, including well vegetated ponds, lakes, canals, ditches, and sometimes sluggish rivers and streams. It inhabits temperate regions of Europe as far east as Siberia and as far south as the northern Sahara. In the UK it is found predominantly in south-east England but is moving north and westwards as numbers in many locations, especially central England, are increasing. Mating between ruddy darter pairs takes place on the wing, with the couple performing a dipping flight over water. The female jettisons her fertilised eggs at the water’s surface by alternating movements of her abdomen.
The male sometimes helps her by swinging her downwards so her abdomen dips in the water. The male also protects her by driving off any approaching males. The larvae spend a year beneath the water surface before emerging to pupate into adults. The most striking thing about the ruddy darter is its colouration. The females have an ochre yellow abdomen and thorax and, with maturity, the males’ head, thorax and abdomen become a vivid red colour, contrasting with their black legs. In honour of this, the ruddy darter has an English beer named after it, described as a ‘rich, ruby ale with a fruity aroma’.
The ragged robin grows in wet areas such as marshes, fens, wet meadows, pond edges, riverbanks and canal sides. It considerably brightens up these areas, with its lacy, deep pink flowers and tall, thin stems which grow above clumps of blue-green, star-shaped leaves. There is also a white variety, called white robin, and the jenny robin has double flowers giving it a pom-pom effect. The ragged robin blooms from May to August, occasionally later, but is an increasingly rare sight in the wild. Human activity, for example, drainage of land for agriculture and the loss of ponds by development, has caused population declines.
This will undoubtedly have an impact on the bumblebees, honey bees and butterflies that feed on its nectar. However, it is an increasingly common garden plant, and made it on to the Royal Horticultural Society’s ‘perfect for pollinators’ list in recognition of its importance for attracting pollinating insects to gardens. It is also a species that once played a role in human society. It was believed that if a single man carried a ragged robin flower in his pocket and the flower survived, he would soon find love. In addition, it was used in traditional, herbal medicines (to alleviate jaundice, headaches and toothaches), and its roots and petals when boiled were used to wash clothes and hair.
The beautiful demoiselle is Britain’s largest damselfly, with a body length of almost 50mm and hindwing length of up to 35mm. It certainly lives up to its name, being one of only two species of damselfly in the UK to have obviously coloured wings—the other being the banded demoiselle. The wings of the mature male beautiful demoiselle are a very dark, blue-black colour and wings of the female are iridescent brown-green in colour with white patches near the tips. The male’s body colour is metallic blue-green and green with a bronze tip in females.
They are found mainly along fast-flowing streams and rivers with a low water temperature, particularly those with sand or gravel bottoms and free from pollution. Males rest on bankside vegetation waiting for females and are territorial, defending territories that are optimal nesting places for females. Males use threatening gestures such as spreading their wings and showing them off and, in rare cases, air combat between rival males ensues. While beautiful demoiselles are perching they have also been observed beating their wings quickly down and then slowly lifting them. Known as ‘windclapping’ this behaviour is thought to play a role in communication or thermoregulation.