Fly, beetle, minnow
1 sound
The River Allen is home to many species of invertebrates, including river flies, beetles, molluscs, dragonflies and damselflies. These are a hugely important part of the river ecosystem, providing a valuable source of food for other organisms, such as fish and birds. The larvae of many river flies, dragonflies and other insects live under the water surface, so are difficult to see. However, using special microphones, we can hear them. The underwater soundscape of a chalk river is surprisingly rich - it sounds a bit like a rain forest, with many species of chirping insects. You can hear some of them on this recording. Very little is known about sound production by freshwater insects, but most of the sounds you can hear in this clip are made by different species of underwater beetle. You can also hear minnows feeding and attempting to nibble the microphone. Most freshwater invertebrates eat water plants and organic debris of different kinds, although some eat other insects or crustaceans.
