river wildlife
Ref: B09

To the mammals (B09c), birds (B09b) and invertebrates (B09a) that live in and near streams and rivers, water and the surrounding habitat provides the food and shelter necessary for survival.

Turbulent stream (Stannon)

A river, near its source, consists of trickles of water between moss covered boulders. These trickles join to form a small stream. As the stream widens further from its source it can be inhabited by small animals. Salmon and sea trout may well lay their eggs in these headwaters. Highland birds like peregrine falcons and dippers can be found nearby.

Trout are often to be found in the Upper Course, sometimes known as the Troutbeck, where the river widens and deepens. Many insects such as stonefly and mayfly species make their homes in these turbulent currents, along with otters and grey wagtails. Insect larva live in the water and adults fly around the area.

Flattened Mayfly Nymph

Trout can be found in the Middle Course of the river, the gradient is less steep and the bottom becomes a mixture of silt and gravel. A variety of birds including the kingfisher live here.

The Lower Course is where the river flows gently and can resemble a lake habitat. Reed fringed and slow, it is a haven for smaller species such as roach and bream and for predators like pike. Moorhen and mallard breed amongst the reeds. NB the rivers in Cornwall are more youthful rivers and fast flowing right to the estuary, so coarse fish species like bream and pike are not found in every river.

Sea trout in river

In the Estuarine Reaches, where the river nears the sea, it becomes influenced by the tides and the water becomes salty or brackish. Freshwater and seawater fish can live here. There are often extensive marshlands and mudflats, these are home to many types of ducks, geese and wading birds.

When you visit a stream or river think about the creatures living in the water, on the water or visiting the water to search for food, perhaps only at specific times of the year, like the Sand Martins (B09b).

Dragon fly nymph

Few of the creatures you find or see signs of remain in the same place all their lives. They may change shape and location many times. The dragonfly nymph will grow, one day climbing up a stalk to shed its old case and enter a new world of flight as a dragonfly.

Rivers and streams also change and so the habitat they provide changes. If you re-visit a stretch of water you might be able to spot some changes. Remember there could be some changes to the water quality that you cannot see, but in time the whole habitat will be affected for better or worse.

Heath spotted orchids	Adult dragon fly