River Wildlife

The River Sid supports a wide range of flora and fauna, many of which have evolved specialised behaviours to survive in its fast-flowing, clear waters.

1. Iconic River Birds

The Sid is a vital corridor for several specialist bird species that rely on clean water and healthy insect populations.

• Kingfisher (Alcedo atthis): Often seen as a "flash of blue and orange," these birds hunt small fish and nest in burrows within steep earthen banks, primarily in the quieter upper reaches. In winter, they move downstream toward the Riverside Walk.

• Dipper (Cinclus cinclus): A specialist of fast-flowing streams, the Dipper is known for its "bobbing" behavior and unique ability to walk underwater to hunt for larvae. They are frequently spotted near the Fortescue bridge and the quieter parts of The Byes.

• Grey Wagtail (Motacilla cinerea): Though their national range is declining, they are the most common birds on the Sid, identifiable by their active "flitting" at the water's edge as they hunt insects.

2. Mammals and Fish

While some populations are small, the presence of these apex predators and ancient species indicates the river's ecological importance.

• Otters (Lutra lutra): Evidence of otters, such as tracks in the mud and spraint, is found along the river. They are nocturnal and wary, but sightings have occurred near the river mouth and within The Byes.

• Brook Lamprey: These prehistoric, eel-like fish still inhabit the Sid.

• Migratory Fish: The river once hosted healthy populations of Atlantic Salmon and Sea Trout, but their numbers are now hindered by barriers like the School Weir.

3. Remarkable Invertebrates

Invertebrates are the "engine room" of the river's ecosystem, providing food for birds and fish while acting as indicators of water quality.

• Beautiful Demoiselle (Calopteryx virgo): Unlike most dragonflies, this striking damselfly thrives in fast-flowing water. It is the most frequent Odonata species on the Sid, notable for its metallic green or blue coloring.

• River Skater (Aquarius najas): In late spring and summer, thousands of these insects can be seen skimming the surface to feed on midges. They are slightly larger than common pond skaters and have lighter undersides.

4. Riparian Plant Life

The powerful current of the Sid means that only highly adapted plants can take root in the riverbed.

• Native Specialists: River Water-crowfoot (Ranunculus fluitans) grows submerged as a green weed but sends white flowers above the surface in August for pollination.

• The "Villain" Plant: Himalayan Balsam (Impatiens glandulifera) is a major threat. Its seeds float downstream to colonize muddy fringes, outcompeting native life, though it remains a popular pollen source for bees.