RSPB Mawddach Valley - Arthog Bog

Arthog Bog is a small wetland and a wonderful place to see weird and wonderful plants, flowers, butterflies and birds. It's one of the remaining fragments of raised bog which once would have covered much of the adjacent Mawddach Estuary. With more than 130 species of plants recorded, there are colourful displays through the year such as marsh marigold and yellow flag in the spring and hemp agrimony, meadowsweet and ragged robin through the summer. There are also many specialised ditch plants such as bog bean and greater spearwort.

In winter there are often flocks of siskins, lesser redpolls and tits and ravens, buzzards and peregrines are commonly seen overhead. Spring sees the arrival of whitethroats, garden warblers and blackcaps, and lesser spotted woodpeckers may venture over from the adjacent oak woodland. The reed-filled ditches around the reserve are also home to reed buntings and water rails.

Many species of butterfly have been recorded on the reserve and common blue, small copper and speckled wood are among those regularly encountered. The visitor trail crosses the reserve and links in with the Mawddach cycle trail; sturdy footwear is recommended on the nature trail. The scarce wetland plants, characteristic of this habitat, thrive on open, wet and well-lit conditions and cannot compete with more aggressive species such as willows or brambles. For part of the year, the bog is lightly grazed by ponies and we make sure the areas alongside wet areas and ditches are free of scrub.