Bracken

Wildlife-Walks_bracken

Bracken could be considered one of the most successful and one of the oldest ferns – there are fossil records over 55 million years old.

The plant spreads from a creeping underground rootstock, or rhizome, which can travel a metre or more underground.

The fronds, or leaves, can grow up to 2m (6 feet) high, and it is deciduous.

It is generally found growing on the sides of hills as it needs well drained soil. 

Due to it’s ability to spread quickly, bracken can take over and smother other habitats, although small areas of bracken can be beneficial for a range of wildlife.

Bracken offers refuge for birds such as warblers and tree-pipits, reptiles such as slow worms and adders and mammals such as voles, mice and stoats.

It provides seasonal shade in the way that a woodland canopy does, and can support some woodland flowering plants beneath including bluebells and common dog violet.

South facing bracken slopes are important for butterflies and other invertebrates.  

Bracken is known to support over 40 species of invertebrate - for 27 species it forms an important part of the diet, and 11 are found only on bracken.

The caterpillars of the Brown Silver-line moth for example feed exclusively on bracken.

Other caterpillars that feed regularly, but not exclusively, on the leaves include the Broom moth and the Small Angle Shades moth, while caterpillars of the Gold Swift moth and the Map-Winged Swift moth feed on the rhizomes (roots).

Another specialist bracken species is a short-winged bug called Ditropis pteridis, 4mm in length with yellow and black stripes.