A guide to the wildlife of Castle Bottom National Nature Reserve

Established by the government to protect habitats, wildlife and geology, National Nature Reserves are vital for the conservation of nature across England. They act as outdoor laboratories to learn more about the natural world – for everyone from scientists to school children. Hampshire Countryside Service manages five National Nature Reserves, each with their own unique ecosystems of plants and animals.

Castle Bottom, near Yateley, is home to one of the most important valley mires in southern England. Despite its name, there’s no evidence a castle ever existed in the area. There are, however, links to a Bronze Age burial mound dating back to 1800-500 BC. Exmoor ponies roam freely on the heathland, helping to manage invasive species as well as with the management of the diverse habitats found at Castle Bottom.

Bog asphodel (Narthecium ossifragum)

The orangey-yellow star-like flowers of the bog asphodel are hard to miss. It springs up in peat bogs during the summer, with red egg-shaped fruits appearing in the autumn. While it can be pollinated, it also has creeping stems growing underground that it can reproduce from too.

When to see: June – September

Conservation status: Common

Dartford warbler (Sylvia undata)

This small brown bird has a red ring around its eyes and a rust-coloured chest . It’s not a migratory bird and spends its winters in the UK. In the 1960s there were only 10 breeding pairs remaining in the UK, but the population has bounced back with about 2,200 breeding pairs recorded now.

When to see: Year-round

Conservation status: Near-threatened

Grayling (Hipparchia semele)

The grayling is a medium-sized butterfly widespread on the coasts and southern heaths. A master of camouflage, the top side of their wings are dark brown with orange markings and the undersides are orange with grey and black markings. They’ve also got eyespots on the underside of their wings, which are what make them identifiable from other brown butterflies.

When to see: July – September

Conservation status: Priority species

Ruby-tailed wasp (Chrysis fulgida )

There are several species of Ruby-tailed wasp which all look very similar. The insect is incredibly distinctive with a shiny blue-green head and thorax and ruby coloured tail. It’s a type of solitary wasp, meaning they don’t live in colonies. They don’t make their own nests, instead using those created by other solitary wasps, earning them another name of ‘cuckoo wasp’.

When to see: April – September

Conservation status: Common

Nightjar (Caprimulgus europaeus)

As its name suggests, the nightjar is a nocturnal bird that nests on heathland. Its feathers look like bark, helping it blend into the trees. These migratory birds travel over 6,000 miles from Africa each year to breed on heaths here in the UK. You’ll have the best chance of spotting it at dusk, which is when males take to the skies in a bid to impress females.

Best time to see: May – September

Conservation status: Near threatened

Woodlark (Lullula arborea)

The woodlark is resident to the UK with large populations in southern and eastern England. You can spot this bird by its streaky brown feathers and the prominent crest on its head that’s sometimes raised. Despite living here year-round, the best time to see it is between February and March. If you see them, make sure to leave them be as it’s illegal to disturb a woodlark.

Best time to see: February and March

Conservation status: Not threatened