Sim Elliott
- Jun 7, 2022
- 4 min read

Butterflies, Moths, Birds and Wild Flowers in the Castle Hill National Nature Reserve. 06.06.22

Castle Hill National Nature Reserve is one of my favourite reserves in Sussex, the abundance and diversity of wildflowers and insects, especially in early summer, is outstanding. I visited on 07.06.22 to prepare for a visit I am leading there on Saturday.

I reached the site by public transport, the number 2 bus from Brighton, 2 - Steyning-Rottingdean | Brighton & Hove Buses getting off at the Down's Hotel and walking up the Falmer Road to the carpark, from which two footpaths lead into the reserve.

From Natural England's East Sussex's National Nature Reserves East Sussex's National Nature Reserves - GOV.UK (www.gov.uk)

The site’s SAC [Special Area of Conservation] designation stems mainly from the chalk grassland being sufficiently rich in orchids to be recognized as of European importance. Species include fragrant, common spotted, pyramidal and autumn lady’s tresses, as well as the rare early spider orchid, for which Castle Hill is the national stronghold.

Typical chalk flowers to note are kidney vetch, horseshoe vetch, birdsfoot trefoil, fairy flax, dropwort and the round-headed rampion, also known as the Pride of Sussex.

Of the 58 UK species of butterfly, 31 have been recorded on Castle Hill, including adonis blue, chalkhill blue, small blue and silver spotted skipper.

This grassland contains a wide variety of grasshopper, cricket and leafhopper species, including rarer species like the long-winged cone head and Roessel’s cricket. Rarest of all is the wartbiter cricket which has its largest UK colony here.

Birds include whitethroat, linnet, yellowhammer, dunnock and blackcap. Kestrel, sparrowhawk, buzzard, red kite and peregrine have also been seen.

From Nature England's Castle Hill NNR: Welcome to the National Nature Reserve [ARCHIVED CONTENT] (nationalarchives.gov.uk)

This fine example of ancient, traditionally-managed chalk grassland is set within the steeply folded landscape between Lewes and Woodingdean. Many of the plants and animals that live on the steeper slopes are now very rare. They only urvive on remaining fragments of ancient downland like Castle Hill, where they are ideally suited to the short downland turf. The Council of Europe has designated the site as one of a network of Biogenetic Reserves, and it is protected under both UK and European wildlife laws. We hope that you enjoy your visit.

Wildlife.

From a distance, the most obvious feature at Castle Hill is the close-cropped downland turf on the hill slopes. This is mainly dense, wiry sheep’s fescue, but other grasses include upright brome, quaking grass, meadow oatgrass and tor-grass. Traditional grazing over hundreds of years has helped to establish plant communities that are well adapted to the chalky soil, creating a rich habitat with up to 30 plant species in a single square metre.

Looking more closely, you’ll find a wide range of colourful flowering plants. Dropwort, salad burnet and several vetches are common in May and June, followed by centaury, yellow-wort and small scabious in late summer. Several unusual plants also grow here, sometimes in considerable numbers. These include spring gentian and Nottingham catchfly, as well as round-headed rampion, known locally as the Pride of Sussex.

Castle Hill supports a rich variety of insects, including rare butterflies like the chalkhill blue, Adonis and small blue that depend on the different chalk herbs for their food. Here you’ll also find the country’s largest colony of wartbiter crickets, which is the focus of a project to re-introduce this rare creature to places where it has become extinct. The work was originally funded by English Nature's Species Recovery Programme.

In June, the purple flowers of fragrant and common spotted orchids push their heads above the turf (pictured below). This is also the national stronghold for the much rarer early spider orchid, with as many as 50,000 plants being recorded in a single year. Other examples of the orchid family include autumn lady's tresses and pyramidal orchids.

The open areas of downland are home to ground-nesting birds like partridge, skylark and meadow pipit. Birds such as linnet, yellowhammer and whitethroat nest in the gorse at the top of the slopes, as well as in other scattered patches of scrub.

All the photographs are in chronological order. I arrived at 10.15 and left at 15.15

House Sparrow on a fence next to the path on to the way into the reserve