Photo 1 - Steep Downland Slope North-East Of The Hill Fort 

Highlights

National Nature Reserve on chalk downland owned and managed by English Nature

Site crowned by Iron Age hill fort providing fine views

One of the best sites in the country for Chalkhill Blue

Decent colonies of Dark Green Fritillary and Silver-spotted Skipper

Grizzled Skipper, Dingy Skipper and Green Hairstreak present in small numbers

Possibility also to see Adonis Blue, although becoming very scarce

Description

Old Winchester Hill is a National Nature Reserve on the South Downs just east of the village of Warnford in the Meon valley. It is also the site of an Iron Age hill fort with many prehistoric features still visible, such as earthworks, barrows and tumuli. The flat topped summit of the fort itself, complete with triangulation pillar provides fine views, especially south towards Portsmouth and the Isle of Wight. This large nature reserve is noted especially for its flora, which includes at least 6 species of orchid, and of course for its butterflies. The butterflies thrive on the species rich grassland, the diversity of species being further enhanced by the habitat variations resulting from the topography of the site.

 

The hill is one of the most prolific sites in the UK for Chalkhill Blue - with numbers reaching many hundreds across the reserve in good seasons! There are also reasonably sized colonies of Dark Green Fritillary and Silver-spotted Skipper. The site was selected by English Nature in the early 2000s to re-introduce Adonis Blue. After early success, the species is only just hanging on there, with the inevitable conclusion that there may not be sufficient suitable habitat to sustain the colony.

 

For this feature, it is convenient to use two widely separated locations which are both good for butterflies, since other areas of the reserve can be readily accessed from one or other of them.I will assume access is from the main car park (arrowed on this map), however for the fort area there is also limited road parking close to pedestrian entrances further south along the minor road.

The first location is at the bottom of the car park slope. Hence, from the car park, enter the reserve through the gate and turn almost immediately right, passing in front of a gazebo shaped structure containing visitor information (take a look!). Continue through another gate and head straight down the grassy slope. Depending on time of year, species which can be found on this heavily rabbit grazed area of the slope include Chalkhill Blue, Meadow Brown and Small Heath. Towards the bottom of the slope, just before the path takes a left turn, pause and look around. The area of more varied vegetation to your left (arrowed on this map) and in front of you, including a small meadow at the bottom of the slope across a partially 'flattened' wire fence, is a good place to look for several key species, depending on timing. In this area I have seen (in small numbers) Green Hairstreak, Grizzled Skipper, Dingy Skipper and Silver-spotted Skipper. Chalkhill Blue can present in significant numbers and it is also an area where Adonis Blue and Clouded Yellow can sometimes be seen. Common species such as Common Blue and Small Heath are also found here.

Photo 2 - View Into The South Field From The Fort Area.

If you continue along the path as it turns, you reach an area of steep open downland (Photo 1 at top of page). Look here for fast flying Dark Green Fritillaries during July. However this very active species rarely seems to settle for long on this site and can be difficult to photograph. In addition, departing from the paths is discouraged, bearing in mind the site was used in World War II for mortar testing. One can continue onwards through the section of woodland to another area of downland and then uphill (keeping to the paths!) to the fort area which is close to the second location I have selected. However, I will describe the route to the fort as if making a separate visit, starting from the car park.

In this case, after entering the reserve from the car park, just continue along the main path. The fort is just over 1km from the car park, the path heading south parallel to the road for about half that distance before turning right towards the fort. In the first section, Marbled White can be very numerous amongst the long grasses, as well as Small/Essex Skippers, Meadow Brown and Chalkhill Blue (which at peak season can be found in almost all grassland areas of the reserve). Some areas of the fort area itself (especially the ramparts) may be roped off to protect nesting birds, but butterflies are normally plentiful even along the rampart edges (Chalkhill Blue, Small Heath, Small/Essex Skipper, Meadow Brown, Painted Lady and even the occasional Clouded Yellow) and a full circuit around the fort is worthwhile if time permits.

The second specific area to explore is the south field which is accessed via an open gate on the south side of the fort (shown in photo 2 above). The lower part of the slope and the scrub area towards the bottom are usually the best places for butterflies with a good variety of common species. Chalkhill Blues can be abundant here and there is normally a reasonable population of Silver-spotted Skippers on the lower slopes, although numbers have been reducing, probably as a result of a greater number of cooler summers. There are also small populations of Green Hairstreak (bushy areas and scrub) and Brown Argus (scrub) with Adonis Blue still occasionally recorded here.