Noar Hill

Site feature providing a more detailed description, photos and other information for the butterfly observer.

Photo 1 - Sheltered Hollow - Typical Duke of Burgundy Habitat

Highlights

  • Hants & IoW Wildlife Trust reserve.

  • Central area based on ancient chalk workings providing sheltered habitat for butterflies.

  • Mosaic of other habitats ensures high species count including chalk downland and woodland species.

  • Good population of Duke of Burgundy. Green Hairstreak and Dingy Skipper are other notable spring species, with Small Blue also gaining a foothold

  • In late summer, Brown Hairstreak present but can be difficult to find in some years. The site is quite badly affected by Ash die-back disease which may be affecting their population.

  • Noar Hill is also well known for wildflowers including a variety of orchids.

Description​

Noar Hill is a Hampshire & IoW Wildlife Trust near Selborne and is a remarkable reserve, being on the site of medieval chalk workings which have long been reclaimed by nature. These former chalk workings now form a patchwork of sheltered hollows (or pits), creating a rich chalk scrub habitat in the central area of the reserve. Around this central area, there are also areas of woodland, woodland margin, blackthorn scrub and rough ground. It is, therefore, no surprise that this diverse range of habitats results in Noar Hill having a very high butterfly species count, totalling about 35 in all, with representatives of chalk downland, including Duke of Burgundy, Green Hairstreak and Dingy Skipper, as well as some woodland species. Noar Hill also has a population of Brown Hairstreak. Sightings of this species seem to be quite variable from year to year and it can seem especially elusive here. On the negative side, Noar Hill seems to be quite seriously affected by Ash die-back and several mature trees are already leafless, with others in various states of decline.

 

There are two access points to the Noar Hill reserve, from the minor road running south-west from Selborne, the one nearest Selborne being arrowed on this map with another one close to Charity Farm. The track heading south-east from there leads, in about 500m to the entrance gate into the reserve. There is limited parking on the minor road along the verge. On entering the reserve through the gate, continue up the incline to the visitor display board, where the site opens out and the first of the chalk scrub hollows will be seen. Throughout the season from late April until early September, there should be good numbers of butterflies on the reserve in fine weather, with the best area being the hollows in the central part of the reserve and around their margins.

 

The most conspicuous larger species (depending on flight period) tend to be Orange Tip, Brimstone, Peacock, Red Admiral, Painted Lady, Comma, Silver-washed Fritillary, Marbled White and other true Whites. There are decent populations of smaller butterflies such as Common Blue, Large, Small and Essex Skippers, Small Heath and Brown Argus, in addition to the 'Duke' already mentioned. Green Hairstreak and Dingy Skipper, whilst not so common, can usually be seen during their flight period, again mainly in the central part of the reserve, the former seeming to favour Juniper bushes growing close to scrub at this site.

 

The 'Dukes' (typically late April through to late May) seem to have a preference for the most sheltered hollows such as the one behind the visitor display board (photo 1 above) and others through to the far end chalk pit (Photo 3 below). These have rough margins with longer vegetation where the males like to perch. By Duke of Burgundy standards there is a good population here but don't expect to see more than a few on a visit. If undisturbed they may remain in the same few yards for several hours.

 

Brown Hairstreak (end of July and through August) can in principle be seen anywhere on the reserve and nearby hedgerows, where there is plentiful young blackthorn close to trees. However, they can be an elusive species and any sightings, especially at a low level, should be regarded as a significant success. Brown Hairstreak spend much of their time high in the trees, often favouring Ash (noting comment above about Ash die-back), where they will rest or feed on aphid honeydew, making occasional short 'jerky' flights. Male Brown Hairstreak occasionally come down to feed on the pink flowers of Hemp Agrimony or Bramble, whereas the low-level forays of the more brightly coloured females are also in search of egg-laying opportunities on blackthorn. An area to the left of the main track called the 'The Triangle' (Photo 2), about 5 minutes' walk from the visitor display board, is still a place to look for both sexes, having all the right ingredients, including hemp agrimony, blackthorn for egg-laying, and Ash trees, although some are now badly affected by Ash die-back which may partially explain a reduced number of sightings here in recent years.  There is also a favoured Brown Hairstreak area on the south (Charity Farm) side of the reserve, with further details in the next paragraph. 

Photo 2 - ' The Triangle' Viewed Across The Main Path

To continue to the end of the reserve, take the middle path of the three-pronged forks just after the triangle, leading to a large chalk pit (and the haunt of Duke of Burgundy in spring). Its flower-rich banks often have many Nymphalid species feeding. Then the path enters a more shady section leading to the final chalk pit (Photo 3). Any of the species found on the reserve could be encountered in the section approaching the final chalk pit and in the pit itself. As an alternative to retracing your steps, you can return to the triangle on the 'high level' route or follow the track westwards to the other entrance. In both cases, use the rudimentary steps cut in the bank leading out of the pit where, on reaching the top, you will see a wooden seat. To return to the triangle, turn right and follow the path passing behind the seat. To explore the southern side of the reserve, take the path in front of the seat, initially through a small wooded area. After about 250m you will reach an open area on the right, at the far end of which, close to the path, is a 3m stone circle made in modern times from chalk stones. This is another favoured area for Brown Hairstreak, with plenty of Hemp Agrimony for feeding, as well trees, including Ash (although some are affected by Ash die-back), shrubs and young blackthorn in the vicinity for perching/egg-laying. You will also notice plenty of Kidney Vetch in this area, so it's not surprising that Small Blue (in modest numbers) are recorded here. The path continues, reaching the Charity Farm entrance after a further 250m.

Photo 3 - Chalk Pit At The Far End Of The Reserve

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