A typical chalk/flint pit at Noar Hill where the Duke of Burgundy can be found in April and May with good amounts of its foodplant the Cowslip, interspersed with the scrub.
Noar Hill NNR
The Duke of Burgundy can be easily found in the pits on a warm day in the middle of May. They can be seen mating and the female lays its eggs on the Cowslips
The Brown Hairstreak can be seen in August and into September (weather permitting) laying their eggs on the many blackthorn thickets dotted around the site. In the early part of August the Males can be seen battling up above the Ash trees holding territories.
Cowslips are very abundant on the reserve feeding the Duke of Burgundy caterpillars (see separate web-page on the Duke of Burgundy)
Noar Hill will draw botanists from far and wide, and the Orchids are the favourite flowers to see as the site has some nationally rare plants.
In the early spring there are a lot of invertebrates on the site to see, and one of the most fascinating is the Bee-Fly, which mimics a Bee hence the name. This one is at rest on a Cowslip flower.
Female Brown Hairstreaks are shy and elusive, but can be quite tame once they come down to feed , normally on Hemp Agrimony. Here they will seem to feed for hours on the nectar, which gives them the strength then to go to the Blackthorn thickets and start to lay her eggs.
Wasp spiders are quite common on the site in the many meadows dotted about. They are very distinctive, and build a unique web in which to catch their prey.
Most years there is a Brown Hairstreak egg-hunt in amongst the Blackthorn thickets in the depths of winter on the site, and these have been quite successful.
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.
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 and others through to the far end chalk pit. 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 single figure counts are not unusual 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.
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.
Text by Alan Thornbury
Noar Hill facing west with the many Hemp Agrimony plants seen on the site, during the late summer. These plants are worth looking at as there is normally a female Brown Hairstreak feeding on them for what seems like hours, which is ideal for studying one of our most beautiful of butterflies.
Three Brown Hairstreak eggs laid on a young Blackthorn twig on Noar Hill