The Small Pearl-bordered Fritillary historically was present on the site but is now extinct locally.

A colony of the Small Pearl-bordered Fritillary (Boloria selene) is found here.

The presence of Marsh Violets makes the bog an ideal supportive habitat for the uncommon Small Pearl-bordered Fritillary.

Butterflies of note are the Small Pearl-bordered Fritillary, Wood White and the White Admiral or Limenitis camilla.

Roe Deer and Purple Hairstreak butterflies can both be seen here, as well as the extremely rare pearl-bordered fritillary and the small pearl-bordered fritillary.

The Small Pearl-bordered Fritillary (Boloria selene), called the Silver-bordered Fritillary in North America, is a butterfly of the family Nymphalidae.

Notable butterflies that may be seen are the Small Pearl-bordered Fritillary, Silver-washed Fritillary, Grizzled Skipper and White Admiral.

It is the foodplant of the Pearl bordered fritillary, Small Pearl-bordered Fritillary, Silver-washed Fritillary and High Brown Fritillary butterfly.

Other notable species at the gorge include dormice, yellow-necked mice, slow worms and adders and the rare large blue butterfly (Maculinea arion), and small pearl-bordered fritillary (Boloria selene).

Bugle, bramble and thistle flowers are favourite nectar sources of the Pearl-bordered fritillary, High brown fritillary, Small pearl-bordered fritillary and Dark Green Fritillary.

Another butterfly, the Small Pearl-Bordered Fritillary, Boloria selene, used to be common at Waldridge Fell but within County Durham is now confined to only four locations, all on heathland at around 300 metres asl.

There are a large variety of butterflies in the countryside around the village, most notably the nationally rare Pearl-bordered Fritillary and the Small Pearl-bordered Fritillary due to the mixture of upland, woodland and meadow habitats that are found.

There are butterfly colonies of the Silver-studded Blue Plebejus argus, Small Pearl-bordered Fritillary Boloria selene on Cribba Head in the eastern part of the site as well as the Thrift Clearwing Synansphecia muscaeformis a day-flying moth.

It is often confused with the Small Pearl-bordered Fritillary, but can be distinguished from it by the triangle along its pearl-border (the Small Pearl-bordered has black chevrons) as well as the presence of a single silver spot in the middle of a row of yellow spots.

The former is the foodplant of the Marsh Fritillary, Euphydryas aurinia, and the Narrow-bordered Bee Hawk-moth, Hemaris tityus, while the latter is the food plant of the Pearl-bordered Fritillary, Boloria euphrosyne, and the Small Pearl-bordered Fritillary.

The Small Pearl-bordered Fritillary (Boloria selene), called the Silver-bordered Fritillary in North America, is a butterfly of the family Nymphalidae.

The Silver-bordered Fritillary has rounder wings than the Meadow Fritillary, has a dark hind wing margin border, and has silver spots on the underside of the hind wing.

A colony of the Small Pearl-bordered Fritillary (Boloria selene) is found here.

The Small Pearl-bordered Fritillary (Boloria selene), called the Silver-bordered Fritillary in North America, is a butterfly of the family Nymphalidae.

Other notable species at the gorge include dormice, yellow-necked mice, slow worms and adders and the rare large blue butterfly (Maculinea arion), and small pearl-bordered fritillary (Boloria selene).

Another butterfly, the Small Pearl-Bordered Fritillary, Boloria selene, used to be common at Waldridge Fell but within County Durham is now confined to only four locations, all on heathland at around 300 metres asl.

There are butterfly colonies of the Silver-studded Blue Plebejus argus, Small Pearl-bordered Fritillary Boloria selene on Cribba Head in the eastern part of the site as well as the Thrift Clearwing Synansphecia muscaeformis a day-flying moth.