Red Lists are standard, objective way of assessing the extinction risk of species at global, continental and country levels. Butterfly Conservation has recently revised the butterfly Red List for Great Britain (butterflies in Northern Ireland are covered by the Ireland Red List) using data kindly provided by thousands of volunteers via our recording and monitoring schemes. The new Red List categorises half of Britain’s remaining species as threatened (Endangered or Vulnerable) or Near Threatened.

The current GB Red List category for each resident, former resident and regular breeding species is given in the table below, alongside brief reasons for qualification and the category in the previous Red List published in 2010. More detailed information on the qualifying criteria for each butterfly species can be found here (downloads as an Excel document) and an overview of the whole process in Fox et al. 2022.

It is worth noting that the IUCN Red Listing process is complex and prescriptive. Some key points to bear in mind are that it is an assessment of extinction risk and not conservation priority, that rarity alone is not sufficient for Red List qualification (at least for the IUCN criteria that are applicable to GB butterflies) and that historical declines that have now ceased are not relevant. We used smoothed trends for abundance and distribution data to minimise the problems associated with measuring short-term trends for species, such as butterflies, with populations that naturally vary greatly from year to year.

 

Species Red List category Qualifying criteria Previous (2010)
Red List category
Swallowtail
Papilio machaon

Vulnerable 32% decrease in abundance 2010-2019 (IUCN criterion A2b). Near Threatened
Dingy Skipper
Erynnis tages
Least Concern Recent trend estimates for both abundance and distribution do not meet IUCN thresholds. Vulnerable
Grizzled Skipper
Pyrgus malvae
Vulnerable 36% decrease in abundance 2010-2019 (IUCN criterion A2b). Vulnerable
Chequered Skipper
Carterocephalus palaemon
Least Concern No longer meets IUCN thresholds. Recent surveys found it to be much more widespread in Scotland than previously known, and its distribution trend is positive. The assessment does not yet include the English reintroduction. Endangered
Essex Skipper
Thymelicus lineola
Least Concern   Least Concern
Small Skipper
Thymelicus sylvestris
Least Concern   Least Concern
Lulworth Skipper
Thymelicus acteon
Near Threatened Small range and extreme fluctuations in population size (IUCN criteria B1c(iv) and B2 c(iv)). Near Threatened
Silver-spotted Skipper
Hesperia comma
Vulnerable 44% decrease in distribution 2010-2019 (IUCN criterion A2c). Near Threatened
Large Skipper
Ochlodes sylvanus
Least Concern   Least Concern
Wood White
Leptidea sinapis
Endangered Retained as Endangered as its distribution decline still exceeded threshold five years ago (IUCN criterion A2c). Endangered
Orange-tip
Anthocharis cardamines
Least Concern   Least Concern
Black-veined White
Aporia crataegi
Regionally Extinct Last recorded as a resident species in 1920s. Regionally Extinct
Large White
Pieris brassicae
Least Concern   Least Concern
Small White
Pieris rapae
Least Concern   Least Concern
Green-veined White
Pieris napi
Least Concern   Least Concern
Clouded Yellow
Colias croceus
Least Concern   Least Concern
Brimstone
Gonepteryx rhamni
Least Concern   Least Concern
Wall
Lasiommata megera
Endangered 70% decrease in distribution 2010-2019 (IUCN criterion A2c). Near Threatened
Speckled Wood
Parage aegeria
Least Concern   Least Concern
Large Heath
Coenonympha tullia
Endangered 57% decrease in distribution 2010-2019 (IUCN criterion A2c). Vulnerable
Small Heath
Coenonympha pamphilus
Vulnerable 37% decrease in distribution 2010-2019 (IUCN criterion A2c). Near Threatened
Mountain Ringlet
Erebia epiphron
Near Threatened Small range and evidence of continued distribution decline (10% decrease 2010-2019) (IUCN criterion B2 c(iv)). Near Threatened
Scotch Argus
Erebia aethiops
Vulnerable 44% decrease in abundance and 33% decrease in distribution 2010-2019 (IUCN criteria A2b and A2c). Least Concern
Ringlet
Aphantopus hyperantus
Least Concern   Least Concern
Meadow Brown
Maniola jurtina
Least Concern   Least Concern
Gatekeeper
Pyronia tithonus
Least Concern   Least Concern
Marbled White
Melanargia galathea
Least Concern   Least Concern
Grayling
Hipparchia semele
Endangered 52% decrease in distribution 2010-2019 (IUCN criterion A2c). Vulnerable
Pearl-bordered Fritillary
Boloria euphrosyne
Vulnerable 33% decrease in distribution 2010-2019 (IUCN criterion A2c). Endangered
Small Pearl-bordered Fritillary
Boloria selene
Vulnerable 37% decrease in distribution 2010-2019 (IUCN criterion A2c). Near Threatened
Silver-washed Fritillary
Argynnis paphia
Least Concern 37% decrease in distribution 2010-2019 (IUCN criterion A2c). Least Concern
Dark Green Fritillary
Speyeria aglaja
Near Threatened 27% decrease in distribution 2010-2019 (IUCN criterion A2c). Least Concern
High Brown Fritillary
Fabriciana adippe
Endangered 64% decrease in distribution 2010-2019 (IUCN criterion A2c) and small range plus ongoing decline and extreme fluctuations in population size (IUCN criteria B2 b(ii),c(iv)). Critically Endangered
White Admiral
Limenitis camilla
Vulnerable 40% decrease in distribution 2010-2019 (IUCN criterion A2c). Vulnerable
Purple Emperor
Apatura iris
Least Concern No longer meets IUCN thresholds. Range expansion and targetted recording effort found it to be much more widespread than previously. Near Threatened
Red Admiral
Vanessa atalanta
Least Concern   Least Concern
Painted Lady
Vanessa cardui
Least Concern   Least Concern
Peacock
Aglais io
Least Concern   Least Concern
Small Tortoiseshell
Aglais urticae
Least Concern Abundance trend (29.6% decrease 2010-2019) meets the threshold for Near Threatened, but there is clear potential for a rescue effect from continental Europe so downlisted to Least Concern. Least Concern
Large Tortoiseshell
Nymphalis polychloros
Regionally Extinct Last recorded as a resident species in 1980s. Possible recent colonisation in southern England has not been included yet in the assessment. Regionally Extinct
Comma
Polygonia c-album
Least Concern   Least Concern
Marsh Fritillary
Euphydryas aurinia
Vulnerable 47% decrease in distribution 2010-2019 (IUCN criterion A2c). Vulnerable
Glanville Fritillary
Melitaea cinxia
Endangered Small range plus ongoing decline and extreme fluctuations in population size (IUCN criteria B1 b(ii),c(iv) and B2 b(ii),c(iv)). Endangered
Heath Fritillary
Melitaea athalia
Endangered 50% decrease in distribution 2010-2019 (IUCN criterion A2c). Endangered
Duke of Burgundy
Hamearis lucina
Vulnerable Retained as Vulnerable as its distribution decline still exceeded threshold five years ago (IUCN criterion A2c). Endangered
Small Copper
Lycaena phlaeas
Least Concern   Least Concern
Large Copper
Lycaena dispar
Regionally Extinct Last recorded as a resident species in 1864. Regionally Extinct
Brown Hairstreak
Thecla betulae
Vulnerable 35% decrease in abundance 2010-2019 (IUCN criterion A2b). Vulnerable
Purple Hairstreak
Favonius quercus
Least Concern   Least Concern
Green Hairstreak
Callophrys rubi
Least Concern   Least Concern
White-letter Hairstreak
Satyrium w-album
Vulnerable Retained as Vulnerable as its abundance and distribution declines both still exceeded thresholds five years ago (IUCN criterion A2b and A2c). Endangered
Black Hairstreak
Satyrium pruni
Endangered Small range plus ongoing decline and extreme fluctuations in population size (IUCN criterion B2 b(ii),c(iv)). Endangered
Small Blue
Cupido minimus
Near Threatened Retained as Near Threatened as its abundance and distribution declines still exceeded thresholds five years ago (IUCN criteria A2b and A2c). Near Threatened
Holly Blue
Celastrina argiolus
Least Concern   Least Concern
Large Blue
Phengaris arion
Near Threatened Small range plus severely fragmented populations (IUCN criterion B2a). Critically Endangered
Silver-studded Blue
Plebejus argus
Vulnerable Retained as Vulnerable as its distribution decline still exceeded threshold five years ago (IUCN criterion A2c). Vulnerable
Brown Argus
Aricia agestis
Least Concern   Least Concern
Northern Brown Argus
Aricia artaxerxes
Vulnerable 39% decrease in distribution 2010-2019 (IUCN criterion A2c). Vulnerable
Mazarine Blue
Cyaniris semiargus
Regionally Extinct Last recorded as a resident species in 1904. Regionally Extinct
Common Blue
Polyommatus icarus
Least Concern   Least Concern
Adonis Blue
Polyommatus bellargus
Vulnerable 40% decrease in abundance 2010-2019 (IUCN criterion A2b). Near Threatened
Chalk Hill Blue
Polyommatus coridon
Vulnerable 42% decrease in abundance and 41% decrease in distribution 2010-2019 (IUCN criteria A2b and A2c). Near Threatened

Richard Fox
Head of Science