CRCritically Endangered

Arran Brown

Erebia ligea

The Arran Brown (Erebia ligea) is a butterfly species belonging to the family Nymphalidae, subfamily Satyrinae. This distinctive brown butterfly is characterized by orange-ringed eyespots on its wings and is part of the mountain ringlet group.

01Classification

Taxonomy & Classification

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Lepidoptera

Family

Nymphalidae

Genus

Erebia

Arran Brown belongs to the family Nymphalidae, order Lepidoptera, within the Insecta class.

02Description

Species Profile

The Arran Brown (Erebia ligea) is a butterfly species belonging to the family Nymphalidae, subfamily Satyrinae. This distinctive brown butterfly is characterized by orange-ringed eyespots on its wings and is part of the mountain ringlet group. In the British Isles, the species is found exclusively on the Isle of Arran in Scotland, representing the northernmost extent of its European range. The butterfly inhabits woodland clearings, forest edges, and areas with scattered trees where its larval host plants, primarily various grass species, are present. Adults typically fly during summer months and are dependent on specific microclimatic conditions. The Arran Brown faces severe conservation challenges that have led to its classification as Critically Endangered. The species has experienced significant range contraction and population decline, with its distribution now extremely limited. Primary threats include habitat loss and degradation, climate change impacts, and the inherently vulnerable nature of small, isolated populations. Forest management practices that alter woodland structure and composition pose additional risks to remaining populations. Conservation efforts focus on habitat management and monitoring of the remaining population. Research initiatives aim to better understand the species' ecological requirements and population dynamics. Collaborative work between conservation organizations, land managers, and researchers is essential for developing effective protection strategies. The precarious status of the Arran Brown highlights the vulnerability of specialized butterfly species to environmental changes and the importance of targeted conservation action for preventing extinctions.

The Arran Brown faces threats from habitat loss and degradation, particularly changes to woodland structure and management practices that affect its specialized habitat requirements. Climate change and the species' extremely limited distribution make it highly vulnerable to environmental fluctuations. Small population size increases risks from genetic bottlenecks and random demographic events.

Key Facts

IUCN StatusCritically Endangered (CR)
GroupInsects
03Habitat

Habitat & Distribution

The Arran Brown inhabits woodland clearings, forest edges, and areas with scattered trees on the Isle of Arran. The species requires specific microclimatic conditions and depends on grassland areas within or adjacent to woodland where its larval host grasses grow.

04Threats

Threats

!

IUCN Red List: Critically Endangered

The Arran Brown faces threats from habitat loss and degradation, particularly changes to woodland structure and management practices that affect its specialized habitat requirements. Climate change and the species' extremely limited distribution make it highly vulnerable to environmental fluctuations. Small population size increases risks from genetic bottlenecks and random demographic events.

Detailed threat classification data is sourced from IUCN assessments as they become available.

07National Status

National vs Global Threat Status

How this species is assessed at the national level compared to its IUCN global status (CR).

CountryNational StatusGlobal StatusComparison
EULCLeast ConcernCRCritically EndangeredLower local risk
EULCLeast ConcernCRCritically EndangeredLower local risk

National Red List data sourced from the National Red List Project (nationalredlist.org, ZSL) and country-specific Red List authorities.

Community

Community Sightings

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07Sources

Sources & Attribution

How to Cite

IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS

GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org

National Red Lists: ZSL (2025). National Red List. Zoological Society of London. Available at: https://www.nationalredlist.org

This page: SpeciesRadar (2025). Arran Brown (Erebia ligea). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/arran-brown

Full citation guide & data usage terms