Aimiréal dearg in Gaeilge. The Red Admiral reaches Ireland as a migrant from continental Europe every year, with a resident population increasingly recorded overwintering in mild southern Irish coastal locations.
Identifying the Red Admiral in the field
Deep chocolate-black upperside with a broad red band across the forewing and a red marginal band on the hindwing. White forewing tips. Underside is a marbled dark brown and grey that renders the closed-wing butterfly cryptic on tree trunks. Wingspan 55 to 65 mm, larger than the Small Tortoiseshell.
Migration and Irish records
The main arrival in Ireland is April to June, with the largest counts often at southern coastal sites (Cape Clear, Old Head of Kinsale, Wexford). A second migration wave in September carries southbound individuals. Overwintering adults are now recorded annually in Cork and Kerry.
Recorded in 22 of 26 Irish counties in the National Biodiversity Data Centre atlas, with the strongest concentrations in Munster and eastern Leinster. Numbers dropped through the 2010s and partially recovered from 2019 onward.1
Source: National Biodiversity Data Centre butterfly atlas 2014 to 2019, and Butterfly Conservation Ireland annual review 2024.
Life cycle and foodplant
Females lay single eggs on the upper leaves of Common Nettle. Larvae live inside a folded-leaf tent and feed alone. One to two broods in Ireland depending on the year.
Every sighting counts
Butterfly Conservation Ireland and the National Biodiversity Data Centre track changes in Irish butterfly populations through recorder submissions. Add a sighting, and a named contributor will verify it within seven days.
