Trans-Atlantic vagrancy in Anax junius (Odonata: Aeshnidae)

Late October 2023 saw an influx of the migratory Nearctic Anax junius into both the Isles of Scilly in south-western Britain and the Île d'Ouessant in north-western France, with at least eleven dragonflies being reported and with further sightings likely to involve additional individuals. This species has only been observed in the Western Palaearctic since 1998, and all known records from the region are documented and discussed; such records are currently restricted to the autumn months, and come predominantly from south-western Britain and western France, with at least one sighting also on the Azores. Meteorological conditions preceding arrivals have been dominated at mid latitudes by mobile westerly airflows across the entire Atlantic, and it is thought the dragonflies arrive in Europe via wind-assisted non-stop flights directly across the ocean, with a likely journey time of approximately four days.