The concept of the aquapelago was introduced into Island Studies in 2012 to identify the close integration of aquatic and terrestrial realms that can arise from human livelihood activities conducted within them. While many aspects of aquapelagos have subsequently been described and analysed, little attention has been extended to their interface with aerial and, particularly, avian domains. This article attempts to redress this through a consideration of human livelihood activities involving seabirds in St Kilda, an isolated group of islands to the west of Scotland’s Outer Hebrides. Using the concept of the aquapelago as a starting point, the article considers various aspects of human-avian relations occurring on St Kilda, and UNESCO’s subsequent designation of the islands as a World Heritage site and intersperses this with the author’s personal experiences of and affective engagements with the islands. In particular, the latter part of the article develops the author’s field notes from a visit in Summer 2022 into a consideration of the limits of isolation occasioned by the presence of the H5N1 strain of HPAIV (Highly Pathogenic Avian Influenza Virus) on St Kilda at that time. The viral colonisation of the bird colonies undermined any sense of St Kilda and similar remote locations being safely isolated refugia and, indeed, signalled a particularly precarious moment of Anthropocene connectivity between mainlands and islands.