Absolutely delightful to watch, but unfortunately linked to seabird declines on the Azores:

Pitta Groz, M., Pereira, J.C. & Silva, A.G. 2002. Invasive alien species as the main threat to Azores seabird populations. In: Proceedings of Workshop on invasive alien species on European islands and evolutionary isolated ecosystems. Horta, Azores, Portugal. 10 October 2002. Convention on the Conservation of European Wildlife and Natural Habitats.