Black Guillemot

The black guillemot or tystie (Cepphus grylle) is a medium-sized seabird of the Alcidae family, native throughout northern Atlantic coasts and eastern North American coasts. It is resident in much of its range, but large populations from the high arctic migrate southwards in winter. The bird can be seen in and around its breeding habitat of rocky shores, cliffs and islands in single or smalls groups of pairs. They feed mainly by diving towards the sea floor feeding on fish, crustaceans or other benthic invertebrates. They are listed on the IUCN red list as a species of least concern. Both sexes have very similar appearances with black plumage and a large white patch on the upper side of their wings in summer. Wikipedia →

<5% of wildlife watchers report a Black Guillemot sighting in Wadden Sea National Park, based on 336 days of visitor records from GBIF citizen-science data.