Iceland's bird fauna has long been the subject of interest. A total of 75 bird species regularly nest in Iceland and a number of others occasionally choose to breed here, although they are slow to establish themselves permanently. Iceland is an extremely important stop for geese and waders migrating between breeding grounds in Greenland and Canada and wintering grounds in Europe. Numerous vagrants also pass through Iceland, arriving both from the west and east. These birds are seen mainly during migratory periods in the autumn and spring. Various arctic birds spend the winter in Iceland. Sightings of around 370 bird species have been confirmed to date. This figure is constantly rising, however, as new species are spotted in Iceland every year.
Although Iceland's bird fauna may not be species-rich, it is in many ways unique. Iceland is home to very large seabird, wader and waterfowl populations. Indeed, some populations are so large that a significant part of the entire world population for a given species is found here in Iceland.
Research on Iceland's birds and bird populations is an important part of IINH operations. Bird monitoring takes place at the IINH, as do studies into the population ecology of bird species and migration patterns.
Bird ringing began in Iceland in 1921 and has been a key tool in most research projects.