The wetland habitat that stands out for richness and diversity of the bird world. Due to its importance in preserving biodiversity, it is protected as an ornithological reserve. There have been registered 163 bird species in the Kolanjsko Blato and its surroundings, of which 66 are the nesting birds. During the time of migration and hibernation, various species of birds are found in the reeds. Some inhabit the surrounding meadows and sometimes nest at a nearby islet while some come to the reserve to feed on plenty of fish.