The dippers are a small family of medium-sized passerines in the single genus Cinclus. They are unique among passerines in habitually diving and swimming underwater in search of invertebrates. Although not web-footed, they have several adaptations to their aquatic habit, notably solid bones to reduce buoyancy, nasal flaps to prevent water entering their nostrils, and a high haemoglobin content to their blood allowing them to stay underwater longer without breathing. There are five species, found in fast-flowing freshwater streams in America, Europe and Asia (and the Atlas Mountains of Morocco).