One of a well-known species pair, breeding in North America and migrating South, both are vagrants to Britain and Europe, but whereas Lesser is annual, this bird is a real rarity, only five records in the last twenty years. This at first seems strange because it has a somewhat more easterly breeding distribution, but Lesser takes a more easterly migration route, and more Greaters migrate overland and coastally. It is often difficult to separate the two on plumage, but Greater is significantly larger and bulkier.