Bird migration evidence. Seabirds fly low over water but gain altitude when crossing land, and the reverse pattern is seen in landbirds. However most bird migration is in the range of . Bird strike aviation records from the United States show most collisions occur below and almost none above . Bird migration is not limited to birds that can fly. Most species of penguin (Spheniscidae) migrate by swimming. These routes can cover over . Dusky grouse "Dendragapus obscurus" perform altitudinal migration mostly by walking. Emus "Dromaius novaehollandiae" in Australia have been observed to undertake long-distance movements on foot during droughts. While participating
Oozlum bird Oozlum bird The oozlum bird, also spelled ouzelum, is a legendary creature found in Australian and British folk tales and legends. Some versions have it that, when startled, the bird will take off and fly around in ever-decreasing circles until it manages to fly up its own backside, disappearing completely, which adds to its rarity. Other sources state that the bird flies backwards so that it can admire its own beautiful tail feathers, or because while it does not know where it is going, it likes to know where it has been. The "Oxford English Dictionary" describes it as "[a]