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
I'm Not the Only One the chords so we returned to them, and then we wrote 'I'm Not The Only One' in like an hour." Lyrically, "I'm Not the Only One" talks about infidelity and betrayal in a relationship, where someone decides to stay with a partner they know is cheating on them. In the chorus, Smith admits: "You say I'm crazy/'Cause you don't think I know what you've done/But when you call me baby/I know I'm not the only one". Smith revealed to Lewis Corner that the song was the only one on the album that is not about his life, but a marriage