Asked by: Rhiannon Williams, DorsetIt depends on the bird! Ostriches can’t even fly. Kakapos only clumsily glide. At the other extreme, large birds like albatrosses use updraughts of wind to soar for hours or days without much more effort than just sitting. However, by catching food while flying, some species of swift never need to stop, sleeping and mating during flight. Juveniles can keep airborne for two or three years, landing only to breed.