Look out of your window and watch a bird take flight. You might see it push off from a perch and gain lift with hard strokes of its wings. Or you might see it drop, open its wings into a glide, and then begin to beat them for lift. On the surface of water neither method works. Water is too level to drop into a glide from, and too fluid to push against. So water birds have the ungainly take off that airplanes do. On Bhigwan lake we watched the long runs of coots (Fulica atra) as they scattered from approaching boats. They don’t flee from perceived danger; they take off in the direction that they face, sometimes towards the approaching boat. Perhaps it would take them longer to turn than to take off. I should time them.
The bar-headed geese (Anser indicus), those champion fliers, have even longer runs to take off. But the longest runs that we saw were those of greater flamingos (Phoenicopterus roseus). The flight of birds is quite different from that of an aircraft of course, but still, a greater weight would require a longer run for take off, unless the musculature and wings of two birds are very different. So a flamingo needs a longer runway than a coot, just as a Dreamliner needs a longer runway than a Cessna Skyhawk. A practical benefit of understanding this is that if you want to find coots and small ducks you could just drop by a small pond, but you need to find lakes if you want to watch geese and flamingos.