A few years ago I saw this video and lately it has been coming back in some social networks.
While swans feeding fish would indeed be interesting and fun to watch, it’s far from what is actually happening.
In reality what is happening is that swans and geese are trying to get their food wet, not feed the fish. They need to get their food wet in order to swallow it, otherwise they might choke, so what they do is pick up the food in their beak, dip their beak in the water, and open and shut their beak quickly so that some water gets in and mixes with the food.
Of course while they do this, a good amount of food falls into the water and fish just take advantage of that. So in a way, you could say the swans are indeed feeding the fish, but they’re doing so inadvertently. If you look closely, in some videos you can actually see the swans clearly trying to avoid the fish.