Though the linguistic tangent was off topic for the OP, I'm glad you shared it, it was a really interesting tangent!
"... All of that isn’t really as significant as what’s more difficult to think about, but much more important: What’s the
fundamental design of language. If you want to understand what the function of the visual system is, you can’t just say “I use it to
watch television.” That’s not biology. You want to understand the visual system, you have to look into its nature. See what it does.
Investigate it. It’s a scientific problem. And then you find things about the visual system that are surprising. It’s the same with
language. Its’ not enough to say “Yeah, I use it to talk to my friends.” If you want to understand something about it, you have to look
into its nature. And you can’t do that in a casual conversation. THat requires investigation, like any other hard topic. And when you
investigate it, you find things like I just mentioned, that linear order just isn’t part of the way language is used. You can see it in
simple cases. Take the example I used last night, take this sentence:
“Eagles that fly swim.”
Ok. And put an adverb in front of it: ..."
A few years ago we were kayaking in Woods Lake (Arizona) and a naturalist told us that Eagle parents had just left the area, leaving behind their juvenile baby. This is normal behavior after parents have taught their offspring how to function. Anyway, the very young Eagle kept trying to catch a fish for about an hour until it snagged a small trout caught on just one talon. I quickly flew to shore looking like it was going to drop the fish and it looked like it eventually ate the entire fish. The same naturalist later told us that this initial 'being on their own' period is a bit dangerous for these young Eagles because they must catch sufficient food all on their own. Tough Eagle parent love.
EDIT: off topic, but in San Diego while diving I have watched Cormorants "flying underwater" - very impressive just how fast they go. As someone else here said, 'flying in a denser medium.'
In this instance it seems to carried by buoyancy to a reasonable degree, I would say swimming.
If you look at the other video linked, the one with a partially waterlogged bird, it almost stops looking like swimming as it floats quite high in the water. Looks more like rowing with terribly awkward oars.
I went fishing with bald eagles once on the beach. I was there early in the morning. There were tons of eagles on the beach. One by one they'd wade out into the water and wait. Then they'd dunk their head down and pull out a fish and fly away until there was only one left by the time i went home that just didn't have any luck.
I wonder if other eagles ever do this? Maybe a distant Golden Eagle swimming in a Scottish loch might be mistaken for a large aquatic creature of some kind - Nessie? Birds are dinosaurs, after all..
I imagine all/most eagles that feed on fish must have to swim at some points in time, so probably develop a fairly decent swimming technique.
As for nessie, I'm not sure there are any outstanding 'unexplained' photos (the 'surgeon's photo' is much like the famous bigfoot film - it's been admitted to being a hoax, but 'true believers' insist that that's just the person being coerced into a cover up)
Because of the low body density needed for flight, I suspect that all flighted birds can swim to one degree or another. It is at least trivial for them to float quite high in the water. And once you're doing that, you've got both legs and wings that should be able to provide some manner of propulsion.
I thought it was just a sentence specifically made to be nonsensical, but no, they actually do swim.
(See for example: http://annarborchronicle.com/wp-content/uploads/2013/07/A2Ch...)