I was at Niagara Falls today. As I was right at the rail near the top of Horseshoe Falls, I saw a bird floating on the water. I’m guessing it was a cormorant, and it had a fish (sardine-class) in its mouth. I watched it float right to the edge of the Falls, and then go over, but I couldn’t see what happened after that.
This raised several questions in my mind.
Can a cormorant fly with a fish sticking out of its mouth, and probably battling some serious downdrafts?
Are there a lot of small fish in the Niagara River, and in the fast-flowing water at the top of the Falls?
If the answer to #2 is ‘yes’, what happens to those fish who go over the edge? If the cormorant hadn’t eaten this fish, was it only going to live another three seconds?
I think the cormorant I saw was probably just fishing for himself, the greedy bastard.
The thing is, animals are usually very good at being animals. This bird went right over the edge of the falls like it was no big deal, and for a bird it probably isn’t. It was a little unsettling to watch, though.
Similarly for the fish, who I assume was caught by the cormorant just upstream of the falls. It seems unlikely that any creatures would routinely hang out in a place where they were facing imminent, grizzly death. But what do I know? Maybe shooting the rapids and going over the falls is an e-ticket ride for a young smelt, but they can only do it once.
Yes cormorants and other birds can fly with fish hanging out of their mouths; the low speeds they fly at don’t require super-precision aerodynamic air flow over their bodies. Planes can also strap small boats to their landing floats and fly, and helicopters routinely fly dragging loads in slings hanging by long straps behind them.
I don’t know the fish populations of that particular river, but yes fish do exist in streams with falls and the small ones generally hang out in lower velocity areas with current breaks. But still, a given percentage of them will venture (or get chased) out too far and get swept downstream or over water falls.
It depends on what the fish lands on at the bottom (or along the way). They can certainly smack into rocks and get killed. But, the smaller the fish the better chance it has to survive. Many of them survive and just continue their lives in the new river stretch. They obviously can’t get back up though.
Moving down stream is not a problem for fish, it’s getting back up is the problem. Small trout are stocked in remote lakes by plane in the US, claimed survival rate is ninety eight percent from one hundred and fifty foot drop.
There is also a dam over four hundred feet high near my house which had a large number of mature trout go over in recent floods, lucky for them I’m locked down by Covid for at least the next two weeks.
It is potetially dangerous for fish to go over falls, because they could get an embolism from the supersaturated water at the bottom. The same for dams.
I think one would expect some birds to have evolved the ability to fly while holding a fish in their beaks, since it would confer obvious advantages while not being particularly difficult.
This amazing short video shows that river fish have undoubtedly evolved the ability not to get washed away in fast flowing water.
