With ships, birds find an easier way to travel | Hacker News Reader

With ships, birds find an easier way to travel

hakaimagazine.com

138 pointssohkamyung32 comments

If you zoom-out a ship is just a small island, a rock or something floating around in the water that can be used as a pit-stop. If birds evolved to judge something as useful to rest - these birds just see a higher quantity of pit stops. Would be interesting if they lower the required calories to make the trip beforehand as time passes.

Container ships steam at ~20 kts. If they need to get somewhere and are picking these pit-stops at random as if they are stationary, about half the time it would be a rather maladaptive choice.

My dad used to work on oil carriers in the North Sea, he said an owl had stowed away and nested on one of bouys near a field. The place was covered with skeletons of birds

Why? They died from no food or something?

Presumably the owl ate them. Owls swallow their prey whole, so the skeleton comes out intact. Dissecting "owl pellets" as they are called, and trying to piece together the skeleton within is a popular educational youth activity.

For those wondering, some of these birds can fly over 5 miles high. From 5 miles above sea level, the distance to horizon is 200 miles. From 5 miles high, you could see the tip of mount Everest above the horizon from 410 miles. Great snipes can fly thousands of miles in one continuous 60-90 hour flight.

https://www.inverse.com/science/migratory-birds-flying-ocean

https://www.omnicalculator.com/physics/earth-curvature

and what's a mile again?

From your article, (which uses metric),

> One of the great snipes stayed above 8,000 meters (4.97 miles) for more than five hours one day, rising to a maximum altitude of around 8,700 meters (5.41 miles). This is the highest altitude ever recorded for an identified migratory bird.

At 8km high it's easier to believe that they'd see ~660km away (410mi), although I don't know if weather, pollution or some distortions get in the way.

I appreciate the translation.

I’d assume they do (get in the way) but I don’t have confirmation. A mile is 5 thousand 200 and eighty feet.

When I visualize the bird’s experience, I would hesitate to cross the Atlantic.

I wonder if, even if the bird doesn't take the boat for a long distance (i.e. cutting off time spent flapping), just having the ability to rest and recover in the middle of the ocean provides it the boost to keep on going. Or some safety factor. Just like Midway Atoll for us...hah.

Landing and taking off again doesn't obviously conserve energy. Midway has fuel, but there's probably not much accessible food on a cargo ship.

I wonder if birds are smart enough to notice which direction the ship is moving?

Landing and taking off could be advantageous if the weather is bad, since the rest can allow the bird to wait out the bad weather.

Also, I wonder how many of these birds are adapting to finding food on the ships.

This is the amazing evolutionary advantage of albatrosses; they fly using a technique called dynamic soaring, which allows them to extract kinetic energy from the wind. It's the same concept really as moving sidewalks in the airport, so their gliding heartrate is about the same as when they're resting on the beach or water. This is what allows them to fly such massive distances across the ocean!

How does that make sense thermodynamically? Where's the gradient? Do they fly at the boundary between different wind speeds?

> Where's the gradient? Do they fly at the boundary between different wind speeds?

At the surface of the water, windspeed is lower than at higher altitudes, so that's where the gradient is. If you watch an albatross soaring over water, you'll watch it dive so low its wingtip touches the water surface, and then it'll climb in altitude, before turning to dive again. Here's a good diagram of the whole process: https://www.researchgate.net/profile/Sameh-Eisa/publication/...

Interesting. Related: I’ve seen pigeons using the subway to travel here in Stockholm. (https://www.thelocal.se/20111110/37278/)

They do that in London too. Strangely they seem to actually know where they are going.

that seems like the opposite of strange

pigeons are smarter than they look. Not corvid smart so far as I know, but clever birds. It's part of why they're so ubiquitous.

Just don't let the Pigeon drive the bus!

https://pigeonpresents.com/books/dont-let-the-pigeon-drive-t...

Blackburnian warbler in Cornwall:

https://www.walesonline.co.uk/news/uk-news/uk-twitchers-floc...

Interesting.

Especially the flock of bird watchers...

https://i2-prod.birminghammail.co.uk/incoming/article2527920...

Rats also travel by ships, reaching islands where they have not been before. I think even the old Romans mentioned cats traveling on their ships. Not to mention the various pathogens that traveled with the people on ocean crossing ships, causing severe epidemics among natives not used to such.

Nature, uh, finds a way...

> Storks give up migrating to live on landfill in Spain

https://phys.org/news/2022-07-storks-migrating-landfill-spai...

Consider this Osprey taking a rest on a boat during migration from the UK to Spain - https://twitter.com/sachadench/status/1569801627757838338

"think this makes us lazy?"

"nah, we're still in the V shape"

https://www.youtube.com/watch?v=tPLK1zvPb-U

I was once in a transatlantic cruise, wild how birds would appear on deck randomly (probably coming from other ships) in the middle of the ocean.

This was a delightful read. I wonder what the consequences will be

We've been sailing around the world for 500+/- years now. Moreso in the past than we used to. Presumably the consequences have already shown themselves.

there are more than 300000 ships traveling today: https://www.marinetraffic.com/

i don't think we ever had that many before than a few decades

It also seems likely that navigation is much more standardized. Ships follow more regular paths, so it may be easier to jump from ship to ship (at least compared to the 1700s or earlier).

They’re birds, they can’t exactly do much

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