[reacweb]

The existence of migratory birds proves that the loss of energy due to the Earth's gravitational pull is not so catastrophic. A vehicle in motion also loses energy because of the friction of the wheels. Above a certain speed, air friction becomes the most significant loss. The comparison of the energy balance of a vehicle on the road compared with a vehicle in the air is not as clear-cut. Vehicles on wheels are much heavier and require infrastructure (roads) that must be taken into account.

[abtinf]

You may have noticed that migratory birds have a somewhat different mechanism of flight than typical drones.

[singularity2001]

zipline has wings

[tyingq]

They do show that: https://www.flyzipline.com/technology (scroll down, it first shows the thing that it drops, rather than the drone itself.)

Lots of CGI and notices about "simulated" though. The videos that appear to maybe be real show something that does have wings, but looks too small/light/thin to carry much around.

[Philip-J-Fry]

The ones they are currently using in Africa are normal drone planes. They drop their payload without stopping though, so the payload has to be packed securely and nothing that can break easily. So it's used for medical supplies. This what Mark Rober's video was about.

If they were to create a drone that can deliver arbitrary packages, then it needs to be able to lower a package safely. That's what those renders are, they show a typical multi-rotar drone with small wings. So it can stop and lower a package. I don't think there's any real footage of these yet.

[Ancapistani]

The concept of a fixed-wing VTOL UAS is well-tested, though. They’re not as simple as a quad or a “native” fixed-wing, but well within reach of a motivated hobbyist.

[bigfudge]

He shows the proposed new model in that video too though, not just the drone planes.

[sllabres]

Came here to say that (i think their operations in Africa are quite impressive) but it seems as their "Zips" are a different kind of breed and more like a drone than a plane.

[da39a3ee]

If you were to ask a migratory bird, they'd tell you that it's fairly tough. You have to put on enough subcutaneous fat to double your body weight, and then do it knowing that either you or some of your friends and family will die.

[hef19898]

Also, with global warming and stuff, if possible those birds migrate less.

[shrubble]

There is no evidence to support this statement.

[hef19898]

Plenty ofnevidence, of e.g. geese, migrating tonplaces further north. But surey birds don't exist anyway.

[da39a3ee]

Please provide your sources for the effect of climate change on bird migration.

[lancesells]

Here's one of many: https://climate.nasa.gov/news/3201/climate-patterns-thousand...

[zitsarethecure]

Yes, but how does the airspeed velocity of an unladen swallow compare to that of one delivering a coconut?