[akudha]

The article says they don’t glide, they are actively flying the whole time. That is mind boggling.

Don’t they need sleep?

How do they know to start on the exact same day every year? Fly to the exact same place?

I am a bit jealous of the scientists who get to work with such amazing creatures :)

[krylon]

I think I read something about some birds being able to sleep with only one hemisphere of their brain at a time, similar to dolphins. The common swift often spends months at a time without touching ground.

And lots of birds perform marvelous feats of long-range navigation, storks, for example, travel thousands of kilometers each year to return to their nest for breeding.

They are amazing creatures.

[diroussel]

I would suppose that they don’t “know” they just feel compelled.

There are dragon flies that migrate from India to Africa. It takes three generations to complete the round trip. So how do they know? It must be just a feeling.

I guess that a long time ago when India and Aftrica were adjacent parts of Gondwana land, the migration must have been quite short. But as the continents drifted apart the dragoon flies had to adapt to the longer route.

[gonzo41]

Isn't it the same with Monarch Butterflies, they make the trip from Canada to Mexico and it also includes a few breeding cycles.

[boudin]

It is still possible to be knowledge that is passed on from generation to generation one way or another.

[anentropic]

Pure guess, but maybe they recognise position of stars in the sky? that could provide both calendrical and navigational utility