immigration

[Lawle$$]

so how do birds find the right direction during immigration?

plz dont move this thread to another section since i guess it has something to d with earth magnetic field!

[iNow]

so how do birds find the right direction during immigration?

plz dont move this thread to another section since i guess it has something to d with earth magnetic field!

 

Hi Lawless,

 

I think you may have meant during "migration?" There aren't too many problems with birds getting stopped at borders, so immigration doesn't appear to be what you meant... Not a whole lot of fences can stop birds, eh?

 

Anyway, there doesn't seem to be one point of consensus how birds navigate during migration. It's definitely something that's "built-in" to them, or "innate," but we haven't yet found one single explanation. It seems to be a combination of things. Also, I imagine some birds rely more heavily on certain mechanisms than others. Additionally, where they are migrating will play a role.

 

Some suggest they use landmarks, like mountains and rivers, and other geographical features that can be identified easily from the sky. Others propose that they were simply taught their migration behavior and paths by their parents, and this gets passed down each generation. The baby birds fly with the rest of the flock, and sooner or later, it's just habit so they do it on their own (well, with the rest of the flock too ). Wind direction has also been proposed, especially for birds who fly across the sea. Placement of the sun and other stars has been studied where birds seem to use the sky as a "map." Last, there are specific hormones involved, and the temperature where the birds are located may play a role.

 

I found this useful link that is really easy to understand to someone who is interested, but doesn't know much about it already. You may want to check it out.

 

http://www.earthlife.net/birds/migration2.html

 

 

As for migrating by the Earth's magnetic field, that's certainly possible (just look at all of the possibilities shared above). After all, this is how many lobsters seem to do it way down on the sea floof. The overall point is that finding direction during migration happens by many things combined, and would be difficult to identify one possible driver in their "homing" mechanisms. Recall that animals which evolve many ways to accomplish the same things tend to survive more often than those that don't (they have redundancy in case one of the other systems fail), so it makes sense that birds would be no different.

 

Enjoy.

 

 

 

Oooh... If you EVER get the chance, check out this special. They show it on Discovery HD and it's beautiful.

http://www.sonyclassics.com/wingedmigration/index_flash.html

[Farsight]

They've maybe got an inbuilt compass, Lawless:

 

http://faculty.washington.edu/chudler/pmagnet.html

[fattyjwoods]

They've maybe got an inbuilt compass, Lawless:

 

http://faculty.washington.edu/chudler/pmagnet.html

 

haha you're soo funny, what kind of compass? a $199 Digital Compass with in-built state-of-the art Navman, new-generation GPS systems? given to the bird by his aunt?

 

Or maybe the bird uses google maps that are delivered to his Motorola RAZR V3X 3G cellphone given to him by his grandmother?

 

Of course not!

 

They know the paths because their parent birds take them flying a couple of times through the path and their parents took them so hey know how to fly through the migration path and it goes on and on! The birds also use landmarks, position of the sun and other means of navigation.

 

To Farsight:

a suncompass is not a compass, it's using the sun to determine where the direction is.

 

They don't have an "inbuilt compass"

 

http://en.wikipedia.org/wiki/Bird_migration

[DrDNA]

haha you're soo funny, what kind of compass? a $199 Digital Compass with in-built state-of-the art Navman, new-generation GPS systems? given to the bird by his aunt?

 

Or maybe the bird uses google maps that are delivered to his Motorola RAZR V3X 3G cellphone given to him by his grandmother?

 

Of course not!

 

They know the paths because their parent birds take them flying a couple of times through the path and their parents took them so hey know how to fly through the migration path and it goes on and on! The birds also use landmarks, position of the sun and other means of navigation.

 

To Farsight:

a suncompass is not a compass, it's using the sun to determine where the direction is.

 

They don't have an "inbuilt compass"

 

http://en.wikipedia.org/wiki/Bird_migration

 

Ha ha ha ha......YOU are too funny yourself fatty.....ha ha ha...

 

"Scientists already suspected birds' eyes contain molecules that are thought to sense Earth's magnetic field. In a new study, German researchers found that these molecules are linked to an area of the brain known to process visual information.

 

Do Birds Use Magnetic Field to Plan Migration Routes?

 

In that sense, "birds may see the magnetic field," said study lead author Dominik Heyers, a biologist at the University of Oldenburg.

"An animal that has to migrate over great distances needs to have both a compass and a map," said Cordula Mora, a biologist who recently completed her postdoctoral research at the University of North Carolina, Chapel Hill. .........

The new research helps explain how this natural compass may work.

 

Heyers and his colleagues injected migratory garden warblers with a special dye that can be traced as it travels along nerve fibers.

 

The team put one type of tracer dye into the eyes and another in a region of the brain called Cluster N, which is most active when birds orient themselves.

 

When the birds got their bearings, both tracers traveled to and met in the thalamus, a region in the middle of the brain responsible for vision.

....................

...Also.........Mora's work suggests that birds may use magnetic crystals in their beaks to sense the intensity of the magnetic field and thus glean information on their physical location. (Related news: "Magnetic Beaks Help Birds Navigate, Study Says" [November 24, 2004].)

 

"If you have a compass, you know where north, south, east, [and] west [are], but you don't know where you are, so you don't know where you should be going," she said.

 

Study author Heyers said "both [map and compass] systems may act in concert."

http://news.nationalgeographic.com/news/2007/09/070927-magnetic-birds.html

 

Plus, maybe you need to actually read Farsight's link.

 

Ha ha ha......