Wednesday, March 25, 2015

Has God given migrating birds built-in navigation sense



We would be wise to acknowledge what God’s Word tells us in relation to migration and feeding of birds.
Even the stork in the sky knows her appointed seasons, and the dove, the swift and the thrush observe the time of their migration—Jeremiah 8:7.

Ultimately, we read that it is the Lord who provides food for the raven when its young cry out for lack of food (Job 38:41). Indeed, all the animals and birds look to God to give them their food at the proper time (Psalm 104:21, 24, 27–28; 136:25; 145:15–16; 147:9). In light of these verses, it is interesting to note the surprise of ornithologists who observed (across a range of species) that young migrant birds, encountering the tropics for the first time, ‘showed an almost uncanny ability to find their species-specific habitat with no discernible fumbling around.’ Evolutionary ornithologists might also do well to ponder the words of rebuke that the Lord spoke to Job: ‘Does the hawk take flight by your wisdom and spread his wings towards the south?’ (Job 39:26).

But perhaps the most telling verse comes from Jeremiah 8:7, which says, ‘Even the stork in the sky knows her appointed seasons, and the dove, the swift and the thrush observe the time of their migration’, and concludes: ‘But my people do not know the requirements of the Lord.’

                    How Birds Migrate
For birds to be able to migrate, they must have a system that enables them to do so. It is now believed that they have three internal compasses - a sun compass, magnetic compass and star compass.
The sun compass gives most, and probably all birds, the ability to determine their direction when there is good visibility. The sun compass works in conjunction with the bird's own sense of time, so at 8am the bird knows where the sun should be. It is also believed that the birds use polarised light - the light that occurs in an arc about 90 degrees form the sun's position. This way, they can use the sun in cloudier conditions or just after sunset.
The magnetic compass is viewed by many as a basic avian compass, especially for long distance migrants, where birds orientate themselves to the Earth's magnetic field. How this compass operates is unknown at present.

Stars, being a constant fixture, provide an absolute

 point of reference. It does seem that using a star 

compass is not innate, and that birds do have to 

observe the starry sky and its rotation during their 

early life in order to be able to develop it.


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