Many birds (probably most) possess some homing ability. Many crocodiles (general sense) also possess strong homing ability over 100s of kilometers in several cases. In the case of some crocodiles there is a bit of a paradox. The saltwater crocs have spread from all the way from
India to Australia via sea; yet, they home over long distances. However, ironically both depend on the same ability of efficient navigation at sea and by rivers using favorable water currents to their advantage. When the current is favorable they use it to drive their travel at
rates of up to 20km per day over several days. One croc homed by covering 411 km in 20 days. In birds a major aspect of the homing capacity appears to be magnetic sense. But when the current is not favorable they dive down and wait or come a shore if close to a bank/shore.
In American crocs putting strong magnets on their heads before release in a distant site is anecdotally reported to prevent homing. This suggests that the ancestral archosaur was capable of homing in using a magnetic sense. However, it is not clear if the magnetic sense is all
there is to homing (birds are said to also use stars and smell, though to what extent is unclear). It is also not clear how this magnetic sense is translated into navigation. Birds tend to take the shortest paths which they can going by air so the initial orientation is key.
At least in migratory birds they sweep their head in peculiar way so that their eyes ``see the geomagnetic field'' before taking off.The crocs however do not have that luxury in terms of a straight path but seem to optimize path for available waterways. The TaittirΔ«ya-Εruti seems
to have cryptic statement which might be one of the first records of an unusual sense that birds use to see ``something'' on the earth.
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