Some time ago, I posted a thread titled "Animals & The Supernatural" in the Paranormal forum, where I briefly discussed homing pigeons and felines finding their way home from unfamiliar locales.
In the article linked below, "Secret of Homing Pigeons Revealed", from Feb. 2004, no secret is revealed for how the pigeons find their way home the first time. They're said to use "their own navigation system" during long distance trips or flights from new locations. That's a wallop of an accomplishment for a pea-sized brain, and I don't think brains have anything to do with the process.
http://www.cnn.com/2004/TECH/science/02/06...reut/index.html
I've heard this chalked up to instinct in the past. A one word label explains nothing, and when scientists are satisfied with this, they do a disservice to their field of study. I'd have better respect for "We don't know" than the remark of "Instinct."
My hypothesis on this topic, as with emperor penguins who must sometimes deviate from their paths toward egg-wielding mates by several miles due to harsh winter conditions, is that the animals follow trails of energy residue. Like beacons, the animals can tune into the energy when their primary path is lost. It makes sense that homing pigeons would follow roadways as stated in the article, because the energy trails that I hypothesize, marking the animals' travels, would remain whether they flew or were transported by vehicle.

