Pigeons have an innate instinct to return to the place they started from. Often when they are circling it is to get orientated and familiar with the landscape.
That said, nobody has come up with a concrete, scientifically proven explanation as to why pigeons circle.
Maybe there isn’t just one catch-all explanation and their ability is a combination of the different theories.
Pigeons aren’t dumb. Their behavior takes on certain patterns for a reason, circling is one of them.
Pigeons are known for having great memories.
They can learn to recognise objects and people.
Apparently, this isn’t just a learned response, but an innate ability that pigeons have.
Pigeons circle to imprint their area of departure on their minds.
They are mapping the area, with all its salient landmarks and important points for them.
Any journey in which there is a return, you have to recognise your start point to know when you have arrived back home.
A pigeon may have been born and bred in that particular place, but that doesn’t mean that changes haven’t taken place.
The circling is probably a cautionary custom, not only to fix the familiar in their minds but also to note any changes in the surrounding landscapes.
Inner-city pigeons will face the different contours that a growing and changing city will throw up because of construction.
Magnetic fields are a scientifically proven phenomenon.
They exist and it is said that pigeons can sense and use these fields as guidance in navigation.
Apparently, the earth is made up of a patchwork of these fields, which emanate from the earth’s core.
Magnetic fields send out electronic pulses that humans can’t sense, but animals, such as pigeons can.
None of these pulses are the same, so the circling behavior may also be used to reinforce the magnetic frequency of their home ground.
Over distance pigeons will cross different fields and mark their differences.
Sense of Smell
The earth is layered or capped with soil, stone and flora.
None of these is uniform and all have different components.
Because of this, the earth gives off different kinds of odours in different areas.
Differences such as latitude or moisture, types of vegetation or the lack of it, high or low elevations will also change the odors coming off the earth.
Once again, these odours are too subtle for humans to notice, but animals, particularly pigeons can detect them.
Pigeons will circle to ingrain the odors of their start point on their memories before taking flight.
In the absence of one proven theory, you can only guess at which of the above the circling behavior of pigeons pertains to.
What is agreed upon is the fact that the circling behavior of pigeons is instinctive, not learned behavior.