While it is true that the birds do perform backward somersaults in flight, the exact neurological causes of the rolling behaviour are still unknown.

A noted pigeon fancier, William Pensom described the motion thus:[2] A Birmingham roller is not necessarily one that is deep to the extreme, but one that displays in its performance a likeness to a cricket ball spinning to earth in a straight line; the old saying put it, "Like a ball and straight as a boat line."

The bird on starting generally raises its wings, claps, spreads its tail slightly downward, and finishes in a similar manner; any deviation from a straight course cannot be classified as a true roll.

The true roller shows no separate movement between each revolution, but continues in an unbroken spin; incidentally, such phrases as "inconceivable rapidity" and "lightning whirl" refer to the rapid manner in which each somersault is executed, and not, as one might suppose, to the descent from the start of the roll until the finish.There have been more recent scientific studies of roller pigeons, including the mode of inheritance[3] and a high-speed video analysis of the specific movements involved in rolling and tumbling in pigeons.

The specific cause of the rolling phenomenon has not yet been determined, but the high-speed video analysis of parlor rollers in motion shows that their head goes backwards and their tail upwards when they raise their wings, the exact opposite of what a normal pigeon would do in attempting to fly.