“Altogether it seems that the visual aspect of head-bobbing is the primary function. Head-bobbing may help in improving object detection when foraging on the ground. The coordination of head-bobbing and leg movements is not necessary for keeping balance but may help in stabilizing position during walking. For those birds that practice head-bobbing, both functions seem to be useful adaptations to cope with walking on the ground.”
But, he also notes:
“Although there are now quite a number of observations available, there is still no unequivocal interpretation of the function of head-bobbing and why some birds bob their head and others do not.“
BONUS: The professor has also compiled a unique online resource, in the form of a ‘List of bird species resting on one leg’ along with a photographic library of supporting evidence.
