Another Test. Aerial feeding by Snowy Egrets has been observed by many people. Among the various forms that have been described are: hovering to retrieve surface food, agitating the water with one or both feet while hovering (hovering-stirring), capturing prey from the water while continuing in direct flight (dipping), and dragging one or both feet in the water while catching prey during direct flight (foot-dragging).
I have observed many Snowy Egrets engaged in the foot-dragging form of aerial feeding and sometimes have been close enough to capture decent photos. A selection of my best captures are shown below.
From the literature I have been able to access, the function of the foot-dragging is unclear. Suggested functions include startling prey, slowing forward momentum, and steering or stabilization effects. One of the interesting ideas about why the birds engage in this behavior is that it is less hazardous than wading or perching behaviors in areas where numerous alligators are present (Davis and Jackson, 2000).
References
Kushlan, J. A. 1972. Aerial feeding in the Snowy Egret. Wilson Bulletin 84:199-200.
Kushlan, J. A. 1976. Feeding behavior of North American Herons. Auk 93:86-94.
Davis, W.E. and Jackson, J.A. 2000. Aerial foraging by Tricolored Herons, Snowy, and Great Egrets. Florida Field Naturalist 28(4):192-194.