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Wood Storks - Foraging Ecology and Food

Foraging ecology: The Wood Stork has an almost unique foraging technique. It generally walks with its bill in the water partially open, swinging the bill in an arc or probing with it in mud and vegetation. When the bill is stimulated by contact with prey, they are captured with an extremely rapid reflex snap, measured at about 25 milliseconds (one of the fastest reflex actions measured in the animal world). Apparently, vision is not needed for capture, since scientists have found that storks can capture prey nearly as well when wearing opaque goggles as when not. Storks may also use their feet to stir the water, presumably flushing fishes and invertebrates towards their open bills. They often flick their wings open and shut, possibly also to scare prey towards the bill. 

The foraging technique is effective in shallow water (5 – 25 cm) where prey are dense (40 – 141 prey items / m2), but becomes much less so in deeper water (>30 cm) and where prey are less available. Thus storks need dense prey in order to be able to forage, and for this reason storks are sometimes seen as indicators of healthy wetlands.Throughout their range, storks usually breed during the driest parts of the year, when prey are likely to be concentrated in shallow pools and depressions. Storks feed solitarily or in groups of up to 100 individuals, and frequently are part of flocks that may include other wading birds, like Great Egrets, Snowy Egrets, White Ibises and others.

Food: Storks eat mostly fishes, but will also take a variety of other aquatic organisms, including insects, crayfishes, shrimps an crabs, amphibians, snakes, small alligators, and occasionally small birds and mammals.In the southeastern U.S., sunfishes, catfishes, killifishes, pickerel, bowfin, and chubsucker are some of the most common food items. Generally, storks tend to avoid the smallest prey and take prey averaging 40 – 85 mm in length.