Living Sanibel: Wood Stork delivers the joy in nature
With its distinctive black-tipped wing feathers and extended neck and legs, the wood stork is easy to recognize in flight. It can often be spotted soaring and circling high above the mainland. Because the wood stork uses thermals to travel as far as 80 miles from its roosting site to arrive at its feeding destination, you are unlikely to spot any of these birds early in the day before the land heats up sufficiently to create these rising air currents. Good places to search for the wood stork are along roadside drainage ditches, swamps, and freshwater canals, especially during times of drought.
The wood stork has a unique way of feeding that makes it amusing to observe. It captures its prey using a specialized technique known as grope feeding or tactolocation. It prefers to feed in water 6 to 10 inches deep, with its long black bills partly open. When the fish touches the bird’s bill, it snaps shut with an average response time of 25 milliseconds, one of the fastest reflexes found in all vertebrates. To put this number into perspective, humans blink at 330 milliseconds, so a stork snaps its bill shut on an unsuspecting minnow 13 times faster than the blink of a human eye.
From a high of 20,000 nesting pairs in the 1930s, the wood stork population in the southeastern United States declined to approximately 5,000 pairs by the late 1970s, mostly because of habitat and nesting-site loss. It takes up to 400 pounds of fish to feed both parents and two chicks from the time they hatch until they reach the fledgling stage.
The wood stork requires almost ideal conditions to nest: summers with high rainfall (producing ample breeding ponds for small fish) followed by winters with little to no rainfall (concentrating the minnows into shallow, crowded ponds where the adult wood storks shuffle their large, pink feet to flush out crustaceans and minnows). Lacking these conditions in any given season, the wood stork does not nest.
One of the best places in southwest Florida to observe the wood stork is the Audubon Corkscrew Swamp Sanctuary, where it roosts every evening in the ancient bald cypress trees. Although slowly rebounding from its record low numbers, the wood stork is struggling to adapt to Florida’s rampant growth. Urban sprawl, coupled with the paving over of feeding ponds and wetlands, is especially hard on this large bird. It has a distinct population in Central and South America that is not endangered, but preserving the North American species may yet prove to be a challenge. Wood stork rookeries are sometimes preyed upon by snakes and owls, and the adult bird is occasionally taken by alligators. Sadly, its primary threats are humans and the demands they make on the environment.
Charles Sobczak is a Sanibel author whose works include the novel “Six Mornings on Sanibel,” and two local guide books, “Living Sanibel A Nature Guide to Sanibel & Captiva Islands” and “The Living Gulf Coast A Nature Guide to Southwest Florida.” His books are available online and at most local bookstores. For more information about Sobczak’s writing, go to www.indigopress.net.
This article is from “The Living Gulf Coast.”