Birdwatching at J.N. "Ding" Darling NWR on Sanibel Island, Florida
Published: September 1, 1990
|The tide ebbs along Commodore Creek as a canoe drifts silently past tangled mangrove roots. The whispering occupants raise their binoculars to study a motionless bird on an overhanging limb 15 feet in front of them. It is a Green-backed Heron, statuesque in its fishing pose. The somber-hued bird relies on camouflage rather than flight, not flinching until the canoeists have passed.|
In a few moments the paddlers emerge from the tunnel of mangrove trees into a small bay. A Royal Tern hovers overhead, then drops with a splash into the tea-colored water. The tern departs with a fat minnow in its beak. An Osprey wings above them, a silvery mullet grasped firmly in its talons.
Fish and shrimp thrive in this tidal estuary, which lies within J.N. "Ding" Darling National Wildlife Refuge on Sanibel Island. Sanibel is located midway down the Florida peninsula, on the Gulf Coast, 20 miles southwest of Fort Myers.
The bird checklist for Sanibel and adjacent Captiva islands denotes 247 regularly seen species. One-quarter of that number nest here, and Christmas Bird Counts annually log at least 110 species. Including casual visitors and vagrants, the number of bird species recorded on Sanibel Island approaches 300.
The bird diversity here is a direct result of the variety of habitats on and surrounding Sanibel. The crescent-shaped, 12-mile-long island is one of several coastal barriers that separate San Carlos Bay, Pine Island Sound, and Charlotte Harbor from the Gulf of Mexico. Fresh water from the Caloosahatchee, Peace, and Myakka rivers flows into the shallow bays, which are important nurseries for the region's shellfish and sport fish. A full complement of the leggy herons, plus abundant pelicans and cormorants, dine in the estuaries. They are attracted by the consistent food source in this rich intertidal zone.
Along the backbone of Sanibel Island are a series of sandy ridges that support dense shrubs and subtropical hardwood trees such as gumbo-limbo, mastic, and strangler fig. These thickets provide excellent cover for resident and migrant songbirds. Interspersed among the dry ridges are freshwater ponds which offer perfect habitat for waterfowl, wading birds, gallinules, rails, and other marsh-dwellers. A number of these species also frequent the mangroves along the northern perimeter of the island. Sanibel's sandy gulf beaches, famous for their abundant seashells, attract shorebirds, gulls, and terns.
According to Laura Riley, author of A Guide to National Wildlife Refuges, "Sanibel's 'Ding' Darling Refuge is one of the best places in the country to see and photograph birds... You can sometimes photograph Yellow-crowned Night-Herons from the car. You're sure to see Red-shouldered Hawks and Ospreys."
The largest unit of the 6,500-acre refuge occupies the middle of Sanibel Island. The refuge is named for Jay Norwood "Ding" Darling, the Pulitzer Prize winning cartoonist and former chief of the U.S. Biological Survey who designed the first federal duck stamp (first duck stamp in the country) and founded the National Wildlife Federation. The sanctuary was established in 1945, and now includes tracts on Sanibel and Captiva islands, as well as small islands near Fort Myers and Tampa.
First-time visitors may wish to begin their exploration at the refuge headquarters on Sanibel-Captiva Road. The visitor center is staffed by knowledgeable birders who update a map of interesting avian sightings daily. The building contains informational displays on the unique species (including gopher tortoises, loggerhead sea turtles, and manatees) that frequent the refuge and a sales area for natural history reference books.
One of the most popular ways to tour the sanctuary is to follow the five-mile wildlife drive that begins at the visitor center. This one-way auto trail is open daily from sunrise to sunset. Watch for a reddish flash in the gravel roadbed ahead of you: it is the rust-colored wings of Ground Doves dust-bathing.
The auto trail meanders across dikes that separate salty tidal inlets on the right from freshwater impoundments on the left. What you see will depend upon the time of day, the tides, and the season. In general, low tide attracts the widest array of birds to the mudflats on the right side of the drive. When low tide occurs around dawn or dusk, large numbers of waders are common. Volunteer naturalists are available throughout the refuge, to set up spotting scopes or otherwise direct visitor attention to interesting wildlife.
Resident wading birds include Great and Snowy egrets, and Great Blue, Little Blue, and Tricolored herons. They prowl through the shallow water, jabbing fish with lightning swiftness. When the waders' paths cross, they raise crests or posture with wings and necks outstretched to defend a bountiful fishing spot against a long-legged intruder. Reddish Egrets have become increasingly common on these flats over the past several decades. They can be identified at a distance by their tipsy, wing-waggling sprints to herd fish within stabbing range. In summer and fall these waders are joined by Roseate Spoonbills and Wood Storks which have dispersed following their nesting seasons. The endangered storks feed by slowly shuffling through the muck, ready to snap up any fish that bump into their touch-sensitive bills.
White Ibises, which often feed close enough to the auto trail for visitors to see their sky-blue eyes, use curved beaks to extract crayfish and crabs from the mud. Double-crested Cormorants sun on the mangrove roots at the edges of the bays. Anhingas, distinguished by dart-sharp orange beaks, perch on higher mangrove branches. Male Anhingas are glossy black with silver patches on the wings and upper back. Females sport buffy brown neck and breast feathers. Russet-maned Brown Pelicans also balance clumsily on the mangrove branches. They peer into the water below, peeling away in a beak-first dive when they spot a fish. These birds bob back to the surface with throat pouches bulging.
While Mottled Ducks and some Blue-winged Teal remain on the refuge year-round, migrant waterfowl concentrations peak in January and February. Impoundments on the left side of the drive have traditionally been favored by puddle ducks, although the past three years of drought have taken a toll on the aquatic plants that attract them. Normally these ponds are populated by wintering Green-winged Teal, Northern Pintails, American Wigeons, Northern Shovelers, Red-breasted Mergansers, and American Coots. Fulvous Whistling-Ducks join these flocks on occasion, and a few Cinnamon Teal have been seen at the refuge. The Eurasian Wigeon, easily distinguished by the male's rusty head and cream-colored cap, is rare but is a regular winter visitor.
Spring songbird migration sometimes erupts into a spectacle of color on Sanibel. The island may be the first rest area for tired migrants which have flown nonstop over the Gulf of Mexico. Especially if they faced head winds or inclement weather, waves of birds are likely to "fall out" of the sky and rest here for a day or two. They feed on the welcome abundance of insects, berries, and seeds on the island to regain their strength.
Records for April — the pinnacle of spring migration at Sanibel — include sightings of 34 species of warblers. Of these, the Northern Parula, American Redstart, and Orange-crowned, Yellow, Yellow-rumped, Yellow-throated, Prairie, Blackpoll, Black-and-white, and Prothonotary warblers are most frequently observed. The best places to encounter birds during a fallout are upland hiking trails with shrubby hardwood cover or the dike-top trails of the Bailey Tract.
Two such trails diverge from the auto road at "Ding" Darling Refuge. The South Dike Trail begins at the visitor center and parallels the wildlife drive on the south side of the freshwater impoundments. In addition to migrant songbirds, it is a good place to look year-round for ibises, moorhens, and other water birds. This trail intersects the wildlife drive near the observation tower, a one-way walk of two miles. Near the end of the auto road, a half-mile loop trail traverses a mangrove forest which has subtropical hardwoods growing nearby on Calusa Indian shell mounds. White-eyed Vireos, Common Yellowthroats, and Prairie Warblers are prominent here. During fallouts they may be joined by Red-eyed Vireos, Painted Buntings, Northern Parulas, and Yellow Warblers.
|The Sanibel-Captiva Conservation Foundation (SCCF) is another fruitful birding sanctuary located a short distance east of "Ding" Darling headquarters. A four-mile network of trails follows the sandy ridges here. Wetlands between the ridges attract moorhens, egrets, and herons, and at one point the trail passes very close to an active Osprey nest. In spring and fall the hardwood overstory shelters flight-weary thrushes, warblers, and buntings. SCCF is open weekdays from 9:30 a.m. to 3:30 p.m. in summer and 9:30 a.m. to 4:30 p.m. September through May. From Thanksgiving to Easter the nature center is also open on Saturdays.|
The Bailey Tract, a 100-acre unit of "Ding" Darling Refuge located on Tarpon Bay Road, admits hikers daily from sunrise to sunset. A 1½-mile trail follows an outer ring of dikes around freshwater ponds and marshy habitat. Several shorter trails bisect the interior of the tract. During spring migration, the shrubs host a rainbow of birds — from Blue Grosbeaks to electric orange orioles, accented with Scarlet Tanagers, Rose-breasted Grosbeaks, and Indigo Buntings. Pied-billed Grebes, Purple Gallinules, Smooth-billed Anis, as well as several species of wrens and rails, reside here. In the summer months, the Bailey Tract is a superb place to spot nesting Black-necked Stilts and Mottled Ducks swimming with their chicks.
Autumn migration, though not quite as spectacular in its display of avian color, still brings respectable numbers of warblers, grosbeaks, tanagers, and buntings that stop briefly at the Bailey Tract, and elsewhere on the island, before winging south for the winter. The city-owned property at the lighthouse, on the eastern tip of Sanibel, is a potentially good birding area during migration.
Peregrine Falcons arrive with the waves of fall migrants and remain throughout the winter and early spring. They may be glimpsed from the wildlife drive while they stoop on flocks of shorebirds at tidal inlets. In addition to the mudflats at the refuge, peeps congregate on the small islands along the three-mile causeway that connects Sanibel Island with the mainland. Especially at low tide, Willets, Semipalmated Plovers, Black-bellied Plovers, Short-billed Dowitchers, and both species of yellowlegs are likely to be seen. A few Snowy and Wilson's plovers also reside on Sanibel and small numbers of American Oystercatchers winter here.
Managers at "Ding" Darling administer three small island refuges in Tampa Bay (125 miles north of Sanibel) and four boat-accessible refuges stretching north from Matlacha Pass, at the mouth of the Caloosahatchee River, to Charlotte Harbor. Many of these tiny, mangrove-covered keys provide roosting and nesting areas for Brown Pelicans, Double-crested Cormorants, Great and Cattle egrets, Tricolored and Little Blue herons, and Black-crowned Night-Herons. Passage Key in Tampa Bay and several dredge-spoil islands along the Intercoastal Waterway near Sanibel offer the quiet, shell-strewn beaches that Least (Little) Terns and Black Skimmers choose for their nests. While these rookeries are closed to visitors during the nesting season, a few Least Terns do nest on the sand beaches of the causeway islands. Adult terns can be readily observed from causeway turnouts as they hover over the bay and plunge into the water to catch small fish.
Although summers on Sanibel are muggy, with mosquitoes and other biting insects sometimes in abundance, birders find good reason to visit the island. Frigatebirds soar overhead, their narrow wings and forked tails in unmistakable dark silhouette against the bright blue sky. Graceful Swallow-tailed Kites swoop over the vegetation, plucking up large insects, lizards, and arboreal snakes to eat on the wing. Gray Kingbirds perch on dead branches, flitting out to grab horse flies, deer flies, and the like in midair.
One of the best finds of a summer visit to Sanibel is the Black-whiskered Vireo, a Caribbean species that resembles the Red-eyed Vireo but has a prominent dark whisker marking. It is easiest to locate by ear: the one-to four-note phrases sound harsher than the Red-eyed Vireo's song. Listen for it along the wildlife drive and also at the Bailey Tract. Also keep a sharp lookout for Mangrove Cuckoos flying across the road or trail. These reticent, black-masked birds often perch quietly in the midst of dense mangroves or hardwood shrubs. In flight, however, their gray-brown upperparts, buffy breast, and black tail feathers broadly tipped with white, are distinctive.
Summer is also a good time to canoe, with wind and water usually calmer than in the winter season. In addition to the two-mile trail along Commodore Creek in the main unit of "Ding" Darling Refuge, there is a four-mile canoe trail through the mangroves at Buck Key, east of Captiva Island. Among the likely summer sights on both canoe trails are young Yellow-crowned Night-Herons learning to catch fiddler crabs beneath the mangrove roots and subadult Little Blues in mottled blue and white plumage.
Perhaps the greatest spectacle of all at Sanibel revolves around the Roseate Spoonbills that spend the summer and fall months here. These unmistakable birds with spatulate beaks feed by filtering tiny marine creatures from the shallow water. They swing their heads from side to side in a jerky rhythm as they slog across the tidal flats. At times, a third of the U.S. population of Roseate Spoonbills frequents the refuge. One of the best areas to encounter them is near the observation tower along the wildlife drive. Should you happen to be there at sunset, you may be treated to the unforgettable sight of small flocks of these breathtakingly beautiful birds gliding to a landing. Sometimes the rays of low light briefly transform their wings into angel flutters of pastel pink, carmine, and gold.
Charming little Sanibel Island draws visitors from all over the world. They come for the beaches, shells, warm sunshine, and solitude. Of all the riches Sanibel has to offer, its varied and spectacular birds always rank as main attractions.
Connie Toops is a freelance nature writer and photographer. She has written several books including Everglades, Birds of South Florida, National Seashores, and The Enchanting Owl.||