Equally as impressive as the Delta’s plant composition is its abundance and diversity of animal life. During the Ice Age, around 10,000 years ago, the Delta’s extensive drainage area escaped the colder, harsher conditions of higher latitudes. In essence, it became a vast refuge for species unable to exist further north.
Historically, over a hundred species found nowhere else in the world, including turtles, snails, crustaceans, and aquatic insects, lived within the drainage basin. The Delta, as the common point of passage for rivers flowing across the basin, was home range for many of these species.
By the beginning of the nineteenth century the vast wilderness along the Mobile, Tensaw, and lower Tombigbee and Alabama rivers was the last stand for our three big mammals: whitetail deer, black bear, and panther. North America’s largest woodpecker, the ivorybill, also nested here. As the great southern forests were cleared for lumber and agriculture, the Delta became a refuge and a last hope for survival for these and other species.
“The only part of the State where deer are still abundant is in the big wooded swamps of the lower Tensaw and Mobile Rivers. In that region a number are killed during the open season every fall. They are hunted with dogs, each hunter selecting a “stand,” where he remains in expectation that the deer will pass within range of his gun—usually a shotgun loaded with buckshot. The deer take readily to the water and swim easily from one island to another in this great swamp.”
“Bears doubtless ranged all over Alabama in early times, but at present are exterminated everywhere except in the swamps of the southern counties. In the big swamps bordering the Tensaw and Mobile Rivers they are still common and a number are killed there every fall. A.J. McIntyre, of Carlton, is reported to have killed in recent years over 100 bears and to have caught 10 cubs.”
--A. H. Howell, 1921. Mammals of Alabama.
Where are they now? Those Delta whitetails later became the breeding stock upon which much of Alabama’s wildly successful deer recovery was founded. Fortunately, some bears still remain, and the newly formed Alabama Black Bear Alliance is an organization working to keep them from going the way of the panther. The big cats lingered in the Delta perhaps into the 1960s, but panthers are almost certainly gone now. Ivorybill woodpeckers disappeared along with the last large tracts of old-growth timber. If any Alabama sturgeon still survive in the Delta, they are nearly gone. We should remember that despite its beauty and diversity, the Delta is neither pristine nor untouched, and it even has a few missing pieces.
Today the Delta puzzle also has pieces that don’t seem to fit anywhere. Not only have some native species been lost; the Delta now hosts unwanted aliens—ecologically destructive exotic species—such as nutria, feral hogs, and fire ants. A large South American rodent, nutria were introduced in the Delta in the late 1940s. Since then, they have wreaked havoc on native aquatic vegetation. Feral hogs are descendants of livestock, and the Delta is overrun with them in places. These wild pigs take a heavy toll on native amphibians, reptiles and ground-nesting birds, including turkey, and they compete for food with deer, turkey and squirrels. Fire ants first invaded this continent through the port of Mobile in the 1930s, but fortunately, their preferred habitat, open areas on relatively high ground, is fairly limited in the Delta. As for the nutria and hogs, the Delta’s native alligators are doing their best to keep their numbers in check.
If you want recent conservation success stories, you need look no further than alligators and bald eagles. Both were on the verge of extinction only a few decades ago. After years of protection and management, there are probably more alligators in the Delta now than in all the rest of Alabama. Bald eagles are again nesting in the area, thanks in part to an aggressive eagle restoration program.
The Delta is a birder’s paradise. Sightings of formerly rare species such as eagles, ospreys, and brown pelicans have become commonplace, and the Delta may be the only place in Alabama where so many different birds can be found in one area. Over 300 species have been recorded from the Delta, including more than 100 that nest here. The bottomland forest of the upper Delta is prime habitat for warblers, vireos, turkeys, and owls. The lower portion is important to shorebirds and wintering waterfowl, although the number of canvasbacks, widgeon, and mallards has declined through the years. Along the watercourses of the interior are graceful swallowtail and Mississippi kites, anhingas or “snakebirds,” and a variety of wading birds. If the endangered wood stork nests anyplace in Alabama, it is probably here.
At least 40 mammal species occur in or around the Delta, and there are few other places in the Southeast where you can find three rabbit species. The Delta has the large swamp rabbit or “canecutter,” the cottontail, and the diminutive marsh rabbit. Otters and bobcats are common, and with the decline of both the fur trade and larger predators, raccoons may be more abundant than ever. Muskrats are still present, but they were much more common before the nutria moved in. Every few years a manatee wanders up the coast from Florida and enters the Delta.
Reptiles and amphibians have a haven in and around the Delta, with about 70 percent of Alabama’s species represented. At least 18 turtles, 40 snakes, 10 lizards, 1 alligator, 20 salamanders, and 20 frogs are here. Alligators may symbolize the place, but the astounding diversity of turtles is the big story. Box turtles and gopher tortoises can be found on the high ground of the Delta’s margins, but get down into the rivers, oxbows, creeks, and sloughs and you can find an incredible sixteen aquatic turtle species. Two, the Alabama red-bellied turtle (our state reptile) and the southern black-knobbed sawback, are found virtually nowhere else. Few places in the world can boast the turtle diversity of the Delta.
Because the Delta is a melting pot of freshwater and marine ecosystems, it supports a phenomenal diversity of at least 126 fish species. Nearly a third of the state’s freshwater fish are represented by the 97 species found here. Largemouth bass, bluegill, and crappie are popular with fishermen, but also present are obscure species with names like taillight shiner, Dixie chub, tadpole madtom, and cypress darter. Twenty-nine saltwater species, including mullet, flounder, bull shark, and striped bass are found here as well.
A full account of the area’s wildlife would take volumes, but to get a feel for the place, imagine a morning float trip through a remote corner of the upper Delta. If you are alert, your ears will tell you more than your eyes. The commotion of cries, croaks, buzzes, whistles, and splashes may resemble a Tarzan soundtrack, but with a little concentration you can isolate each sound. Katydids, cicadas, and tree crickets provide a contrasting backdrop to the bellows of alligators and grunts of pig frogs. Distant choruses of green treefrogs echo faintly as prothonotary, parula, and Swainson’s warblers sing from the moss-draped tupelos. As you glide beneath a noisy rookery of squabbling egrets and herons, a soaring swallowtail kite gives its klee klee klee cry. Barred owls begin their morning hoot-fest, triggering a gobbler to sound off on the high levee. Even the fish are boisterous here; huge alligator gar wallow on the surface and jumping mullet splash up and down the river. Despite the clamor, your passing does not go unnoticed. Alarmed deer snort from the banks. Turtles plop from their basking logs. A beaver slaps the water. Wood ducks explode from the shallows and whistle off upstream. A crashing in the trees is probably only a hog, but you smile to think it just might be one of the Delta’s bears putting a safe distance between him and you.
Rare Animals of the Delta
Scientific Name Common Name Standing
Acipenser oxyrhynchus desotoi gulf sturgeon T
Ammocrypta asprella crystal darter SP
Cycleptus elongates blue sucker R
Hybognathus nuchalis Mississippi silvery minnow R
Notropis edwardraneyi silverside shiner R
Percina lenticula freckled darter R
Polyodon spathula paddlefish R
Scaphirhychus suttkusi Alabama sturgeon R
Ambystoma texanum small-mouthed salamander R
Amphiuma Mean’s two-toed amphiuma R
Amphiuma pholeter one-toed amphiuma R
Farancia erytro gramma rainbow snake R
Rhadinaea flavilata pine woods snake R
Graphtemys nigrinoda delticola delta map turtle R
Macroclemys temminckii alligator snapping turtle SP
Pseudemys alabamensis Alabama red-bellied turtle E
Aimophila aestivalis Bachman’s sparrow R
Anas fulvigula mottled duck R
Elanoides forficatus American swallow-tailed kite R
Haliaeetus leucocephalus bald eagle T
Icitinia mississippiensis Swainson’s warbler R
Mycteria American wood stork E
Pandion haliaetus oprey SP
Ursus Americanus floridanus Florida Black Bear R