AMNH - Expedition : Endangered

'Gator Hole

Beneath the saw grass and soil of much of southern Florida lies a porous bedrock of limestone, pockmarked with thousands of water-filled depressions lined with peat and silt. These "gator holes" are wetland ecosystems in miniature, dry-season oases tended by one of the top predators of the Everglades, the alligator.

A place in the sun.

Gar and other fish populate these shallow ponds, along with freshwater shrimp and snails. Clusters of trees grow in the soft soil around the rims.

During the rainy season there is a constant, shallow flow of freshwater across this broad, flat landscape. In the winter, the rains stop, and parts of the Everglades dry up under the hot Florida sun. But in the limestone depressions, pools of water remain.

Enter the alligator.

During the rainy season, alligators range throughout the wetlands, but as the waters recede, they seek out the remnant pools. Individual 'gators will often lay claim to a particular pool, returning to it year after year. Wallowing on the bottom, the alligator cleans out accumulated silt and vegetation and enlarges its living area.

Pond Beautiful.

The rich soil that the alligator deposits in banks around the edge of the pool becomes a seedbed for a wide variety of plants: pickerel weed, cocoplum, red bay, sweet bay, and many others. Aquatic plants such as alligator flag, arrow arum, and arrowhead emerge from the water around the edges of the hole.

Full house

As the freshwater recedes, 'gator holes become magnets for many Everglades residents. Soft-shell turtles make their way to the pools. The great blue heron (pictured here) and other wading birds come to feed on the small fish and snails. Otters and deer also find nourishment here. The growing congregation in and around the 'gator hole draws nocturnal predators like raccoons and bobcats.

The landlord
The alligator is the "landlord" of the 'gator hole, making it ready for the myriad "guests" who stay there during the dry season. In return, the 'gator gets an ample supply of prey for the dry months. Fortunately for the visitors, their host only eats a few times a month, so most of them find safe harbor until summer.

Where did the flow go?

Over many decades, the flow of freshwater through south Florida has been cut in half, diverted for crop irrigation and water supplies for the region's rapidly-growing human population. The water that does still flow is polluted by fertilizers and pesticides that run off from farms to the north.

The result of this and other human impacts is far fewer alligators, fewer dry-season oases, and a drastic drop in Everglades wildlife. There are more endangered species in the Everglades than in any other U.S. national park.