The American alligator is an iconic denizen of the American Southeast and an important ecosystem engineer. An ecosystem engineer’s legacy on the landscape can be erased by anthropogenic disturbance or climate change, and this has occurred in the Everglades where the natural landscape pattern has been replaced by extremely dense stands of Typha sp. (cattail) from increased nutrient inputs. This cattail plume is considered low quality habitat for many wildlife species and it was assumed that alligators occupy only edge habitat and associated canals instead of the interior. However, after restoration projects opened up sections of the cattail marsh, alligators were observed in the interior, cleared sections. While observing this area in historical imagery (1940 and 1983 aerial imagery), we discovered that a current alligator trail in a restored site was also present in the 1940’s imagery.
Results/Conclusions
To quantify how many present-day trails were historic trails/open water sloughs, we digitized current trails in restored plots and overlaid them on the 1940’s imagery. Trails were categorized as in a historic slough/trail or surrounding sawgrass ridge. Over 80% of current trails (14.6 km) were present as alligator trails or part of an open slough in 1940. While the duration of these landscape features—almost 80 years—was remarkable, even more extraordinary was the persistence of the trail through extreme landscape change. Decades of nutrient enrichment and cattail growth/peat production has filled in the microtopography of the landscape, except in areas that alligators inhabited. This suggests that alligators may contribute more as ecosystem engineers to the Everglades than previously thought—they may create and maintain a network of infrastructure through time and extreme landscape change, and in doing this, they act as collaborators in the current Everglades restoration efforts.