Day 2: Corkscrew Swamp

 

28/10/22

Sunny

28 °C

Corkscrew swamp

We left for corkscrew swamp at 8.20 am and drew in at around 10am

As I walked round to the center a cardinal bird was perched in a small tree.

Here, we met Sharon, a volunteer who was to guide us round the reserves board walk

Corkscrew Rookery

The first threat to Corkscrew was plume hunting in the early eighteenth century. Egret and heron feathers were especially prized by plume hunters. To protect the birds, Rhett Green was hired as a warden and in 1913 began to act as a guide around the swamp. Their fate was further secured by the 1918 migratory bird treaty act banning the killing and trading of birds.

The next wave of danger was logging in 1944. Pine was the most sought after then cypress. Cypresses were heavy and the wood would sink, so waters had to be drained for a year before they could be cut down.

Cypress Tree

Locals, the National Audubon Society and other supporters bought the rookery to prevent deforestation. 5,680 acres were purchased by 1954 and the rookery was made into corkscrew swamp sanctuary. 

Corkscrew swamp was named after corkscrew river, but this river was renamed the imperial river.

About the sanctuary

Corkscrew swamp is 13,450 acres of freshwater ecosystem fed by the watershed through the everglades. Within the swamp, there are 700 acres of untouched cypress forest, making it the biggest in the world. Because of this, the sanctuary is home to the largest colony of nesting threatened wood storks in America. Habitats in the sanctuary range from wet prairies to pond cypress and the oldest growth of bald cypress

Tour:

Mary leads us around ipe board walks that stretch round the swamp

Slash Pine, Pinus elliottii

strangler fig around tree, Ficus aurea

American Alligator, Alligator mississippiensis

Eastern Ratsnake, Pantherophis alleghaniesis

Sharon points out a slash pine. In defense against fire the pines drop their branches

Racoon, Procyon lotor

Video: Alligator mississippiensis

Fires and hurricanes

Alligator Flag, Thalia geniculate

Both fires and hurricanes are key to a healthy swamp.

Fires burn and control trees meaning understory plants are free to flourish, soon after fires, Mary exclaims that wildflowers and new grasses will be growing. The area of shrubs is reduced as well, meaning the habitat is more accessible to species such as deer.

At corkscrew swamp, controlled fires are set from December to July

Hurricanes have a similar effect.

When hurricane Irma hit, Mary says, branches and foliage had to be picked off the board walks. In this way, hurricanes compare to fires by allowing light to fall to the swamp floor.

Although, we did not see any butterflies as populations are in recovery after the extreme weather event.

Climate change

The wet season runs from May to November.

The consequence of climate change is that the wet season is shortening, so the same amount of rain arrives in a shorter time. Hence the water level in the swamp will rise more than usual, impacting the delicate ecosystem.

Effects of this flooding include the arrival of exotic fish, for instance catfish and gars, from other areas. Saplings are also drowned by the water so it is easier for invasive species to take hold.

Pickerelweed with purple flowers,

  Pontederia cordata

Rains come later as well. Because wood storks need enough water to sustain the number of fish they require, late rain means it is too dry for wood stork nesting.

Wood storks need enough water to sustain chicks, as the 450 pound in total of fish required to feed their young will not be found at these masses in little water.

I was a bit surprised that we did not see any wood storks, 

Threats

Pollutants from farming drain into the swamp raising its nutrient levels.

This encourages different plant growth and changes the ecosystem. Efforts are focused on trying to change farming practices, when it is argued the most effective method is to build water purification systems.

Man-made canals and drainage systems all the way up North Florida redirect water around the everglades, meaning the whole habitat is changed from the plants it supports to the animals.

Thankfully, the comprehensive Everglades Restoration Plan has been put in place to help restore water flow through the everglades.

Additionally, many shallow and upland wetlands once drainage began and road building became more frequent were converted into pastures.

Invasive species threaten the habitat as well. Originally shipped in from Cuba, brown anoles are not native where greens are.

Brown anoles are found from the south of Georgia to Florida, pushing green anoles into higher habitats. Where there is no higher undergrowth for the green anoles to inhabit they are outcompeted.

Green Anole, Anolis carolinensis

Brown Anole, Anolis sagrei

Walk

Almost everyone on the fieldtrip went on a walk that night, most likely as a result all we saw only many southern toads that night around Archbold an a cuban tree frog.

Useful links:

https://corkscrew.audubon.org/