Headquarters Pond lies about five miles past the St. Marks NWR Visitor
Center on Lighthouse Road. It is not a particularly large pond, only
17-acres or so. Named for its proximity to the refuge’s former
headquarters site, it was formed when the construction of Lighthouse Road
dammed a section of marsh. It has a raised viewing platform that gives you
a good vantage point over the pond. To get to it, park at the Tower Pond
Trailhead, where the bathrooms are located, and walk out the short,
well-marked trail.
I have been watching Headquarters Pond slowly change over the years. It
was once a good spot for ducks. I have a photo taken back in the eighties
that shows open water, but no cattail or floating-leaved plants. I have
recorded about a dozen duck species there, including Long-tailed Duck, a
winter sea duck normally found in the Gulf. The bare branches of an old
dead oak at the back of the pond are a favorite resting spot for Roseate
Spoonbills in early summer and for White Ibis in winter, when herons and
egrets roost on the pond. Black-crowned Night Herons roost in the trees at
the back of the pond year-round.
Both of the refuge’s gallinule species, Common and Purple, are found at
Headquarters Pond. Common Gallinules are dark duck-like birds with
red-and-yellow “candy corn” bills that extend up to a red frontal shield on
their forehead. They spend most of their time swimming near floating leaved
plants and will occasionally walk on them. They are year-round residents at
St. Marks. Once called the Florida Gallinule, in 1983 ornithologists lumped
them with the Common Moorhen, a species found in Eurasia and considered
them a single species. In 2011, they were separated from the moorhen and
the Common Gallinule is again considered a distinct species.
Their Purple Gallinule cousins are slimmer and more brightly colored with
deep purple, light blue, and iridescent green plumage. They also have a
red-and-yellow bill, but have a pale blue frontal shield. Unlike Common
Gallinules, they spend almost of their time walking on floating leaves.
They have long toes that spread their weight and allow them to climb stems
to reach seed heads. Although some overwinter, they are mainly summer
residents. Headquarters Pond has always been the easiest spot on the refuge
to find Purple Gallinule.
The pond has always had a marshy edge; a good place for Green Herons and
Least Bitterns or for Sora and Virginia Rails, depending on the season.
Shallow wetlands like Headquarters Pond can evolve over time. Successive
generations of wetland plants die and decompose, forming an ever-thickening
layer of mud that fills the pond. New species of wetland plants are brought
in by birds, wind, or storm surge.
White water lily, a common wetland plant at St. Marks, became established
on Headquarters Pond and for years its large round floating leaves covered
parts of the pond, providing habitat for Purple Gallinules and leaving
deeper open areas for ducks, American Coots and Common Gallinules. This
changed after Hurricane Michael’s storm surge inundated the pond. In the
years since that storm, American Lotus has replaced the water lilies.
American lotus has large yellow flowers that open in late morning and
close in mid-afternoon. The plant’s seed pods resemble a showerhead. Some
of its large round leaves float on the surface of the water, while others
are raised above the surface. This summer, its leaves have almost
completely covered the pond, leaving few spots of open water. Common
Gallinule numbers are down, but Purple Gallinules, which feed on lotus seed
pods, seem to be doing well.
There are also other changes occurring on the pond. Cattail has become
established and now forms a border along the edge of the pond. Cattail
creates a single-species thicket, crowding out all other plants. Each year
the cattail border gets wider.
The changes that are occurring at Headquarters Pond are natural processes
of wetland succession. Other natural processes, like drought, storm surge
or fire, may intervene, but unless they do, cattail will eventually form a
monoculture in the shallows and American lotus will dominate the deeper
areas. Both American Lotus and Cattail are native species and are not
without wildlife value. However, a wetland dominated by two plant species
has less diversity of insects and birds and is a less interesting place.
St. Marks NWR is a dynamic and ever-changing landscape. The larger pools
at St. Marks are actively managed by refuge staff, primarily for waterfowl,
but also for species like Wilson’s Plover and Least Tern. Without periodic
draining and flooding, they would slowly fill with vegetation. However, the
refuge has limited staff and resources and is facing increasing shortages.
Because of that, Headquarters Pond can no longer be actively managed and is
slowly changing into Headquarters Marsh.
