March 3, 2015. March is the month of big change for the swamp. It starts out in winter and ends in spring. The Congaree forest of early March is still a bare one, but only thirty days later becomes a light-green, spring forest. The change-over seems gradual, but in actuality it happens quickly, almost overnight. Just a few days of absence means you’ve missed a lot of the show. Some birds – crows, cardinals, wrens, turkeys, and others – are sitting on eggs by the end of March, and the butterweed, violets, and yellow jessamine are blooming. The tiny Northern parula warbler is the swamp’s best vocal indicator of spring, since it often arrives from its tropical wintering grounds (after a four-and-a-half month absence) on or near the first day of spring. The males immediately announce their presence with buzzy, insect-like songs from what appears to be every hardwood tree.
I walk over to “Sweetgum Hill” on this pretty, pre-spring afternoon. The swamp has been partially flooded recently, and the trails are wet and muddy in places. Nearly all the bald cypress catkins have spent their pollen and turned from green to brown. The cone-like buds of ironwood catkins are enlarged to about half an inch, and green with another year’s promise of flowers. A few pawpaw buds catching abundant sunlight have begun enlarging, too.
The warm weather has the sap flowing, and I spot a large grape vine coated with a six- feet length of dripping sap, oozing from holes created by a yellow-bellied sapsucker. The sap is thin and watery with no taste that I can discern. Grape-vine sap must be ideal for the cultivation of slime molds, as most of the brilliant-orange ooze that I find at Congaree is growing on grape vines. February is typically slime-mold month, but the past two have been so cold that I’ve not seen that much.
On the way back to the parking lot, at 6:00 PM, I hear another sound of spring, a loud frog chorus coming from the wet muck swamp at the edge of the floodplain. Loudest are the leopard frogs with their sonorous, guttural calls, but there are many spring peepers trying to make their high-pitched, bird-like calls heard as well.
Note: in the previous post I mentioned a buckthorn bumelia growing right by the River/Oak Ridge Trail at Wise Lake as a possible state champion tree. Well, it is! and here are the measurements: height, 38 feet; circumference, 12 inches; and average crown spread, 33 feet. It is easy to overlook Congaree’s many understory trees, like this one, when you are focused on big giants.