December 12, 2015. Even at 9 AM, the weather is almost balmy, and the high is forecast to be 78º. By noon I have peeled off two layers of clothes and am down to a T-shirt. This is some kind of weather! I cover some of the same ground I did two days ago. Birdlife is even less than it was then; I see not a single kinglet, but I do find a neat bird, an American woodcock that I flush from a sweetgum ridge. Rather than taking off with its usual, near-vertical helicopter flight that scares the daylights out of you, my woodcock only makes a short, low flight of forty feet and lands back on the leaf-covered ground. I look for any tell-tell sign of small holes in the soft earth where it may have been probing for earthworms with its long beak but find nothing. I also try and sneak up on the hiding “timber doodle,” but it flushes again, this time for good, before I can get a good look. Woodcocks appear to be greatly reduced in numbers compared to forty or fifty years ago when I used to flush a fair number during winter walks in the woods. Now I can generally count on one hand the number I see in a year.
A handsome cloudless sulphur butterfly, Phoebis sennae, flies by in the early, sunny afternoon, a late migrant perhaps making its way to southern Florida to overwinter. With the kind of weather we’ve been having I’m sure the sulphur could spend the winter here at Congaree.
After arriving back home, I notice for the first time a small, dark tick embedded in the skin on the underside of my forearm. It’s a black-legged tick, Ixodes scapularis, also known as the deer tick, the notorious carrier of Lyme disease. It’s the first tick I’ve had on me from the swamp in quite some time.
Swamps and floodplains are not typical tick habitats. In fact, I never saw a tick in Congaree until sometime in the early to mid-1990s. And the same goes for chiggers, too. Several things came together that may have introduced both. Hurricane Hugo punched numerous holes in the canopy that allowed sunlight to invigorate lush stands of sedges, switch cane, and other undergrowth favored by ticks; a reduction in the amount of flooding (during the late 1990s and early 2000s, the swamp went through a several-year period of almost no floods) allowed tick and chigger populations to flourish; and a proliferation of hundreds of feral swine provided ticks ample blood meals and the means of rapid population increases.
Deer ticks must be increasing in the South. I don’t ever remember seeing one in my youth when I spent a lot of time in fields, woods, and other tick habitats. Then, the American dog tick, Dermacentor variabilis, was the only one to worry about.
The swamp went through a period a few years ago when deer ticks were very prevalent; after a day’s tromp you might pull several off your body. More recently, they have become scarce or nonexistent. Interestingly, the only time I get ticks at Congaree is in winter, even on cold days, and I started referring to them as “winter ticks.”