May 3, 2015, continued. After a delicious breakfast of shrimp and grits, egg casserole, scones, hot coffee, and juice, catered by the Friends of Congaree Swamp, I make a slow bird walk loop along the Sims Trail and the low boardwalk. The morning is still young and the air cool. Along the trail at the edge of the swamp I spot my first vireo nest of the year, hanging down in cup-like fashion from the end of a slender swamp chestnut oak limb eighteen feet off the ground. The owner is sitting on the nest with her tail sticking out, and I see enough of a head to notice the pale iris of a white-eyed vireo. A few pieces of what looks like dried cane leaves, along with a thin grass blade, are hanging down rather carelessly from the bottom of the nest, perhaps indicating this is her first attempt at nest building. This is not intended to be a criticism, however, since a vireo nest is a marvel of avian architecture, especially considering that it’s all constructed with a beak.
I notice the green fruit of red mulberries in the few trees I see on the walk and wonder why the fruits don’t ripen in time to correspond with peak spring migration, which is right now. By the time the fruits do ripen in the next few weeks, most of the migrants will have moved on, leaving the resident birds to enjoy the tasty fruit. I would think for maximum dispersal efficiency that having your fruit available for the greatest number and variety of seed consumers would be the best reproductive strategy, but perhaps other factors I’m not aware of have come into play for the red mulberry.
The catbirds are moving through in good numbers, and I end up seeing five on this one-mile walk (but surprisingly no thrushes). We are now down to four woodpecker species in the swamp, at least until next October: pileated, red-bellied, hairy, and downy. The flickers departed about two weeks ago, the sapsuckers a little earlier than that. I’m predicting a good year later this fall for red-headed woodpeckers since there should be a good crop of red oak acorns to feed them (but how wrong I was; the winter of 2015 turned out to be a bad year for red-heads, and the only red oak that produced any acorns to speak of was the cherrybark).
A short time after I turn north on the low boardwalk towards the visitor’s center, I hear a noise of wings high above me and turn around to see a pileated woodpecker flying to the side of a tall, slender cypress about sixty feet up. The woodpecker pauses a second, then disappears into a tree cavity! I realize then that it’s a nest and back track for a better look. The nest entrance is a large, almost perfectly round hole, and then I hear the buzzing call of the nestlings, clamoring for food. The sound they make is so loud that you’d think the noise would attract every predator of woodpecker chicks in the neighborhood. The adult stays inside the cavity for a couple of minutes, then flies out, making a bee line to the east. Her brood continues calling for a minute or two after she’s gone.