This week for Flora and Fauna Friday we have the king of the cane, the piper over the palms, the Swainson’s Warbler (Limnothlypis swainsonii).
Past the break of winter, beside the brake of cane, a spell of birdsong suddenly sunders the silence in the stagnant steamy air. A brown blob at the bend of a branch beelines below the bamboo. Switchbacks through Switch Cane it snakes swiftly into a sightline, sneaking peeks to guess your intent before dissolving into the shadow of the thicket; a Swainson’s Warbler patrolling his kingdom of cane.
Among our Warblers in family Parulidae, the Swainson’s Warbler stands out for its stout frame, sharp and sturdy bill, and muted plumage. Unlike the radiant golden Prothonotary and Hooded Warblers or the contrasting bi-chromatic Black-and-white and Yellow-throated Warblers, all of which are neighbors in the spring bottomland forest, Swainson’s Warblers instead don a cryptic cloak of camouflaged colors. Their back is bronzed-brown and belly olive-stained-ivory. A dark stripe runs through the eye, a pale eyebrow borders above and is capped with a crown of chestnut. Not a fleck of extra color to stand out against the standing timber’s shadows. What the Swainson’s Warbler lacks in prismatic presence it makes up for with its pipes.
The song of the Swainson’s Warbler is a short verse of sharp whistles: three flat notes slowly rising, a fourth cut short jumps high and falls low, “Tea, Tea, Tea, Te-wi-two”. Although easy to hear it’s a hard song to commit to memory, falling lyrically somewhere between the tunes of the oft adjacent Louisiana Waterthrush and Hooded Warbler. Despite being readily heard when present, Swainson’s Warblers are hard birds to find and even harder birds to lay eyes on.
Swainson’s Warblers are found across South Carolina in summer. Yet, they are secretive birds, singing low below heavy canopies and just barely above dense thickets of bushes, bamboo, and palmettos amidst the depths of blackwater swamps, heath thickets, and bottomland floodplains. Even within these vast and nearly inaccessible ecosystems, breeding pairs of Swainson’s Warblers are often few and far between. Swainson’s Warblers are a species of conservation concern across much of the Southeast. Conversion of floodplain forests to agricultural fields and intensive hardwood timbering and pine planting of floodplains have supplanted or upset the delicate balance of these ecosystems. This destabilizes the palmetto thickets and canebrakes in the coastal plain that Swainson’s Warblers rely on to nest. Without consistency in these wetland systems their populations have fluctuated and shrunk for over a century, making them a species in need of special attention. Thankfully the forever protected floodplains of the lower South Edisto River remain a stronghold for the species, where Swainson’s Warblers still peacefully reign over the cane.
