On April 3, 1837, John James Audubon is aboard a cutter ship called the Campbell exploring the coast of the Gulf of Mexico. After exiting the Southwest Pass of the Mississippi River, the Campbell turns northwest towards Louisiana’s Ile de Barataria. Soon thereafter, the Crusader joins the Campbell. Crusader is smaller and has the capability of moving over shallower water. On the occasions where Crusader needs more maneuverability through marsh areas and bayous, the sail is furled to allow four “grunters” to propel the boat with oars.
As the sun is setting and with a storm approaching, Campbell and Crusader find a spot on the southern side of Ile de Barataria to drop anchor. John James Audubon and his fellow sailors are not alone in seeking cover. “Some hundreds” of Cerulean warblers are dropping into the trees. Some of those trees are very likely the Dahoon holly (Ilex cassina) in which Audubon places the bird in his drawing for Birds of America.
Similar to the Cerulean warbler in the first edition, i.e. double elephant folio, of Birds of America is the Blue-Green warbler (Sylva rara) that Audubon presumably spotted perching on a stem of American beautyberry (Callicarpa americana).
The bird’s existence was short-lived after Audubon realized the Blue-Green warbler was a female Cerulean warbler. In the octavo edition of Birds of America, the male and female Cerulean warbler are together along with a Dahoon holly on which is also growing a beautyberry.
The next day, the weather is clear. Audubon notes only a few Cerulean warblers have yet to continue their migration north. Based on fellow explorer John Kirk Townsend’s report of seeing the bird along the Columbia River, Audubon speculates that “The whole breadth of our country, from the Atlantic shores to those of the Pacific, is visited by this bird.” If it was then, it is no longer.
The highest number of Cerulean warblers in the entire United States on Cornell’s e-Bird system is 106. Stephen Stedman counted the birds on June 4, 1994, in the Cumberland Mountains while completing the walking loop at the Frozen Head State Park. When nesting, the Cerulean warbler seeks mature trees in large deciduous forests in North America. Logging and the timber industry have left only a few places like Tennessee’s Frozen Head State Park that meet the Cerulean warbler’s particular habitat requirements.
Also on the southern side of Ile de Barataria are 30 Long-legged sandpipers (Tringa himantopus). Audubon is curious about their feeding technique and interactions. But the wait must not last too long lest Audubon misses the chance of collecting a specimen. He fells 11 of the 30 birds. The chance to examine closely the birds reveals considerable variance in the colors of their plumage.
At first, Audubon speculates that the different coloring depends on the sex of the bird, but then he determines that it is merely the adults molting into their breeding plumage. This discovery brings together into one a number of species thought different: Bonaparte’s TRINGA HIMANTOPUS, Swainson’s Douglass’ Sandpiper (TRINGA DOUGLASSII), Swainson’s and Richardson’s Slender-shank Sandpiper (TRINGA HIMANTOPUS), and Nuttall’s Douglass’ Stilt Sandpiper. Audubon’s Long-legged Sandpiper is now called the Stilt sandpiper (Calidris himantopus).