Bachman's warbler (Vermivora bachmanii) is a type of bird that may no longer exist. This warbler traveled long distances, nesting in wet areas with blackberry and cane plants in the Southeastern and Midwestern United States and spending winters in Cuba. Some people have reported seeing the bird in the 21st century, but these reports are not widely accepted. A few experts believe a sighting in Louisiana in August 1988 is confirmed, but the most recent sightings that are not disputed happened in the 1960s.
Taxonomy
This bird was first discovered in 1832 by Reverend John Bachman, who found the species near Charleston, South Carolina. He sent preserved feathers and descriptions to his friend and collaborator, John James Audubon. Audubon never saw the bird alive but named it after Bachman in 1833. Some 19th-century writers used another name for the species, "Bachman's swamp warbler," which is similar to names used for other birds once grouped in the genus Helinaia.
The blue-winged and quickly decreasing golden-winged warblers, which also belong to the genus Vermivora, are believed to be the closest relatives of this warbler. No subspecies of this bird are known.
Description
Bachman's warbler is a species where males and females look different. Adult birds have two different feather colors during the year: one in spring and one in fall. In spring, male adults have a yellow stripe above the eye and a yellow area below the eye. The area between the eye and beak is a dark olive. The front of the head is black with gray edges, and the back of the head and neck are olive-gray. The rest of the upper body is olive green, with the rump being the brightest. The chin and upper throat are yellow, while the middle of the throat and upper chest are black. The belly is yellow, and the feathers under the tail are white. Young males in their first spring look almost like adult males, but have less black on their head and chest.
In spring, female adults have a light yellow stripe above the eye and a gray crown and neck. The area between the eye and beak is gray-olive, and they have a white ring around the eye. The rest of the female's upper body is olive-green, with the rump being the brightest. The chin and throat are light yellow, and the sides of the neck and upper chest are gray. Older females may have a few black feathers on the chest. The rest of the chest and belly are light yellow, blending into white under the tail. The sides of the body have a grayish tint. Young females in their first spring look similar to adult females but appear less bright.
During summer, Bachman's warbler changes to its fall feathers. Adult males look almost the same as in spring, except the front of the head changes from black to gray. Young males in their first year look like their spring feathers but have an olive-colored front head and less bright yellow underparts. Adult females have the same feather pattern as in spring, but their feathers look fresher in fall. Young females in their first year have a yellowish-olive front head and a less bright eye ring.
Baby Bachman's warblers get their first feathers in May and molt again in June. Juvenile birds have a dark brown head and upper body, and a lighter brown body that becomes dull white on the lower body and under the tail.
Bachman's warbler is 4.25 inches (10.8 cm) long. It is small for a warbler and has a short tail. It is unique among warblers for its thin, curved bill. Adult birds have a blackish brown bill, while young birds have a brown bill. The legs are grayish-brown, and the eyes are dark brown.
Scientists have recorded the songs of this bird. The song includes a quick series of six to twenty-five buzz sounds, sometimes ending with a sharp, slurred zip sound. The song is similar to that of the northern parula, but it sounds more monotone. Different call sounds have been recorded, ranging from a soft "tsip" to a low, hissing "zee-e-eep."
Distribution and habitat
Bachman's warbler mainly bred in two different areas: the southern Atlantic coastal plain and the Gulf Coast states north along the Mississippi River watershed to Kentucky. In the southern Atlantic coastal plain, the bird bred in South Carolina near Charleston. It is believed to have once bred as far north as Virginia and as far south as Georgia. The Gulf Coast breeding habitat was mostly in central Alabama, though reports from northern Mississippi and Louisiana are also known. The bird bred north of Alabama along Arkansas's and Missouri's St. Francis River. Unconfirmed reports of breeding in eastern Texas, Oklahoma, and Tennessee are also known. During migration, the species was mainly recorded in Florida and the Florida Keys, though a few birds traveled along the eastern Gulf Coast. One spring migration record from the Bahamas in 1901 is also noted. The species primarily winters in Cuba. It was also recorded wintering on Isla de la Juventud, and one wintering record is known from Florida. Unconfirmed reports of the species wintering in Georgia's Okefenokee Swamp exist.
Bachman's warbler bred in forested bottomland swamps with pools of still water. These swampy forests are mainly made up of deciduous trees such as cypress, sweet gum, dogwood, red oak, hickory, black gum, and tupelo. It is not certain which specific part of these swamps Bachman's warblers preferred, but they may have favored small areas created by fire or storms with a dense understory of the cane species Arundinaria gigantea and palmettos. Some people think this species may have relied heavily on cane plants.
During migration, the species preferred bottomland forests, though it was also seen in scrubby habitats. In Cuba during winter, it may have used a wide range of habitats, including dry, semideciduous forests, urban parks, and swamps. Hibiscus forests may have been important for wintering warblers.
Ecology and behavior
Because this species is rare, scientists know little about its behavior. Bachman's warblers do not often move their tails up and down. When they feel scared, they quickly jerk their tails and lift the feathers on their heads.
This species does not sing much while traveling. Once they reach their nesting areas, they prefer to sing from high places. The female bird stays near the nest to keep the eggs warm, while the male searches for food.
Bachman's warblers usually forage near the ground, between 3 and 10 feet (0.91 and 3.05 meters) high. During migration, they have been seen searching for food in the tops of trees. They may hang upside down to look under leaves for food. They also find food by searching through leaf clusters. Some scientists think this behavior suggests they specialize in eating insects from dead leaves in canebrakes. Their main food includes caterpillars, spiders, and other small creatures. In Cuba, they may eat nectar, but this idea has not been proven.
Bachman's warblers may live in groups during breeding season. Their nests are deep and large. The outside of the nest is made from dead leaves, moss, grass, and weed stems. The inside is lined with fine fibers from Ramalina lichen and Spanish moss. These nests are built in blackberry bushes, cane stalks, and palmetto plants in lowland forests, 1 to 4 feet (0.30 to 1.22 meters) above the ground or near water. Unlike most warblers, their eggs are completely white with occasional small marks on one end.
Bachman's warblers begin migrating earlier than most New World warblers. In spring, they start moving in late February and arrive in south Florida and southeastern Louisiana by the first week of March. The most common time for them to pass through south Florida is during the first three weeks of March, and along the northwestern Florida coast during the third and fourth weeks of March. The last Bachman's warbler seen in Florida was on April 9. They reach their breeding areas in South Carolina around mid-March, though some arrive as early as late February. Birds traveling to southeastern Missouri arrive between mid-April and late April. Some birds travel past their nesting areas and are found in Virginia and North Carolina.
In South Carolina, all Bachman's warblers leave their nesting areas by July 19. Fall migration is not well recorded, but the earliest bird seen in southern Mississippi was on July 4, and the first in Key West was on July 17. Migration happens between late July and August 25. The last Bachman's warbler seen during fall migration was in coastal Georgia on September 24.
Conservation
Bachman's warbler was first collected by John Bachman in South Carolina in 1832 and described by Audubon in 1833 from skins sent by Bachman. It was not widely known until the mid-1880s. Selective logging in the 1800s may have temporarily helped the species by creating more habitat. The warbler was often seen in its breeding area from the mid-1880s to 1910. However, when clear-cutting replaced selective logging, sightings of the species became rare. By the 1930s, sightings were uncommon. The last confirmed winter sighting was recorded in 1940. The last male specimen was collected on March 21, 1941, on Deer Island, Mississippi, and the last female specimen was collected on February 28, 1940, on Ship Island, Mississippi.
Reports of the warbler breeding in Missouri and Arkansas continued into the 1940s, and birds were seen breeding in South Carolina's I'on Swamp until 1953. Individuals were reported in Fairfax County, Virginia, in 1954 and 1958, and a male was seen singing near I'on Swamp in April 1962. On March 30, 1977, an immature female was seen in Brevard County, Florida. The last confirmed observation was in Louisiana in 1988. In the early 2000s, reports of Bachman's warbler in Congaree National Park led to an investigation. However, these reports were later found to be mistakes, as people confused them with hooded warblers and northern parulas. A thorough search using recorded Bachman's warbler songs did not find any territorial males or provoke responses from other birds. The survey leaders concluded the species was not present in the park during their search.
The main cause of the species' decline was habitat destruction. It is believed the warbler nested in canebrakes, and the loss of these habitats threatened its survival. Loss of wintering habitats in the Caribbean and plume hunting also contributed to its decline. Small-scale logging in the 1800s may have briefly increased breeding habitat. Clear-cutting and draining swamps through water channels were the main causes of habitat loss. It is unknown if changes in wintering grounds in Cuba affected the species, but a winter hurricane in 1932 may have made the species too rare to find mates. In September 2021, the United States Fish and Wildlife Service proposed declaring the species extinct due to a lack of survival evidence. The species was officially delisted and declared extinct in October 2023 under the Endangered Species Act.
In culture
John James Audubon created detailed drawings of a male and female Bachman's warbler. These drawings were painted over an earlier illustration of the Franklinia tree, which was originally painted by Maria Martin. Maria was the sister-in-law of John Bachman and one of the first women in the United States to illustrate natural history.
In the comic strip Doonesbury, a character named Dick Davenport, who was a bird watcher, died in 1986 from a heart attack while observing and photographing this bird species. This event confirmed that the species was still alive. This scene is considered a notable moment in the history of comics.