Vermivora bachmanii (Bachman's Warbler)

[Deleted]

The song of this bird can be heard here.:

macaulaylibrary.org/audio/10717

[RSN]

BACHMAN’S WARBLER Vermivora bachmanii 11–11.5cm (4.25–4.5in). Yellow eyering. ADULT MALE: Large black patch on throat and breast; black patch on crown; yellow forehead, chin, and belly. ADULT FEMALE: Duller; black on breast reduced to fine streaks or absent; crown and hindneck gray. STATUS AND RANGE: Critically endangered if not extinct, formerly uncommon and local non-breeding resident in Cuba September through April. Last widely accepted record 1964. 1980 report dubious. HABITAT: Undergrowth in moist woods, canebrakes, and forest edges bordering swamps.



From ''Birds of the West Indies (Princeton Field Guides)''

[Melanie]

Robert D. Barber: A recent {1977} record of the Bachman's Warbler in Florida www.fosbirds.org/ffns (PDF)

With the probably last two photographs of the Bachman's Warbler.

[Melanie]

BACHMAN'S WARBLER OBSERVATIONS CONTINUE IN I'ON SWAMP
JAY SHULER, PERRY NUGENT, JOHN TROCHET, and JOE VAN OS

www.carolinabirdclub.org/chat/issues/1978/v42n2bawa.pdf

[surroundx]

Stevenson, Henry M. (1972). The recent history of Bachman's Warbler. Wilson Bulletin 84(3): 344-347.

[surroundx]

Carlson, Colin J., Burgio, Kevin R., Dallas, Tad A. and Bond, Alexander L. (2018). Spatial extinction date estimation: a novel method for
reconstructing spatiotemporal patterns of extinction and identifying potential zones of rediscovery. bioRxiv preprint. doi: dx.doi.org/10.1101/279679

[surroundx]

Robbins, Mark B. (2018). The Status and Distribution of Birds in Missouri. Lawrence, Kansas: University of Kansas Biodiversity Institute. viii + 332 pp.

[surroundx]

Local Biologist shares experience with the now extinct Bachman’s Warbler

“In 1971 I was living in Key West, Florida, a naturalist’s paradise. I had been stationed there while serving in the U.S. Navy and fell in love with the tropical habitats. On Oct. 6, 1971, a low country swamp loving bird came to visit me. I had the rare, and evidently not to be repeated pleasure, of watching a large number of migrating warbler species from my bedroom window — one of which was a Bachman’s Warbler.”

When I first read this email from Capt. John “Crawfish” Crawford, I gasped. The Bachman’s Warbler, like our Carolina Parakeet and Ivory-billed Woodpecker, is now extinct.

Crawford, senior naturalist and marine educator with the University of Georgia’s Marine Extension and Georgia Sea Grant, went on to tell me, “It was the only one I have ever seen and I am certain of my identification. The bird concentration was attracted by a major hatch of Royal Poinciana Moth caterpillars, which climb the trees at night, to feed, from hiding places on the ground and in bark crevices. There were many thousands of them, the caterpillar droppings sound like rain at night! That fall I identified 17 species of warblers in and around the base of the huge poinciana tree just outside my bedroom in Key West. Florida is a migrant bird funnel and the keys an even tighter one before they jump off to Cuba.”

The Bachman’s Warbler (pronounced BACK-man’s), first described by John James Audubon in 1833, was mostly gone from Earth only a little over 100 years later. Audubon named the warbler for his colleague and friend John Bachman (1790-1874), an American Lutheran minister and naturalist who collaborated with Audubon to produce “Viviparous Quadrupeds of North America.”

According to “The Breeding Bird Atlas of Georgia” (2010, UGA Press), the bird “was very likely once a breeder in Georgia.” Considered a bird of old-growth bottomland and swamp forests, the Bachman’s Warbler apparently frequented light gaps within such forests — small clearings vegetated with rank growth of a bamboo-like plant called giant cane (Arundinaria gigantea). These “canebrakes” were also thick with briars and/or swamp palms. Even in virgin, unlogged stands, such areas occur from treefalls resulting from hurricanes, beetle outbreaks and occasional wildfires. Such habitats never went missing entirely from the bird’s southeastern United States breeding range, thus its decline and disappearance is enigmatic.

This warbler wintered exclusively in Cuba (western Cuba and the adjacent Isle of Pines) where, historically, forests were cleared for agriculture, particularly sugarcane, and this dramatic loss of habitat on the bird’s winter range likely led to its demise.

The last confirmed sighting (i.e., supported by photo documentation) of a Bachman’s Warbler occurred in April, 1962, in the vast I’on Swamp near Charleston, South Carolina. A number of unconfirmed but highly credible sightings like Crawford’s trickled in through the 1970s. Crawford has long been renowned in ornithological and herpetological circles for his expert level knowledge and I have no doubt whatsoever that his Bachman’s report is solid.

Like Crawford, in high school I got ahold of a field guide to the birds of eastern North America and a modest but functional pair of binoculars. My first spring-summer actively birding, in southern Illinois, opened a new world. Looking closely, often looking up, I found verdant foliage bejeweled with color — olive-green Kentucky Warblers, vibrant canary-yellow Prothonotaries, black-and-orange American Redstarts fanning their tails like butterflies.

Similar to our still-abundant Northern Parula Warbler, the Bachman’s Warbler was a performer, bouncing about acrobatically, sometimes dangling upside down from clumps of Spanish moss, while gleaning caterpillars and other small insects from leaves. Males were identified by their olive-yellow foreheads and black breasts. The song of the Bachman’s is described as a buzzy pulsating trill ending in a sharp, slurred note. A sound insect-like and reminiscent of the Northern Parula’s song.

Crawford shared with me another formative experience from earlier in his youth, when he was still polishing his avian I.D.. skills. “I clearly remember a day in a swamp when I heard a loud unfamiliar call. The bird was close and I crept (you might say slogged) towards the sound. I saw movement on the side of a huge tree. Not one but two huge woodpeckers moving around the trunk toward the nest hole. They repeated the calls and I had butterflies in my stomach, I was sure they were the famous Ivory-billed Woodpeckers! I rushed home to check my bird book and, of course, they were not ivory-bills. But my first sighting of the equally spectacular Pileated Woodpecker was exciting enough. My love of swamps grew!”

Dirk J. Stevenson is a naturalist, educator and lead biologist and owner of Altamaha Environmental Consulting LLC in Hinesville. Learn more information at altamahaec.com . He can be reached at [e-mail]

Source: www.savannahnow.com/entertainmentlife/20200419/natural-georgia-local-biologist-shares-experience-with-now-extinct-bachmans-warbler

[Melanie]

Songbird that once lived in Florida is now considered to be extinct

nbc-2.com/weather/weather-blog/2021/11/01/songbird-that-once-lived-in-florida-is-now-considered-to-be-extinct/

[Melanie]

Genomes of the extinct Bachman's Warbler shows high divergence and no evidence of admixture with other extant Vermivora Warblers

Bachman's Warbler (Vermivora bachmanii), last sighted in 1988, is one of the few North American passerines that have gone extinct. Given the extensive ongoing hybridization of its two extant congeners, the Blue-Winged Warbler (V. cyanoptera) and Golden-Winged Warbler (V. chrysoptera), and shared patterns of plumage variation between Bachman's Warbler and hybrids between those extant species, it has been suggested that Bachman's Warbler might have also had a component of hybrid ancestry. Here, we use historic DNA (hDNA) and whole genome sequencing of Bachman's Warblers collected at the turn of the 20th century to address this possibility. We combine these data with genomes of the two extant Vermivora species to examine patterns of population differentiation, inbreeding, and gene flow. In contrast to the admixture hypothesis, the genomic evidence is consistent with V. bachmanii being a highly divergent, reproductively isolated species, with no evidence of introgression. We show that both V. bachmanii and V. chrysoptera have elevated runs of homozygosity compared to V. cyanoptera, consistent with the effects of a small effective population size or population bottlenecks in the former two species. We also found-using population branch statistic estimates of all three species-previously undocumented evidence of lineage-specific evolution in V. chrysoptera near a novel pigmentation gene candidate for warblers, CORIN, which is a known modifier of ASIP, which is in turn involved in melanic throat and mask coloration in this family of birds.

www.biorxiv.org/content/biorxiv/early/2022/12/21/2022.12.20.521272.full.pdf

[another specialist]

Extinct warbler’s genome sequenced from museum specimens

The Bachman’s warbler, a songbird that was last seen in North America nearly 40 years ago, was a distinct species and not a hybrid of its two living sister species, according a new study in which the full genomes of seven museum specimens of the bird were sequenced. Genome comparisons of Bachman’s warbler with the golden-winged and blue-winged warblers also helped researchers identify a new candidate gene involved in feather pigmentation in the group. A paper describing the study, led by Penn State researchers, highlights the crucial role that museum collections can play in science and appears June 16, 2023 in the journal Current Biology.

“The Bachman’s warbler is the only songbird known to have recently gone extinct in North America,” said David Toews, assistant professor of biology in the Penn State Eberly College of Science and the leader of the research team. “It is one of three species in the genus Vermivora. Our lab studies the two living species of this genus, which are known to mate with each other producing hybrid offspring.”

Golden-winged and blue-winged warblers produce a spectrum of hybrids, but two distinct types of hybrid offspring, each with a unique combination of the parent species’ coloration, have been the focus of bird watchers and ornithologists. This is because these two hybrids were thought to be distinct species themselves, known as Brewster’s warbler and Lawrence’s warbler, until careful study of wild hybrids and, now, modern genetic analysis has confirmed their hybrid origins. The extinct Bachman’s warbler resembles one of these hybrid offspring in coloration, so there was some question as to whether the Bachman’s warbler was itself a distinct species or if it might also have been a hybrid.

The research team collected seven specimens of the Bachman’s warbler from museum collections and extracted DNA from the birds’ toepads. They then performed whole-genome sequencing to compare the Bachman’s warbler genome to existing genomes for the two living species in the genus.

“It’s never easy to get DNA for sequencing from museum specimens,” said Andrew Wood, the first author of the paper, who was a research technologist in Toews’ lab at the time of the research and is now a postdoctoral researcher at the University of Minnesota. “These birds were collected over a hundred years ago and were not preserved in any special way, but we were able to extract enough DNA to get genome sequences that are comparable to those from the living species.”

The genomes of the golden-winged and blue-winged warblers are very similar to each other, except for a few regions that are involved in determining the coloration patterns of the bird’s feathers. In comparison, the Bachman’s warbler genome was very different, which indicated to the researchers that it was, in fact, a distinct species.

“We only have a small sample size for the Bachman’s warbler genome, but one of the interesting findings we saw by comparing the seven specimens was that there were long ‘runs of homozygosity,’” said Toews. “These are regions of the genome where the two copies of the genome—one inherited from each parent—are identical to each other and is an indication that the population may have been small and there was a lot of inbreeding. We see similar patterns in the living species, so understanding if this might have contributed to the extinction of Bachman’s warbler could help us to better understand the health and conservation of the living population.”

The researchers also compared the genomes of the three species to look for regions of the genome that may have evolved differently in each lineage. These differences can be indicators that a particular region of the genome evolved via natural selection for a particular trait or because of another evolutionary process. Having a third species’ genome to compare allowed the researchers to identify a region that contained a new candidate gene involved in warbler pigmentation.

“We began this study because we were interested in learning about the history and biology of Bachman’s warbler,” said Woods. “But our results also highlighted how we can use extinct species to learn about their living relatives. We lose a lot of biological and evolutionary context through the process of extinction and being able to compare Bachman’s warbler to the two living species allowed us to identify a gene that we might not have otherwise found. Context is crucial to understanding biology. Natural history collections allow us to place new observations into contexts that may have disappeared from the natural world. This fuels discovery, and makes museums powerful, and underappreciated, tools.”

In addition to Toews and Wood, the research team includes Zachary A. Szpiech, assistant professor of biology at Penn State; Irby J. Lovette at the Cornell Lab of Ornithology; and Brian Tilston Smith at the American Museum of Natural History in New York. The research was funded by the U.S. National Science Foundation, the Huck Institutes of the Life Sciences at Penn State, and the Penn State Eberly College of Science. Computations were performed using the Penn State’s Institute for Computational Data Sciences’ Roar supercomputer.

www.eurekalert.org/news-releases/993572?fbclid=IwAR2759vzMDa_AnwUPxJyqx3drEWiC0NeYiJi-yzZwhOt1VnSSnQipfANOU0

[Melanie]

The Bachman's warbler is now officially declared extinct by the USFWS. I think the IUCN Red List will follow (current status CR(PE))

www.tampabay.com/news/environment/2023/10/17/bachmans-warbler-recently-extinct-animals-2023/

[Sebbe]

Museum genomics provide insight into the extinction of a specialist North American warbler species.

Museum genomics provide an opportunity to investigate population demographics of extinct species, especially valuable when research prior to extinction was minimal. The Bachman’s warbler (Vermivora bachmanii) is hypothesized to have gone extinct due to loss of its specialized habitat. However, little is known about other potential contributing factors such as natural rarity or changes to connectivity following habitat fragmentation. We examined mitochondrial DNA (mtDNA) and genome-wide SNPs using specimens collected from breeding and migration sites across the range of the Bachman’s warbler. We found no signals of strong population structuring across the breeding range of Bachman’s warblers in both mtDNA and genome-wide SNPs. Thus, long-term population isolation did not appear to be a significant contributor to the extinction of the Bachman’s warbler. Instead, our findings support the theory that Bachman’s warblers underwent a rapid decline likely driven by habitat destruction, which may have been exacerbated by the natural rarity, habitat specificity and low genetic diversity of the species.

link.springer.com/article/10.1038/s41598-024-67595-5

[koeiyabe]

explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.106306/Vermivora_bachmanii

[Sebbe]

Removal of 21 Species From the List of Endangered and Threatened Wildlife.

Although Bachman’s warbler was first described in 1833, it remained relatively unnoticed for roughly the next 50 years. Population estimates are qualitative in nature and range from rare to abundant (Service 1999, pp. 4–448). Populations were probably never large and were found in ‘‘some numbers’’ between 1890 and 1920, but afterwards populations appeared to be very low (Hamel 2018, pp. 16–18). For instance, several singing males were reported in Missouri and Arkansas in 1897 (Widmann 1897, p. 39), and Bachman’s warbler was seen as a migrant along the lower Suwannee River in flocks of several species (Brewster and Chapman 1891, p. 127). The last confirmed nest was documented in 1937 (Curson et al. 1994, p. 96). A dramatic decline occurred sometime between the early 1900s and 1940 or 1950. Recognition of this decline resulted in the 1967 listing of the species (see 32 FR 4001; March 11, 1967) under the Endangered Species Preservation Act of 1966. Between 1975 and 1979, an exhaustive search was conducted in South Carolina, Missouri, and Arkansas. No Bachman’s warblers were located (Hamel 1995, p. 10). The last (though unconfirmed) sighting in Florida was from a single bird observed near Melbourne in 1977. In 1989, an extensive breeding season search was conducted on Tensas National Wildlife lotter on DSK11XQN23PROD with RULES2 Refuge in Louisiana.

Six possible Bachman’s warbler observations occurred but could not be documented sufficiently to meet acceptability criteria established for the study (Hamilton 1989, as cited in Service 2015, p. 4). An experienced birder reported multiple, possible sightings of Bachman’s warbler at Congaree National Park, South Carolina, in 2000 and 2001. These included hearing a male and seeing a female. In 2002, the National Park Service partnered with the Service and the Atlantic Coast Joint Venture to investigate these reports. Researchers searched over 3,900 acres of forest during 166 hours of observation in March and April; however, no Bachman’s warbler sightings or vocalizations were confirmed. As noted previously, females and immature birds are difficult to positively identify. Males (when seen) are more easily distinguishable from other species. Researchers trying to verify the sightings traced several promising calls back to northern parulas and finally noted that they were confident the species would have been detected had it been present (Congaree National Park 2020, p. 3). In several parts of the Bachman’s warbler’s range, relatively recent searches (since 2006) for ivory-billed woodpecker also prompted more activity in appropriate habitat for the Bachman’s warbler. Much of the search period for ivory-billed woodpecker is during the winter, and the searches usually continued until the end of April, when the Bachman’s warbler would be expected in its breeding range.

Because the Bachman’s warbler was a very early migrant, many knowledgeable searchers looking for ivory-billed woodpeckers would have had opportunities to encounter this warbler as early as February across the southeastern United States, yet no putative encounters were reported. Given that Bachman’s warbler habitat overlaps with ivory-billed woodpecker habitat, the probability that the Bachman’s warbler would be detected, if present, has recently increased (Service 2015, pp. 5–6). Further, in general, substantial informal effort has been expended searching for the Bachman’s warbler because of its high interest among birders (Service 2015, p. 5). Despite these efforts, the Bachman’s warbler has not been observed in the United States in more than three decades. With a likely maximum lifespan of 7 years, the time period through which this species has not been seen constitutes at least 7 generations, and the time period since its last confirmed breeding constitutes more than 10 generations. In Cuba, the species’ historical wintering range, the last ornithologist to see the species noted that the species was observed twice in the 1960s in the Zapata Swamp: one sighting in the area of a modern-day hotel in Laguna del Tesoro and the other one in the Santo Tomas, Zanja de la Cocodrila area. Some later potential observations (i.e., 1988) in the same areas were thought to be a female common yellowthroat (Geothlypis trichas) (Navarro 2020, pers. comm.). A single bird was reported in Cuba in 1981 at Zapata Swamp (Garrido 1985, p. 997; Hamel 2018, p. 20). However, additional surveys in Cuba by Hamel and Garrido in 1987 through 1989 did not confirm additional birds (Navarro 2020, pers. comm.). There have been no sightings or bird surveys in recent years in Cuba, and all claimed sightings of Bachman’s warbler from 1988 onwards have been rejected by the ornithological community (Navarro 2020, pers. comm.). Curson et al. (1994, p. 96) considers all sightings from 1978 through 1988 in Cuba as unconfirmed.

www.govinfo.gov/content/pkg/FR-2023-10-17/pdf/2023-22377.pdf