New bird species discovered through scientific collections

Natural history collections are full of surprises, with scientists updating what is known about different species and uncovering new ones.

Dr. Matthew Halley, Assistant Curator of Birds, is the lead author of a recently-published paper that splits the Slaty-backed Nightingale-Thrush (Catharus fuscater) into seven different species and four subspecies — including a newly-described species from eastern Panamá: the Darién Nightingale-thrush (Catharus arcanus).

Photo of Matthew Halley by Jenna McCullough

These genetically distinct populations live in secluded mountain rainforests in Central and South America and began to diverge from each other nearly three million years ago.

The species look very similar to an untrained eye. To document their differences, Dr. Halley and his team sequenced DNA from multiple populations, studied physical features like plumage color, iris color and bill color, and analyzed differences in their vocalizations.

Dr. Halley shared the findings on his Twitter (now X) account. Read on for a summary, along with some of the figures from the paper:

This figure shows the geographic distribution of the C. [fuscater] complex in Central and South America. Lines point to type localities. The variation in shapes denote sampling locations for different molecular data. Shape size is correlated with the number of samples (1–3).

The C. fuscater complex (Turdidae) is composed of several disjunct populations that inhabit cloudy mountain rainforests, ranging from Costa Rica to Bolivia. These birds are diabolically shy and more often heard than seen. Their song is a series of sweet, musical whistles.

The research identified 10 genetically distinct populations that have been evolving independently for multiple glacial cycles. Molecular clock suggests most lineages diverged in early Pleistocene / late Pliocene— ancient lineages with independent evolutionary trajectories.

This figure shows taxonomic variation in the structure of ‘punctuation calls’, visualized in RavenPro 1.5 (Cornell University), recognizing three groups based on shared acoustic structure: (Type 1) pulsed/rippling: C. [f.] hellmayri, Undescribed 1 (now C. arcanus), C. [f.] mirabilis; (Type 2) long/sinuous: C. [f.] sanctaemartae, C. [f.] fuscater, C. [f.] berplepschi; (Type 3) short/simple: Undescribed 2 (now C. o. tenebris), C. [f.] opertaneus, Undescribed 3 (now C. b. nebulus), C. [f.] mentalis.

Populations were divergent in the acoustic structure of three different call types, which are presumed to be innately acquired (i.e., not learned), and there were subtle differences among populations in song structure, which is presumably learned.

This image is a side view of polychromatic adult plumages in C. [f.] mentalis (from left to right): 1, FMNH 433742, a ‘grey’ male with enlarged testes; 2, FMNH 433738, a ‘brown’ male with enlarged testes; 3, FMNH 364458, a ‘brown’ male with testes not enlarged; 4, FMNH 433740, an adult female with an enlarged ovary. Adults of both colour types (FMNH 433742, 433738) were collected at the same site in November
2001.

Halley traveled to the American Museum of Natural History, the National Museum of Natural History and Carnegie Museum of Natural History to study their C. fuscater specimens, and borrowed specimens from the Field Museum, LSU Museum of Natural Science, and the Academy of Natural Sciences of Drexel University, bringing them to the museum to look at sexual and age-related differences in plumage color.

This image shows ventral and dorsal views of the adult male plumages in C. b. berlepschi, C. b. caniceps, C. o. tenebris ssp. nov., C. b. nebulus ssp. nov., and C. mentalis.

With a large sample of study skins assembled under one light source (flat panel LED), subtle differences between populations, difficult to appreciate in the field, became easier to notice — Halley scored this variation by comparing the specimens to published color standards.

The taxonomic revision splits the C. [fuscater] complex into seven species, of which one is newly described, and four subspecies, of which two are newly described (C. opertaneus tenebris, C. berlepschi nebulus). New English names were proposed for each species. The seven species are:

Talamanca Nightingale-thrush (Catharus hellmayri) – monotypic – Northern mountains of Costa Rica (Rincón de la Vieja, Miravalles, Tenorio) to west-central Panama (Parque Nacional Santa Fé, Veraguas). (Photo: alchetron.com)

Darién Nightingale-thrush (Catharus arcanus, sp. nov.) – monotypic – E Panama, endemic to Serranía de Majé and Serranía del Darién, from Cerro Azul in the west, to Cerro Tacarcuna in the east

Pirre Nightingale-thrush (Catharus mirabilis) – monotypic – Endemic to Cerro Pirre, Darién province, E Panama. (Photo: ML 242929041)

Cordilleran Nightingale-thrush (Catharus fuscater) – polytypic – (1) C. f. sanctaemartae, endemic to Sierra Nevada de Santa Marta, NE Colombia; (2) C. f. fuscater, Sierra de Perijá of Venezuela, N and E Andes of Colombia and Venezuela. (Photo: ML 206115721)

Trans-Andean Nightingale-thrush (Catharus berlepschi) – polytypic – (1) C. b. berlepschi, W Andes in Ecuador; (2) C. b. caniceps, W Andes in Ecuador, S to NW Peru; (3) C. b. nebulus, ssp. nov., E Peruvian Andes. (Photo: ML 38468741)

Antioquia Nightingale-thrush (Catharus opertaneus) – polytypic – (1) C. o. opertaneus, NW and Central Andes in Colombia, S to Napo, Ecuador; (2) C. o. tenebris, ssp. nov., Río Chinchipe watershed of N Peru and SE Ecuador

Cochabamba Nightingale-thrush (Catharus mentalis) – monotypic – S Peru, east of the Río Apurímac, E to Santa Cruz, Bolivia

Note: Monotypic species are not divided into subspecies. Polytypic species can be divided into at least two subspecies.

Halley, M. R., Catanach, T. A., Klicka, J., and J. D. Weckstein. 2023. Integrative taxonomy reveals hidden diversity in the Catharus fuscater (Passeriformes: Turdidae) complex in Central and South America. Zoological Journal of the Linnean Society zlad031. LINK

If you are unable to access the paper and would like a copy, please email Matt Halley.

Learn more about Dr. Halley’s research projects and publications on his website.

The du Pont Trophy

On exhibit in the Community Room: the du Pont Trophy original paintings by artist Lauren J. Sweeney

For more than 50 years, the museum has presented the du Pont Trophy Award to the “overall outstanding exhibit” entered at shell shows around the country. The award honors exceptional citizen scientists having a passion for shells, shell collecting, and the natural history of mollusks.

For the majority of its history, the du Pont Trophy was a simple engraved plaque. As part of the Museum’s 40th anniversary celebration in 2012, Director of Collections and Curator of Mollusks, Liz Shea, Ph.D. re-imagined the award to celebrate the variety in the museum’s vast collection of more than two million mollusks. She turned to long-time museum supporter and local artist, Lauren J. Sweeney, Ph.D. to make this vision a reality. The result is an original watercolor highlighting a different shell from the collection each year. A framed limited-edition, signed print of this commission is presented to the du Pont Trophy winners.

Lauren Sweeney’s paintings are informed by a lifetime of scientific observation. Originally a biologist who focused her talents on research, teaching, and scientific illustrations, Lauren is now a full-time artist. Her attention to detail brings the shape, color, texture, and pattern of her subjects into sharp focus. Lauren has exhibited her work in the greater Philadelphia area, including the Sketch Club, Gallery Twenty Two, and the Main Line Art Center.

For more information about the artist, visit www.inliquid.org.

The original paintings, currently on exhibit, are for sale for $600 to benefit the museum’s collections.

2023 duPont Trophy

Lambis lambis

The 2023 du Pont Trophy features the changing morphology of Lambis lambis. These dramatically different stages are symbolic of the major metamorphosis the museum experienced over the past few years. The Delaware Museum of Nature and Science reopened to the public in May 2022 with completely renovated exhibit spaces.

2022 duPont Trophy

Melongena corona

This painting depicts the marine snail Melongena corona as positioned on Curator of Mollusks Elizabeth Shea, Ph.D.’s kitchen table. The specimen (and setting) was chosen in recognition of the chaotic year ushered in by COVID.

SOLD

2020 du Pont Trophy

Spirula spirula

This painting features the internal shell of Spirula spirula, a deep sea cephalopod commonly referred to as ram’s horn squid. They are more often collected as shells than as live organisms. S. spirula was selected for the painting in recognition of research projects conducted by Widener University students.

2019 du Pont Trophy

Tellina radiata

This specimen of Tellina radiata, a bivalve mollusk commonly known as the Sunrise Tellin, is from the Alison Bradford collection, bequeathed to the museum by Alison Bradford, a longtime volunteer and member of the Board of Trustees. Bradford had been at the museum for over 30 years. She passed away in the summer of 2018 and transferred her collection of more than 1,000 shells to the museum, most collected in Gasparilla Island, Florida, where she owned a home.

2018 du Pont Trophy

Haliotis fulgens Philippi

The pearlescent marine sea snail abalone is the inspiration for the 2018 du Pont Trophy, featuring two specimens of the green abalone Haliotis fulgens Philippi, 1845 (DMNH 10958). These specimens have a beautiful nacreous layer and were selected by the museum’s first Mollusk Curator, R. Tucker Abbott, for illustration in the second edition of American Seashells. Published in 1974, the book is an essential resource for shell lovers and an important part of the museum’s history.

SOLD

2017 du Pont Trophy

Liguus crenatus variation

The 2017 du Pont trophy was based on shells owned by renowned Delaware illustrator Frank Schoonover, a gift from one of his most well-known clients, Irénée du Pont, owner of Granogue in Delaware and the fabled Xanadu mansion in Cuba, where the shells were collected. The shells were donated to the museum in December 2015 by Schoonover’s grandson John Schoonover.

2016 du Pont Trophy

Anodonta imbecilis from Florida

This year’s shell is a group of freshwater bivalves, commonly known as Paper Pondshells, collected in Lake Talquin, Florida in 1954. Freshwater bivalves are the focus of a recent National Science Foundation grant that will help the museum share its collections on the web.

2015 du Pont Trophy

Leporicypraea mappa variation

The museum’s mollusk collection contains over 250,000 boxes (or “lots”) of shells, making it one of the largest collections in North America. The Map Cowries in this painting highlight the depth of the museum’s holdings and the variation found within a single species.

2014 du Pont Trophy

Spondylus with data label

New collections come into the museum from many sources, often accompanied by old data labels. This specimen of Thorny Oyster is a beautiful and ornate U.S. species, complete with an interesting original data card.

2013 du Pont Trophy

Scaphella junonia on sand

Finding a Junonia on the beaches of the Florida Gulf Coast is cause for celebration. This composition highlights the popular marine snail resting on a background of sand collected from Boca Grande, Florida by long-time museum trustee and volunteer Alison Bradford.

SOLD

2012 du Pont Trophy

Festilyria duponti holotype

The subject of the first watercolor is Festilyria duponti, a shell named by Clifton Stokes Weaver in honor of Delaware Museum of Natural History founder, John E. du Pont. The background is a representation of a technical book on shells, co-authored by du Pont and Weaver.

New species discovered using museum’s online collection data

Introducing Bourciera ovata

In the summer of 2020 — the first year of the pandemic — a team of European scientists began compiling a checklist of known terrestrial and fresh water mollusks of mainland Ecuador. The effort included occurrences recorded in past scientific reports or literature, museum datasets available online, and verified observations from citizen science projects like iNaturalist.

In reviewing our records, one of the scientists, Marijn Roosen of the Natural History Museum of Rotterdam, noticed some unusual records of a unique land snail in the Andes Mountains. Marijn requested more information about the snails and photographs to confirm their identifications. It turned out that some of the specimens from Puyo, Ecuador represented species previously unknown to researchers, including the newly-named Bourciera ovata.

With high resolution photographs of different aspects of the snail’s shell, Marijn was able to describe it as a new species, demonstrating a greater diversity of Ecuadorian land snails and the importance of having museum collection data accessible, as surely there are many more new species to be discovered. The research was published in September in the journal Folia Malacologica.

DMNH 151926, formerly thought to be *Bourciera fraseri*, is now the type specimen for the newly-discovered species *Bourciera ovata*. A type specimen is the specific specimen on which a new species is based. The museum’s mollusk collection already included around 1,200 type specimens. Photos by Alex Kittle.

Roosen, M. and Dorado, C. Revision of the genus Bourciera Pfeiffer, 1852 (Gastropoda: Helicinidae), with the description of six new species from Ecuador and Peru. Folia Malacologica, 30(3), 155–167. https://doi.org/10.12657/folmal.030.018

Taxonomy changes reflected in new specimen organization

The introduction of Bourciera ovata is just one example of how what scientists know about species and their taxonomy continues to develop. While working from home during the pandemic in 2020, Collections Manager Alex Kittle began reorganizing the mollusk collection based on updated information and species names, and later moved the actual specimens to reflect these changes. Information about our entire mollusk collection is now publicly available on the Symbiota portal, InvertEBase. Our collection profile shows 233,603 records are available online, representing 500 families and 15,658 species; 32% are georeferenced to specific locations.

Collection Manager of Mollusks Alex Kittle in the DelMNS scientific collections.

Mobilizing millions of marine mollusks

The museum has teamed up with scientists at several major museums and universities for a $2.3 million, four-year grant from the National Science Foundation to digitize data for more than 4.5 million marine mollusk specimens such as mussels, oysters, clams, and snails collected along the Eastern seaboard from the U.S.-Canada border to U.S.-Mexico border.

The project, Mobilizing Millions of Marine Mollusks of the Eastern Seaboard, will have a world-wide impact on biodiversity documentation and study by making data from these ecologically and commercially important species available through online portals. Previous digitization projects have focused on freshwater and land mollusks; this is the first major project of this type for marine mollusks.

The Field Museum of Natural History is the lead (principal investigator) for the project. Other collaborating institutions include the Academy of Natural Sciences of Drexel University, Carnegie Museum of Natural History, Harvard University, University of Florida, University of Michigan Ann Arbor, Los Angeles County Museum of Natural History, and North Carolina State Museum.

This material is based upon work supported by the National Science Foundation under Grant Nos. 2001510, 2001290, 2001507, 2001515, 2001523, 2001528, 2001536, 2001546, 2001570, 2001600. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.