Biodiversity Heritage Library - Program news and collection highlights from BHL
Blog Reel, User Stories

From the La Brea Tar Pits to the Biodiversity Heritage Library: Exploring Passenger Pigeon Populations in the Western United States
passenger pigeons sitting in a tree
passenger pigeons sitting in a tree

Passenger pigeon (Ectopistes migratorius). The Birds of North America. 1903. Contributed in BHL from Smithsonian Libraries.

The passenger pigeon’s demise is one of the most infamous examples of human-caused extinction. Once the most abundant bird species in North America, it was hunted relentlessly, with large-scale commercial hunting facilitated by railroad distribution placing excessive pressure on the species. The population declined from billions to none in less than one hundred years.

The last passenger pigeon, Martha, died at the Cincinnati Zoological Garden at about 1pm on September 1, 1914.

While stories of passenger pigeon flocks blackening the skies underscore the species’ once staggering abundance, its distribution was concentrated in the eastern United States. But could there have been resident populations in the western U.S.?

Passenger pigeon bones uncovered from the La Brea Tar Pits in Los Angeles, California inspired Dr. Libby Ellwood to ask this very question and embark on a research project empowered by the Biodiversity Heritage Library’s collections.

woman standing in front of photos of animals

Dr. Libby Ellwood. Photo credit: Deborah Paul, Florida State University.

Ellwood has been studying ecology, and its intersection with climate change, conservation, and citizen science, for ten years. For the past year, she has been engaged as a Research Fellow at the La Brea Tar Pits & Museum. She first discovered BHL several years ago during her postdoc at iDigBio, a national resource for digitizing natural history collections and associated information. Since then, the Library has had a significant impact on her research.

“It may sound like hyperbole, but BHL truly is an invaluable resource,” lauds Ellwood. “I have used BHL to fill in datasets with historical data, to research foundational information, and, let’s be honest, just to look at the beautiful images. I have crossed paths with BHL staff and affiliates at conferences near and far and appreciate not only their digitization work, but equally their work to engage the online community in their efforts.”

When working on a research project, Ellwood sometimes accesses BHL daily for months at a time, reading publications online, taking notes and citation information as she goes, and downloading custom PDFs as needed. The Library has saved her precious time during these research projects.

“I know firsthand that weeks of travel to various libraries and special collections is resource and time-intensive,” shares Ellwood. “I have painstakingly used texts that have later been digitized by BHL. Had I to do it again, a good portion of that time and energy would be saved by using information available through BHL. All in all, I have a deep appreciation for BHL’s contributions to the digital landscape.”

Since BHL has proven to be such a valuable source of information for her research, it was the natural place for Ellwood to turn with questions surrounding the possibility of western passenger pigeon populations. In fact, as Ellwood shares, “In this particular case, the text and images in BHL have not only improved my research but have even driven it.”

Ellwood shared her preliminary research findings at the 2018 BHL Annual Meeting during an evening reception hosted by the Natural History Museum of Los Angeles County.

What did she find?

Read on to explore Ellwood’s account of her research to date and topics for further investigation.

Passenger pigeons of the western US – accident or resident?

By Dr. Libby Ellwood

Soon after starting my current position, I learned of the passenger pigeon bones we have in our collections at La Brea Tar Pits. While I might normally have considered this just another in a long list of cool fossils that we have in our collections, the relatively recent extinction of passenger pigeons got me thinking a little more deeply about it. More specifically, were there resident populations of passenger pigeons in southern California, or were these birds accidental visitors?

passenger pigeon bones

Three of the passenger pigeon bones found at La Brea Tar Pits, Howard, Hildegarde. “A Pleistocene record of the Passenger Pigeon in California.” The Condor 39.1 (1937): 12-14.

The La Brea Tar Pits fossils inform us that tens of thousands of years ago passenger pigeons were in what is now Los Angeles, California, though the extent of their range and population size at that time remain unknown. Passenger pigeons are a species that was so abundant in the eastern U.S. that their flocks would darken the skies…at least that was the case until we hunted them to extinction just over a hundred years ago.

While I might not be able to reconstruct tens of thousands of years of passenger pigeon abundance data in the western U.S., just how much information is out there about western populations of passenger pigeons? Is there information from the near historical past that could provide more information about this species’ distribution?

Enter BHL.

To cut to the chase, using documents accessed through BHL, I found numerous accounts of passenger pigeons west of the Rocky Mountains in the 1800s. Some accounts point to numerous birds, perhaps even resident populations of the species, while other accounts portray sightings of a lone individual, likely far from its intended route. My research using BHL has not yet been able to solidly answer whether or not passenger pigeons were ever residents of the western U.S., but it does open the possibility more widely.

map with locations of passenger pigeon localities

Map of passenger pigeon localities from a variety of sources. The western BHL points are the ones added through this current research. Image credit: Libby Ellwood.

With BHL, I added five additional points to the passenger pigeon range map. Where only one poor data point of modern-day western passenger pigeon sightings existed in the past, now there are six. And with this we now have an even more compelling reason to keep digging into this story. If in fact passenger pigeons lived in the western U.S. in some abundance, how far back do those populations go? Or, looking at it from the opposite direction, if there’s a possibility that the La Brea Tar Pits fossil specimens represent resident populations, for how long did those populations persist?

From here, I will continue this investigation by compiling more information about passenger pigeon fossil specimens as well as the more recent historical information to see if I can more deeply piece together a timeline of occurrence and abundance of this once common species.

————————————————-

Thank you, Dr. Ellwood, for sharing your research findings at our 2018 Annual Meeting and as part of our BHL User series! We look forward to learning more as your research progresses, and are thrilled to know that BHL is helping to paint a fuller picture of the passenger pigeon’s story.

May we learn from our past to make better decisions in the future and support a healthy, biodiverse planet.

September 13, 2018by michelle.underhill
BHL News, Blog Reel

We Need Books To…Learn from Past Extinctions

This month, we’re publishing a series of blog posts outlining the importance of biodiversity literature, made available for free and open access through the Biodiversity Heritage Library, to today’s scientific research and conservation initiatives. With your help, we can help save biodiversity. 

Remembering Extinct Species

On September 1, 1914, at approximately 1pm in the afternoon, a passenger pigeon named Martha died. Her death marked the extinction of her entire species. It is “one of the fastest and most dramatic extinctions in human history,” according to the Zoological Society of London.  A population of several billion birds was decimated in less than a century thanks to over-hunting and habitat destruction. From the first published image of a passenger pigeon by Mark Catesby in 1754, to a poignant record of population declines by Vernon Bailey in an 1892 fieldbook, and the final autopsy report of “the last living representative of its race,” the passenger pigeon’s tragic demise is well-documented in BHL.

As many as 30%-50% of all species may be facing extinction by the mid-21st century, according to the Center for Biological Diversity. Some extinctions, such as that of the passenger pigeon, are internationally notorious, while others, such as the Rodrigues Day Gecko, Sloane’s Urania moth, or the Saint Helena Olive, are less infamous but no less dispiriting. Each represents another step towards earth’s sixth great extinction event.

Historical literature, accounts in archival sources like fieldbooks, and museum specimens are the only remaining record of these species. “Historic literature provides written accounts and illustrations of [extinct species] from first-hand observations before they became extinct,” including phenotypic descriptions like habitat, diet, behavior, and phenology, explains Dr. Helen James, curator of Birds at the National Museum of Natural History, in a Smithsonian Libraries article. This depth of data does not always accompany museum specimens, not to mention the fact that the physical appearance of some species undergoes a radical transformation in death. Thus, for scientists to obtain a complete picture of the life, morphology, and phylogeny of extinct species, taxidermied specimens must be used in conjunction with written and illustrated primary sources.

Learning from Extinctions

Preserving knowledge about extinct species is about more than just maintaining a record of the life we have lost. These historic accounts can also be used to help conserve endangered species. Examination of the behaviors and anatomy of extinct organisms can help tell us what made them vulnerable in the first place and can be directly applicable to threatened species.

The historic record also provides insight into how an extinction will affect an ecosystem. Species do not live in a vacuum. “The demise of one…species can indirectly cause another to become extinct,” according to a 2012 study from the University of Exeter. “Any extinction can create a ripple effect across a food web, with far-reaching consequences for many other animals.” Examining the relationships within an ecosystem, richly documented in literature and fieldbooks, can help us identify which species will be affected by biodiversity loss, and what form those effects might take. Extrapolating knowledge about ecosystems affected by extinctions to similar environments can help us predict the ramifications of biodiversity loss in expanded locales.

New Hope for Rediscovered Species

Occasionally, species that were believed extinct are miraculously rediscovered. For example, the Arakan Forest Turtle was thought to be extinct for nearly 100 years until a team of conservationists stumbled upon specimens at a Chinese food market in 1994. The information in historic literature about these species is critical to crafting policies to protect remaining populations.

To Clone or Not To Clone…

Recent advances in genetics have ignited the possibility of resurrecting extinct species. While debates over the wisdom of such actions continue, should the passenger pigeon ever take flight again, historic records will be vital for success. What kind of habitat do these species require? What do they eat? What wants to eat them? These answers can be found in the pages of books and journals from days gone by.

Fighting Human-induced Extinctions

Over the past 450 million years, Earth has lost up to 90% of its species on five different occasions, reports a 2014 Time article by Jeffrey Kluger. Asteroids, volcanoes, and gamma rays were to blame in the past. Humans are largely to blame today. But while, barring a genetic miracle, we will never again see a dodo waddle through the woods or the Jamaican Giant Galliwasp scurry across the ground, the historic record ensures that these lost species are not forgotten. Knowledge is power, and thanks to BHL and other like-minded open access initiatives, the knowledge necessary to prevent future human-induced extinctions is available to everyone on any corner of the globe.

We rely on donations from users like you to help grow our library and keep it free and open. As you think about your holiday giving, we hope you’ll consider making a tax-deductible donation to help save biodiversity.

Learn more about the critical roles BHL and historic literature play in discovering new species, supporting conservation, and saving Earth’s biodiversity

December 23, 2014by michelle.underhill
Blog Reel, Campaigns, Featured Books

From Billions to None: The Story of the Passenger Pigeon

Ohio, 1854. A dense, black shadow begins to creep across the northern edges of the horizon, slowly but incessantly blotting out a bright cerulean sky. Residents take notice, and pour out of their homes and businesses to stare in wide-eyed awe and trepidation at the phenomena edging towards them.

Hours pass, and the sky is hurled into unwavering darkness. Finally, as the day fades, the sun itself succumbs to this nameless power.

Men and women fall to their knees in prayer, begging for deliverance from the Revelational apocalypse. A thundering roar, like the beating of a million drums, assaults the kneeling petitioners, and their fingers turn icy as an arctic gale whips around their bodies.

A lone figure, hunting rifle in hand, stands atop a hill and stares at the pitiful scene before him. Shaking his head, he lifts his muzzle, peers straight and true through his sights, and pulls the trigger. Dozens of shapes, like tiny meteors, break away from the mass overhead and plummet towards the earth. Swinging his weapon over his shoulder in satisfaction, he picks up a burlap sack and swaggers towards the fallen celestial bodies. As he stoops and retrieves one of the mysterious figures, a pair of slate wings unfurls. He stuffs the Passenger Pigeon unceremoniously into his bag and moves on to the next bird.

Ohio, July 1914. A ten year old boy sidles through a mob of men, women, and children ogling exotic animals at the Cincinnati Zoological Garden. Desperate to find a quite haven to escape the crowd, the child slips around the corner and finds himself staring directly into a pair of bulging eyes. Startled, he jumps back, and the eyes tilt sideways in response, as though curious about this new creature.

Brow furrowed, the boy takes a timid step forward, mesmerized. What he had momentarily mistaken for the glare of some ferocious predator he realizes is simply the quizzical stare of a rather drab looking bird. Her feathers, ever so slightly ruffled, are an unimposing brown dotted with gray and black. She stands with her back to him, her head facing him atop a neck turned 180 degrees like a broken porcelain doll.

“So I see you found Martha,” a deep voice rumbles behind him.

Startled again, the boy turns and finds a gray-haired, mustached zoo keeper standing behind him.

“Martha?” he responds, confused.

“Martha, our passenger pigeon. She’s the last of her kind, you know. When she dies, a whole species will go extinct.”

Frowning, the boy turns again to look with new appreciation into the eyes of this modest animal. Unexpectedly, he is filled with sorrow. She may not be as exciting as a dinosaur or as fierce as a saber-tooth tiger, but she looks very innocent and very lonely.

A surge of purpose rises up in his chest.

“Can’t we do anything to help her?” he asks fervently.

The man shakes his head sadly.

“It’s too late. Maybe we could’ve done something forty years ago, when people first realized they were in trouble. But now, there’s nothing we can do.”

The boy turns back despondently. She was the very last of her species, and it was too late to do anything to save her. Why hadn’t anyone done something when there was still time?

Losing interest in the boy, Martha turns her head, puffs up her chest, and tucks her beak tightly into her breast. She’d had enough of humans for one day.

The Fall of a Mighty Empire: The Passenger Pigeon

Two hundred years ago, the Passenger Pigeon (Ectopistes migratorius) was the most abundant bird species in North America. A population numbering in the billions, as much as 40% of all land birds on the continent shared the same genome as Martha. Migrating flocks were so large that they literally blocked out the sky, stretching up to a mile wide and 300 miles long and taking 14 hours to pass a single point. Flocks were so densely packed that a single shot could bring down dozens of birds. The beat of up to 3.5 billion pairs of wings literally created its own cold front below, and those unaccustomed to the marvel feared the end of the world was upon them.

Nesting colonies were just as large, covering several hundred square miles of forest. A single tree often contained up to 100 nests, causing many to topple over at the sheer weight of an aviary kingdom. By the end of the nesting season, blankets of pigeon droppings several inches thick saturated the forest floors. However, while colonies were staggeringly massive, a mating pair of passenger pigeons produced only one, occasionally two, eggs per season.

The Passenger Pigeon was nearly twice as large as the common city pigeon, with males averaging 16 inches in length and up to 12 ounces in weight. Frames built for speed and maneuverability, the birds could reach up to 60 mph, making them ideal targets for not only hunting parties but simple target practice. The onset of large-scale commercial hunting and railroads for distribution turned a sustainable hunting practice into a frenzied genocide. In 1869, Van Buren County, Michigan, alone shipped 7.5 million passenger pigeons to the east, where they sold for mere pennies.

The dangerous decline of the species was noted as early as the 1850s, but cheap meat and a seemingly endless supply of birds dampened any resolve to implement hunting restrictions. In 1896, a majority of the last wild flock of 250,000 birds were killed during a sporting event heralded as the “last chance to shoot the passenger pigeon in the wild.” On March 24, 1900, a 14-year old boy killed the last known wild Passenger Pigeon in Pike County, Ohio.

From billions to none in less than 100 years.

Remembering Martha

Martha the Passenger Pigeon is perhaps one of the most famous animals in the world, for she is a tangible reminder of the human capacity to decimate biodiversity. At nearly 30 years old, Martha, the very last of her species, died at the Cincinnati Zoological Garden at about 1pm on September 1, 1914. Immediately after her death, she was entombed in a 300 pound block of ice and shipped to the Smithsonian, where she was taxidermied.

In remembrance of the centennial of her death, Martha is on display at the Smithsonian’s National Museum of Natural History until October, 2015, as part of  the joint BHL/Smithsonian Libraries exhibit: “Once There Were Billions.” The exhibit documents the tragic histories of four extinct North American birds: the Passenger Pigeon, Great Auk, Heath Hen, and Carolina Parakeet.

Millions of people have rallied to commemorate the Passenger Pigeon this year, and help raise awareness about endangered species, extinction, and the impact of human activity on healthy ecosystems. The “Fold the Flock” initiative is an effort to recreate the staggering passenger pigeon flocks of the 19th century through origami pigeons. “The Lost Bird Project” has created a film and book to investigate extinction and memory. Also as part of the project, Todd McGrain has crafted stunning bronze sculptures of extinct birds, including the passenger pigeon, which are on display across America.

Other initiatives like Project Passenger Pigeon, the film From Billions to None, and a multitude of exhibits nationwide are working to raise awareness about extinctions and excite action to prevent future biodiversity calamities.

Finally, as always, BHL is here to help! Find books about the Passenger Pigeon and illustrations of the species for free from BHL.

How Can Historic Literature Help Modern Scientists Save Species?

Reports, illustrations, and photographs in historic literature and taxidermied specimens are the only remaining record we have of extinct species. Thus, preserving this knowledge is important simply as a means of documenting the biodiversity we have lost. But retaining and providing access to this legacy literature is not just about creating a memorial for extinct species. It’s also about helping to prevent future extinctions.

Historical records allow scientists to study the morphology, behaviors, habitats, diet, and breeding patterns of species, which help determine where those species might be vulnerable and inform strategies for rehabilitating endangered populations. Similar information about extinct species, and an evaluation of the circumstances that led to their demise, can help scientists identify threats to similar species. Records of migration pathways and changes in distribution patterns allow scientists to provide educated recommendations to policy makers about the lands and species to protect.

Without a concrete evaluation of earth’s biodiversity history, and an understanding of the mistakes we have made in the past, we are doomed to repeat our darkest moments. But just as humans have a capacity to annihilate a species, so have we the power to save one (take the American Wolf, for example). Supporting initiatives like the Biodiversity Heritage Library gives scientists, policy makers, and concerned citizens the information they need to protect life on earth. Take a look at what your donation can do, and we hope you’ll consider giving a tax-deductible gift today.

July 15, 2014by michelle.underhill
BHL News, Blog Reel, Campaigns

Breathing Life Into a Museum Exhibit About Extinction

You are living in the midst of earth’s sixth great extinction event. You’ve been living in it since you were born. So have your parents, your grandparents, your great-great-great-great-grandparents, and all of your ancestors for about 10,000 years. It dates back to the extinction of the mammoths and has been increasingly accelerating as human actions and climate change reshape the balance of our planet.  Within the next century, 75% of the conservatively estimated 8.75 million species on earth may be extinct.

When many of us think of extinctions, we think of the countless species disappearing in the Amazon rainforest, the ocean’s coral reefs, or the forests of South-east Asia. But the truth is that extinctions happen in every corner of the globe. Some are noticeably notorious, others occur without us even knowing that the species existed in the first place. One of the most infamous North American extinctions is the demise of the Passenger Pigeon.

By the time Europeans first came to the New World, approximately 40% of all land birds in North America were a member of the species Ectopistes migratorius, or the Passenger Pigeon. Their population numbered in the billions, and their abundance spurred intense human hunting in the mid-1800s. Less than a century later, the Passenger Pigeon was extinct.

The fate of the Passenger Pigeon, and three other extinct North American bird species (Great Auk, Carolina Parakeet, and Heath Hen), are the focus of the new joint BHL/Smithsonian Libraries‘ exhibit at the National Museum of Natural History: Once There Were Billions.

The exhibit represents the culmination of three years of work for its curators, Gilbert Borrego (former BHL Library Technician for Smithsonian Libraries) and Dr. Helen James (Curator in Charge, Division of Birds, National Museum of Natural History). The histories of these lost species are told through compelling narratives, taxidermied specimens (including Martha, the last Passenger Pigeon), books from the Smithsonian Libraries’ collection (many of which are available digitally in BHL), and images from BHL.

Most people are unaware of how involved and sometimes challenging building an exhibit can be. Several years, countless meetings, copious research, and dozens of individuals are required to bring an exhibit from conception to public launch. Sometimes the most difficult part can be simply honing in on the exact story you want to tell.

“The most challenging part of the exhibit was narrowing down our source material,” said Borrego. “The topic [of the exhibit] was originally much more general, focusing on extinct species. We knew Martha the Passenger Pigeon was to be included, but we looked at many other types of animals and plants before settling on the plight of birds from North America.”

Borrego first presented the proposal for “Once There Were Billions” in 2011, and since then he, James, and an army of scientists, librarians, and museum support staff defined the scope, drafted a script, selected specimens and images, and fashioned layouts for the physical and supplementary digital exhibits.
Once all the foundational work was complete, it was time to bring the exhibit to life. Plaques fresh off the press, freshly-cleaned bird specimens, and carefully conserved books were artistically arranged within two mammoth exhibit cases in the Evans Gallery on the Ground Floor of the National Museum of Natural History.

And voila! This specialized hub for extinction education opened to the public this past Monday, June 24, 2014, and will remain open until October, 2015.

If you’re visiting D.C., be sure to check out the exhibit. And if you’re an art fan, take some time to see the massive bronze sculptures of the birds crafted by artist Todd McGrain as part of “The Lost Bird Project” and situated around the Smithsonian grounds.
If you’re not in the area, you can still enjoy “Once There Were Billions” via the online exhibit, by browsing digital versions of select exhibit books in BHL, or by downloading free, spectacular illustrations of the featured species.
Educating each and every person about the plight of biodiversity on our planet, and the repercussions of doing nothing, is a critical part of ensuring that today’s species do not become just another extinction statistic. Exhibits like “Once There Were Billions” are just one way we can achieve this global awareness. But while you might not be in a position to build a museum exhibit, there are other ways you can help change the fate of doomed species. Supporting initiatives like BHL, which enable the research of scientists trying to document and conserve species around the world, helps prevent species decline.

Everyone can make a difference. What will you do to help curb the tide of the Sixth Great Extinction Event?

June 27, 2014by michelle.underhill

Help Support BHL

BHL's existence depends on the financial support of its patrons. Help us keep this free resource alive!

search

About BHL

The Biodiversity Heritage Library (BHL) is the world’s largest open access digital library for biodiversity literature and archives. BHL operates as a worldwide consortium of natural history, botanical, research, and national libraries working together to digitize the natural history literature held in their collections and make it freely available for open access as part of a global “biodiversity community.”

Join Our Mailing List

Sign up to receive the latest news, content highlights, and promotions.

Subscribe Now

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 319 other subscribers

Subscribe to Blog Via RSS

Subscribe to the blog RSS feed to stay up-to-date on all the latest BHL posts.

Access RSS Feed

Inspiring Discovery through Free Access to Biodiversity Knowledge.

The Biodiversity Heritage Library makes it easier than ever for you to access the information you need to study and explore life on Earth…for free, anytime, anywhere.