As 2014 fades into history, this post celebrates two bittersweet events that marked the last year—the 100th anniversary of the extinction of the passenger pigeon (Ectopistes migratorius) and preservation of the last known Pinta Island tortoise (Chelonoidis nigra abingdoni).
After a long and stimulating stroll through the halls of the Smithsonian Institution’s National Museum of Natural History, you may find yourself at the museum gift shop where there is a diorama containing a light brown bird mounted on a tree branch. Her name is Martha and she was the last known passenger pigeon and one of the most famous birds in the world. The Smithsonian handles her with the same extreme care as their other prized specimens, such as those collected by John Audubon, Charles Darwin, and Alfred Wallace.
Martha died at the Cincinnati Zoo in 1914. She was about 29 years old. Just forty years earlier, 136 million breeding adults would occupy 850 square miles of Wisconsin’s oak barren communities that served as the pigeon’s communal nesting sites. The passenger pigeon was then the most abundant bird in North America and possibly of all time. Habitat destruction and hunting on an industrial scale led to its demise.
Earlier this year, a 67-year-old monument to the passenger pigeon was rededicated at Wyalusing State Park, about 2 miles south of Prairie du Chien, Wisconsin. The monument is perched on a bluff overlooking the confluence of the Wisconsin and Mississippi Rivers. A plaque installed at the monument is dedicated to the last Wisconsin passenger pigeon, which was shot in Babcock, in September 1899.
In 1947, Aldo Leopold wrote an essay for the dedication of the monument. The essay is considered by many to be the most poignant piece ever written about species extinction. His essay was later published in A Sand County Almanac (1953), which serves as a foundation of conservation biology and environmental ethics. Here are the first paragraphs of Leopold’s essay:
We meet here to commemorate the death of a species. This monument symbolizes our sorrow. We grieve because no living man will see again the onrushing phalanx of victorious birds, sweeping a path for spring across the March skies, chasing the defeated winter from all the woods and prairies of Wisconsin.
Men still live who, in their youth, remember pigeons; trees still live that, in their youth, were shaken by a living wind. But a few decades hence only the oldest oaks will remember, and at long last only the hills will know.
The historical marker below was erected in 1973 by the Wisconsin Historical Society, in Black River Falls, Wisconsin. The inscription illustrates the unimaginable size of the flocks that would darken Midwestern skies.
Through the 19th century, witnesses marveled at the pigeon’s migrations, noting the hours it would take flocks to pass over head. The murmurations must have been a sight to see—one of nature’s most awesome displays. There are a few online videos of bird murmurations, but these examples pale in comparison to the scale of the passenger pigeon’s flocks. Here is a popular video that offers a tiny hint of the spectacle witnessed in the mid-1800s.
In 2014, birders, organizations and museums paid tribute to the pigeon’s legacy through many conferences, lectures, and exhibits across the U.S. The largest group commemorating the pigeon’s centenary is Project Passenger Pigeon led by a group of scientists, artists, museum curators, and birders. These events were intended to draw attention to the importance of species conservation and our role in species extirpations and extinctions. Here in Chicago, the Field Museum had a special exhibition and produced this backgrounder video.
The famous Galápagos tortoise known as Lonesome George (c. 1910—June 24, 2012) was a male Pinta Island tortoise (Chelonoidis nigra abingdoni) and the last known individual of the subspecies. George became a conservation icon in 1971 after he was discovered on the island of Pinta in the Galápagos archipelago. The subspecies was last seen in 1906 and presumed to be extinct.
George was relocated for his safety to the Charles Darwin Research Station on Santa Cruz Island, and placed with two females of a different subspecies. Eggs were produced, however, none hatched. The Pinta Island tortoise was later judged to be functionally extinct while George was in captivity.
Scientists spent years trying to get George to mate and propagate the subspecies, but all efforts failed. When he died of old age in 2012, the entire subspecies may have been lost. However, several months after George died, a study published by Yale University researchers in the journal Biological Conservation suggested that DNA from George’s ancestors survives. On the northern tip of the island of Isabela—the largest island in the Galápagos chain—the researchers found 17 hybrid descendants of C. (nigra) abingdoni among a population of 1,667 tortoises.
After his death, George’s body would be shipped to the American Museum of Natural History (AMNH) to be preserved. Unfortunately, preparing for the journey to the museum was fraught with difficulties. Because he died in captivity on the remote island Santa Cruz, there were significant challenges in finding an appropriately large freezer to hold George’s five-foot-long, 165-pound body. Through the resourcefulness of experts in Ecuador and New York, a suitable freezer was found and George was held in a nine-month deep freeze while the AMNH obtained the permits to transfer him to the U.S.
Here is a short video produced in part by the AMNH that highlights George’s legacy; the video’s description follows.
Museum scientists and a master taxidermist describe the painstaking process—part art, part science—of preserving Lonesome George, the famous Pinta Island tortoise who died in 2012 in the Galapagos Islands. As the last known survivor of the tortoise species Chelonoidis abingdoni, Lonesome George served as a global icon of conservation—and a reminder of the urgent need to address ever-increasing extinctions. After a limited time on view at the Museum Lonesome George returns to Ecuador as part of that nation’s patrimony.
George made the long journey from Ecuador to New York, where expert preservationists would sculpt George’s final pose. Preparing a lifelike rendering that reflected George’s majestic character and status as the world’s most famous tortoise would be extremely difficult. The team was fortunate to have access to many photographs of George and, in the end, he was set in a dignified stance with his long neck outstretched as if he were reaching for a leafy lunch. In fact, green stains were added around George’s mouth to lend more realism to the pose.
A thermoplastic resin was used to seal George’s skin to help protect it and allow for further restoration or repair of the overlying layer of paint, if necessary. The task of painting George’s skin was tedious and meticulous. While George was alive, his body and carapace (or shell) were always covered by the reddish brown dust from the island. So, the preservationists used soil collected from Pinta Island as a reference for producing a truly authentic skin tone.
Reproducing George’s eyes was a critical final touch. The team photographed the eyes of other tortoises found in local zoos and from those photos were produced the first and most accurate tortoise eyes. All of these extraordinary preservation efforts were necessary because George was widely revered by many people and his preserved state would have obvious educational and scientific value.
The Lonesome George exhibit is on view in the Astor Turret on the AMNH’s fourth floor, from September 19, 2014, through January 4, 2015. He will be returned to Ecuador as part of that nation’s natural heritage.
Perhaps Homo sapiens can for once commit to a noble and worthwhile New Year’s resolution: reduce the catastrophic rate of global species extinction. Or, will our effect on the planet’s plants and animals mirror that of the extraterrestrial impact that wiped out the dinosaurs?