From 5 billion to none: The cautionary tale of the passenger pigeon

On Sept. 1, 1914, at approximately 1 p.m., Martha, named after George Washington's wife, aged 29 and the last surviving passenger pigeon, died at the Cincinnati Zoo and Botanical Garden. Once the most common bird in the country — perhaps as many as five billion passenger pigeons filled the skies, particularly during migration, when they collectively sounded like thunder, created gale force winds and eclipsed the sun — was now inexplicably, unceremoniously and inexcusably extinct. How could such a thing have happened? How could it be permitted to happen? Passenger pigeons were communal, often forming huge congregations — able to fill trees to the point that branches would break from their weight. These migratory birds were built for speed and grace and could fly up to 60 miles per hour. They had small heads and necks with long pointed wings — with large breast muscles to power their flight. Males were bluish gray, with black streaks and pink iridescence. They were typically about 16 inches long. The females were a bit duller in appearance. Its closest living relative is the mourning dove. As the eastern United States was developed through deforestation, the migratory path of passenger pigeons from Canada to the southern United States was pushed west into the heartland of the country. This change also altered their diets from acorns, chestnuts, berries and seeds to grains. It is not surprising that this number of pigeons was an unwelcome layover in large agricultural fields due to the damage they could inflict on crops. But passenger pigeons were also killed for sport, as professional hunters began to slaughter them to sell (a dozen pigeons went for about 50 cents). One of the most unconscionable events happened in Petoskey, Michigan. in 1878 in which 50,000 passenger pigeons were killed per day for five months. An estimated seven million birds were killed. Not all passenger pigeons were shot, others were netted in large numbers using decoys, while others would simply fall off trees when hunters placed pots of burning sulfur under roosting sites. Conservation attempts to limit the amount of passenger pigeons killed in Michigan and Ohio were not seriously considered or enforced, as many believed it absurd to think that such an abundant bird could be slaughtered into extinction. Reportedly, the last wild passenger pigeon was shot and killed in Pike County, Ohio in 1900. Thus, from the time early settlers reached North America until the turn of the 20th century, the span of perhaps a little more than a couple generations, but mostly throughout the 1800s, each and every passenger pigeon in the wild, upwards of five billion individual birds, had been killed. Today, Martha resides at the Smithsonian Museum in Washington D.C., where she is a reminder of the importance of conservation efforts and responsible ecosystem management. There are of course several other birds that have gone extinct over time. Many know the story of the dodo, a flightless bird measuring about three feet tall, an endemic to Madagascar, which hasn't been seen since 1662 — less than 100 years after its first recorded sighting by Dutch sailors. Similarly extinct is the great auk, another flightless bird resembling a penguin, but more closely related to razorbills, which were hunted to extinction for their meat, feathers and eggs. Our only native parakeet, the Carolina parakeet, went officially extinct in 1939, most killed by farmers, while the dusky seaside sparrow survived until only six males were left in 1979. It went extinct due to pollution, pesticides and loss of habitat. And, most famously, there hasn't been a verified account of the ivory-billed woodpecker for 50 years. Daniel Simberloff, professor of environmental studies at the University of Tennessee, stated that "of about 10,000 bird species worldwide, at least 128 have disappeared in the last 500 years, about 1,200 are currently seriously threatened with extinction (all but three from human activities); there is a real prospect of the loss of 500 bird species within this century." This year, the International Union for Conservation of Nature's Red List of Threatened Species, sadly added 66 new plant and animal species the extinct list. Among those was the mauritus duck. More than 42,100 species are on the red list of threatened species, of which 13 percent are birds. The causes of extinction are well understood and often distinctly human-related, such as habitat loss, which is the leading cause of extinction. Human persecution (hunting or purposeful extermination), pollution and competition from invasion species (often due to humans) are other factors. Additional causes include environmental factors, such as climate change and natural disasters. Each species has its own challenges, its own story. Surprisingly perhaps, as Simberloff notes, "Introduced species – those who migrate to a new area – are the second leading cause of endangerment and extinction. Information on the rate of species introduction and the nature of the impacts of introduced species on native species and ecosystems allows inferences about extinction rates. The evidence all points to a global tragedy with a profound loss of biodiversity." Many regard the Anthropocene, the Age of Humans, as the sixth great extinction. It of course was not just birds, as the 15 million buffalo that existed in the wild at the end of the Civil War was on the verge of extinction by the 1880s. They were killed for not only sport and food, but also to put subsistence pressure on Native Americans who relied on the buffalo for food and clothing. Today, only about 30,000 buffalos live in the wild. The insatiable slaughter of some species has always made it difficult for me to extend the conservation credit sought by, and often given to, sport hunters. It is important to maintain conservation efforts, such as impactful laws like the Migratory Bird Treaty Act and the Endangered Species Act, and not let them be weakened by industry or special interest groups. For endangered species, already on the brink of extinction, we need more protections, not less. With everything we do, we must consider the impact of our species on other species. Peter Ward, professor of geological studies at the University of Washington, stated, "In some ways it is very much like the dinosaur-killing event of 65 million years ago, when a biosphere already stressed by rapid changes in climate and sea level was knocked into mass extinction by the impact of asteroids. And then, 100,000 years ago, another great asteroid hit Earth, this time in Africa. That asteroid is named Homo sapiens." Black River Audubon January Program What: "The Past, Present, and Future of Biological Diversity and the Environment: Why NE Ohio and the Great Lakes Matter," with Dr. Bort (Robert) Edwards When: Jan. 3, 7 p.m. Where: Carlisle Reservation Visitor Center, 12882 Diagonal Road, LaGrange, OH As the world prepares for a more volatile environment under climate change, the NE, mid-west, and Great Lakes regions are expected to face increasing pressure to support and sustain both natural and human resources. Understanding how organisms are distributed in the present, and how they experienced and responded to change in the past, is vital to trying to anticipate how best we can prepare for this impending crisis.