Quantcast
Environmental News for a Healthier Planet and Life

Humans to Blame for Extinction of Only Parrot Native to U.S., Study Finds

Science
The Carolina parakeet went extinct in 1918. James St. John / CC BY 2.0

The Carolina parakeet, the only parrot species native to the U.S., went extinct in 1918 when the last bird died at the Cincinnati Zoo. Now, a little more than 100 years later, researchers have determined that humans were entirely to blame.


How? Researchers sequenced the bird's genome and found none of the signs of inbreeding or population decline that usually mark an endangered species' slow road to extinction.

"As such, our results suggest its extinction was an abrupt process and thus likely solely attributable to human causes," the study, published in Current Biology Thursday, concluded.

The Carolina parakeet once ranged from New England in the North to Florida in the South to Colorado in the West, according to National Geographic. But the bright green, orange and yellow birds were killed by farmers as pests and by hunters for their feathers, which were popular in hats. They also tended to flock around dead comrades, making them more vulnerable to attack. Tree clearing for agriculture also threatened their survival. As early as 1832, American naturalist John James Audubon observed that their numbers were decreasing, BBC News explained.

But until now scientists were unsure that humans were entirely to blame for their extinction, National Geographic noted. They thought natural disasters could have divided populations from each other, or that diseases caught from poultry could have played a role.

Scientists put those suspicions to rest by sequencing the genome of a preserved parakeet found in a private collection in Ginora, Spain. To fill in the gaps, they first sequenced the genome of the South American sun parakeet, a close living relative.

Study co-author Carles Lalueza-Fox, from Barcelona's Pompeu Fabra University (UPF), explained to BBC News why the results pointed to human-caused extinction. If a population shrinks and declines slowly, the chromosomes from the specimen's mother and father will be very similar or identical. The chromosomes of the Carolina parakeet specimen were distinct, suggesting it belonged to a larger population.

"The inference is that this bird was not subjected to a very long demographic decline for thousands of years, it was something very quick," Lalueza-Fox told BBC News.

Further, the scientists found no evidence of any poultry disease in the genome, National Geographic reported.

The study was the work of the Globe Institute at the University of Copenhagen and the Institute of Evolutionary Biology (IBE), which brings together UPF and the Spanish National Research Council (CSIC) in Barcelona, according to a UPF press release published by Phys.org.

The study was partly conducted because there is interest in seeing if it would be possible to bring the Carolina parakeet back from extinction, the IBE Twitter feed noted.

But Lalueza-Fox said the results showed how hard this would be.

"Despite the Carolina parakeet appears in all de-extinction lists, we found hundreds of genetic changes predicted to be deleterious with the closest living relative, the sun parakeet, which indicates the enormous difficulties of undertaking such enterprises," Lalueza-Fox said in the press release.

However, the research could help save endangered species today. Because the species went extinct during a period of rapid industrialization, understanding the process could help us save species threatened by contemporary urbanization.

"We need to get at which human activity was largely to blame and how we can prevent the same thing happening to others," Cary Institute of Ecosystem Studies ecologist Kevin Burgio, who was not involved in the study, told National Geographic.

EcoWatch Daily Newsletter

Pexels

By Charli Shield

At unsettling times like the coronavirus outbreak, it might feel like things are very much out of your control. Most routines have been thrown into disarray and the future, as far as the experts tell us, is far from certain.

Read More Show Less
Pie Ranch in San Mateo, California, is a highly diverse farm that has both organic and food justice certification. Katie Greaney

By Elizabeth Henderson

Farmworkers, farmers and their organizations around the country have been singing the same tune for years on the urgent need for immigration reform. That harmony turns to discord as soon as you get down to details on how to get it done, what to include and what compromises you are willing to make. Case in point: the Farm Workforce Modernization Act (H.R. 5038), which passed in the House of Representatives on Dec. 11, 2019, by a vote of 260-165. The Senate received the bill the next day and referred it to the Committee on the Judiciary, where it remains. Two hundred and fifty agriculture and labor groups signed on to the United Farm Workers' (UFW) call for support for H.R. 5038. UFW President Arturo Rodriguez rejoiced:

Read More Show Less
Sponsored
A woman walks to her train in Grand Central Terminal as New York City attempts to slow down the spread of coronavirus through social distancing on March 27. John Lamparski / Getty Images

By Julia Conley

A council representing more than 800,000 doctors across the U.S. signed a letter Friday imploring President Donald Trump to reverse his call for businesses to reopen by April 12, warning that the president's flouting of the guidance of public health experts could jeopardize the health of millions of Americans and throw hospitals into even more chaos as they fight the coronavirus pandemic.

Read More Show Less
polaristest / Flickr / CC BY-NC-ND 2.0

By Melissa Kravitz Hoeffner

Over six gallons of water are required to produce one gallon of wine. "Irrigation, sprays, and frost protection all [used in winemaking] require a lot of water," explained winemaker and sommelier Keith Wallace, who's also a professor and the founder of the Wine School of Philadelphia, the largest independent wine school in the U.S. And water waste is just the start of the climate-ruining inefficiencies commonplace in the wine industry. Sustainably speaking, climate change could be problematic for your favorite glass of wine.

Read More Show Less
Pixabay

By Rachael Link, MS, RD

Spinach is a true nutritional powerhouse, as it's rich in vitamins, minerals, and antioxidants.

Read More Show Less