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Birds in crisis: N America loses 3 billion birds in 50 years | News



Bird numbers in the United States and Canada have declined by an astounding 29 percent, or nearly three billion, since 1970, scientists said Thursday, saying their findings mean a widespread environmental crisis.

Pasture birds are most affected by the disappearance of meadows and prairies and the expansion of farmland, as well as the increasing use of pesticides that kill insects that affect the entire food chain.

Birds in crisis, Peter Marra, director of the Georgetown Environmental Initiative at Georgetown University and co-author of the study, published in Science magazine, was quoted by Reuters.

"Birds are the most important indicators of environmental health, the canaries in the coal mine, and they" tell us that it is urgent to take action to ensure that our planet can continue to sustain wildlife and humans. "

Forest birds and species that occur in a greater variety of habitats ̵

1; known as the genus of habitat eralists – also disappear.

"We see the same thing happening all over the world, increased agriculture and changes in land use putting pressure on these bird populations," Ken Rosenberg, an ornithologist at Cornell University and co-author of an AFP science article.

"Now we see fields from corn and other crops to the horizon, everything is repaired and mechanized, there is no place for birds, fauna and nature." [19659005] More than 90 percent of the losses are of only 12 species, including sparrows, prick , black birds and fine birds.

The numbers mirror the decline seen elsewhere, particularly in France, where the National Biodiversity Observatory estimates that there has been a 30 percent decline in grassland birds between 1989 and 2017.

Climate change

The U.S. study combines two data sources and covers 529 species.

  Museum of the Field - Chicago

Scientists at the Field Field in Chicago study a specimen of a migratory Canadian geese

The second source comes from observations from 143 radar stations to detect flocks of birds migrating at night.

Radar information was less accurate but also showed a decline of 13.6 per

cents between 2007 and 2017, with a margin of error of nine points.

While climate change has not been a major driver of population sinking, it is likely to exacerbate existing threats to bird populations, Rosenberg said.

Researchers claim that the disappearance of the passenger pigeon, once in the billions of billions at the beginning of the 20th century, shows that even abundant species can disappear

Some bird species show profits.

Waterfowl management policies, including protection and restoration of wetlands, also allow ducks and geese to thrive, they added.

"These are important examples that show that when we decide to change and actively manage the threats that birds face, we can positively impact bird populations," Rosenberg said.

Ornithologists say other factors have also contributed to the reduction in the number of birds, including cats left to roam outside and birds dying after they hit the windows of houses.

The death toll in these ways is far from insignificant: in 2014, researchers estimated between 365 million and one billion birds killed each year.


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