Bird species rely on stable patterns of habitat, food, and weather that were formed thousands of years ago.

But these patterns are being disrupted as the global environment undergoes dramatic changes and birds are being threatened as a result, according to a new study by Bird Life.

One in eight, or 1,469, bird species are now threatened with extinction, and more than 40% of species have declining populations, the study found.

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“The data are unequivocal,” Tris Allinson, BirdLife’s senior global science officer, said in a press release.

“We are undergoing a steady and continuing deterioration in the status of the world’s birds,” she continued. “The threats driving the avian extinction crisis are many and varied, but invariably of humanity’s making.”

Birds as varied as vultures, puffins, cranes, penguins, and parrots are all declining and could meet the same fate as the infamous carrier pigeon, which was rapidly pushed to extinction in 1914.

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The report found that agricultural expansion is the leading threat against birds, with 74% of threatened species being affected by agriculture.

Over the past 300 years, agriculture has increased six-fold around the world, covering more than 38% of all land surface, the report notes.

This expansion has caused deforestation, destroyed habitats, drained marshlands, and filled landscapes with toxic pesticides.

“The conversion of natural habitats to farmland is now occurring most rapidly in tropical regions—driven by global demand for commodities such as coffee, cocoa, sugar, palm oil and soya,” the report notes.

Other primary threats facing birds include logging, invasive species, hunting, residential and commercial development, and fire.

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Deforestation, in particular, has had a devastating effect on birds because so many species live in rainforests.

“Nearly two-thirds of bird species are found in forests, mainly in the tropics, and many can live nowhere else,” the authors of the report wrote. “Yet more than seven million hectares of forest are destroyed each year, driven by global demand for timber, paper and land for commodity crops and biofuels.”

While these threats have only been increasing in recent years, the report identifies several ways in which they can be mitigated and bird species can be rescued.

In fact, countless bird populations have recovered due to targeted interventions, according to the report.

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To spread this recovery more broadly, habitats have to be restored around the world by ending deforestation, repairing coastal saltpans, and allowing landscapes to return to wild states.

Next, parks and landscapes shielded from exploitation need to be expanded so that birds can have vast spaces where threats are minimal.

These efforts are not just about placating bird enthusiasts who camp out in swamps with binoculars.

They’re fundamentally about saving a group of animals that speaks to the broader health of the planet. If birds are protected, then much larger aspects of wildlife can be protected, too.

By improving agricultural practices, soil around the world can be rehabilitated. By reversing deforestation, mammal and insect species can be protected. By curbing greenhouse gas emissions, ice caps can stay icy.

“Birds are more popular and better studied than any other comparable group and are consequently an excellent means through which to take the pulse of the planet,” Allinson wrote in the report. “So, while the report focuses on birds, its conclusions are relevant to biodiversity more generally.”

Global Citizen campaigns on the United Nations’ Global Goals, which call on countries to protect biodiversity. You can take action on this issue here.