In 2004, amid fears of bird flu, Europe banned the import of birds from Southeast Asia. Fourteen years later, Mexico declared monk parakeets, commonly kept as pets, an invasive species. These two events are directly linked, according to a study published in PLoS ONE and reported by Allie Wilkinson for Nature. The birds are agricultural pests and flocks can cause blackouts, writes Wilkinson.

How it happened: The ban (and a 2007 law expanding it to all countries) meant European demand for exotic birds declined. In 2008, Mexico banned the capture of native birds to protect wild populations. This shifted the monk parakeet market from Europe to Mexico, which imported over a half-million of the birds.

Why it matters: "This whole invasion seems like it was just a fascinating series of unforeseen consequences of regulation changes," study author Elizabeth Hobson told Nature. It shows how policies can have impacts an ocean away.

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Mayors plan multifront attack on census shutdown

Illustration: Sarah Grillo/Axios

A growing number of mayors are banding together to fight what they consider to be an inaccurate and abruptly curtailed 2020 census, using an arsenal of legal, legislative and congressional efforts.

Why it matters: The outcome may determine whether President Trump or Joe Biden controls the redistricting process, which governs everything from congressional representation and redistricting to funding for schools and Head Start.

Updated 2 hours ago - Politics & Policy

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Illustration: Aïda Amer/Axios

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3 hours ago - Technology

Facebook Oversight Board begins hearing appeals

Illustration: Aïda Amer/Axios

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Why it matters: The board, a first-of-its-kind internet governance body, will begin hearing cases from users ahead of the U.S. election.