[hacker news] Butterflies are in decline across North America, a look at the Western Monarch]

摘要

Butterflies are in decline across North America, a look at the Western Monarch]

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本文首发于 hacker news。

阅读原文：[Butterflies are in decline across North America, a look at the Western Monarch]](https://www.smithsonianmag.com/science-nature/butterflies-are-in-dramatic-decline-across-north-america-a-close-look-at-the-western-monarch-shows-why-180988582/)