How evolution contributed to the demise of the passenger pigeon

Passenger pigeons were once the most abundant bird in North America, and quite possibly the world.

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In a matter of decades, the continent’s most common bird has been completely wiped out, down to the last individual. “It’s always astounded me how something could have that large a population and entirely disappear,” says Beth Shapiro from the University of California, Santa Cruz. “Why didn’t tiny populations survive somewhere in refugia? I mean, we are pretty good at murdering things, but how did we kill every one of them?”

These questions have been debated for decades. But Shapiro and her colleagues Gemma Murray and André Soares have found some new twists to the old answers.

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[W]hy did this superspecies die out? Shapiro thinks it’s because the bird specifically evolved to live in mega-flocks, and developed adaptations that became costly when their numbers suddenly shrank at human hands.

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The fact is that “human persecution was relentless right up until the very end,” [researcher Ben Novak] says. “The rarer the birds became, harvesting efforts only grew more intense. Whatever maladaptive trade-offs may have existed for the passenger pigeon, their decline was simply too rapid for these trade-offs to show symptoms.”

The GLP aggregated and excerpted this blog/article to reflect the diversity of news, opinion, and analysis. Read full, original post: What DNA Says About the Extinction of America’s Most Common Bird