Bird’s-eye views of the globe highlight avian trouble spots

Recent maps reveal trouble spots for the world’s imperiled birds.

In South America, two swaths light up with unusually high concentrations of birds at risk of extinction: southeastern Brazil plus a strip along the northwest coast of the continent, say nine eminent biologists in a status review of biodiversity in the May 30 Science.

Warmer colors indicate a greater number of birds classified as vulnerable or worse by the International Union for Conservation of Nature. This pattern contrasts with a map showing where the most bird species live. Species remaining to be discovered and eventually added to the map are likely to be vulnerable ones.

The authors’ analysis suggests that newly discovered birds are more likely than older, well-known species to be naturally rare and have small ranges. Both are disadvantages for withstanding the pressures of human activity.