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

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


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.

A new map shows details of where South America’s imperiled bird species are concentrated. (Red areas have the most species in trouble.) CLINTON JENKINS AND FÉlIX PHARAND-DESCHENES
A red-billed curassow (Crax blumenbachii), one of the imperiled birds in the previous map’s data, ranks as endangered on the IUCN conservation group’s list. Forest loss and hunting have thinned the estimated population, in eastern Brazil, down to not quite 250 birds. TELEUKO/WIKIMEDIA COMMONS
On this map, warmer colors indicate the densest concentrations of bird species. CLINTON JENKINS AND FÉlIX PHARAND-DESCHENES
On the other end of the spectrum from endangered birds, the bay-headed tanager (Tangara gyrola), lives in a wide sweep from Venezuela south to Bolivia and east into Brazil. Trends in Amazonian forest depletion suggest this habitat will shrink, but for now, the bird is in the conservation category of least concern. FRANCESCO_VERONESI/FLICKR
Birds with small ranges (below the median, about the area of France) can suffer greatly from even small amounts of habitat loss. These birds are especially common in a strip down the western side of the continent. CLINTON JENKINS AND FÉlIX PHARAND-DESCHENES
One of the birds with a small range, the giant antpitta (Grallaria gigantea), lives in Andean forests in an area of Ecuador and southeastern Colombia that’s smaller than New Jersey. Rated as vulnerable to extinction by conservation monitors, the species’ whole estimated population doesn’t quite reach 2,500 birds. FRANCESCO_VERONESI/FLICKR

Susan Milius is the life sciences writer, covering organismal biology and evolution, and has a special passion for plants, fungi and invertebrates. She studied biology and English literature.

More Stories from Science News on Earth