Nature Conservancy Magazine: Summer 2009

Go Deeper

Migratory Birds
Nearly half the world’s 10,000 bird species depend on the forests, wetlands and grasslands of the Americas — from Canada to Argentina. But habitat loss is threatening their ability to survive.

While traveling through the Bolivian Andes in 1989, the renowned ornithologist Ted Parker heard a fast and high-pitched birdsong he couldn’t place. He reported that he was certain the bird was an unidentified species — probably a flycatcher. But Parker was never able to conclusively study the bird, and his search ended when he died in a plane crash in 1993.

Now a team of researchers believes it has discovered the bird Parker described, having heard — and spotted — the species at a handful of field sites in the Bolivian and Peruvian Andes. The scientists, led by Sebastian Herzog, identified the song of a green-backed flycatcher that matches Parker’s description. They gave the bird the common name Yungas tyrannulet, after the species-rich Neotropical region where it resides: The deep valleys and mountain forests of the Yungas extend from the eastern slopes of the Andes to the western edge of the Amazon basin.

The scientists, who were sponsored in part by The Nature Conservancy, made the discovery while searching for the winter range of the rare cerulean warbler, a sky-blue songbird that nests in North American deciduous forests. Loss of breeding sites has made the cerulean warbler “the fastest declining migratory bird in eastern North America,” says David Mehlman, director of the Conservancy’s migratory bird program.

Preserving the warbler’s North American breeding areas has been a high priority. Now the Conservancy, the Forest Service and other partners have teamed up to sponsor surveys of the warbler’s distribution during its annual migration to South America, which will help guide conservation priorities in the region.

Despite the excitement of the flycatcher discovery, the initial results of the warbler survey were disappointing: The research team found the bright blue bird at only one of six field sites. However, the results do show that protecting habitat for migratory birds is likely also to benefit local nonmigratory species like the Yungas tyrannulet.

“This important discovery illustrates the connections between the Americas provided by migratory birds,” says Mehlman.

— Joshua Zaffos