New South American Bird Species Discovered in Old Museum Drawer
A group of tropical passerines adds another member to its ranks (sort of).
For 70 years, the small brown-and-gray songbirds stashed in a drawer at the Smithsonian were a mystery that no one thought to question. Their labels read White-crowned Tapaculos, a species native to mountain forests across equatorial South America. But as scientists recently discovered, the birds are actually an entirely unique species.
This species, which is named the Perijá Tapaculo, after the mountain range in which it lives, is the newest member of a group of tropical, New World songbirds that forage for insects near the ground. It’s a perilous practice (“tapaculo” essentially means “cover your ass” in Spanish) that leaves them vulnerable to predation. A few species sport bright colors and patterns, but the majority are somber in shade—hence the ambiguity. Of the 50 known species of tapaculos, 10 have been discovered within the last 20 years, thanks to DNA analysis and vocalizations.
“The recognition of the new tapaculo in the Perijás is welcome and exciting news, but it's not totally unexpected,” says Kenn Kaufman, birding expert and Audubon field editor.
The tale of the Perijá Tapaculo’s discovery began in 1941, when ornithologist Melbourne Carriker Jr. collected 27 tapaculo specimens in the Andes on the Colombia-Venezuela border. Carriker sent his bounty to the Smithsonian, where they were recorded as White-crowned Tapaculos, and forgotten. Additional specimens from the area were added to the collection from 1951 to 1978, but they too gathered dust, Jose Avendaño and colleagues report in The Auk: Ornithological Advances.
Tapaculo research stalled during Colombia’s long-running armed conflict. But as the 21st century came about, scientists began speculating that Carriker’s specimens were part of a new subspecies or species. Finally, in 2006, Avendaño’s team gained access to the region. They spent three years gathering additional tapaculo specimens from high-elevation forests and paramos of the Serranía de Perijá. They also recorded the birds’ vocalizations and found that they differed from those of the White-crowned Tapaculo.
While examining both new and old specimens, the researchers noticed differences in physical characteristics between the two species. The Perijá Tapaculo, for example, lacks a white patch on its crown and has a darker throat. Genetic tests then confirmed that the newly collected specimens were not White-crowned Tapaculos, which live at lower elevations on the mountains. Furthermore, the genomes differed by 8 to 9 percent when compared with three species that were more closely related.
The Perijá Tapaculo remains locally common in certain parts of Colombia and Venezuela, the authors write, and likely tolerates some habitat fragmentation. Yet its small range leaves it vulnerable to extinction, as does continued habitat destruction.
In order to protect the newly discovered species and the region’s other charismatic wildlife, including more than 20 endemic bird species, Avendaño recommends the establishment of a new Colombian national park or a network of reserves that links with the Sierra de Perijá National Park in Venezuela. “In Venezuela the forests are very well preserved,” Avendaño says. “But in Colombia very few forests, very few paramos, are left.”
That’s enough motivation to find the next “new” tapaculo, before a fresh layer of dust settles on the specimens.