New Discovery Doubles Known Breeding Sites of Rare Sparrow

The number of known breeding sites of one of the world’s rarest birds, Worthen’s sparrow, doubled last month when researchers announced they found three new breeding localities. The globally endangered bird is endemic to the Mexican Plateau, and just a couple hundred individuals are left.

Though the Worthen's sparrows have been spotted in winter (they're sometimes tallied during the Christmas Bird Count), little is known about where they spend the summer or breed. The discovery of nests in La Carbonera and San Rafael in the state of Nuevo León, and San José del Alamito in the state of Coahuila adds to the body of scientific data indicating that the birds breed in grassland habitat. The findings highlight the need to protect that habitat, the authors say.

“Because conversion of land to agriculture continues to be a major threat to grasslands in northeastern Mexico, we recommend that conservation efforts be implemented to protect the known breeding areas of Worthen's Sparrow,” the scientists write in the Journal of Field Ornithology.

The researchers, led by Ricardo Canales-del Castillo of the Universidad Autonoma de Nuevo Leon in San Nicolas de los Garza, Mexico, found a total of 51 sparrows; as of 2008 the estimated global population as 150–200.

In terms of conserving the grasslands and shrubby habitat the birds use for breeding, one effort is already underway, the BBC reports. Coordinated by the Bird Conservation Alliance, the project aims to “purchase prime grassland habitat in the Saltillo Savannah in Mexico, which will also help preserve habitat vital for other species such as long-billed curlews, burrowing owls, mountain plovers, Sprague's pipits and Ferruginous hawks.”

Finally, a little friendly competition: How many of you have checked the Worthen's sparrow off your life list?