The Chihuahuan Desert grasslands of northern Mexico and the southwestern United States are the principal wintering grounds for 90% of grassland bird species breeding in the western Great Plains of North America. Species such as Baird’s Sparrows, Chestnut-collared Longspurs and Sprague’s Pipits, which rely on this region during the winter, have declined by upwards of 80% since the 1960s. Results from Rocky Mountain Bird Observatory and cooperators’ research, published in February in the journal Biological Conservation, shed light as to why these birds are declining and emphasize that unless immediate action is taken, forecasts are dire.
The field season is under way in northern Mexico, where RMBO and partners are studying the winter survival and habitat use of Baird’s and Grasshopper Sparrows in the Chihuahuan Desert grasslands. Writing from Chihuahua, biologist Erin Strasser provides an update on capturing and tracking sparrows, insights gained so far this season and stunning photos from the field.
Grassland birds are declining faster than any other group of North American birds. The key to reversing these declines may lie on their wintering grounds in northern Mexico. Writing from Chihuahua, biologist Erin Strasser provides a preview of RMBO’s second season studying the overwintering ecology of Baird’s and Grasshopper Sparrows in the Mexican grasslands.
Rocky Mountain Bird Observatory had a productive and successful first field season studying Baird’s and Grasshopper Sparrow overwintering survival and habitat use in the Chihuahuan Desert grasslands of northern Mexico. From early November to early March, RMBO gathered a massive amount of novel and informative data on these two species at Reserva Ecológica El Uno near Janos, Chihuahua, Mexico.
A herd of bison grazes the golden-hued grasslands, Ferruginous Hawks patrol the skies for jackrabbits, and packs of coyotes yip back and forth across the prairie dog colonies. Thus was our welcoming as we arrived at Reserva Ecológica El Uno near Janos, Chihuahua, Mexico on the afternoon of Nov. 11. Our mission: Catch and place radio transmitters on Baird’s and Grasshopper Sparrows this winter to track them and study their habitat use and overwinter survival.
RMBO has released Wintering Grassland Bird Densities in Chihuahuan Desert Grassland Priority Conservation Areas, 2007-2011documenting bird abundance, distribution, habitat use and other information collected over five years in three U.S. and six Mexican states.