The Chihuahuan Desert grasslands of northern Mexico and the southwestern U.S. 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 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 shares 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.
"Another nest has failed." This is the recurring news that technicians monitoring Aplomado Falcons in Chihuahua, Mexico, have reported over the last 18 years. Private Lands Wildlife Biologists Roberto Rodríguez and Pedro Calderón report from Chihuahua on last season's monitoring of this iconic grassland species and efforts to conserve its dwindling habitat there.
Grassland bird populations have declined more steeply than any other group of North American birds. Since 2006, RMBO has partnered with the City of Fort Collins to inventory and monitor grassland birds on city-owned properties near the Colorado-Wyoming border. These properties represent some of the most significant grasslands in northern Colorado and support populations of more than 20 high-priority bird species. Read about a day in the field with biologist Erin Youngberg and field technician Denis Perez surveying birds on these properties and the impact of the Mountains to Plains Region project.
Last month, Rocky Mountain Bird Observatory completed its first field season studying winter survival of Baird's and Grasshopper Sparrows in Janos, Chihuahua, Mexico. Both of these grassland species have declined between 70 and 80% since the 1960s. The key to stemming these population declines may lie on their wintering grounds in Chihuahua. Biologist Erin Strasser provides a wrap-up of the study including some interesting preliminary data.
Grassland birds are declining faster than any other group of North American birds. The key to reversing this decline may lie on their wintering grounds in Chihuahua, Mexico. Biologist Erin Strasser provides an update from Chihuahua on a study that's using radio-telemetry to better understand the overwintering ecology of Baird's and Grasshopper Sparrows.
Grady Grissom, a rancher in southeast Colorado, had a problem playa. Someone had pitted a playa lake on his ranch many decades earlier to make a deeper water pond for cattle. While good for cattle, it concentrated the water into the pit, degrading the wetland habitat for other wildlife. To solve the problem, he turned to the Stewardship team at Rocky Mountain Bird Observatory for help.
The Rocky Mountain Bird Observatory has released the first-ever conservation plan for grassland bird species that winter in the Chihuahuan Desert, with support from the Rio Grande Joint Venture and American Bird Conservancy. The plan provides a wide range of science-based information to guide everyone from on-the-ground land managers to program- and policy-level decision-makers in maintaining and improving habitat for grassland bird species of high conservation concern.
RMBO has released "Wintering Grassland Bird Densities in Chihuahuan Desert Grassland Priority Conservation Areas, 2007-2011," documenting bird abundance, distribution, habitat use and other information collected over five years in three U.S. and six Mexican states. The Chihuahuan Desert is the primary wintering grounds for more than 90 percent of western North America’s migratory grassland birds.
Rocky Mountain Bird Observatory’s International Team is monitoring and banding birds in the Chihuahuan Desert grasslands in northern Mexico with the help of 26 local field techs the team trained in early January.
As shown in the photo, field crews remove birds that are harmlessly captured in mist nets to gather data to guide conservation efforts. After receiving a USGS-issued leg band, the birds are weighed, measured and inspected before being released.
Birds including Baird’s Sparrow (pictured below), Grasshopper Sparrow, Chestnut-collared Longspur and many others winter in Mexican grasslands before returning to the Great Plains in spring. RMBO is working to conserve their disappearing winter habitat and boost their winter survival.
Photos by Arvind Panjabi, International Program Director, Rocky Mountain Bird Observatory