U.S. DEPARTMENT OF THE INTERIORBUREAU OF LAND MANAGEMENT
As part of their Conservation and Land Management internship, two recent college graduates have been following the elusive sage-grouse (Centrocercus urophasianus). They hope to learn where the birds breed, nest and rear their broods.
Biologists Bridger Cohan, U.S. Geological Survey, and Leah Nagel, California Department of Fish and Wildlife, have been partnering with BLM staff to asses and track populations of sage-grouse in the Bi-State Distinct Population segment found in California and Nevada.
The spring surveys started off with counts of lekking males, but as some of the radio-collared females started to settle down for nesting, the season kicked into high gear. Staff from several agencies helped locate the exact shrubs that the birds were nesting under and monitoring the expectant mothers from a distance while they incubated their clutch.
After radio-telemetry indicated ‘momma grouse’ had left the area, the next step was to locate the empty nest and assess whether the clutch had been a success or fallen victim to a passing raven or other nest predator. Finally, a vegetation survey was conducted to characterize the species composition and height of plants at the nest site. By determining the specific locations and plant communities that successful mothers choose for their nests, the BLM and its partner agencies can better protect similar habitats, and hopefully boost numbers of surviving chicks.
Now, with the chicks approaching maturity it’s time for a new season of tracking, determining where the collared birds are foraging via aerial and on-the-ground radio telemetry surveys. It’s also time to collar new birds to add the body of data being collected, a process which involves spotlights, loudspeakers, nets and more than a bit of luck!
-- Bridger Cohan, Intern, Bishop Field Office (November 2013)