GRAND JUNCTION, Colo. – Wildlife managers, biologists, and researchers from Colorado Parks and Wildlife are gearing up for a busy winter season. During the winter months, CPW will be using helicopters and fixed-wing aircraft to capture and classify big game species.

Winter study work will include operations to capture, assess, and collar elk, deer and pronghorn in the Bears Ears, White River, Roaring Fork, Steamboat Springs and Middle Park areas. The elk studies are in the second year of a six-year study. CPW is capturing and collaring adult female elk and calves to assess the health of herds, estimate survival rates, identify major sources of mortality, and evaluate the influence of human recreation on elk herds. Mule deer studies are conducted annually to assess survival rates and monitor seasonal movements. A pronghorn movement study will begin in Middle Park this winter. CPW will capture and collar 40 female pronghorn to assess migration patterns, herd connectivity, and seasonal movement patterns to aid in conservation efforts.

Winter classifications – often thought of as “counts” – will take place December through February; utilizing helicopters and fixed-wing airplanes. These classification flights occur statewide. It’s not possible to count all of the deer and elk across the landscape, so CPW staff classify animals by age and sex to determine the health of the herds and to compare to objectives in herd management plans. These operations provide wildlife managers with supplementary data that is used to generate computer models which estimate wildlife population numbers and composition. Video of the classification process and more information about how classifications become part of herd management can be found in the CPW video at https://vimeo.com/203181357.

While animals are under pressure to survive harsh winter conditions, winter remains the best time of year for the success of these operations and the overall long-term health of big game herds.

“Winter is the safest time to conduct capture work,” explained Nathaniel Rayl, a big game researcher for CPW. “Cool ambient temperatures and moderate snow depths help prevent overheating and injury when capturing big game species with a helicopter.”

Area Wildlife Manager Matt Yamashita oversees the Glenwood Springs CPW operations. He adds that winter provides other advantages for wildlife flights.

“Winter weather conditions typically concentrate deer and elk and provide increased visibility for staff who are conducting the aerial surveys,” Yamashita said. “The short duration of flight disturbances is warranted by the important biological information that is gathered.”

Northwest Colorado residents are reminded that they may see low flying aircraft during these surveys. Helicopters may be operating at low elevation and spend time in one area before moving on to the next survey area. CPW contractors and staff attempt to minimize noise or disruption to residential areas.