Colorado Parks and Wildlife recently started two major big game research projects in southern Colorado aimed at understanding local elk populations and the movement patterns of Rocky Mountain bighorn sheep.
The studies are being conducted in the south San Juan Mountains on the west side of the San Luis Valley and east of Pagosa Springs.?
“These studies will help us to learn important information about the elk and bighorn populations in this area of Colorado,” said Stephanie Steinhoff, terrestrial biologist for Colorado Parks and Wildlife in the San Luis Valley.
In the elk study, 25 animals — eight bulls and 17 cows — were captured and fitted with VHF radio collars which allow biologists to track the animals’ movements from the air. The animals were captured in mid-February.
To estimate elk populations, Parks and Wildlife staffers conduct what are called “classification flights.” Biologists fly over areas where elk herds gather during winter and conduct population surveys. Then, using specialized survey techniques, harvest results, historical information, survival rates and computer analysis, biologists estimate herd composition and size.
For the study, biologists will fly over the area to locate elk via the signal from the collars. They’ll then provide the location to another crew that will fly over the area in a helicopter in a specific pattern and try to spot and count elk. That crew’s count will then be compared with the counts that are made during the regular classification flights.
“We know that on our survey flights we see only a fraction of the elk that are on the ground,” Steinhoff explained. “This study will help us learn more about what factors prevent us from seeing animals or help us to spot animals in certain types of terrain. That will help us improve our classification flights and modeling techniques,” Steinhoff said.???????????
Another objective of the study is to attempt to determine the migration patterns of elk in the area and their movement patterns during the hunting seasons. Some animals from this area move south into New Mexico during the winter, but the extent of the migration is not known.
Battery life on the radio collars is from three to five years; research will continue as long as the batteries last.
There are three distinct bighorn herds in the south San Juan mountains. The population of two of the herds is holding steady, while the third herd seems to be in decline.
In mid-February, biologists captured seven bighorns — five ewes and two rams. Each was fitted with GPS transmitter collars that allow biologists to track their movements continuously. Nasal and oral swabs and blood samples were also taken for disease testing.
Researchers want to learn how far these bighorn sheep move from year to year, if they interact with the other bighorn herds and if they venture into areas grazed by domestic sheep. Bighorns are susceptible to diseases carried by domestic sheep.
The collars will last about three years. Steinhoff hopes that more collars will be put out in the future.
“We don’t have much information about these bighorn herds, so the data we gather will be very valuable,” Steinhoff said.
To learn more about elk and Rocky Mountain bighorns, go to http://wildlife.state.co.us/WildlifeSpecies/Profiles/Pages/WildlifeProfiles.aspx.