Rocky Mountain Elk Movement Patterns Offer Suprises
SCI Foundation is proud to team up with the Rocky Mountain Elk Foundation and the Colorado Parks and Wildlife Department to uncover previously unknown information about elk habitat usage and movement patterns – information that is starting to help guide elk management decisions for the state wildlife agency. GPS collar data will be turned into ‘Heat Maps’ to provide important occupancy patterns for elk in the Gunnison Basin that will help guide management decisions for the Colorado Parks and Wildlife Department. Long distance movements recorded from the GPS collars are already showing how elk move across federal jurisdictional and game management unit boundaries more than initially thought. Local state and federal managers are taking notice of this and starting to plan differently in terms of long term elk conservation. This study will shed light on how a growing human footprint can destabilize the elk movements, and thus elk hunting opportunities.
Elk are captured with a netgun fired from a helicopter crew member. Once restrained, the elk is fit with a GPS collar and a blood sample is collected for pregnancy testing.
Over the past two decades, populations of elk, mule deer, and domestic livestock in the Gunnison Basin were intentionally reduced in response to documented stress on vegetation due to browsing. Habitat management strategies and treatments such as prescribed burns, sage brush mosaic thinning, juniper removal, and oak-brush removal have and continue to improve conditions for elk. For decades the Rocky Mountain Elk Foundation, Colorado Parks and Wildlife, and U.S. Forest Service have improved the Gunnison Basin with the help of private landowners. In addition, forest communities have been hit hard by diseases such as bark beetle infestation, which impacted 50% of the spruce-fir forest type over the past decade. These planned, and unplanned, events have set the stage for increasing the elk population numbers once again.
The drivers of elk movements are determined using statistics that analyze how the movement path may be attracted to or avoiding certain features or habitat types of the landscape.
Migration path of a single elk with a GMU 54 winter range (blue) and a GMU 63 summer range (red). Multiple migration paths were utilized by this one individual on back-to-back years.
Science-based habitat management is crucial. Learning the exact locations of movement corridors, refuge habitats (places where hunting is not allowed), and areas of attraction or avoidance will ultimately increase the effectiveness of conservation efforts. So far, preliminary data are yielding information about attraction and avoidance behavior, which is helpful in determining the effects of physical barriers such as roads, vegetation types, and human activity on elk distribution and movement. Migration timing information is extremely useful, as it can help managers identify critical periods in the annual cycle along with how different landcover types and human activity influence elk behavior. For example, the GPS data uncovered a previously unknown mid-winter migration behavior when the Gunnison Basin is hit with deep snow.
GPS collar data can be turned into heat map representations of elk utilization on the landscape. The maps will allow managers to compare habitat utilization patterns from one area (i.e., box B) to another area (i.e., box A).
A final capture and collaring of 35 cow elk is scheduled to take place over the winter of 2019. Altogether, over 200 collared elk will be monitored throughout the Gunnison Basin. A side benefit of this capture and collaring effort is pregnancy rates and cow survival information. Pregnancy rates and cow elk survival are potentially crucial factors for understanding how elk population sizes can change. While results are still preliminary, it appears the survival rate for cow elk in the Gunnison Basin, excluding hunting-related mortality, is 95.4%. A survival rate above 90% is extremely encouraging! The Gunnison basin herd is part of a long-term elk research effort and data from this study will be compared to previous studies of this elk population to see how habitat use and population dynamics are changing over time. Furthermore, this project will include outreach to inform and involve the local community in decisions about elk management. Informational presentations have been provided since December 2015 to educate like-minded organizations, conservation leaders, and outdoor recreationists.
Percentage of elk captured in GMU 54 in winter that reside outside of the GMU 54 by season. This data revealed a majority of the elk (almost 70%) using GMU 54 winter range were not available to GMU 54 hunters during the hunting season.