by Jim Parker, Hamilton
Established wildlife biology literature provides clear, quantitative metrics projecting how high-frequency aerial and motorized disturbances during calving season devastate calf survival rates.
“Quantitative Impacts of Calving-Ground Disturbance
While an isolated helicopter flight may only cause temporary flight behavior, a high frequency of overflights—such as a portion of the 2,200 flights planned by USCM over a single season—creates chronic, additive stress:
The “8-Disturbance” Threshold: Controlled studies tracking human and motorized disruptions on elk calving grounds indicate that an average of just over 8 disturbances per cow elk results in nearly 40% fewer surviving calves.
Cumulative Mortality Risk: Within these studies, each repeated high-level disturbance event carried an average of a 5% probability of calf death due to tracking exhaustion, abandonment, or separation.
Zero-Growth Ceiling: When cumulative human-induced disturbances reach an average of 10 events per cow above ambient baseline levels, monitored elk herds demonstrate no net population growth.
Predation Vulnerability: Forcing nursing cows to abandon heavy timber security cover for open slopes leaves neonates highly exposed to apex predators.
Larry Campbell says
Good find, Jim. Very relevant. Can you provide a citation for this research? We want to use it in our official comments to the Bitterroot NF.
Thanks.
Jim Parker says
Larry *Absaroka Elk Ecology Project: https://wyocoopunit.org/kauffman-lab/absaroka-elk-ecology-project/ Started in 2007 ran for 5 years as I recall.
Larry Campbell says
Thanks Jim,
I also feel for the people living along the flight path. They will pay the price of industrial noise disturbance, along with all the other costs of this mine. Some people and wildlife get the shaft even before the company leaves town with the profits and leaves the mess for taxpayers to clean up.
Jim Parker says
Yes, potential investors in the Trapper Creek Lacrophagic Meditation Institute (TCLMI) have put offers of millions of dollars in planned investments. on hold pending the outcome of the BNF decision to pursue a CE (Categorical Exception) for USCM’s “Exploration Plan Permit.” Some say compromising the tranquility of the West Fork categorically violates the 4th amendment rights of every West Forkian. Personally I have tens of thousands of $”s in speculative investments at risk because of the impunity of Mathew Andeson’s eagerness to advance his own career by proposing a CE for USMC’s Helicopter Plans.
Lee Wollrab says
Larry,
You are so right about residual impacts from extractive industry activities. and you can find additional info on disturbances to elk in this study which focused on seismic activity that demonstrated impacts from using dynamite charges and the associated animal displacement: https://upload.wikimedia.org/wikipedia/commons/6/68/Riley_Ridge_natural_gas_project%2C_Exxon_LaBarge_project_-_elk_wildlife_study_report%2C_1979-1987_%28IA_rileyridgenatura00unse_0%29.pdf
There was also USFS work done by A.L. Ward in 1984 that determined helicopter flights of <150 m elevation caused significant disruptions to elk and that citation is: Ward, A.L. 1984. The response of elk to seismograph activity in the Little Snake River Known Recoverable Coal Resource Area of Southcentral Wyoming. USDA Forest Service, Rocky Mtn. For. and Range Exp. Sta., Laramie, WY.