Colorado Elk Herds Declining: To etter understand the reasons for waning elk herds, let talk about emerging research into how bird reproduction rates affected by human intrusion. I believe elk herds are dealing because of unrelenting noise and expanding development of many types Colorado has a vibrant petroleum extraction industry. The horizontal drilling for and extraction of oil and gas has often overwhelmed government regulators. Some researchers are trying to keep up with how oil exploration affects wildlife. University of Colorado scientist Nathan Kleist conducted a 2010- 2014 study of the effects of oil exploitation noise influencing the health of two species of birds - the western and mountain bluebird and the ash-throated flycatcher. They analyzed the hatchling success, nestling body size, and feather length (a proxy for normal body health/growth). Blood sample analyses disclosed the birds had lower levels of the key stress hormone corticosterone in areas where noise was historically unusually elevated. “You might think this means they [birds} are not stressed,” said coauthor Christopher Lowrey, a stress physiologist at CU’s Denver Department of Integrative Physiology. “But when organisms are under chronic stress that is inescapable for long periods of time, the organisms adapt to dial down the stress response systems. You might think of this as making the best out of a sad situation, but there are negative outcomes associated with this.” Humans also have negative, long-term effects of unusual stress. Post-Traumatic Stress Syndrome, Post- Partum stress of mothers, chronic fatigue syndrome, fibromyalgia and hypothyroidism are human responses to unrelenting stress(es). Epigenetic frontier researchers disclose these stress reactions can be biogenetically encoded to affect problems in future generations. [See deer avoid nonexistent fences link]. Let’s look at the observation’s of bluebird and flycatchers. Nathan Kleist and other researchers noticed historically abnormal oil and gas drilling noise affected the health of hatchlings. Their feather growth was reduced, as was their body size. Offspring were less equipped to survive. A study conclusion was that regions of loudest machinery noise was birds could not hear predator sounds as well, and survival declined. Parenting birds were overpowered in communicating, and this resulted in reduced parental efficacy for raising young; more young died. Lowrey said, “It is easy to kind of accept human-made noise is just a part of our modern environment, and that’s just the way it is. But is that desirable? This study would suggest it is not.” Hernandez – Denver Post – January 13, 2018 Eagle Valley Elk Herd Declines 50% - Or More: In ten years, the number of elk in Colorado’s prime elk area declined to half from Vail to Glenwood Springs – a short time for such a catastrophic change. CPW’s Craig Westcoat said “We are not seeing the animals migrate to another area or permanently move somewhere else. They are just dead and gone.” Aerial surveys and computer modeling disclosed the 2002 resident elk population of 10,600 declined in only fourteen years to 6,554 in 2016. The ominous data showed that the elk calving decreased from 50/100 to 30/100 cows. The threshhold for a stable herd is 34 to 35 calves per 100 cows. CPW’s wildlife manager Bill Andree said, “There is no one individual reason for this population decline.” While there was drought and predator pressure, the biggest contributor was disruptive intrusion of recreationists. It is increasingly difficult for animals to find respite from humans. D. Post, Kyle 19, 2018 p7a Flat Tops Habitat Loss : I predicted in my 2013 book that motorized recreationists were overloading the southern Flat Tops north of the Eagle Valley. It is becoming increasingly difficult for animals to find sanctuary from human intrusion throughout the year. This writer has witnessed the southern Flat Tops being inundated by after work and weekend joy riders exploring 4WD enthusiasts, and roving ATV advocates probing the more remote areas. This is occurring because of the Eagle-Gypsum-Glenwood Springs very rapid, rocketing home and business development occured during the past decade. The constant travel of ATVs, dune buggies, dirt bikes and “souped up” trucks create an intrusive noise far away from roads. The bourgeoning towns of Eagle and Gypsum have also experienced a cultural change. Many recent residents regard loud mufflered vehicles as a sign of prestige, while others use (of necessity?) poorly maintained noisy rattling vehicles. The stylish gnarly tires used on gravel roads emit a low frequency, far-traveling sounds. Add to this the current rage to go sport shooting with guns, especially high capacity ones, and you recognize the recipe for extreme animal stress with its consequences. There is no place of real quiet if you stop and listen. Humans can hear SOME of the din that continues from dawn to well into the night. However, humans cannot hear the higher and lower frequencies heard by animals. Particularly, the midrange frequencies are acoustically absorbed by the air, vegetation and topography. Very low frequencies travel much farther because they travel not through the air, but over the ground surface. These long-traveling background infrasounds are a constant irritation to animals. [see our web page on infrasounds]. So, it is no wonder to me that the elk herds are diminishing. The elk will eventually only be able to propagate in remote valleys and inaccessible wilderness areas. These too are under assault by recreationists who want to allow bicycling, hang gliding, drones, and aircraft/ballon aerial tourism. I do agree with some wildlife biologists that there is an increase in lion and bear populations which result in elk casualties. My observation is that lions have moved into higher altitudes as the climate warms. Bears seem to be restricted more because their mast food supply is still pinned to lower wetter altitudes. However, bears emerging from hibernation are villians at killing young elk calves. D. Post June 19-2018