In western Colorado, hoofed animals and birds of prey are among those most adversely affected by human activities.

 Contrary to popular belief, most deer in Durango dislike humans.

By Christian Burney, Staff Writer for the Herald

December 30, 2022, at 2:10 PM

Mule deer search for food near 32nd Street and E. Fourth Avenue in August. During the 1960s and 1970s, western Colorado’s mule deer population was strong, but it has since declined significantly. The Uncompahgre deer population near Montrose dropped from 60,000 in the 80s to about 10,000 today. (Jerry McBride/Durango Herald)

Living among wildlife and seeing animals in their natural habitat are some of the things that draw people to Southwest Colorado as residents and tourists. However, it usually only attracts humans, as most raptors and hoofed creatures are scared off by our presence.

Mule deer numbers were high in western Colorado during the 1960s and 1970s. However, as the population increased and outdoor recreation gained in popularity, Jamin Grigg, a senior wildlife biologist with Colorado Parks and Wildlife in Southwest Colorado, noted a steady reduction in the mule deer population. According to him, there are now only 10,000 people living close to Montrose, down from 60,000 in the 1980s.

Some residents of the Durango area may find that surprising because they frequently observe hoofed creatures while out for walks, drives, and bicycle rides. They amble past communities, graze on the sides of the road, and step into traffic.

Although these town deer may seem accustomed to human presence, they are not typical of the wider mule deer population in Southwest Colorado, which typically avoids humans, pets, cars, and machinery, according to Grigg.

The majority of our deer populations have decreased over time due to human development and general habitat loss, whether it be direct habitat loss or indirect habitat loss through human disturbance, as we've observed over the course of the last 30 to 40 years, he said.

According to him, the mule deer herds in the Durango area have not been as badly affected as those in other western Colorado regions.

According to him, habitat disruption forces wildlife to expend more energy. Animals that coexist with people become more watchful and always on the alert for human activity, which reduces the amount of time they spend hunting for food.

According to Grigg, human activities will push species farther from their preferred habitats and out into other areas. Animals frequently maintain a "buffer zone" between their living areas and people.

Since people cease using those regions, a lot of habitat that would otherwise be accessible to animals ends up being sort of devoid of species, according to him.

When wildlife is forced out of its chosen habitat, one common result is that it ends up in less suited environments. Animals that run from people may wind up in places where there is less food available or where they are more vulnerable to predators.

Or, he continued, "just habitats of inferior quality where they simply aren't getting the same kind of nourishment they would get in their more preferred habitats."

In western Colorado, elk, bighorn sheep, raptors, and other birds are adversely affected by human activities.

According to him, a good deal of study on raptors and other bird species has demonstrated the detrimental effects of noise pollution and simple human activity.

Wide-ranging effects of wildlife leaving a place include plant species not being grazed any longer and predator species running out of prey. Even those who enjoy shooting or seeing wildlife can experience the negative impacts, he claimed.

Research, according to Grigg, has shown that wildlife reacts to motorised activity more so than nonmotorized activity. Human activity has an effect, whether it is noise pollution from cars on busy highways or dogs running loose.

However, it has a price for the wildlife populations that depend on that same terrain, he added. Recreation has a significant effect.

According to Colorado Parks and Wildlife, motorised vehicles erode soil, aid in the spread of noxious weeds, and disturb wildlife.

The possibility for wildlife disturbance is one of the factors that La Plata Open Space Conservancy will examine in the city of Durango's desire to change some conservation easements to permit e-bikes on specific routes in Horse Gulch.

Research studying the effects of human activity can be time-consuming and expensive, according to Amy Swarzbach, manager of Durango's natural resources.

Grigg cited a study on the sustainability of forests that was carried out in Oregon in 2003–2004 and published in the journal Forest Ecology and Management.

ATVs, horses, and mountain bikes were used in the study to apply different forms of recreation to different sections of a forest trail in order to observe how the local elk population responded.

Elk stayed away from the trail in real time during the recreation activities mentioned, at distances between 558 and 879 metres from the trail portions in use, according to the study.

According to the study, "distances between elk and recreationists were largest while operating an ATV, lowest and similar while operating a horseback, and intermediate while operating a mountain bike."

According to reports from all throughout the nation and the world, wildlife quickly occupied spaces left empty by people during the pandemic. Wildlife is once more retreating into the countryside now that the pandemic has lost some of its momentum and human activities resemble the Before Times more than they did a year ago.

According to Grigg, "the majority of animal species are fairly adaptive and versatile." "Wildlife will react to human presence or disturbance by returning to those regions fairly fast, and then when human presence or disturbance ramps up and escalates in certain locations, wildlife will respond to that by leaving those areas once more."

Colorado Parks and Wildlife, according to Grigg, encourages people to get outside, have fun, and appreciate the state's public lands and natural resources. However, it also promotes awareness of one's influence on the environment.

He said, "We encourage people to stay on trails as much as they can and not build unauthorised paths, or what we refer to as user-created trails, across the landscape that further fragment habitat. Most of all, just be conscious of your level of disruption while you're out there. When you're out there, keep your dog on a leash and try not to make too much noise.