Tag: ecology

According to Colorado Parks & Wildlife (CPW), the state’s current mule deer population of around 450,000 is about 25{66eaadba41c14e7e553ffe7a4ee73fbae213b19704eda0514b3dd79e37e4c0c5} below their objective. Populations have been declining over the last several decades due to human population growth resulting in habitat loss and vehicle collisions, as well as other factors like climate change, malnutrition, diseases like chronic wasting disease, and predation. A recent technical report from CPW examines the causes of deer mortality, specifically to help wildlife investigators determine the difference between predation and scavenging so that accurate causes of death can be determined and addressed. Since 2016 CPW has been studying whether predator control can help boost mule deer populations. You can read more about this strategy on CPW’s website.

CPW has also recently released The Story of Colorado’s Mule Deer, a short publication for general readers that explores the history of mule deer in Colorado and some of the factors behind the recent population decline. Additional information can be found in Mule Deer in Northwest Colorado, a fact sheet from CPW summarizing their research in that part of the state.

Colorado is not the only western state to experience declining mule deer populations. In 2004 CPW (then the Colorado Division of Wildlife) teamed with other western U.S. wildlife agencies to produce the North American Mule Deer Conservation Plan, which examines a variety of population decline factors including hunting, disease, and habitat loss. A few years prior, the Division of Wildlife also submitted a report to the Colorado legislature on declining mule deer populations. Our library collection includes numerous other resources on Colorado mule deer research; search our library’s online catalog for titles.

Photo by David Hannigan courtesy Colorado Parks & Wildlife

If wolves were reintroduced in our state, would they benefit the environment or be a nuisance for ranchers? In spite of a 2016 resolution passed by Colorado Parks and Wildlife stating that wolves would not be purposefully reintroduced into the state (although those that wander here on their own won’t be removed), the debate continues.
Andrew Gulliford, a professor if history and environmental studies at Fort Lewis College, is an advocate for reintroduction and recently co-edited a book outlining the science, and the debate, behind the reintroduction of wolves. According to Gulliford’s blog posting for University Press of Colorado — the publisher of his book The Last Stand of the Pack — evidence for wolves’ contribution to the ecology of the mountain west can be seen in Yellowstone:

I teach my college students that wolves brought songbirds back to Yellowstone. I explain that wolves cut the coyote population in half. With fewer coyotes there are more small rodents and mammals aerating the soil and providing better grasses. But the largest and most dramatic effect has been the culling of the Yellowstone elk herd. By 1995 the ungulates had done severe damage to the vegetation of the park. Wolves changed that. As wolf packs began to hunt elk, the wapiti were slowed and caught in downed timber along rivers and streams. So elk learned safety meant higher sagebrush benches where they could see and smell better. With fewer elk, plants recovered. Aspen thrived. And in this new thicker forest of riverine vegetation, beaver colonies established small pools, attracting other animals, insects, and, yes, butterflies.

The State of Colorado has been studying the issue of wolf reintroduction since the 1980s. In our library you can find several reports on the topic, including

• Colorado Residents’ Attitudes and Perceptions Toward Reintroduction of the Gray Wolf (Canis lupus) into Colorado (available for checkout in hard copy)
• Findings and Recommendations for Managing Wolves That Migrate into Colorado
• Guidelines for Response to Gray Wolf Reports in Colorado
• State of Colorado Wolf Management Plan 
• Wolves: Knocking at Colorado’s Door 

The Last Stand of the Pack is also available for checkout from our library. This book was originally issued in 1929 by famed Colorado naturalist Arthur Carhart and Stanley P. Young. Gulliford and the aptly-named Tom Wolf edited the new edition for University Press of Colorado. This expanded edition contains new writings by Gulliford and other contributors who discuss the debate over reintroduction since Carhart’s time.

Have you ever seen a tropical bird flying around Denver, or caught a strange-looking fish in a mountain stream?  It happens — but it shouldn’t.  Sometimes people think releasing an animal back into the wild is a kind way of letting it go free — but this is far from the truth.  In fact, when you release a pet or laboratory specimen into the wild, it generally is either not adapted for Colorado’s climate, or never learned the necessary skills to fend for itself, or both.  Further, non-native species can harm the ecosystem in a variety of ways, from spreading foreign parasites and diseases to altering native species’ gene pools.  Therefore, if you have an unwanted animal, consider donating it to a shelter (if a pet animal) or see about donating it to a classroom or a local museum or aquarium.  You can find out more information about the hazards of releasing non-native species into the wild by visiting the Colorado Division of Wildlife’s Don’t Turn it Loose webpage.  You can also search our library’s web catalog for further information on non-native and invasive species and their effects.