COLORADO PARKS & WILDLIFE The Story of Colorado’s Mule Deer PAST . . . PRESENT . . . FUTURE? © WAYNE D. LEWIS/CPW D. WAYNE © © CPW © © CPW © © CPW © © WAYNE D. LEWIS/CPW D. WAYNE © cpw.state.co.us human population was hungry for meat, Market hunting at the end of the What’s Happening To and commercial hunters began killing large 19th Century led to massive popu- numbers of big-game animals to meet mar- lation declines of mule deer. Our Mule Deer? ket demand. By the beginning of the 20th century, Colorado’s vast herds of deer and They’ve got big ears. They bound around elk were no more. on spring-loaded legs. Tourists love to see them. Hunters enjoy the sport they offer “The time was in Colorado when deer were and the meat they provide for the table. so plentiful that it seemed almost impossi- They live throughout Colorado and are a ble for them to be killed off; but with the in- valuable part of Colorado’s wildlife heritage. crease in population; and the more general They’re mule deer, the iconic deer of the settling-up of our state, the deer have been American West. But a declining trend in killed; until now they must be carefully population numbers of Colorado “muleys” protected, or they will meet the fate of the in the western part of the state has biolo- buffalo and become entirely extinct.” gists, hunters, wildlife watchers and the — Colorado Game and Fish Commis- general public asking, “What’s happening sioner James Shinn, 1911 to our mule deer, and how can we work to-

gether to have sustainable deer populations CPW © “The wilderness has been conquered and into the future?” Roller Coaster Ride all the game killed off.” The Deer With the Big Ears Fluctuations in mule deer populations are — Theodore Roosevelt, 1899 nothing new. Like a roller coaster, popula- Muleys . . . even the nickname conveys the Population Boom affection westerners have for this long-eared tions constantly travel upward, then down, Colorado’s rangelands quickly became the animal. Mule deer live throughout Colo- then up again over time, tugged along in a basis of a booming livestock industry. By rado, from the Eastern Plains to western giant game of crack-the-whip by a variety the end of the 20th century, a million sheep canyonlands. They inhabit grasslands, of causes. Natural factors like drought and hundreds of thousands of cattle grazed suburban open spaces, mountain forests, and severe winters have always impacted on private and public rangeland. even the alpine tundra. But shrublands of wildlife populations. But with the beginning big sagebrush, mountain-mahogany, bit- of European settlement in the 1850s, many Over decades, overgrazing by sheep and terbrush and other woody vegetation give of the factors “cracking the whip” have been cattle destroyed much of the native grasses them the best combination of what they human caused. that kept woody shrubs from spreading. need — leaves, stems, and young twigs to Settlers and ranchers also did their best to browse for food, and cover for security. Meat For Market eliminate wildfires. This unwittingly favored Mule deer are found in the greatest num- When gold was discovered in 1859, the growth of shrubs and reduced native bers in western Colorado shrublands. hundreds of thousands of eager pros- pectors flooded into Colorado. Settlers grasses. While they seem to be everywhere, the and ranchers followed and Big sagebrush, bitterbrush and other large number of mule deer in Colorado has been towns sprang up across the shrubs — favored foods for mule deer going down in recent decades. A 2012 landscape. This booming — spread across rangelands. Mule deer Colorado Parks and Wildlife (CPW) populations began to recover from the population estimate of 408,000 decimation of market hunting. muleys statewide is 22 percent John Torres conducts to 29 percent below the goal of a range survey near At the same time, wildlife manage- 525,000 to 575,000 animals. Craig in 1970. ment and conservation efforts began. In 1903,the first licenses were issued to regulate hunting and commer- cial outfitting. Efforts to control or eradicate predators, such as wolves, in- creased. In the winter of 1921-1922, the Mule deer fawns showcase first large-scale winter feeding campaign the species’s big “mule” ears. began to prevent the loss of thousands of deer and elk from severe winter condi- tions. In 1932, the Pittman-Robertson Federal Aid in Wildlife Restoration Act © CPW © © WAYNE D. LEWIS/CPW D. WAYNE © was passed, providing the first federal fund- choice feeding areas. The impact of elk on ing for research on the nutritional require- mule deer populations hasn’t been rigorous- ments of mule deer. ly studied, but might warrant a closer look.

By 1950, there were more deer in Colo- What Can We Do? rado than at any previous time in the 20th Mule deer management must be done century. Fifty years earlier, there had been for the long term, not as a quick fix. It is too few to hunt. In 1963, a record number unlikely the population highs of the 20th of deer, more than 147,000, were taken by century will be seen again. For populations hunters. to be sustainable, they must be managed for the numbers of animals the habitat can The population roller coaster was at the top support over time. Exactly how to do that is of the hill. constantly evolving.

Continued Challenges The first step is gathering reliable informa- In the latter half of the 20th century, devel- tion, such as how many deer inhabit Colo- opment of ski areas and a growing interest rado. But how do you count large, mobile in outdoor recreation brought thousands Ear tagging at Little wildlife? CPW monitors herds in five Inten- of new enthusiasts into the Colorado Hills Experimental sive Mule Deer Monitoring Areas — in the outdoors. Colorado’s population grew and Farm, around 1969. Piceance Basin, Middle Park, Uncompahgre thousands of acres of wildlife habitat were CPW © Plateau, Gunnison and Cripple Creek — developed for residential housing. Oil feed on. This allowed cheatgrass and other that best represent mule deer herds west of and gas development also boomed. These noxious weeds to establish on rangelands, Interstate 25. By estimating the survival of activities continue to displace wildlife and transforming sagebrush and mountain shrub adult does year-to-year in these areas, and fragment and degrade habitat, or convert it habitats to grasslands with invasive plant how many fawns survive winter, biologists to human use. species that offer less nutrition. Elsewhere, can better understand and estimate overall fire suppression has allowed tree cover to mule deer populations. Severe winters also impact mule deer increase too much, crowding out the shrubs numbers. When the effects of a severe and plants mule deer feed on. To reduce tree In addition, mule deer populations winter would be catastrophic for the deer cover and increase the plants deer feed on, throughout western Colorado are surveyed population, CPW distributes pelletized feed managers use prescribed fires or mechani- by helicopter after the hunting season to es- at feeding stations. In the winter of 1983-84, cal thinning to increase the quality of deer timate the ratios of bucks, does, and fawns. Colorado launched the largest winter feed- habitat. Sex and age ratios, harvest information, and ing program in the U.S., a $4 million opera- survival data from the intensive monitoring tion. In spite of this effort, fawn mortality Disease and accidental deaths also affect areas are then used to estimate population that winter was as much as 95 percent. mule deer populations. Thousands of deer size. Comparing population estimates with are killed each year from collisions with the goals in CPW’s Herd Management Plan In 1989, the mule deer population was automobiles. Outbreaks estimated at an impressive 600,000 animals, of hemorrhagic disease, a up from an estimated 6,000 deer at the virus transmitted by biting beginning of the 20th century. In spite of midges, can drastically this, concerns about a mule deer decline affect deer populations. had been raised by the public and wildlife Losses as high as 50 percent managers beginning in the early 1970s. By of an affected popula- 1999, these concerns were growing. tion have been estimated. Chronic wasting disease is Although sometimes beneficial to deer, in also a concern. recent decades, wildfires on some low-ele- vation mule deer winter range have burned Could resurging elk popu- off much of the woody shrubs mule deer lations be hurting mule Wildfires and deer? Evidence suggests controlled there might be a connec- burns can Mule deer buck tion. As elk populations actually be © CPW © found frozen in have gone up in recent de- beneficial to Gunnison River. cades, mule deer numbers deer habitat. have gone down. Elk are larger and can better sur- vive winter. Their calves are less vulnerable to predation than deer fawns, and elk cows defend their young more aggressively than does. Elk are less selective in their food, and may displace mule deer from © WAYNE D. LEWIS/CPW D. WAYNE © Because hunting is a long-standing tradi- tion in Colorado, and important economi- cally for many communities and families, public input is an important component of CPW’s mule deer management planning process, which takes into account not just biology but social and cultural factors.

Colorado’s Mule Deer: Not Out of the Woods Yet Coloradans love their long-eared muleys, but decisions on their management can’t be based solely on tradition, science or social trends. They must incorporate all these things.

Sustaining mule deer numbers at an opti- mal level for the future lies in collaboration . . . between citizens, farmers and ranchers, government, biologists, hunters, conserva- tionists and everyone who cares about the future of Colorado wildlife. © WAYNE D. LEWIS/CPW D. WAYNE © Big sagebrush, bitterbrush and other large shrubs are the favored foods for mule deer.

helps determine ongoing management, The Colorado Wildlife Habitat Program such as how many hunting licenses to issue (CWHP) brings together private landowners, in the next season, and for what areas. local governments and conservation orga- Regulating the harvest of deer is an im- nizations to protect and enhance important portant tool. Using telephone and Internet wildlife habitat. CWHP is funded through surveys of hunters, CPW gathers informa- sales of the Colorado Wildlife Habitat Stamp, tion on numbers, locations, age and sex of which is required before purchasing a hunt- CPW works with farmers, ranchers harvested animals; state/out-of-state status ing or fishing license. Since 2006, Habitat and other landowners, land manage- of hunters; and hunter satisfaction. In 1999, Stamp funds have protected 174,000 acres of ment agencies, sportsmen’s groups CPW responded to concerns about low wildlife habitat in Colorado, including over and other organizations to enhance buck numbers and fewer fawns by elimi- 100,000 acres of big-game winter range and deer habitat. nating over-the-counter buck licenses. The migration corridors. LEWIS/CPW D. WAYNE © number of bucks to does increased dramati- cally from an average of 17 bucks to 100 CPW monitors herds in five does to 32 bucks per 100 does. Intensive Mule Deer Monitoring Areas — in the Piceance Basin, CPW also analyzes how landscape changes Middle Park, Uncompahgre Pla- between 1970 and the present might be teau, Gunnison and Cripple Creek connected to declines in deer numbers over — that best represent mule deer the past 40 years. herds west of Interstate 25. Studies done between 1999 and 2011 found that the severity of winters, and the amount of summer precipitation, were the most important influences on mule deer popula- tion growth.

Improving wildlife habitat is an ongoing goal. CPW works with farmers, ranchers and other landowners, land management agencies, sportsmen’s groups and other organizations to enhance deer habitat. COLORADO PARKS & WILDLIFE Techniques include mechanical thinning, 6060 Broadway prescribed fire, noxious weed control and Denver, CO 80216 by providing input for land management (303) 297-1192 statewide. cpw.state.co.us version 2/Sept. 2017 © WAYNE D. LEWIS/CPW D. WAYNE ©