ECOLOGY AND MANAG eme NT of Mule Deer and White-tailed Deer in Montana Ecology and Management of Mule Deer and White-tailed Deer in Montana By Richard J. Mackie, David F. Pac, Kenneth L. Hamlin, and Gary L. Dusek Montana Fish, Wildlife and Parks Wildlife Division Helena, Montana Federal Aid Project W-120-R 1998 About the Authors Richard J. Mackie is Professor Emeritus, Fish and Wildlife Program, Department of Biology, Montana State University, Bozeman. He conducted and supervised research on deer in Montana since 1960. During 1975-94, he served as coordinator of the statewide deer research program. David F. Pac is Research Biologist, Wildlife Division, Montana Fish, Wildlife and Parks, Bozeman. He studied mule deer in the Bridger Mountains since 1974 and assisted in deer studies on other areas. Kenneth L. Hamlin is Research Biologist, Wildlife Division, Montana Fish, Wildlife and Parks, Bozeman. His studies of mule deer began in 1972. During 1975-89, he conducted studies in the Missouri River Breaks, prairie-badlands, and prairie-agricultural environments. Gary L. Dusek is Research Specialist, Wildlife Division, Montana Fish, Wildlife and Parks, Bozeman. His studies of deer began in 1969. During 1980-93, he conducted studies on white-tailed deer in plains riverbottom, prairie-agricultural, and northwest montane forest environments. Illustration and Photo Credits Illustrations: Diana Haker - Cover, pps. 11, 23, 27, 34, 40, 48, 67, 71, 75, 110, 117, 136, 141, 153, and 161; Media Works - Figs. 6, 8, 27, 28, 63, 64, 65, 66, 120; Robert Neaves - p. 58 Photos: Mike Aderhold - p. 156; Kevin Berner, courtesy North Dakota Game and Fish Dept. - p. 66; Brad Compton - p. 51; Kevin Dougherty, Glendive Ranger Review - p. 8 (lower right); Gary Dusek - Fig. 5A & B, pps. 8 (upper left), 79, 130, 149, and 160; Michael Francis - Fig. 9; Ken Hamlin - Fig. 3A, pps. 1, 102, 139, and 142; Terry N. Lonner - Fig. 2A & B, pps. 7, 69, 72, 101, 105, and 107; Rick Mace - Fig. 6B; Richard Mackie - Fig. 6A, pps. 3, 25, 50, 53, 77, and 159; MFWP - Fig. 19 and p. 94; Greg Pierson - p. 125; Craig Sharpe - p. 111; Frank Siroky Jr. - p. 147; USFWS, CMR - Fig. 3B; Dan Wesen - pp. 108, 124, 131, and 150; Tom Wesen - p. 122; Gene Wolfe - p. 119; Alan Wood - Fig. 4A & B ©1998 by Montana Fish, Wildlife and Parks. All rights reserved. Designed by Media Works, Bozeman, Montana. Printed in the United States of America by Color World Printers, Bozeman, Montana, on recycled paper. Permission to reproduce or copy any portion of this bulletin is granted on condition of full credit to Montana Fish, Wildlife and Parks and the authors. Foreword Mule deer and white-tailed and methods and their applications. deer are the most widely distributed By the early 1970s, the and abundant big game mammals in environments in which deer existed Montana. Although evolved to live and were changing rapidly. Some methods thrive in broadly different environments, for deer management became outdated the two species are remarkably adaptive. and it was evident that new information Both occur in a wide variety of habitats, and approaches were necessary. In under widely fluctuating environmental 1975, an important long-term and conditions, in the presence of numerous comprehensive statewide research other wild mammals and domestic effort was initiated employing new livestock, and in the wake of extensive and emerging technologies in research human development and disturbance. on both species and across a broad Managing deer across diverse spectrum of environments in Montana. habitats and conditions in Montana Numerous ancillary studies mostly in the begins with understanding both their form of 2-year graduate student research biology and behavior. It also requires projects were conducted in association effective methods for monitoring with this long-term investigation. populations and habitats as well as for This bulletin was prepared as a manipulating deer numbers or habitat comprehensive summary of results factors to meet diverse social and from all of these studies. Like earlier economic objectives. efforts, the results lend additional Montana has a long history of insight to understanding the behavior, research to provide basic information biology and ecology of the two about deer and their habitats and to species. However, unlike earlier develop and test new and improved investigations, this investigation focused methods and criteria for deer on formulating research results into management. Studies during the 1940s management recommendations. This and ’50s provided most of the first resulted in important advances to refine scientific data, laying the foundation management strategies and practices for “deer management based on facts.” to help reduce some of the uncertainty Later, studies evaluated and refined that always exists in dealing with wildlife some of the early management concepts resources in complex environments. Donald A. Childress Administrator, Wildlife Division Montana Fish, Wildlife and Parks ECOLOGY AND MANAG eme NT OF Dee R IN MONTANA iii Preface The research presented in this of habitat is described in terms of report was funded and sponsored by juxtaposition of all components and hunters and the Federal Aid in Wildlife their use by individual deer or family Restoration program. Together they have units of deer, does habitat become provided major funding for scientific truly meaningful. Deer habitat is game management since 1941, including multidimensional and must include not numerous short-term and comprehensive only the basic components for survival, long-term field research investigations but also the social behavior of deer. as reported in this bulletin. Although Individual deer of both sexes the information presented herein is comprise the basis of a deer population. definitive, no reader should be deluded However, partitioning environments into thinking these are the “last words” into deer matriarchal units surrounded in our understanding of Montana’s two by nearby and overlapping younger most numerous large mammals. Our female units is integral to understanding knowledge can never be complete, both how populations operate and for nor will management be conducted management options of the two species. with certainty. As the environment and Male habitat selection and survival, society changes, so must our knowledge while necessary for species continuance, of deer-habitat relationships. Research is is peripheral to the importance of one means of obtaining the wherewithal matriarchal units for maintenance or to recognize and adapt management to increases in deer populations. Females those changes. establish the ultimate pattern of deer It is difficult to consider deer population distribution in both new separate from their environment. All habitats and in habitats recolonized after that deer are and all that deer do are population declines. biological and behavioral responses to Understanding population the environments in which they occur characteristics and dynamics, including as individuals, populations, and species. age structure of the female segment and This bulletin expands on that view in discussions of deer-habitat relations and patterns and rates of fawn recruitment deer population ecology. For example, and adult mortality, are crucial to the term “habitat” has been defined and managing deer at the local level. The characterized by many but understood severe reduction or loss of one cohort by few. Ask anyone what constitutes due to environmental stress often linked “deer habitat” and most will describe a with predation may not be critical to landscape that usually includes a buck the population, but severe reductions and/or a doe, and often a fawn or two in two or more consecutive cohorts can in a picturesque outdoor setting. Such set the stage for a significant population images are designed for economic decline. Conversely, good survival of markets or artwork and not scientific consecutive cohorts can foretell an understanding. Only when the “concept” imminent population increase. iv ECOLOGY AND MANAG eme NT OF Dee R IN MONTANA The probability of survival is high for almost 50 years, only in the past for most deer after achieving adulthood. decade or so have biologists begun to The majority of adult deer mortality define, quantify, and understand the can be accounted for by legal hunting, interaction of all causes of mortality in terminal wounding losses and illegal population ecology. killing. This human-induced mortality In terms of management, the replaces some natural mortality in results herein indicate that many adults, but those latter rates are existing theories or “principles of normally quite low. However, occasional deer management” are less applicable episodes of high natural mortality of than commonly believed. Traditional adult females also can trigger population interpretation of “carrying capacity” declines, especially in association with did not explain observed deer- low fawn recruitment. habitat interactions on or among the The authors have emphasized various study areas. The concept of a the importance of behavior in habitat consistent “limiting factor” influencing relationships and population dynamics. deer population dynamics statewide Social behavior, while hard to quantify could not be identified. Similarly, the and explain, is often the driving force concept of “compensatory” increases in selection of certain habitats and in fawn recruitment and deer numbers avoidance of other habitats. It also is or decreases in natural mortality