Winter resource selection by female mule deer Odocoileus hemionus: functional response to spatio-temporal changes in habitat

Populations of mule deer Odocoileus hemionus have declined throughout most of their historic range in recent decades, and habitat alteration has been hypothesized as one potential cause of those declines. Consequently, understanding how patterns of behaviour change as landscapes are altered through time may provide important insights into mechanisms underlying observed demographic trends in populations of mule deer. We examined resource selection in relation to habitat change by mule deer on the Tex Creek winter range in southeastern Idaho, USA. We created a GIS-based map of habitats available to mule deer during two time periods, past (1985-1986) and current (2007-2009), to document changes in habitat over time. We then modeled past and current patterns of resource selection by mule deer based on locations obtained from visual observation, radio-telemetry and GPS collars. Abundance and distribution of juniper Juniperus spp., aspen Populus tremuloides, sagebrush steppe Artemisia spp. and riparian habitat did not change significantly between past and current time periods. In contrast, we documented an increase in grassland from 3.5 to 30.7% of our study area, and a corresponding decrease in agricultural land, which provides high-quality forage for mule deer, from 37.8 to 12.5% of our study area. Patterns of resource selection largely were similar between the two time periods. Nevertheless, mule deer significantly increased selection of agricultural fields and areas far from roads between the 1980s and 2007-2009. In addition, juniper stands were strongly selected in all years, and importance values (use × availability rescaled to 100%) for grassland and sagebrush steppe increased between past and current time periods. Our results indicated that mule deer responded behaviourally to declining availability of high-quality forage (i.e. agricultural land) by increasing selection of agricultural fields. Such functional responses in habitat selection may have important consequences for dynamics of mule deer populations, but additional research is necessary to link those responses to demography and population performance. Although juniper encroachment often is thought to have affected mule deer negatively on many summer ranges, strong selection for juniper in our study highlights the potential importance of that species on winter range, likely because it provides both thermal and hiding cover.

[1]  R. Sikes,et al.  Guidelines of the American Society of Mammalogists for the Use of Wild Mammals in Research , 2007 .

[2]  Mark A. Hurley,et al.  Spatial Distributions of Mule Deer and North American Elk: Resource Partitioning in a Sage-Steppe Environment , 2010 .

[3]  G. Mowat,et al.  Winter habitat relationships of deer and elk in the temperate interior mountains of British Columbia , 2005 .

[4]  John W. Kern,et al.  DAILY AND SEASONAL MOVEMENTS AND HABITAT USE BY FEMALE ROCKY MOUNTAIN ELK AND MULE DEER , 2003 .

[5]  B. Johnson,et al.  TEMPOROSPATIAL DISTRIBUTIONS OF ELK, MULE DEER, AND CATTLE: RESOURCE PARTITIONING AND COMPETITIVE DISPLACEMENT , 2002 .

[6]  R. Tausch,et al.  Age Structure and Expansion of Piñon-Juniper Woodlands: A Regional Perspective in the Intermountain West , 2008 .

[7]  Terry R. Thomas.  Yearlong movements and habitat use of mule deer associated with the Willow Creek winter range in southeastern Idaho , 1987 .

[8]  R. Bowyer,et al.  HABITAT SELECTION BY MULE DEER: FORAGE BENEFITS OR RISK OF PREDATION? , 2004 .

[9]  J. Malechek,et al.  Forage Selection by Mule Deer on Winter Range Grazed by Sheep in Spring , 1979 .

[10]  S. Mccorquodale.  LANDSCAPE AND PATCH SCALE HABITAT USE BY MIGRATORY BLACK-TAILED DEER IN THE KLICKITAT BASIN OF WASHINGTON , 1999 .

[11]  J. Kie,et al.  Herbivore Optimization by North American Elk: Consequences for Theory and Management , 2006 .

[12]  G. White,et al.  Mule deer survival in Colorado, Idaho, and Montana , 1999 .

[13]  K. Harper,et al.  Factors influencing productivity of two mule deer herds in Utah. , 1978 .

[14]  B. Manly,et al.  Resource selection by animals: statistical design and analysis for field studies. , 1994 .

[15]  Andrew E. Derocher,et al.  Functional responses in polar bear habitat selection , 2003 .

[16]  T. Stephenson,et al.  Timing of seasonal migration in mule deer: effects of climate, plant phenology, and life‐history characteristics , 2011 .

[17]  Hall Sawyer,et al.  Mule deer and pronghorn migration in western Wyoming , 2005 .

[18]  Douglas H. Johnson.  THE COMPARISON OF USAGE AND AVAILABILITY MEASUREMENTS FOR EVALUATING RESOURCE PREFERENCE , 1980 .

[19]  D. Whittaker,et al.  EFFECT OF COYOTE PREDATION ON EARLY FAWN SURVIVAL IN SYMPATRIC DEER SPECIES , 1999 .

[20]  B. Worton.  Kernel methods for estimating the utilization distribution in home-range studies , 1989 .

[21]  Ryan M. Nielson,et al.  Influence of Well Pad Activity on Winter Habitat Selection Patterns of Mule Deer , 2009 .

[22]  Michael L. Morrison,et al.  A Proposed Research Emphasis to Overcome the Limits of Wildlife-Habitat Relationship Studies , 2001 .

[23]  L. Graumlich.  Precipitation Variation in the Pacific Northwest (1675–1975) as Reconstructed from Tree Rings , 1987 .

[24]  K. Parker,et al.  Estimates of Critical Thermal Environments for Mule Deer , 1990 .

[25]  Kim E. Ragotzkie,et al.  Desert mule deer use of grazed and ungrazed habitats. , 1991 .

[26]  John G. Kie,et al.  Habitat selection and survival of mule deer : Tradeoffs associated with migration , 1997 .

[27]  David R. Anderson,et al.  Model selection and multimodel inference : a practical information-theoretic approach , 2003 .

[28]  James A. Young,et al.  A viewpoint: rangeland health and mule deer habitat. , 1997 .

[29]  C. D. Kemp,et al.  Density Estimation for Statistics and Data Analysis , 1987 .

[30]  Michael J. Wisdom,et al.  Resource Selection and Spatial Separation of Mule Deer and Elk during Spring , 2000 .

[31]  J. Kie,et al.  Habitat Selection by Neonatal Black-Tailed Deer: Climate, Forage, or Risk of Predation? , 1998 .

[32]  Jeffrey L. Beck,et al.  Diet Composition, Forage Selection, and Potential for Forage Competition Among Elk, Deer, and Livestock on Aspen–Sagebrush Summer Range , 2005 .

[33]  J. Kie,et al.  Foraging behavior by mule deer : the influence of cattle grazing , 1991 .

[34]  Nevelyn E. Headrick.  Mule Deer Conservation: Issues and Management Strategies , 2003 .

[35]  Mark S. Boyce,et al.  Scale for resource selection functions , 2006 .

[36]  W. Elmore,et al.  Wildlife habitats in managed rangelands—the Great Basin of southeastern Oregon: mule deer. , 1982 .

[37]  G. White,et al.  Effect of adult sex ratio on mule deer and elk productivity in colorado , 2001 .

[38]  V. Lamarche,et al.  Paleoclimatic Inferences from Long Tree-Ring Records , 1974, Science.

[39]  J. Kie,et al.  THERMAL LANDSCAPES AND RESOURCE SELECTION BY BLACK-TAILED DEER: IMPLICATIONS FOR LARGE HERBIVORES , 2009 .

[40]  Fred Lindzey,et al.  Winter habitat-use pattern of elk, mule deer, and moose in southwestern Wyoming , 1987 .

[41]  Lee A. Vierling,et al.  Effects of habitat on GPS collar performance: using data screening to reduce location error , 2007 .

[42]  D. Hosmer,et al.  Applied Logistic Regression , 1991 .

[43]  J. Bailey,et al.  Distribution of Mule Deer and Elk in Relation to Roads , 1979 .

[44]  Atle Mysterud,et al.  Temporal scales, trade-offs, and functional responses in red deer habitat selection. , 2009, Ecology.

[45]  E. O. Garton,et al.  MULE DEER SURVIVAL AMONG ADJACENT POPULATIONS IN SOUTHWEST IDAHO , 2005 .