HABITAT SELECTION AND SIGHTABILITY OF MOOSE IN SOUTHEAST ALASKA A THESIS Presented to the Faculty of the University of Alaska Fairbanks in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE By Susan A. Oehlers, B.S. Fairbanks, Alaska August 2007 iii Abstract We examined the role of scale and sex in habitat selection by radiocollared Alaskan moose (Alces alces gigas) on the Yakutat forelands, Alaska, USA. We used conditional logistic regression to quantify differences in habitats selected between sexes and seasons at 3 different spatial scales (250, 500, and 1000 m), and multi-response permutation procedure (MRPP) to test for differences in spatial distribution between the sexes. Sexes selected for habitats similarly during the mating season, when sexes generally were aggregated, whereas sexes exhibited differential habitat selection during the non-mating season when sexes were segregated. Both sexes selected habitats at the 1000 m scale; models limited to 2 variables, however, demonstrated differences in scales selected by the sexes. There was a significant difference between male and female spatial distribution during all months (MRPP; P <0.0001), and distances between individuals were higher in females than in males, particularly during spring. We also developed a sightability model for moose with logistic regression, and used Distance Sampling to develop sightability correction factors (SCFs). Application of the sightability model and Distance Sampling to a sample data set of 600 moose yielded population estimates of 652–1124 ( x = 755) and 858–1062 ( x = 954) moose, respectively. iv Table of Contents Page Signature Page ..................................................................................................................... i Title page ............................................................................................................................ ii Abstract.............................................................................................................................iii Table of Contents ............................................................................................................. iv List of Figures.................................................................................................................. vii List of Tables .................................................................................................................... ix List of Appendices............................................................................................................ xi Acknowledgments ..........................................................................................................xiii Introduction....................................................................................................................... 1 Literature Cited ................................................................................................................ 5 Chapter 1. Sex and Scale: Implications for Habitat Selection in Moose ................... 9 Abstract.............................................................................................................................. 9 Introduction................................................................................................................. 11 Materials and Methods............................................................................................... 16 Study site.................................................................................................................. 16 Capture and handling............................................................................................. 19 Data collection ......................................................................................................... 20 Landscape classification ......................................................................................... 20 GPS collar testing.................................................................................................... 22 GPS data .................................................................................................................. 23 v Statistical analyses .................................................................................................. 25 Results .......................................................................................................................... 31 Sample size and physical data................................................................................ 31 Home range.............................................................................................................. 32 Spatial distribution ................................................................................................. 32 Habitat selection...................................................................................................... 33 Seasonal habitat selection....................................................................................... 36 Habitat selection by scale ....................................................................................... 38 Model accuracy ....................................................................................................... 39 Discussion..................................................................................................................... 40 GPS and GIS ........................................................................................................... 40 Spatial distribution ................................................................................................. 40 Habitat selection...................................................................................................... 42 Conclusions.................................................................................................................. 58 Acknowledgments ....................................................................................................... 59 Literature cited............................................................................................................ 87 Chapter 2. Moose Detectability Results From Sightability Trials Employing Telemetry And Aerial Surveys .................................................................................... 129 Abstract...................................................................................................................... 129 Introduction............................................................................................................... 131 Study Area ................................................................................................................. 136 Methods...................................................................................................................... 138 vi Capture and Handling.......................................................................................... 138 Sightability Trials.................................................................................................. 139 Statistical Analyses................................................................................................ 143 Results ........................................................................................................................ 146 Sample Size and Descriptive Statistics................................................................ 146 Logistic Regression ............................................................................................... 148 Distance analysis ................................................................................................... 150 Discussion................................................................................................................... 151 Management Implications........................................................................................ 159 Acknowledgments ..................................................................................................... 160 Literature Cited ........................................................................................................ 178 General Conclusions ..................................................................................................... 189 Literature Cited .................................................................................................... 194 vii List of Figures Page Figure 1.1 Study area for studying habitat selection by GPS telemetry ............................61 Figure 1.2 Winter 95% fixed-kernel home ranges.............................................................62 Figure 1.3 Multi-response permutation procedure delta (within-group) values................63 Figure 1.4 Mean ± SE values of variables analyzed for habitat selection by adult female moose .................................................................................................................................64 Figure 1.5 Mean ± SE values of variables analyzed for habitat selection by adult male moose .................................................................................................................................65 Figure 1.6 Aspect used by adult female moose .................................................................66 Figure 1.7 Aspect used by adult male moose ....................................................................67 Figure 1.8 Relative probability of occurrence predicted for adult moose on the Yakutat forelands, Alaska, USA,