SUMMATION OF GEOGRAPHICAL DISTRIBUTION 39 ECOLOGY 41 Habitats 41 Trails 41 Influence of weather on distribution 43 Influence of food supply on distribution 44 Influence of insects on distribution 45 Effect of combined environmental factors on distribution 46 Relations to man 47 Ethnological material from caribou products 59 Relations to Black Bears 62 Relations to foxes 62 Relations to Wolves 63 Relations to birds of prey 67 Relations to miscellaneous animals 69 Relations to flies 69 Ectoparasites 73 Relations to Reindeer 74 NUMERICAL STATUS 78 GENERAL HABITS 79 Daily periods of activity and rest 79 Organization of herds 81 Disposition 83 Senses 86 Gaits 86 Tracks 87 Swimming 88 Shaking off moisture and insects 95 Signaling 96 Food 98 Scatology 99 Voice 100 Reproduction 101 Fawns 103 Growth 104 Antlers 105 Rubbing trees 108