Range Ecology of the Porcupine Caribou Herd in Canada

Abstract

Contents Page List of tables 8 List of figures Acknowlegements 13 Executive summary 14 14 Food habits 15 Activity Cratering dynamics Late spring Characteristics of the range 15 Habitat selection 1° Food habits 16 Activity Late spring range use by bulls 17 Summer Movements and distribution 18 Insects and weather 18 Climate and weather patterns 18 Caribou response to insects 18 Activity, food and habitat • 18 Energetic implications CHAPTER 1. Introduction CHAPTER 2. Winter Terrain 28 Surficial geology Historical winter distribution Methods 34 Snow • Lichen biomass Fire history Results • Snow Lichen biomass Fire history Discussion Snow Lichen biomass Fire history Summary : Food habits Methods Results and discussion Effect of analysis at different times 48 Differences among years 48 Differences over winter 49 Seasonal diets 49 Fecal sample versus ingested diet 49 Conclusions 51 Winter activity 51 Methods 51 Results Band size 53 Activity pattern Activity budgets Proportional use of active periods 57 Discussion 57 Effect of daylength on percent lying 57 Activity budgets 59 Range quality 60 Cratering dynamics 61 Methods 61 Results and discussion Conclusions Conclusions from winter 70 CHAPTER 3. Late spring Calving grounds Porcupine caribou calving distribution Characteristics of the range 78 Methods 78 4 Rangifer, Special Issue No. 8, 1993 Weather Biomass Tussock density 79 Phenology Nutrients Results and discussion Weather • • • • 79 Phenology • Biomass 81 Tussock density 82 Nutrients Summary Habitat selection Methods Results and discussion • Food habits Methods 91 Results 91 Effect of analysis at different times 91 Differences between periods 91 Differences among years Fecal sample versus ingested diet 92 Discussion Caribou activity Methods Results Band Size Movement rate 95 Active and bedded cycles 95 Activity budgets Focal animal observations 97 Nursing Discussion Summary discussion 101 Spring range of bulls 103 107 Habitat selection •. RangiSer, Special Issue No. 8 1993 5 Food habits Summary and conclusions 109 Comparison of bulk and cows 110 CHAPTER 4. Summer Introduction 113 Study area. : 113 Summer movements 114 Historical Herd movements-1984, 1985 Methods Results Discussion Activity of dipterans in relation to date and weather 120 121 Oestrid flies 121 Result Mosquito sweeps 122 Discussion Influence of season and weather on Dipterans 123 Climate and weather patterns 126 Introduction Methods Results and discussion Data summaries Average daytime air temperatures 127 Average hourly air temperatures 127 Average hourly wind speeds 128 Correlations between permanent and temporary sites 12 Regional weather versus insects 129 Response of groups and individual caribou to insect harassment 131 133 Annoyance responses of individual caribou 133 Caribou annoyance responses in relation to date and weather 13 Relationship between position in group and insect harassment 13 Discussion Caribou group dynamics 134 Behavioral responses of individual caribou 135 Position in a group 135 Activity budgets, food and habitat selection 13...

Long-term patterns of abiotic drivers of mosquito activity within summer ranges of Northern Alaska caribou herds (1979–2009)

“…Although the MAI estimates were based on a theoretical model derived from empirical relationship between abiotic drivers of mosquito activity (Russell et al, 1993), the potential "hot spots of mosquito activity" (i.e., the areas showing highest mean MAI in the summer ranges for 1979-2009), and the potential "mosquito relief areas" (i.e., areas of low MAI that we identi ed), warrant further veri cation with eld data. Our analysis demonstrates a novel way for using climatology datasets to model long-term spatial and temporal distribution of potential mosquito harassment for caribou.…”

“…We computed a "Mosquito Activity Index (MAI)", a theoretical measure of mosquito harassment potential based on instantaneous air temperature and wind speed (Russell et al, 1993; Table 1). We applied this relationship between mosquito activity and its abiotic drivers to every grid cell in the study region using 3-hour climate data, for every day of an a priori de ned season (i.e., 1 June to 31 August) for every year over our 31-year study period to compute daily MAI for each grid.…”

“…Algorithm for computing Mosquito Activity Index (MAI) are adapted from Russell et al (1993). MAI is computed for every 3-hourly period using instantaneous surface air temperature and wind speed data from the North American Regional Reanalysis (NARR) gridded climate dataset using this algorithm.…”

“…Harassment by mosquitoes is an important factor in uencing caribou (Rangifer tarandus) activity and movement patterns during summer (Kelsall, 1968;White et al, 1975;Russell et al, 1993). Incidence of mosquito activity, and consequently harassment to caribou is spatially and temporally dynamic in response to temperature and wind ( omson, 1971;White et al, 1975;Dau, 1986).…”

Harvest impacts on caribou population dynamics in South West Greenland

“…Normally, however, female caribou have their first calf in their third summer (Dauphine, 1976, Adams & Dale, 1998, Russell & McNeil, 2005. We applied a uniform prior for age of first reproduction from one to three years capturing this range for reproductive maturity.…”