Feeding site selection by woodland caribou in north-central British Columbia

Abstract

We examined the foraging habits of the northern woodland caribou ecotype {Rangifer tarandus caribou) at the scale of the individual feeding site. Field data were collected in north-central British Columbia over two winters (Dec 1996-Apr 1998). We trailed caribou and measured vegetation characteristics (species composition and percent cover), snow conditions (depth, density, and hardness), and canopy closure at terrestrial and arboreal feeding sites, and at random sites where feeding had not occurred. Logistic regression was used to determine the attributes of feeding sites that were important to predicting fine scale habitat selection in forested and alpine areas. In the forest, caribou selected feeding sites that had a greater percent cover of Cladina mitis and Cladonia spp, lower snow depths, and a lower percentage of debris and moss. Biomass of Bryoria spp. at the 1-2 m stratum above the snow significantly contributed to predicting what trees caribou chose as arboreal feeding sites. In the alpine, caribou selected feeding sites with a greater percent cover of Cladina mitis, Cladina rangiferina, Cetraria cucullata, Cetraria nivalis, Thamnolia spp., and Stereocaulon alpinum as well as lower snow depths

Cratering behaviour and faecal C:N ratio in relation to seasonal snowpack characteristics in a High-Arctic ungulate

“…This corresponds well with previous values reported for Svalbard reindeer (Hansen et al 2010) as well as caribou in Alaska (e.g., Collins & Smith 1991) and on Coats Island, Canada (Adamczewski et al 1988). Although Pruitt (1959) and LaPerriere & Lent (1977) suggested that caribou crater in snow with thickness up to around 50-60 cm, and Johnson et al (2000) found craters up to 1 m deep, Bergerud & Nolan (1970) Table 2). In ( craters in our study were well within these limits.…”

Straight from the caribou’s (Rangifer tarandus) mouth: detailed observations of tame caribou reveal new insights into summer–autumn diets

“…Fecal microhistology (Thompson and McCourt 1981;Boertje 1984;Russell and Nixon 1990), rumen content analysis Bergerud 1972;Thomas and Edmonds 1983), and post hoc investigation of feeding craters (Thomas et al 1996;Johnson et al 2000) provide a general index of species consumed by caribou. Post-ingestion techniques, however, may not provide accurate diet composition due to their biases and limitations (Bergerud and Russell 1964).…”

Spatial factors influencing northern mountain caribou (Rangifer tarandus) survival and distribution in the Telkwa Range

“…Second, to ensure an adequate sample size, I separated location data into two broad seasons: summer and winter. Selection strategies are known to differ between early-and late-winter, and calving and rut seasons, thus, these results are generalised across several different periods (Cichowski 1989, Johnson et al 2000, Gustine et al 2006. Third, the majority of caribou between 1997-2007 were collared with VHF collars, whereas caribou between 2013-2015 were equipped with GPS collars.…”