Synchronicity of movement paths of barrenground c

Authors: Ingebjorg Jean Hansen Chris J Johnson H Dean Cluff

Publish Date: 2013/06/27

Volume: 36, Issue: 9, Pages: 1363-1371

PDF Link

Abstract

Movement patterns of highly mobile animals can reveal life history strategies and ecological relationships We hypothesized that wolves Canis lupus would display similar movement patterns as their prey barrenground caribou Rangifer tarandus groenlandicus and that movements of the two species would covary with season We tested for interspecific movement dynamics using animal locations from wolves and caribou monitored concurrently from midOctober to June across the Northwest Territories and Nunavut Canada We used a correlated random walk as a null model to test for pattern in movements and the bearing procedure to detect whether movements were consistently directional There was a statistical difference between the movements of caribou and wolves F 19 = 13232 P = 0005 when compared to a correlated random walk and a significant interaction effect between season and species F 19 = 6815 P = 0028 During winter the movements of caribou were strongly correlated with the 80°–90° overlineX r = 0859 SE = 0065 and 270°–280° overlineX r = 0875 SE = 0059 bearing classes suggesting an east–west movement gradient Wolf movements during winter showed large variation in direction but were generally east to west Peak mean correlation for caribou movements during spring was distinct at 40°–50° overlineX r = 0978 SE = 0006 revealing movement to the northeast calving grounds During spring wolf movements correlated with the 80°–90° overlineX r = 0861 SE = 0043 and 270°–280° overlineX r = 0850 SE = 0064 bearing class Directionality of movement suggested that during winter caribou and wolves had a similar distribution at the large spatial scales we tested During spring migration however caribou and wolves employed asynchronous movement strategies Our findings demonstrate the utility of the correlated random walk and bearing procedure for quantifying the movement patterns of cooccurring speciesWe acknowledge support of the Natural Sciences and Engineering Research Council University of Northern British Columbia and the Government of the Northwest Territories Collaring of caribou and wolves was funded by the West Kitikmeot Slave Study Society We thank K Poole C Demars and one anonymous reviewer for constructive comments that improved the paper

Keywords: