title: Barren-ground caribou (Rangifer tarandus groenlandicus) behaviour after recent fire events; integrating caribou telemetry data with Landsat fire detection techniques.
abstract: Fire regimes are changing throughout the North American boreal forest in complex ways. Fire is also a major factor governing access to high-quality forage such as terricholous lichens for barren-ground caribou (Rangifer tarandus groenlandicus). Additionally, fire alters forest structure which can affect barren-ground caribou's ability to navigate in a landscape. Here, we characterize how the size and severity of fires are changing across five barren-ground caribou herd ranges in the Northwest Territories and Nunavut, Canada. Additionally, we demonstrate how time since fire, fire severity, and season result in complex changes in caribou behavioural metrics estimated using telemetry data. Fire disturbances were identified using novel gap-free Landsat surface reflectance composites from 1985 to 2011 across all herd ranges. Burn severity was estimated using the differenced normalized burn ratio. Annual area burned and burn severity were assessed through time for each herd and related to two behavioural metrics: velocity and relative turning angle. Neither annual area burned nor burn severity displayed any temporal trend within the study period. However, certain herds, such as the Ahiak/Beverly, have more exposure to fire than other herds (i.e. Cape Bathurst had a maximum forested area burned of less than 4 km2). Time since fire and burn severity both significantly affected velocity and relative turning angles. During fall, winter, and spring, fire virtually eliminated foraging-focused behaviour for all 26 years of analysis while more severe fires resulted in a marked increase in movement-focused behaviour compared to unburnt patches. Between seasons, caribou used burned areas as early as 1-year postfire, demonstrating complex, nonlinear reactions to time since fire, fire severity, and season. In all cases, increases in movement-focused behaviour were detected postfire. We conclude that changes in caribou behaviour immediately postfire are primarily driven by changes in forest structure rather than changes in terricholous lichen availability.
authors: Integrated Remote Sensing Studio, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4.
authors: Gregory J M
authors: GJ
authors: Rickbeil
authors: Integrated Remote Sensing Studio, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4.
authors: Txomin
authors: T
authors: Hermosilla
authors: Integrated Remote Sensing Studio, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC, Canada, V6T 1Z4.
authors: Nicholas C
authors: NC
authors: Coops
authors: Canadian Forest Service (Pacific Forestry Centre), Natural Resources Canada, 506 Burnside Road, Saanich, BC, Canada, V8Z 1M5.
authors: Joanne C
authors: JC
authors: White
authors: Canadian Forest Service (Pacific Forestry Centre), Natural Resources Canada, 506 Burnside Road, Saanich, BC, Canada, V8Z 1M5.
authors: Michael A
authors: MA
authors: Wulder
mesh_terms: D025041:Animal Migration; D000818:Animals; D002170:Canada; D005247:Feeding Behavior; D005390:Fires; D015873:Northwest Territories; D020957:Nunavut; D012053:Reindeer; D013686:Telemetry
keywords: Landsat; arctic; disturbance; mammal; movement; remote sensing; telemetry; ungulate