Archaeological documentation of wood caribou fences using unmanned aerial vehicle and very high-resolution satellite imagery in the Mackenzie Mountains, Northwest Territories

Abstract

Indigenous peoples of Canada’s North have long made use of boreal forest products, with wooden drift fences to direct caribou movement towards kill sites as unique examples. Caribou fences are of archaeological and ecological significance, yet sparsely distributed and increasingly at risk to wildfire. Costly remote field logistics requires efficient prior fence verification and rapid on-site documentation of structure and landscape context. Unmanned aerial vehicle (UAV) and very high-resolution (VHR) satellite imagery were used for detailed site recording and detection of coarse woody debris (CWD) objects under challenging Subarctic alpine woodlands conditions. UAVs enabled discovery of previously unknown wooden structures and revealed extensive use of CWD (n = 1745, total length = 2682 m, total volume = 16.7 m3). The methodology detected CWD objects much smaller than previously reported in remote sensing literature (mean 1.5 m long, 0.09 m wide), substantiating a high spatial resolution requirement for detection. Structurally, the fences were not uniformly left on the landscape. Permafrost patterned ground combined with small CWD contributions at the pixel level complicated identification through VHR data sets. UAV outputs significantly enriched field techniques and supported a deeper understanding of caribou fences as a hunting technology, and they will aid ongoing archaeological interpretation and time-series comparisons of change agents.

The Multisource Vegetation Inventory (MVI): A Satellite-Based Forest Inventory for the Northwest Territories Taiga Plains

“…For example, multispectral airborne LiDAR has the potential for predicting boreal tree species composition [71][72][73]. GNWT is also increasingly using remotely piloted aircraft systems (RPAS, also known as drones) to acquire data for research and other applications [74][75][76]; such data could extend the network of field plots currently limited by physical access and resource availability. The strategic acquisition of RPAS data (specifically point clouds, both LiDAR and photogrammetric), as well as cross-disciplinary leverage of existing RPAS archives and other data, would extend the availability of forest structure information across an ecologically broader range of forest types than what the existing network of FI plots currently offers.…”

Power, security, and exchange: Impacts of a Late Holocene volcanic eruption in Subarctic North America

“…The timing of caribou migration was relatively predictable but, owing to open and relatively flat topography, the prime hunting locations were less so (Gordon, 1996;Ives, 1990;Pike, 1892). In the basin west of Mackenzie River, barren ground caribou are rare and people relied more on scattered mountain caribou, upland sheep and goats, as well as moose (Andrews et al, 2012b;Gillespie, 1981;MacKay and Andrews, 2016;van der Sluijs et al, 2020). Salmon do not spawn in the Mackenzie River.…”