Caribou vital sign annual report for the Arctic Network Inventory and Monitoring Program: September 2022?August 2023

Abstract

Caribou (Rangifer tarandus) are an integral part of the ecological and cultural fabric of northwest Alaska. Western Arctic Herd (WAH) caribou roam over this entire region, including all 5 Arctic Network (ARCN) Inventory and Monitoring Program?s National Park units. Conservation of healthy caribou populations is specifically mentioned within the enabling legislation (Alaska National Interested Lands Conservation Act or ANILCA) for 3 of these park units and is of importance to subsistence hunters. Caribou are, by far, the most abundant large mammal in northwest Alaska and are famous for their long-distance migrations and large population oscillations. For these reasons, the ARCN parks chose WAH caribou as a Vital Sign for long-term monitoring. This report documents the monitoring results of this Vital Sign during its 14th year (September 2022?August 2023) of implementation. Results from the previous years of monitoring are also included for ease of comparison. Periodic syntheses of these data will be performed and reported on as appropriate. National Park Service (NPS) monitoring of the WAH is done in conjunction and cooperation with the Alaska Department of Fish and Game (ADFG). Thanks to a 2015 data sharing agreement, the report includes data funded by the ADFG dating back to September 2013. That particular year was chosen as it represents when the ADFG started deploying a substantial number of GPS collars on an 8-hour relocation schedule. Monitoring of the herd relies heavily on the use of Global Positioning System (GPS) radio telemetry collars that are capable of transmitting location data to a satellite. Given the extremely remote area that the WAH inhabits, this system provides the most efficient and accurate means to track individual caribou. These data are utilized to monitor the timing and location of migrations, as well as seasonal distributions of WAH caribou. Monitoring movement and the phenology of movement is perhaps the simplest means to track the influences of climate change, natural perturbations, development, and other potential impacts on a species?an analysis of which is outside the scope of this current report. This report also documents the NPS commitment and involvement with the WAH Working Group. The group is composed of important stakeholders including representatives for rural villages, sport hunters, conservationists, hunting guides, hunting transporters, and reindeer herders. In addition, all the agencies charged with managing the WAH, including the ADFG, NPS, US Fish and Wildlife Service (FWS) and Bureau of Land Management (BLM), serve as advisors to the group. Information gathered by the Caribou Vital Sign monitoring program are intended to supplement and complement existing data streams gathered by the other cooperating agencies and will be important in future management decisions.