Status of endangered and threatened caribou on Canada's arctic islands

Anne Gunn,Frank L Miller,John Nishi

doi:10.7557/2.20.5.1623

Abstract

Caribou (Rangifer tarandus) on the Canadian Arctic Islands occur as several populations which are nationally classified as either endangered or threatened. On the western High Arctic (Queen Elizabeth) Islands, Peary caribou (R. t. pearyi) declined to an estimated 1100 caribou in 1997. This is the lowest recorded abundance since the first aerial survey in 1961 when a high of ca. 24 363 caribou was estimated on those islands. Peary caribou abundance on the eastern Queen Elizabeth Islands is almost unknown. On the southern Arctic Islands, three caribou populations declined by 95-98% between 1973 and 1994 but our information is unclear about the numerical trends for the two other populations. Diagnosis of factors driving the declines is complicated by incomplete information but also because the agents driving the declines vary among the Arctic's different climatic regions. The available evidence indicates that severe winters caused Peary caribou die-offs on the western Queen Elizabeth Islands. On Banks Island, harvesting together with unfavourable snow/ice conditions in some years accelerated the decline. On northwestern Victoria Island, harvesting apparently explains the decline. The role of wolf predation is unknown on Banks and notthwest Victoria islands, although wolf sightings increased during the catibou declines. Reasons for the virtual disappearance of arctic-island caribou on Prince of Wales and Somerset islands are uncertain. Recovery actions have started with Inuit and Inuvialuit reducing their harvesting but it is too soon to evaluate the effect of those changes. Recovery of Peary caribou on the western Queen Elizabeth Islands is uncertain if the current trends toward warmer temperatures and higher snowfall persist.

Highlights

In 1991, the Committee on the Status of Endangered Wildlife in Canada classified caribou Rangifer tarandm on both eastern and western Queen Elizabeth Islands (Fig. 1) and on Banks Island as "Endangered" and those on Victoria, Prince of Wales, and Somerset islands and the Boothia Peninsula as "threatened" (Miller, 1990b)
The rationale for the endangered status was the steep population declines during the 1970s and no discernible overall recovery in the early 1980s
The status is unknown for the endangered caribou on the eastern Queen Elizabeth Islands and the threatened caribou on southern and east-central Victoria Island and the Boothia Peninsula

Summary

Introduction

In 1991, the Committee on the Status of Endangered Wildlife in Canada classified caribou Rangifer tarandm on both eastern and western Queen Elizabeth Islands (Fig. 1) and on Banks Island as "Endangered" and those on Victoria, Prince of Wales, and Somerset islands and the Boothia Peninsula as "threatened" (Miller, 1990b). Pearyi on the western Queen Elizabeth Islands have further declined and the endangered caribou on Banks Island appear to have declined further in the late 1990s. The threatened population on Prince of Wales and Somerset islands has almost disappeared, and the threatened northwestern Victoria Island population had further declined but has, perhaps, started to increase. The status is unknown for the endangered caribou on the eastern Queen Elizabeth Islands and the threatened caribou on southern and east-central Victoria Island and the Boothia Peninsula.

METAPOPULATION BOUNDARY population boundary

Causes of declines

Findings

The effect of environmental severity is the most