New forest growth (following destruction of vegetation) provides habitat and food for other ungulates, which in turn attracts more predators, putting pressure on woodland caribou.

[17] Mallory and Hillis explained how, "In North America, populations of the woodland caribou subspecies typically form small, isolated herds in winter, but are relatively sedentary, and migrate only short distances (50 – 150 km) during the rest of the year.

from the Early Pleistocene of Omsk, Russia dates back to 2.1-1.8 Ma and suggests northern Eurasia as a center of reindeer origin (Bondarev et al.

[19] Its pedicles (antler bases), unlike modern reindeer, are inclined backward and set parallel to each other, demonstrating the primitive morphology for archaic cervids.

[22] Archaeologists distinguish “modern” tundra reindeer and barren-ground caribou from primitive forms — living and extinct — that did not have adaptations to extreme cold and to long-distance migration.

[22] They include a broad, high muzzle to increase the volume of the nasal cavity to warm and moisten the air before it enters the throat and lungs, bez tines set close to the brow tines, distinctive coat patterns, short legs and other adaptations for running long distances, and multiple behaviors suited to tundra, but not to forest (such as synchronized calving and aggregation during rutting and post-calving).

Molecular data also revealed that the four western Canadian montane ecotypes shared a common ancestor with modern barren-ground/tundra reindeer and caribou, but distantly, having diverged 120,000–130,000 years ago.

[32] Woodland caribou, a rather large subspecies, is a medium-sized ungulate which inhabits boreal and subarctic environments and exhibits "tremendous variation in ecology, genetics, behavior and morphology."

[34] The boreal woodland caribou is well-adapted to cold environments, with a compact body covered with a thick and long coat (thicker in winter than in summer).

[18] Previous classifications of Rangifer tarandus, either with prevailing taxonomy on subspecies, designations based on ecotypes, or natural population groupings, failed to capture "the variability of caribou across their range in Canada" needed for effective species conservation and management.

[38] "Across the range of a species, individuals may display considerable morphological, genetic, and behavioral variability reflective of both plasticity and adaptation to local environments.

As definitions of "species" evolved, taxonomists began to rein in this excess, for example, bringing the four western montane ecotypes under Arctic caribou, R. arcticus Richardson 1829, as subspecies.

In 1961, A. W. F. "Frank" Banfield, who had succeeded Anderson as Chief of the CMNH Biology Division, published a revision of the genus Rangifer that was widely rejected by other caribou specialists.

The SARC 2012 report provided the following reasons for its assessment:[58] "Boreal caribou need large tracts of undisturbed habitat so they can spread out to minimize predation risk.

The 15 northern caribou herds of the Southern Mountains National Ecological Area (SMNEA) were federally listed as "Threatened" by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).

According to a June 2014 article in The Wall Street Journal, the ABMI report was released during a period of "controversy over Alberta's recent sales of oil and gas development leases in areas populated by both boreal and mountain caribou.

[71] In their Annual Report 2006–2007,[81] the Office of the Environmental Commissioner of Ontario argued that, "Woodland caribou represent the "hard-to-perceive, slow-motion crisis"[82][83] that faces many species at risk.

The success or failure of conservation efforts for this species also may serve as a benchmark to measure the sustainability of policy choices made by the Ontario government.

[85] The migratory forest-tundra woodland caribou, numbering about 20,000 in 2007[81] is found in northern Ontario, on the coastal plains south of Hudson Bay was not considered to be endangered.

[89] There are six designated units in Ontario – ON1 Sydney, ON2 Berens, ON3 Churchill, ON4 Brightsand, ON5 Nipigon, ON6 Coastal (a small, isolated local population), ON7 Pagwachuan, ON8 Kesagami and ON9 Far North (a very large range).

[94][Notes 4] The decline continued along the southern edge of woodland caribou distribution throughout the 1960s, 70s and 80s with the direct loss of habitat to logging, mines and dams.

A 2018 survey confirms a continuing decline of the George River migratory caribou herd population, as reported by the Canadian Broadcasting Corporation, it is estimated to be fewer than 9,000 animals,[98] down from 385,000 in 2001, 74,131 in 2010,[99][100][101] and 27,600 in 2012.

In the U.S. there was only one naturally occurring herd of woodland caribou in extreme northern Idaho, eastern Washington, and British Columbia, Canada, of about 40 animals.

Another location for reintroduction by the NCCC was [Isle Royale] National Park, Michigan on Lake Superior off the coast of Minnesota and Ontario not far from the Slate Islands.

At that time, the entire woodland caribou population in the Selkirks consisted of one herd of 20-25 animals that occurred in extreme northeast Washington, northern Idaho, and the Stagleap Park area of British Columbia (B.C.).

[26] Ecosystem degradation of the "stands of old growth forest", for example, are caused by "mining, logging, oil and gas exploration and even excessive motorized recreation" which result in "a fragmented and altered landscape often leading to increased populations of deer, moose, elk, and their predators.

Through the South Athabaska Sub-regional Strategic Environmental Assessment, the Government of Canada and Alberta will "further align regulatory processes, while addressing cumulative effects by employing an ecosystem-based approach.

"[115] On 11 May 2012, the briefing notes for the meeting with Suncor VP and Environment Canada included EC's concerns for the cumulative effects of oil sands development.

"By February 2013, Suncor's March report reflects their concerns with the Species at Risk Act (SARA), in particular on the implications of the Proposed Recovery Strategy for Woodland Caribou.

While the financial implications of statutes, regulations and frameworks under development are not yet known, the company is committed to working with the appropriate regulatory bodies as they develop new policies, and to fully complying with all existing and new statutes, regulations and frameworks as they apply to the company’s operations.Caribou are monitored through a capture and collaring with VHF or Global Positioning System (GPS)[120] tracking collars.