The males grow their antlers from March to August and the females from June to September, and in both cases the velvet is gone by October.

The Peary caribou population has dropped from above 40,000 in 1961 to an estimated 13,000 adults in 2016, according to the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).

[4] During this period, the number of days with above freezing temperatures has increased significantly, resulting in ice layers in the snow pack.

[9] In Inuvialuktun Aulavik means "place where people travel" and caribou have been hunted there for more than 3,400 years, from Pre-Dorset cultures to contemporary Inuvialuit.

[9] Archaeologists have found bones of pearyi-sized caribou that occupied Greenland in the Illinoian-Wisconsin interglacial and through the LGM and early Holocene (Meldgaard 1986).

Bennike (1988),[13] comparing bones and noting that Peary caribou have been documented crossing Nares Strait to Greenland, doubted that pearyi and eogroenlandicus were subspecifically distinct.

That Peary caribou shared certain mtDNA haplotypes and morphological similarities with it (Kvie et al. 2016)[14] casts further doubt on the validity of R. t. eogroenlandicus.

Inuit Qaujimajatuqangit (traditional or community knowledge) records that Peary caribou do, occasionally, cross to Greenland.

From a population high of 22,000 in 1987, the species experienced a catastrophic die-off in the mid-1990s related to severe icing events in some parts of its range.

Of four subpopulations, two are currently showing an increasing trend, one is stable, and the fourth had fewer than 10 individuals at the last count in 2005, with no evidence of any recovery.

The highest-impact threats derive from a changing climate, including increased intensity and frequency of rain-on-snow events negatively affecting forage accessibility in winter, and decreased extent and thickness of sea ice causing shifts in migration and movement patterns" Originally named Rangifer pearyi Allen, 1902,[17] it was made a subspecies of barren-ground caribou in 1960 as R. arcticus pearyi.