What If Gone

Species → Muskox

Muskox

Ovibos moschatus

135,000 mature individuals
Extinction risk Least Concern
Arctic environmentNutrient cyclingEcosystem engineerClimate change
Muskox (Ovibos moschatus)
Photo: Charles J. Sharp, Wikimedia Commons (CC BY-SA 4.0)

What if it disappeared?

Impact Moderate
Ongoing (Ellesmere)

In the single sector studied using GPS collars, wolves there take between 5.5% and 17% of the muskox population older than ten months each year — a steady predation pressure under which both populations nonetheless remain relatively stable.

Documented
Detail

Anderson, M. et al. (2025). Wolf density and predation patterns in the Canadian High Arctic. Journal of Wildlife Management.

A study using GPS collars fitted to wolves from six packs on Ellesmere Island (2014-2018), with ground verification of hundreds of location clusters to confirm kill sites. One pack tracked in detail killed an average of about 0.12 muskoxen per day over the study period.

Ongoing (Zackenberg)

The muskox grazes mostly in grass-dominated areas but preferentially defecates in willow-filled hollows — a mismatch that transfers nitrogen from one habitat type to the other each year, fertilizing the willows at the expense of the grasses it grazed.

Documented
Detail

Mosbacher, J.B., Kristensen, D.K., Michelsen, A., Stelvig, M. et Schmidt, N.M. (2016). Quantifying Muskox Plant Biomass Removal and Spatial Relocation of Nitrogen in a High Arctic Tundra Ecosystem. Arctic, Antarctic, and Alpine Research, 48(2), 229–240.

A study conducted at Zackenberg, in northeastern Greenland. Despite high muskox densities, plant biomass removal remains low (less than 5% of available forage even late in the season) — so most of its effect on the landscape comes not from the amount grazed but from this spatial transfer of nutrients between habitats.

15 years (Greenland)

By keeping dwarf birch and grey willow — the two dominant plant species — in check, grazing by muskox and caribou helps rarer plants, lichens and fungi persist rather than be crowded out, a buffering effect against warming that would otherwise favor these dominant shrubs.

Documented
Detail

Post, E. et al. (2022). Caribou and muskoxen buffer climate impacts for rare plants. Scientific Reports, 12, 1558.

A 15-year monitoring study at a Greenland site comparing grazed plots with grazing-exclusion plots. Without muskox and caribou to limit the spread of dominant shrubs, their canopy shading and leaf litter disadvantage less competitive species — a competition mechanism, not direct predation, but with a measurable effect on local plant biodiversity.

By extrapolation

In other large Arctic herbivores (horses, bison, reindeer), high animal density compacts the snow in winter and cools the permafrost beneath it — a mechanism that has not been specifically measured in the muskox, but that its size and winter behavior make plausible by extrapolation.

Extrapolated
Detail

Extrapolation à partir de Beer, C., Zimov, N., Olofsson, J., Porada, P. et Zimov, S. (2020). Protection of Permafrost Soils from Thawing by Increasing Herbivore Density. Scientific Reports, 10, 4170 — étude qui ne porte pas sur le bœuf musqué.

The reference study modeled this effect using herds of horses, bison and reindeer as part of the Siberian 'Pleistocene Park' project, not the muskox. The physical mechanism (snow compaction reducing its insulating power) should apply to any large gregarious species living on snow-covered tundra, but no direct measurement confirms it for this particular species.

What's missing to confirm it: A direct measurement of the muskox's effect on permafrost temperature beneath its winter grazing areas, comparable to the one carried out for the Pleistocene Park herds, has yet to be done.

Documentation

Last verified: August 14, 2026

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