Long-term patterns of muskox (Ovibos moschatus) demographics in high arctic Greenland

Abstract

Animal abundance is a key measure in conservation and management and tightly linked to population demographics. Demographic data from remote regions, however, are often scarce. Here, we present long-term (1996-2013) demographics on the muskox Ovibos moschatus population at Zackenberg in northeast Greenland. We examine both the inter-and intra-annual patterns in demographic parameters and relate these to environmental conditions. The sex and age composition of muskox groups changed during the study period, and changes were particularly evident in the increasing versus the decreasing phase of muskox abundance. The seasonal pattern of muskox density and group size was a parallel increase from late winter to autumn, which peaked at high densities (approximately seven individuals per km 2 ) in the autumn. The composition of muskox groups also changed between seasons. Across years, the muskox population dynamics was mainly driven by spring snow cover (an indicator of winter conditions), which primarily impacted the calf and yearling recruitments. This relationship, however, appeared to have a temporary decoupling, which may be attributable to pathogens. Our study provides rare insight into the longterm demographics of a remote ungulate population in relation to drivers of change and thus aids the development of adequate monitoring and management plans for muskoxen in a changing Arctic.

Introduced megafauna are rewilding the Anthropocene

“…Muskox 313 G Arctic tundra Few other herbivores adapted to extreme arctic environment (Schmidt et al 2015).…”

Interaction webs in arctic ecosystems: Determinants of arctic change?

“…At Zackenberg, the abundance of muskoxen is high compared to other arctic sites (Schmidt et al 2015), and we have therefore examined the potential effects of their grazing activities in particular detail. During summer, muskoxen feed extensively in the productive fen areas dominated by graminoids (Kristensen et al 2011).…”

Spatiotemporal Characteristics of Seasonal Snow Cover in Northeast Greenland from in Situ Observations

“…Hence, the snow-depth evolution through the autumn and winter governs the amount and timing of plant-available nutrients at the end of the winter and the following spring in tundra ecosystems (Schimel et al, 2004;Buckeridge and Grogan, 2008). The nutrient availability along with the meltwater released from the snowpack in spring (Jones, 1999) regulate, in turn, the vegetation growth far into the growing season (Blankinship et al, 2014) and thus the main food source for herbivores-for example, the muskoxen (Ovibos moschatus) (Kristensen et al, 2011;Schmidt et al, 2015;Mosbacher et al, 2016). Hence, the snow conditions in the preceding winter may have legacy effects on the following growing season(s), which makes snow observations essential in the understanding of ecosystem functions and feedbacks (Hollesen et al, 2015).…”