The Icelandic reindeer (Rangifer tarandus) population descends from a small group of semi-domesticated animals introduced from Kautokeino, Norway, in the late 18th century. Their current range is limited to East Iceland, bounded by natural barriers such as glaciers and rivers, and in rare instances, by human intervention. Since their introduction, the presence of reindeer in Iceland has been controversial, but over time, they have become integral to the region's identity, fostering a culture of regulated hunting and conservation while gaining broad acceptance.

Organized population management began in the mid-20th century. Early efforts focused on reducing the number of bulls in the herds.  Over the next decades, a quota-based management system balancing conservation and population control emerged and evolved with improved understanding of population dynamics as well as technological and methodological advances. 

In the 1940’s the population is believed to have numbered between 100-250 animals but at the turn of the 21’st century the numbers had risen to 3000 animals in summer and their range expanded from the highlands around Mount Snæfell to most of East Iceland. In the next decade, 2000-2010, the population roughly doubled in size but seemed to stabilize at around 6,000 animals in summer (pre harvest), from 2010 to 2019. This growth was likely aided by milder winters, decreased mortality and increased recruitment rates. However, since 2019, numbers have declined, and the last population estimate suggests that the summer population in 2024 barely exceeded 4000 animals. The cause of this decline is largely unknown but increased anthropogenic disturbance and overgrazing in key areas, habitat fragmentation, high hunting pressure due to erroneous population estimates and range shifts and various combinations thereof have been suggested. 

Reindeer have to a large degree abandoned traditional habitats near the Vatnajökull Glacier, moving into ranges further north and further southeast. This shift coincides with population growth and likely habitat disruption caused by the 2003 construction and aftermath of the Kárahnjúkar hydropower dam and Iceland’s largest reservoir, Hálslón. These developments fragmented prime reindeer calving areas and pastures, and eased access for hunters and tourists to previously undisturbed areas, possibly prompting changes in reindeer distribution and raising questions about future management strategies.

In the absence of natural predators and any serious diseases the reindeer in Iceland must be managed through annual hunting quotas which balance conservation, animal welfare and population control. in 2000, the East Iceland Nature Research Centre (EINRC) was legally tasked with monitoring the population and to advice officials with annual hunting quotas. EINRC conducts aerial and ground surveys to monitor population size, distribution, recruitment, and herd composition. Physical data, such as carcass weight and fat reserves, are collected from hunters to assess the overall health of individuals. The management goals are to maintain population densities under 1 animal per km² of suitable habitat and balanced sex ratios (4-6 bulls per 6-10 cows). Quotas are set regionally for nine hunting areas, ensuring sustainability and preventing overgrazing. EINRC’s monitoring is furthermore used to form the basis for how landowners are compensated, reflecting reindeer distribution. 

Despite the recent decline the Icelandic reindeer population appears to be quite healthy. There are no signs of deteriorating individual condition (e.g. decreased slaughter weights), mass mortality events or large-scale recruitment failures. The most urgent threats appear to be increased habitat disruption with further plans to develop large-scale hydropower and wind energy projects within the highland ranges.

Interplay between human activity and habitat alteration will continue to shape Iceland's reindeer populations. As habitats change, further research and adaptive management are vital to preservation and sustainable harvest management. EINRC is currently undergoing revision of monitoring practices as policy changes with clearer and more adaptable management goals are being called for.