How Reindeer Introductions Caused Ecological Disasters on Remote Islands

Logistical Solutions That Created Ecological Traps

The introductions began as practical responses to isolation. According to historical accounts, Norwegian whaling station Carl Anton Larsen introduced reindeer to South Georgia in 1911 to provide fresh meat and recreational hunting for seasonal workers stationed far from home. Additional animals arrived in 1912 and 1925, establishing stable herds in an environment devoid of native land mammals and natural predators like wolves or bears.

Decades later, French expeditions replicated the strategy in the Kerguelen archipelago. According to data published by the Overseas Invasive Species Network (REINFO), researchers introduced reindeer in 1955 and 1956 to supply personnel stationed on the islands. Without predators to check population growth, the herds expanded unchecked across both regions.

Population Explosions and Habitat Destruction

On the Kerguelen Islands, the reindeer population grew significantly. According to historical surveys, researcher Pascal estimated the Grande Terre herd at roughly 2,000 individuals by 1974, leading to the localized decline of native plant species such as Kerguelen cabbage and Azorella. Modern estimates place the Kerguelen reindeer population between 3 000 and 5 000 animals, maintaining constant grazing pressure on ecosystems unaccustomed to large herbivores.

The impact was even more severe on South Georgia. Following the closure of whaling stations in the 1960s, unmanaged herds grew to several thousand animals, eventually occupying at least one third of the island’s vegetated surface, according to environmental assessments by the South Georgia Heritage Trust. The animals heavily overgrazed tussac grass—a tall plant critical for coastal stability and bird nesting—leaving large coastal areas and ridges completely denuded and exposing burrowing species like prions and petrels to increased predation and burrow collapse.

Contrasting Management Strategies: Eradication Versus Regulation

Faced with severe environmental degradation, authorities adopted divergent management approaches. According to the South Georgia Heritage Trust, a multi-year eradication project launched in 2013 successfully removed all reindeer from South Georgia, processing nearly 1,000 animals for meat distribution while restoring the island’s native flora.

In contrast, the French authorities in the Kerguelen archipelago chose to regulate rather than eradicate the herds. The reindeer continue to inhabit parts of the islands under ongoing scientific monitoring, illustrating two distinct approaches to managing introduced ungulates on isolated sub-Antarctic lands.