Some southern rockhopper penguin nesting colonies have recently shown dramatic falls in the number of breeding pairs. The Falkland Islands once housed the stronghold for southern rockhopper penguins, but over the last 60 years, numbers have declined by 90 percent (2).
A number of threats may be contributing to the declining populations of the southern rockhopper penguin, although the importance of individual threats and how they interact to impact on penguin populations are currently poorly understood (8).
Pollution and increasing disturbance at breeding colonies are thought to be major factors in driving declining rockhopper populations, due in part to the recent surge in ecotourism (2). Similarly, fishing operations, particularly squid fisheries may affect this species’ food supplies, although to what extent has yet to be fully ascertained (2) (7) (8).
Climate change is also likely to be affecting the southern rockhopper penguin, with warming temperatures affecting both terrestrial and marine habitats (10), and causing shift in marine food webs (2). Increases in sea surface temperatures associated with changes in the climate have been linked to penguin population declines. However, how this affects prey abundance is not well known, especially given the confounding effects of fisheries and other human activities on the penguin populations (11).
Other threats to the southern rockhopper penguin may include hydrocarbon exploitation off Argentina, energy production and mining within this species’ range, oil spills and oil pollution, introduced predators and invasive species, and harmful algal blooms (2) (7) (8). Smaller penguin colonies in particular may be more affected by land-based threats (8).