Northern Rockhopper Penguins
by Mike King
Off the coast of South Africa lives one of the world’s most iconic and charismatic birds – the Northern Rockhopper Penguin (Eudyptes moseleyi). These birds, native to the southern islands Gough, Amsterdam, and the Tristan archipelago, are one of 18 different penguin species alive today. Unfortunately, they are also one of the most endangered.
Northern Rockhopper Penguins have the longest crest feathers of any penguin species
Northern Rockhoppers are striking in physical appearance. These penguins have a slate-colored back and head, and a white front and underside. The most unique morphological feature on these birds is certainly the long, frayed yellow feathers extending like long eyebrows across their forehead. The most noticable difference between Northern Rockhoppers and Southern Rockhoppers (Eudyptes chrysocome) is that the “eyebrow” of the Northern variety is significantly longer than that of their Southern relatives.
Northern Rockhoppers are stout, athletic birds. Like all penguins, they have modified wings that act as flippers to help them glide gracefully through the water. Aptly named, these birds often hop around awkwardly on land; but they occasionally slide on their bellies on smooth downhill landscapes. Their diet consists mostly of krill, but as opportunistic foragers they will also readily eat fish and squid when they are available.
Once a common sight on islands in the Southern Ocean, the Northern Rockhopper Penguin population has declined at a rate of 3-4% per year since the early 1970s, totaling at a 57% decline. So what has contributed to this drastic population decrease, and what can be done to reverse the current trend?
Threats to Northern Rockhopper Penguins
Several introduced species pose threats to Northern Rockhopper Penguins. Chief among these species were feral pigs, until their eventual eradication in the 20th century. Dogs and introduced mice also pose certain threats, though there is a lack of data quantifying the magnitude of their impact on the birds.
Although scientific data quantifying the effect of climate change on penguins is still in the process of being conducted, researchers have reason to believe that abnormalities in the Earth’s natural climate can negatively affect birds like penguins. The main reason being studied is that rising ocean temperatures in the areas in which Northern Rockhoppers live are leading to the decline of fish for the penguins to eat.
Human activity is by far the harshest threat to the Northern Rockhopper Penguin. For years, the birds were killed for feathers, hunting bait, and bushmeat. Their eggs were also harvested to feed the people of the island until as recently as 2011. The rapidly increasing development of human housing, roads and cities have led to a severe decrease in habitat availability for the penguins as well.
Conservation of Northern Rockhopper Penguins
A series of laws recently passed in the Tristan island community has sectioned off an entire island to the penguins for habitat without the threat of human intervention. This provides a large area for the penguins to hunt, breed and raise their young. Citizens have also taken action by putting up a fence to keep penguin predators away from the island. Ultimately, the future of the Northern Rockhopper Penguin relies on the continued research, outreach and community education for the benefit of this species.