The rockhopper penguins face an uncertain future in the Falkland Islands, where the population of these birds has drastically declined over the last century.
The species recorded an alarming decline: from 1.5 million breeding pairs in the 1930s to less than 300,000 in 1996, according to Smithsonian Magazine.
In particular, climate change, extreme storms, and food scarcity have altered breeding and survival patterns.
The International Union for Conservation of Nature (IUCN) listed the rockhopper penguins as “vulnerable” in 2020.
Characteristics and habitat of the rockhopper penguins
With their distinctive yellow eyebrows and bold temperament, these penguins measure between 45 and 58 centimeters.
They are the smallest of the subantarctic penguins and weigh between 2 to 4 kilograms, depending on the time of year.
They thrive in cold waters north of Antarctica and nest in colonies far from the sea.
Their gregarious behavior and ability to hop between rocks allow them to withstand the hostile environment.
They use their strong claws to climb and choose more inaccessible locations than other penguins.
This skill has made them a symbol of resilience for local communities, stated farmer Adrian Lowe to Smithsonian Magazine.
The threats endangering the species
Ocean warming has displaced nutrient-rich currents, making access to krill and small fish more difficult.
Since 2005, the subantarctic region of the Falklands has absorbed much of the atmospheric excess heat.
This has intensified winds and altered the pattern of rain and storms. Years with nutrient-poor waters have caused food shortages, increasing mortality in adults and chicks.
“The food supply is insufficient this season,” warned Petra Quillfeldt, a seabird ecologist at the University of Giessen.
The females, responsible for feeding the chicks, have lost more weight than usual.
Over the past decade, toxic algal blooms and strong storms have caused mass mortality.
Out-of-season storms have affected the survival of the young, who lost protection before developing waterproof feathers.
The reproductive cycle of the rockhopper penguins, under pressure
Each female lays two separate eggs: the first smaller and the second noticeably larger.
The chick from the second egg hatches first, giving it a developmental advantage.
In tougher years, the number of nests with two chicks has decreased, according to Quillfeldt. It is uncommon to see particularly robust chicks when food is scarce.
“Personality can be very important in the survival of seabirds,” observed ecologist Juan Masello.
For decades, high mortality among chicks has prevented enough young from reaching adulthood.
Conservation efforts in the Falklands
Various NGO projects have promoted actions to protect the rockhopper penguins in the Falklands.
Goicoechea Island was turned into a nature reserve after decades of intensive grazing.
The initiatives included:
- Restoration of the native grassland
- Elimination of invasive species
- Provision of artificial shelters for nests on Sea Lion Island
- Annual planting of tussac, a native grass
Thanks to these shelters, the number of chicks surviving to leave the nest increased from 86 in 2022 to 260 in the last season, detailed biologist Sarah Crofts.
However, scientists warned that the colonies remain small and vulnerable to future catastrophic events.
“As long as there are no new harmful events between seasons, reproductive success can be acceptable,” noted Quillfeldt.
Uncertainty prevails: environmental threats are rapidly evolving, and conservation strategies only mitigate some risks.
The fate of the species will depend on its ability to adapt to an altered world.
