Sentinels of climate change

Penguin species in Antarctica and the remote Subantarctic regions are already feeling the brunt of global warming. Researchers have established that shifting weather and ice patterns, altered ocean currents, and changes in food availability have affected their breeding success and survival rates. What does the future hold for these charismatic flightless birds? 

Words and photographs by Julie Chandelier

Standing in the heart of sprawling penguin colonies brings a sensory overload. No images can really do it justice. It is an endless cacophony of sound and motion that will leave a lasting impression on anyone fortunate to experience it. I, for one, feel very privileged to have travelled to some of the most remote corners of the earth where unforgiving nature meets the extraordinary. Antarctica, South Georgia and The Falkland Islands are home to a remarkable array of penguin species, each contributing to the rich mosaic of life in our planet’s southernmost reaches. These charismatic birds have captured the hearts of many, including mine as I travelled to these southern latitudes in 2022 where I would encounter all penguin species except the rare emperor penguin.

As we sailed to South Georgia, my heart was filled with trepidation. The many books, documentaries, and images I had seen over the years were to become reality. South Georgia’s noisy, shuffling penguin community comprises four species, including the world’s largest population of macaroni penguins as well as gentoo and chinstrap penguins. But it is the island’s king penguins that waddle away with much of the spotlight. There are around 450,000 pairs of king penguins in South Georgia – about half of the world’s population. The island has over 30 colonies in total but the largest is at St Andrews Bay, home to an impressive 150,000 pairs. When I set foot on the bay’s shore, I was overwhelmed. I couldn’t fathom how such a place can exist. 

What drew my attention the most was the numerous king penguin chicks bobbing around. They are odd-looking creatures, boasting a unique appearance that sets them apart from their adult counterparts. Due to their looks, some early explorers believed that they were a completely different penguin species. Covered in soft brownish-grey down feathers, they navigate the bustling colonies, often forming crèches where they huddle together for warmth and protection. 

South Georgia is a hotspot for penguins due to it proximity to the Antarctic Convergence, where cold polar waters meet the more temperate ocean. This fosters extraordinary levels of marine productivity, especially for Antarctic krill – the favourite food source of most of Antarctica’s seabirds, whales, seals, and penguins. In breeding season the coast of South Georgia – only 104 miles (166 km) long – is home to over 60 million breeding birds of over 30 different species. More than four million seals also call these coastlines home and South Georgia is known as the largest colony of elephant seals with over 6,000 animals. 

We often associate the remote Antarctica and the Subantarctic regions as inadequate for life, due to their extreme cold temperatures and harsh weather conditions. However, beneath their seemingly barren, frozen exterior, these regions are teeming with life and possess some of the richest biodiversity on the planet. All around Antarctica, these frigid waters provide lifeblood for wildlife. Penguins have established themselves far and wide, and are the perfect example of resilience in these seemingly inhospitable regions. Symbolically speaking, they serve not just as ambassadors for these regions, but also the fragile ecosystems they inhabit. Due to their sensitivity to environmental changes, penguins are an important indicator of ecosystem health. They are also integral components of a complex food web and are commonly referred to as sentinels of climate change.

As we were sailing through these southern parts, I learned that, despite the apparent abundance of them, these penguins are under threat. They are particularly vulnerable to shifting ice patterns, altered ocean currents, and changes in food availability as these all affect their breeding success and survival rates. One of the most pressing issues in these regions is an unusual increase in rain and snowfall. Typically, snow ceases by early November, but over the past two to four years, heavier snowfall has persisted until the end of December, a direct result of climate change. 

Gentoo penguins face particular challenges as they rely on dry rocks to construct their nests, which sometimes consist of up to 1,300 pebbles and stones, piled high and proud. Being the only species breeding on ice-free grounds, they are vulnerable to late snowfall, which delays breeding. When so much snow is afoot, they cannot breed. They simply have to wait. This could lead to delayed hatching and a reduced likelihood of chicks successfully fledging before winter. 

Guillaume De Rémacle, an expedition guide and ornithologist who has been working in Antarctica for several years, has made rather poignant observations during the past two seasons. “During these challenging times, the gentoos’ desperate urge to reproduce becomes evident. I have witnessed them attempting to lay their eggs on the beach during low tide, only to see them washed away when the tide rises, or on precarious nests in the snow, leading to the unfortunate freezing of the eggs,” he said. 

Undeniably, keeping eggs warm in snowy conditions is a hard task. A decade-long study revealed a 25% decline in chick survival in regions experiencing above-average rainfall and/or snowfall compared to drier areas. Not to mention increased runoff from rain or snowmelt can also flood penguin nests, regardless of the species. Natalie Long, a master’s student at the Institute of Marine and Antarctic Studies in Tasmania and a lecturer onboard polar expeditions, told me: “The IPCC (Intergovernmental Panel on Climate Change) has found with high confidence that precipitation will increase in polar regions, in Antarctica, over coastal regions.”

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Issue 32
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This feature appears in ISSUE 32: SENTINELS OF CHANGE of Oceanographic Magazine

Issue 32
Supported by WEBSITE_sponsorlogos_blancpain
Supported by WEBSITE_sponsorlogos_blancpain

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