Penguins, Puffins, and the Science of Seabird Scat

gemma clucas on Georgia island collects poop with an albatross; Seabird Research on Climate Change Impacts and Conservation

On a secluded island off the coast of Maine and New Hampshire, hundreds of seabirds circle above in the sunny, blue skies while Dr. Gemma Clucas purposefully paces beneath them, getting pelted by bird excrement as an avian defense mechanism. Little do the birds know, this is all according to plan. Gemma is conducting groundbreaking seabird research on climate change impacts and conservation on these remote islands.

By collecting fecal samples on her designated “poop hat,” Gemma can use the DNA in the poop to determine what prey the birds are consuming. This allows her to conclude how the oceanic food chain is being altered by human activity and climate change.

To accomplish this, Gemma must travel to some of the most remote places on the planet.

The Path to Poop

plastic garbage bag on a hat for collection bird poop; Seabird Research on Climate Change Impacts and Conservation
Gemma’s poop collection hat, with common tern fecal sample, 2019.

In November 2023, I had the pleasure of diving more in-depth with Gemma about her work over a hot pot of hibiscus tea at a cozy bar in Ithaca, New York. We met at a book club focusing on environmental topics and inspirational outdoor recreation—topics that speak to both of us. I quickly learned that she traveled to extreme places in the world to study birds, but I didn’t know for what purpose. 

During our conversation, I learned that Gemma’s interest in birds began in her childhood when her parents took her birdwatching, but, as a child, attempting to locate different bird species wasn’t exactly an exhilarating activity. Instead, her avian interest developed when she went to Cambridge University for her undergraduate studies in Natural Sciences with a focus on Zoology. 

“I naturally tended towards bird-based research projects,” Gemma explained. “After I left university, I realized I had an interest in oceanography as well, and so seabirds brought those two interests together in terms of marine biology and birds.”

Gemma can use the DNA in the poop to determine what prey the birds are consuming.

After graduation, Gemma spent a year gaining more work experience. She knew that she wanted to focus on conservation efforts, and her gap year studying penguin genetics convinced her to return to school to strengthen her understanding of marine biology and ocean science. So, she pursued a Master’s in Ocean Sciences at the University of Southampton in England, followed by a Ph.D. at the University of Oxford, where she researched processes that affected penguin populations. 

As a result, Gemma’s research took a turn and sent her down a path with a more peculiar focus: poop.

First Stop: The Gulf of Maine

Gemma’s research agenda takes her to places off the beaten path. For example, approximately six miles east off the coast of Maine and New Hampshire, Gemma sails to the Isles of Shoals, a collection of islands bustling with avian activity. While not too far from the United States coastline, these islands are both beautiful and devoid of humans.  

view of White Island light house from a bird blind;
The lighthouse surrounded by common and roseate terns, as viewed from a bird blind, 2021.

“There will be just a handful of researchers and technicians on the island with thousands of birds,” Gemma enthusiastically described. “And the islands I’ve worked on have lighthouses, so we get to stay in the lighthouse keeper’s cottage. It’s very romantic being on a remote island with tons of seabirds.”

While on these islands, Gemma gets busy collecting the fecal samples. 

As we chatted together in the Ithaca bar, Gemma continued to share what her research involved: “With common terns, they will poop on you as a defense mechanism, so I wear a hat covered in a trash bag and walk through the colony while they poop on me. Then, I collect the poop off my hat!”

Once Gemma acquires the samples, she transports them back to the lab to determine what fish DNA is present in the feces. Gemma follows a simple laboratory procedure, extracting the DNA sequences and comparing those sequences to an online library of known genes that will tell her exactly what fish species the birds ate. 

“It’s relatively straightforward because we use genes known as ‘barcoding genes,’ which work like a barcode at the supermarket: you just sequence the gene and match it to your reference, and that tells you what species it is.” 

So, what are the birds’ diets saying about their own health and of the ocean’s health?

The Fish are Moving North

common tern chick next to an egg in a ground nest;
A recently hatched common tern chick begging for food, 2019.

“Terns and puffins in the Gulf of Maine feed on a lot of herring,” Gemma explained. “Herring is thought to be a very good fish for raising chicks because it’s relatively fatty, and so it has a lot of calories for the chicks. As temperatures warm, we’re seeing less herring in birds’ diets, and that’s being replaced by, in some years, a really mixed bag of fish species.”

Gemma suggested that the lack of herring could be due to the fish moving further north or going into deeper waters to seek colder temperatures. On top of that, general overfishing is decreasing the herring populations. Since the birds can’t find them as easily, they must eat other fish species. 

“One of the problematic species that the birds catch is the Atlantic butterfish which is quite round bodied,” Gemma said. “A herring is, comparatively, long and skinny, and the chicks can swallow it easily, but these butterfish are much rounder. The adults bring them in, but the chicks can’t swallow them because they’re too wide, and the chicks will starve because they’re not able to eat them. In very warm years, this happens a lot.”

Following the Poop: Maine to Antarctica

Similar concerns have arisen on the South Sandwich and Zavodovski Islands, which are very desolate, windy, and uninhabited islands in the southern Atlantic Ocean, hundreds of miles off the east coast of Argentina. It takes Gemma a week to get there by sailboat, her crew rotating in three-hour work shifts to help change the sails or cook, fighting seasickness all the while. Upon arrival, she must always carry a gas mask as some island volcanoes still actively smoke. 

Gemma Clucas with a penguin colony a volcano smokes in the background; Seabird Research on Climate Change Impacts and Conservation
Gemma collecting ancient penguin bones and eggshells. In the distance, the volcano smokes, 2020.

Her reason for the last excursion to these islands in December 2023 was to study the largest penguin colony in the entire world, with over 1.5 million Chinstrap and Macaroni penguins. 

Because these islands are challenging to get to, researchers do not know precisely how many penguins there are, what they are feeding on, how far they must travel for food, or how the 2016 volcano eruption may have affected them.

To address these questions, Gemma and her team spent three weeks collecting poop for DNA analysis, using drones to count the population and gluing tracking devices on the penguins to examine their foraging ranges. The team was worried that the dense penguin population was depleting the prey around the islands, thus forcing the penguins to forage outside the fifty-kilometer marine protected area. The tracking devices would allow Gemma to watch the penguins travel to and from the island on their daily feeding trips. Understanding the true foraging range helps increase the protected zone, preventing humans from overfishing that area, and potentially impacting the whole penguin population.

scientists collects fecal sample in the foreground with a colony of king penguins behind her; Seabird Research on Climate Change Impacts and Conservation
Gemma collecting King Penguin fecal samples on South Georgia Island, 2022.

Climate Change and Conservation

Like the common terns, penguins’ diets are being impacted by climate change as well, and it’s concerning for Gemma because penguins that more exclusively eat krill (compared to penguins that might also eat fish) are more intensely impacted as krill populations decline. 

“Juvenile krill spend the year under the sea ice, and they feed on diatoms and algae that live on the ice,” Gemma explained to me during our conversation, “With ice declining, it seems to be impacting the krill since the krill’s prey are losing their habitat. That must be impacting the penguins.”

In addition to the decline in krill, climate change is increasing precipitation and snow, which is troubling since some penguin species need ice-free ground, such as bare rock, to build their nests. Gemma explained that increased snowfall over the last few years had delayed the start of breeding because the penguins needed to wait for the snow to melt and expose the rock. Those chicks were not ready to fledge by the time winter arrived. 

“The 2022-2023 winter had a massive early breakout of sea ice in one part of Antarctica, which likely caused a complete breeding failure in multiple Emperor penguin colonies,” Gemma said. “They breed directly on the ice, and if that ice breaks, the chicks aren’t waterproof at that point, and they’ll all be lost.” 

It’s difficult to monitor the diets of the birds, but it’s important work as the oceans warm and prey availability changes.

Research on penguins and other seabirds in remote areas comes with its difficulties. The travel time alone to and from the islands can take weeks, and the weather is subject to dramatic changes. This can make it difficult to dock boats or operate weather-sensitive equipment, like drones. 

In Gemma’s own telling, “The dexterity in your fingers is also affected when you’re trying to glue little tracking devices onto penguins. We are always looking at the weather as far in advance as possible to make the most of this weather window, and then we need to find a safe spot to hide. You just need to be flexible.”

For the Love of Seabirds

scientist launches drone from sailboat;
Gemma launching a drone from a sailboat, 2020.

Regardless of these challenges, there are also many meaningful experiences when traveling and researching in places that are inaccessible to the public.

“One of my favorite memories is hearing leopard seals singing under the hull of the boat,” she reminisced over tea. “I think they use icebergs and boat hulls to kind of regulate their songs, and so the males will sing to attract mates. I remember one night lying in my bunk just hearing this seal singing for hours under the boat. It is otherworldly, like an alien-like sound; very strange but lovely. Another time, a leopard seal was asleep on an iceberg, and it was just singing in its sleep like it was dreaming. It was so amazing.”

Importantly, this research is incredibly rewarding for Gemma. It’s difficult to monitor the diets of the birds, but it’s important work as the oceans warm and prey availability changes, which will have a growing impact on seabirds. 

Her research has garnered international support. At the Lab of Ornithology at Cornell University, where Gemma currently works, she founded and maintains a program called The Seabird Conservation Analytics Team (or SCAT). The team involved continues to assess seabird populations using dietary DNA and drones to count penguin and tern populations, and they receive bird fecal samples from around the world to examine how bird diets and prey are changing due to climate change and other environmental and human-influenced factors. 

Gemma concluded, “I really love being able to provide data on what the seabirds are feeding on so that we can track changes over time. I’m just hoping that I can keep working with lots of people around me, not just in North America but around the world. To provide more data right now on our birds so that we can hopefully protect them moving forward.”

Featured image: Gemma Clucas collecting grey-headed albatross fecal samples from their nests in the tussock grass, South Georgia Island in the southern Atlantic Ocean, January 2022.

*All photos provided by Gemma Clucas to use with permission. 

Erin Hassett is a Ph.D. student at SUNY College of Environmental Science and Forestry (ESF) in Syracuse, NY where she researches greenhouse gas cycling in wetlands. She is an editor for ESF Unearthed, the campus literary magazine, and she has published several scientific articles and maintains a blog on environmental topics and outdoor recreation, called The Footprint. When not writing, you can find her on two wheels or a mountaintop. Contact. Instagram. X.