Port Lockroy blog 8: Pebbles are forever

20/01/2024

Port Lockroy wildlife monitor Jérôme Viard reports on the first whole-island penguin survey of the season.

When I was offered the job of wildlife monitor here at Port Lockroy, I knew I had landed the best job on the island!

I am responsible for gathering important data on the gentoo penguin colony and contributing to one of the longest penguin surveys on the continent.

The survey began at Port Lockroy in 1996 and has run every year since except when the base closed due to the pandemic in 2020/21. The survey monitors the breeding success of the penguins on our island. This important work enables us to better understand all factors involved in changes in penguin populations and helps shape better policies and guidelines to protect them.

How does the survey work?

Goudier Island is divided into two sections, both roughly the same size. One that is visited by tourists and one that is out of bounds for everyone including our team. The study aims to count all of the nests, eggs and chicks on Goudier Island and to make comparisons with previous years across both areas. 

We have nine sub-colonies on Goudier Island. To minimise footfall, I only count one of the nine sub-colonies every two days. That colony is called the ‘chronology colony’ because it determines when to trigger whole island counts.

Jérôme at work (Credit: Laura Büllesbach/UKAHT)

Every two days since we arrived on the island, I have visited the chronology colony to count all nests and their content from a safe distance. This year is very much a ‘normal’ breeding year compared to last year when significant snowfall delayed the penguins’ breeding season by a month. 

This season, we observed our first eggs being laid at the end of November 2023. Once 95% of the nests in the chronology colony had eggs, it triggered the whole island count of the nests and eggs on 15 December 2023. The entire team went out, divided into two groups and we spent the morning counting nests and eggs in all the sub-colonies on the island. We counted 647 nests and at least 781 eggs. Great work everyone!

Leave no stone unturned

Gentoo penguins nest on mounds of pebbles to keep their eggs dry and insulated from the cold ground. They can travel quite far to gather pebbles from the seashore at low tide. Gentoo penguins love their pebbles, to them they are the most precious gems and deserve fighting for.

Gentoo penguins build their nests from pebbles (Credit: Jérôme Viard/UKAHT)

Male gentoos use offerings of stones to attract a female and create a strong relationship. Those stones are closely guarded with noisy disputes and physical fights not uncommon in the neighbourhood. There is constant thieving of stones from one nest to another and it’s always entertaining to watch all the different tactics in play to seize these coveted gems.

The first chicks of the season

Gentoo penguins lay one to two (occasionally even three) eggs and share incubation, carefully rotating duty every day. Chicks hatch 35 days later and this year our first chick was born under the boat shed on Christmas Eve. 

It was such a special moment. We all get very attached to our penguins here on the island. We are so lucky to follow their entire breeding cycle and go through the highs and lows of parenthood with them, from the first pebbles being laid to the moment the chicks leave the nest. 

The first chicks appeared late last year (Credit: Jérôme Viard/UKAHT)

So, seeing a chick being born was the best Christmas present we could have asked for. From then on, more and more chicks were born and we witnessed the whole process from the first crack in the egg to the tiny beak poking out followed by the rest of the soggy body and then, finally, the chick's first meal. 

The chicks eat food that has been partially digested and regurgitated straight from the parent’s bill. They need constant feeding throughout their development to stay healthy and grow rapidly. We noticed this with our first-born chick and were amazed by his growth, almost doubling in size every day!

Now that chicks are being born, I keep going to my chronology colony, checking every nest every two days and waiting for 95% of those nests to have chicks to trigger a whole island count of all the chicks on Goudier Island. I am already looking forward to it!

A game of guano 

Counting penguins can be a perilous job. Penguins have a fast metabolism and poop every 20 minutes. Jets of guano can travel as far as 1.2 metres! Depending on their daily diet, the colour varies from white if they had a fish supper or pink if they enjoyed a dish of krill. 

Gentoo guano can travel! (Credit: Jérôme Viard/UKAHT)

Unfortunately, that means they regularly project guano onto each other. Some poor birds are unlucky enough to get it right across their face! It is a messy business. Thankfully the penguins take turns scrubbing themselves in the sea before returning to their nests and getting covered all over again!

Penguins are outrageously cute and we love them dearly but my god they stink! I thought I’d come to Antarctica to breathe in the pure air but instead, our noses are filled with the pungent and putrid smell of rotten shrimp.

Gentoo guano gets everywhere! (Credit: Jérôme Viard/UKAHT)

Our clothes and hair are infused with the smell, so much so that cruise ship passengers can smell us before seeing us, – which is good because we immediately get offered a shower onboard!

Despite their smell, we are extremely attached to our penguin neighbours and we wouldn’t have it any other way. I feel so privileged to be here and witness their life from the moment they are born. I am so proud to be following in the footsteps of past wildlife monitors and adding my ‘pebble’ to the edifice of science.

– Jérôme Viard, Wildlife Monitor, Port Lockroy