Port Lockroy Blog #11: Mairi's Penguin Update

Wildlife monitor Mairi Hilton explains how the team assesses the breeding success of the local Gentoo colony.

Port Lockroy Blog #11: Mairi's Penguin Update

Wildlife monitor Mairi Hilton explains how the team assesses the breeding success of the local Gentoo colony.

Port Lockroy Blog #11: Mairi's Penguin Update


Pictured: Wildlife monitor Mairi at Port Lockroy (Credit: Clare Ballantyne)

I have the great privilege of being wildlife monitor here at Port Lockroy, which means that I’m in charge of surveying the penguins!

The penguin survey started at Port Lockroy in the 1995-96 season and has run every year since, with the exception of when the base closed due to Covid-19 in 2020-21. The study monitors the breeding success of the Gentoo colony which is our neighbour on the island.

A proud gentoo next to the water
A proud Gentoo strikes a pose (Credit: Mairi Hilton)

We survey the penguins every second day. Rather than disturb the whole colony, which would also take a long time, the colony are divided into seven smaller colonies, and we survey one regularly. This colony live beside the old Stevenson screen that housed equipment for weather monitoring on the base, so we refer to them as the ‘screen colony’. Every second day since we arrived, we’ve been counting the number of nests and noting down how many of these nests contain one or two eggs, and how many are empty.

The idea of this is that once the screen colony reach 95% of nests with eggs, we then survey the whole population of penguins – usually around 1,000 individuals.

an empty snowy nest

Heavy snow has impacted the breeding season (Credit: Mairi Hilton)

However, as you may have gathered from our earlier blogs, there has been a lot of snow this year, and the snow was quite late in the season. This has unfortunately impacted our penguins here at Port Lockroy. The breeding season has been delayed by a few weeks, and the number of nests with eggs is less than we would expect.

However, we still have hopes for a good breeding season here. Thanks to a week of sunshine, followed by a few days of heavy rain, the snow melted considerably within just a few weeks, and the penguins are now mostly nesting on little mounds of pebbles.

A close-up of Gentoo feet

Gentoos don't keep their eggs on their feet (Credit: Mairi Hilton)

Unlike emperor penguins, Gentoos don’t always keep the eggs on their feet, and sometimes rest them directly in the pebbles. The male and female take turns lying on top of the eggs to keep them warm. They both have a small, almost bald patch on their stomachs, that has a lot of blood vessels near the surface, to help keep the eggs at body temperature. Cleverly, when the adult penguins stand up, this area is covered over by feathers, so it isn't exposed to the cold.

The sudden change in the weather resulted in a week or so where the penguins lived in little swamps of guano, which we referred to as ‘poo soup’. It necessitated finding some overalls to wear over my usual outfit to protect my clothes! You may also notice that I’m wearing goggles in the picture. Penguins may look cute and cuddly, but they're extremely protective of their nests and eggs, so I have to wear safety goggles when checking nests!

A close up of Gentoo feathers
Gentoo feathers (Credit: Mairi Hilton)

The sun has been shining here for the last few days, even getting up to a balmy 10 degrees. The guano swamps have now dried up, so the penguins are on nice dry nests. We’re keeping our fingers crossed that in the next few days, we’ll see some eggs turn to fluffy, grey chicks, and we’ll start hearing some peeping coming from the nests.

Mairi Hilton, General Assistant, Wildlife Monitor, Port Lockroy