Adélie penguin

Secret life of penguins

Video transcript

Adelie penguins near Casey research station have been studied for the last 60 years.

Seabird Conservation Ecologist, Dr Colin Southwell: "It's a long time series, there aren't many time series in Antarctica that long. Over that time the regional population has increased by a factor of 6. So it used to be about 30,000 breeding pairs, and now it's almost 200,000 breeding pairs. That's nearly half a million breeding birds. So it's a very large population in the Windmill Islands – the third largest in East Antarctica."

The penguin population grew rapidly from the 1960s to the 1990s – the question is, has that continued?

Colin Southwell: "We also realised that some populations were still going gangbusters, in terms of growing at very fast rates; and some were flatlining, so they were not changing at all. What we've found is that the populations that are stable don't have much breeding habitat left. So they've expanded in their growth in previous years, and virtually filled that habitat, so they can't grow any more. We've found that the populations that have been increasing quickly have a lot of habitat left."

Many of the Windmill Islands near Casey station are 'penguin heaven'.

There's space to lay eggs, surrounded by krill to eat with not too much sea ice.

Colin Southwell: "Good breeding habitat on land is ice-free land, snow-free land, not too steep, not flat – because flat gets too wet – and with lots of pebbles so they can build their nests."

40,000 breeding Adelies live on Shirley Island alone, in less than one square kilometre.

Colin Southwell: "So we can count them from helicopters flying overhead; taking photos, and counting the penguins from the photos; or, if we can get to an island, we can do a direct count from the ground. It's not a trivial task. There are tens and hundreds of thousands of penguins in this population, so it's a very difficult and time-consuming thing to do."

As well as field work, automatic cameras can spy on the penguins all year round.

That's exactly what Madi did, studying 45,000 photos from Adelie colonies.

Institute for Marine and Antarctic Studies Honours student, Madison McLatchie: "I looked at 10 photos per day for every season, and I did 10 seasons at the 5 camera sites."

Adelie penguins use rocks to build their nests.

Madi McLatchie: "Stealing rocks from other penguins, that's a major thing that they do. They'll just go take rocks, no permission asked, and then take that back to their nest. Otherwise, they'll just go scrounging for rocks around the colony as well."

From the photos, she recorded the breeding success of 450 Adelie penguin nests.

The more rocks in the nest, the better the chance of one or more chicks surviving.

Madi McLatchie: "So the higher the nest's off the ground, the more likely they are to be away from the snow cover and the moisture on the ground."

It seems obvious, but the results were a surprise.

Madi McLatchie: "We weren't expecting that nest structure would have such a big impact on breeding success, because that was a relatively new finding. Only a few people prior to me have found that."

Knowing about nests is all part of a bigger picture beyond the cameras.

Colin Southwell: "We've been focusing on Adelie penguins all this time, but the penguins are part of a larger ecosystem. What we're trying to understand is how that larger ecosystem works."

They're indebted to the people who keep the cameras going and collect the images.

Madi McLatchie: "All the expeditioners who went down in that 10 year period I was looking at – I need to thank them so much for giving me and other people the opportunity to find out as much as we can about Adelie penguins to help them into the future."

[end transcript]

Name

Scientific name: Pygoscelis adeliae

Adélie penguins were discovered in 1840 by scientists on the French Antarctic expedition led by explorer Jules Dumont d’Urville. D’Urville named Adélie Land, in southern Antarctica, after his wife, Adéle. Scientists Jacques Hombron and Charles Jacquinot also attributed this name to the species.

Physical description

Adélie penguins are medium sized penguins, weighing 3 to 6 kg and standing 70 cm tall. They are distinguished by the white ring surrounding the eye. Males and females are of similar size and difficult to tell apart.

Like all penguins, Adélies are excellent swimmers. They are also very determined and successful long distance walkers travelling across many kilometres of fast ice on the return journey to their colonies. Their walking speed on ice averages 2.5 km/h and swimming speed 4 to 8 km/h. When enough snow covers the ice, they prefer to plonk onto their bellies and toboggan.

They are closely related to the gentoo (Pygoscelis papua) and the chinstrap (Pygoscelis antarctica) penguins.

Distribution and abundance

Adélie penguins are one of only 5 species of penguins that live on the Antarctic continent (Adélie, emperor, gentoo, chinstrap and macaroni penguins).

Adélie penguins breed around the entire Antarctic coast and small islands in places where there is exposed rock. Many of these locations are close to the Australian research stations.

Long-term population research focuses on the Windmill Islands near Casey, home to the third largest Adélie population in East Antarctica. Scientists have shown the colonies here have increased from 30,000 breeding pairs in the 1950s to nearly 200,000 today. A small colony of about 1,800 breeding pairs are studied on Béchervaise Island near Mawson, as part of a long term ecosystem monitoring program.

Scientists know much more about the behaviour of Adélies in the warmer months, because they breed on land between October and February. Less is known about their behaviour in the winter where they spend time at sea in the pack ice. Scientists are tracking their routes so they can find out exactly where the Adélies go on their long sea journeys. So far, scientists know that these penguins can swim more than 1,200 km away from their breeding site.

Their main predators are leopard seals, and also skuas who take eggs and chicks from breeding colonies.

Conservation status: least concern

View over colony showing Adélie penguins nesting — Adélie penguins nesting at Shirley Island colony Photo: Tony Fleming

Breeding

In spring, Adélie penguins build nests out of the pebbles they find on dry land. They choose a sloping site so that, when the snow melts, water runs away from the nest. When the pack ice has not yet broken up, finding food nearby can be a problem. Adélies may have to walk over 50 km across the ice to reach the sea. Individuals always return to the same nest and the same mate, if they can.

By mid-November there are 2 eggs in the nest. Parents take turns to incubate the eggs and find food. The first 2 incubation shifts tend to last 11 to 14 days and are followed by shorter shifts. The chicks hatch in December and the parents alternate guard and feeding duties swapping every few days. The adults catch fish, krill and other small crustaceans, which they regurgitate for their chicks. The chicks on Béchervaise Island put on around 80 grams per day.

In January, when chicks are 3 weeks old, they are big enough to be left alone. This allows both parents to simultaneously collect food for them. When the parents are away the chicks group together for protection and warmth.

In February, the chicks replace their down with adult feathers. At the age of 7 to 9 weeks they are ready to go to sea. Most chicks will not return to the breeding colony until they are 3 to 5 years of age and capable of breeding. Adélie penguins have a life expectancy of 10 to 20 years.

Adélie penguin breeding cycle

An Adélie penguin with its egg – the chick’s beak is breaking through the shell at the front — An Adélie penguin with its egg – if you look carefully you can see the chick’s beak breaking through Photo: Matt Pauza

Diet and feeding

The diet of Adélies differs according to the location where food is captured. Local meals (those within 20 km of the colony) consist mostly of fish, amphipods and ‘crystal krill’ (Euphausia crystallorophias), while offshore meals consist of mainly ‘Antarctic krill’ (Euphausia superba). Meal sizes range from about 300 to 650 g depending on the size of the chicks.

Breeding adults swim between 5 to 120 km offshore to catch food for their chicks. Feeding trips range from 5 to 72 hours in duration.

Some Adélie penguins are capable of diving to depths of up to 175 m but usually feed within the upper 70 m of the water column.

Adélie penguin chicks 14 days after hatching — In just 14 days of constantly being fed krill and fish the chicks turn into rather demanding little blobs Photo: Matt Pauza

Adélie satellite tracking

Scientists have attached satellite transmitters to selected Adélies so they can track their movements when out at sea feeding. The transmitters send signals to an orbiting satellite which relays the signals to the Australian Antarctic Division at Kingston, Tasmania. The sea routes of the penguins can then be mapped. Scientists often use dive depth recorders as well to determine how deep the penguins dive to catch their prey.

Automated Penguin Monitoring System

Australian scientists have revolutionised the gathering of data from penguins. Before the new method was in place, scientists had to handle penguins repeatedly to obtain the data required. Now, the Automated Penguin Monitoring System is used to automatically weigh, identify and determine the direction of penguins as they walk across a weighing platform placed between the breeding colony and the sea. This method of gathering data ensures the least disturbance and is less stressful for the penguins.

To identify each bird, scientists use a tiny electronic tag which they implant under the skin of the penguins. As the birds step onto the platform, their tag activates the system. Readings can then be obtained of how long each bird has been away foraging and how much food the bird gives to its chick. The weighing of penguins is important, as scientists can then tell how much krill and fish they are eating and delivering to their chicks.

Three Adelie penguins cross over a weighbridge, set up over rocks and between small gates — The Automated Penguin Monitoring System on Béchevaise Island Photo: Kym Newbery

Adélie penguins squabbling

Adélie penguin colony

Credit: Mark Horstman

Photo gallery

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Close up of Adélie penguin head with big round eye looking at camera

This content was last updated 4 weeks ago on 23 October 2024.