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A penguin’s perspective – How tiny cameras reveal underwater theft and cooperation

A penguin’s perspective – How tiny cameras reveal underwater theft and cooperation
The footage also revealed that African penguin help other seabirds forage by corralling sardine shoals from deep waters to the surface, where they are easier to catch. (Photo: Alistair McInnes)
Julia Evans
By Julia Evans
1 Aug 2024
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By taping a tiny camera on penguins’ backs, researchers have observed the birds stealing prey from one another, a behaviour previously unrecorded in the marine environment.

Historically, scientists have used tracking devices (GPS and satellite-linked transmitters) to follow marine life.

“But we don’t know what they do at sea and what their behaviour entails,” said Prof Pierre Pistorius at the Plett Marine Science Symposium in July 2024.

To address this gap, researchers now deploy miniaturised video cameras on marine animals, capturing the context of their activities and decision-making processes.

pistorius penguin Pierre Pistorius holds an Eastern Rockhopper Penguin as part of a research project on Marion Island in 2014. (Photo: Mariette Wheeler)



Pistorius is a marine biologist and head of the Marine Apex Predator Research Unit, which forms part of the Institute for Coastal and Marine Research and the Department of Zoology at Nelson Mandela University. There, he uses a blend of technology and ecology to showcase the underwater world from a penguin’s perspective, feeding research results back into conservation management. 

The waterproof cameras are taped to the backs of penguins at their nests, where it’s easy for researchers to catch and handle the birds.

pistorius Professor Pierre Pistorius integrates the fields of population and behavioural ecology with climate change science and resource management. (Photo: Supplied)



After the penguin returns from a foraging trip during their breeding season, the researchers catch the bird, retrieve the video camera and download the footage. When Pistorius initially started with this research, the cameras would record for 90 minutes, but now they can record for eight hours.  

This allows researchers to watch penguin behaviour and interactions in real-time, providing never-before-seen insights into their underwater lives.

How gentoo penguins forage


Much of Pistorious’ research revolves around the use of penguins and other predators as ecological indicators. For gentoo penguins, Pistorius’ research has shown that these predators adapt well to changes in the environment and are good indicators of environmental conditions.

In 2009, Pistorius enlisted PhD student Jonathan Handley to study the foraging behaviour of gentoo penguins around the Falkland Islands. One key finding was that these penguins feed on lobster krill, a crucial food source for many predators in the South Atlantic.

In one scenario, a camera on a gentoo’s back revealed that the bird didn’t feed on a densely aggregated swarm of krill, opting instead to feed on a single individual. In another scenario, the camera showed that a penguin encountered a less densely aggregated swarm and fed on the periphery. The footage Handley collected revealed that the probability of penguins feeding is lower with denser swarms and higher with sparser ones.

gentoo penguins Two Gentoo Penguins make an approach on the beach of Yellow Point on the outskirts of the Comandante Ferraz Station, on 1 January 2020 in King George Island, Antarctica. (Photo: Alessandro Dahan / Getty Images)



“This intrigued us, especially considering that we use their diet as an indicator of what food is out there,” said Pistorius.

“It’s something that we would never have anticipated or got hold of if it wasn’t for the use of video footage.”

Remarkably, the cameras also captured instances of lobster krill fighting back against penguins.

“We never thought this would be the case, but you can see from the footage that about two metres before the penguin hits the krill, it flares up,” said Pistorius. “And we saw numerous instances of this, where the krill survived.”

Kleptoparasitism in penguins


One of the most fascinating discoveries from this research is kleptoparasitism among penguins. Through the camera’s lens, on several occasions, Pistorius and his research group have observed penguins stealing prey from one another, a behaviour previously unrecorded in the marine environment.

At the Falkland Islands in the Southern Atlantic, the cameras documented the first instance in the marine environment where a penguin was seen stealing food from another animal. Similar behaviour was also observed at Marion Island in the Indian Ocean, showing that kleptoparasitism among penguins is not rare.

“We didn’t expect this, but we found exactly the same thing,” said Pistorius, speaking of what field researcher David Green found while spending a year on Marion Island.

“But what we found here was the largest size prey consumed ever reported for a gentoo penguin, and per unit size for any penguin,” said Pistorius.

Footage collected from a gentoo penguin saw the bird going for a large squid (240mm), capturing it in its mouth, and heading to the surface to swallow it – but before it could, a second penguin grabbed the squid and swam off with it.

squid Still from camera footage showing two gentoo penguins battling each other to catch a squid. (Source: David Green)



The camera captured a fierce battle, with about eight exchanges between the two penguins, before the penguin with the camera finally regained the squid and was able to get to the surface to swallow it whole.

 



“There is a lot to be seen and a lot of information,” said Pistorius, as the video played at the symposium. “We can actually see a penguin physiologically really stressed – they’re grafting as hard as they can.”

Another interesting finding, which Pistorius took comfort in, is that the bird with the camera won its battle for the squid. “We’re always worried about the influence of instruments on the behaviour and welfare of the animal,” he said. 

squid Still from footage showing a gentoo penguin swimming away with a stolen squid. The squid had an estimated mantle length of 240mm and was the largest-sized prey consumed ever reported for a gentoo penguin, and per unit size for any penguin. (Source: David Green)



“In this case, through this really fierce battle, the one with the camera got it, which at least gives some indication that it’s not impacting its foraging ability.”

Working together


Off the South African coast, cameras have documented the importance of group foraging among African penguins, which researchers have seen on the surface of the sea – but the video footage provided a detailed look at their interactions and context during foraging.

As with other penguin species, researchers know where African penguins go because of trackers, but they wanted to get a better idea of their interactions and the context in which they forage, and how that can help better manage the endangered species.

Working in Pistorius’ research group, Alistair McInnes from BirdLife deployed cameras on several African penguins to gauge their success when feeding alone and in groups. The footage showed that their catch was much more successful when feeding cooperatively.

“What this demonstrates is one of those negative spirals – as the population gets lower, there are fewer penguins in the environment and less opportunity for them to feed cooperatively,” said Pistorius. This is crucial information for a species as threatened as the African penguin.

penguins forage The footage also revealed that African penguins help other seabirds forage by corralling sardine shoals from deep waters to the surface, where they are easier to catch. (Photo: Alistair McInnes)



The footage also revealed that African penguins play an important role in the ecosystem by helping other seabirds forage by corralling sardine shoals from deep waters to the surface, where they are easier to catch.

“From a management perspective, we often focus on single species. But we need to think much bigger and recognise the ecological importance and role that these species play in the environment.” DM

https://www.youtube.com/watch?v=REeWvTRUpMk

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