Scientists Strapped Cameras to African Penguins—Here's What They Saw

Scientists that strapped cameras to penguins in Africa have found the animals dive deep into the ocean to drive their prey to the surface, enabling other seabirds to pick off the fish.

The researchers at Nelson Mandela University om South Africa attached the equipment to the lower backs of 20 African penguins living at Stony Point in the country to learn about how seabirds feed.

The resulting 31 hours of footage—shot over a period of four breeding seasons between June to August 2015 and 2018—showed 57 dives. By watching these videos, the team learned about how deep and far the penguins swam, and the types of fish they caught.

The footage showed penguins herding anchovy schools from depths of 30 meters up to 5 meters of the water surface, which enables other seabirds to reap the benefits, study co-author Alistair McInnes told Newsweek.

"As such, penguins may be integral to important processes that influence the structure and integrity of marine communities," the authors of the study wrote in their paper published in the Royal Society Open Science.

McInnes said: "The paper confirms what fisherman and scientists have thought for a long time based on observations from boats, i.e. diving birds, such as penguins, can drive prey to the surface where they become more accessible to other seabirds."

This is the first study to show this association from a penguin's perspective using video loggers attached to the animals, he said.

"This is similar behavior observed in dolphins, for example common dolphins, which are known to corral sardines to shallow waters where they are taken advantage of by Cape gannets and other marine predators."

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African penguins on the boulder in sunset - Stock image Getty

The team also learned seabirds like sooty shearwaters and Cape cormorants show an active interest in African penguins at the surface, even if they haven't gathered prey.

"This may be especially advantageous when prey is scarce as penguins are known to track the distribution of their prey effectively around their breeding colonies, usually within 40 km of their colonies between April and October," explained McInnes.

The team were surprised by how quickly other seabirds can locate African penguins, "especially when they are in large groups at the surface."

"This study shows that diving seabirds can play an important role in improving the foraging efficiency of other seabirds," said McInnes.

"African penguins are currently endangered having lost more than 70 percent of their population since 2004 largely due to a reduction in the availability of their prey," he said. "Studying how they find and catch their prey at sea will give us insights into how to best manage their prey supplies."

The fish they eat has been targeted by commercial operations which fish using the purse-seine technique. This involves using a net to enclose and capture a school of fish.

Scientists have been able to stick cameras to penguins for about two decades, McInnes said. But animal cameras have become a lot more affordable in the last few years. In the past, scientists would rely on observing these birds from boats.

"It is fairly easy to attach loggers to the birds while they are breeding as when African penguins are attending their chick at the nest they take turns to forage at sea—so we deploy the camera on one partner and retrieve [it] in two days time," McInnes explained.

Natasha Gownaris, a postdoctoral researcher in the Center for Ecosystem Sentinels at the University of Washington, who did not work on the research, told Newsweek: "A lot of processing time is required for these videos because encounters have to be coded by a human. This likely limits the sample size, which was only 20 individuals in this study.

"We also know little about how device attachment impacts the foraging behavior of seabirds."

She continued: "This study helps us to understand the complex role that species, including penguins, play in their ecosystems—not only as prey, predators and competitors, but also through more nuanced, indirect interactions.

"The African Penguin population has decreased from over 1.5 million pairs to a little over 20,000 pairs since the early 1900s, and this study shows how difficult it is to predict how the continued decline of this species will impact other species in South Africa."

Last month scientists who took a similarly hands-on approach to studying sealife published a paper showing that baby tiger sharks feed on songbirds before they have learned to hunt. The scientists, who published their work in the journal Ecology, arrived at the conclusion by pumping baby tiger sharks stomachs.

This article has been updated with comment from Natasha Gownaris.

Scientists Strapped Cameras to African Penguins—Here's What They Saw | Tech & Science