Some penguins like their fish with a side of jelly, a new study shows. By looking at the DNA in the birds’ poop, researchers found that they eat a surprising amount of gelatinous prey, including tiny tube-shaped animals called salps. Knowing what’s on the menu for penguins is important for understanding the health of not just these seabirds, but of their whole ecosystem.
Catherine Cavallo, a PhD candidate in ecology at Monash University in Australia, is trying to turn seabirds into tools for learning about ocean environments. In particular, she studies little penguins, which get their name for being the smallest of all penguins at just 30 centimeters high. These penguins stay close to home when they hunt, Cavallo says. That means observing what they eat could help researchers track changes in the local environment.
The traditional way of studying an animal’s diet is to examine its stomach contents or feces. “It’s usually some random assortment of body parts and mush that are pretty hard to identify,” says Travis Gerwing, an ecologist at the University of Victoria in British Columbia who wasn’t involved in the new study. Even if you can tell what you’re seeing, this method over-represents species with hard parts such as shells, bones, or beaks. Soft, squishy prey are more likely to disappear entirely in the digestive process, Gerwing says.
Photo: JJ Harrison/Wikimedia Commons
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