Poop From Southern Right Whales Reveals That the Animals Might Be More Resilient to Climate Change Than We Thought

Scientists long believed that these whales, which swim throughout the Southern Hemisphere, mainly feasted on krill and small crustaceans called copepods, which are disappearing from the warming ocean. A new study suggests that the cetaceans have a more varied, flexible diet

Sarah Kuta | Daily Correspondent

July 20, 2026 10:00 a.m.

Share

Copy linkEmailSMSFacebookXRedditLinkedInBlueskyPrint

Add as preferred source

Southern right whales might be eating a more diverse diet than previously thought, an adaptation that scientists hope will make them more resilient in the face of changing environmental conditions.

Scientists had long assumed that the hulking marine mammals were mostly eating krill and tiny crustaceans called copepods. But after investigating the creatures’ poop, they’ve discovered that young crabs, shrimp and lobster also make up a large portion of their diet.

The findings, published June 15 in the journal Molecular Ecology, paint a more encouraging picture for the species amid human-caused climate change, which is putting pressure on what was thought to be their main food sources in the Southern Ocean.

“Resilience is good,” says study co-author Emma Carroll, a biologist at the University of Auckland, on Radio New Zealand’s “Checkpoint” program. “Not having reliance on one or two types of prey has to be good, when ecosystems are changing.”

Found throughout the Southern Hemisphere, southern right whales are large filter-feeders that can weigh up to 176,000 pounds and reach lengths of up to 56 feet. After being hunted to the brink of extinction during the 19th and 20th centuries, experts placed legal protections on the animals, and their global population has since rebounded to an estimated 15,000 individuals.

However, their recovery has been uneven, and some regional populations continue to struggle. Additionally, southern right whales also face numerous modern threats, including chemical and noise pollution, entanglement in fishing gear, climate change, vessel strikes and overall habitat degradation.

As global warming heats up the Southern Ocean and melts sea ice, scientists wanted to understand what southern right whales were eating—and whether they could adapt to these shifting ocean conditions. So, Carroll and her colleagues analyzed 52 southern right whale fecal samples, collected between 2003 and 2021 from the state of South Australia, as well as South Africa and New Zealand’s Auckland Islands.

“I’m looking at their diet using DNA metabarcoding—basically, using a genetic method to see what prey DNA we can pick up in the poop,” study co-author Aashi Parikh, a biologist at Macquarie University in Australia, told Jodie Hamilton of the Australian Broadcasting Corporation (ABC) last year.

The investigation revealed that southern right whales are eating a much wider variety of seafood than expected. They were feasting on krill, but also lots of other critters—including jellyfish, mantis shrimp, saltwater clams and nudibranchs—which hints that their diet might be somewhat flexible.

“This is the first time we’ve been able to get to the real nitty-gritty of exactly what they’re eating,” Parikh says in a statement. “It’s exciting because it opens a lot of questions about what alternative prey sources they might be able to survive on if climate change continues to threaten krill and even copepod populations, as it has been over the last several decades.”

Some of the samples came from Rod Keogh, a South Australia-based whale tour operator who’s been collecting whale poop for nearly a decade.

“I’m stockpiling it again in my freezer, much to my wife’s disgust,” he told the ABC last year.

According to Keogh, whale poop is a lot smaller than most people imagine—up to the size of a fist, with a clay-like consistency. It’s also “ridiculously smelly,” he added.

Although scientists now have a better understanding of what the whales are eating, many questions remain. For instance, southern right whales have started giving birth to calves every four years on average, instead of every three, and researchers want to investigate whether the animals’ diet might be affecting their reproduction.

“We don’t know if they’re getting enough nutrients,” Carroll tells Yahoo News’ Michael Dahlstrom. “What might be good for an individual might not provide the right mix of nutrients for a calf.”

Additionally, the researchers were able to study whale poop from just a handful of locations, leaving major gaps in their understanding of what the whales are eating across much of their broad feeding range.

“Ninety percent of our whales are foraging in a region south of Australia, but we’re not able to sample their poo when they’re out in the open ocean like that, and, in fact, this region is virtually unstudied,” Carroll tells “Checkpoint.” “We don’t really know what kind of ecosystem and plankton are there.”

Sarah Kuta | Read More

Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food and beverage, sustainability, economics and other topics.