Study reveals right whales live 130 years -- or more

Extreme longevity is a trait common to the right whales' cousins, the bowheads.

Scientists working with Indigenous subsistence hunters in Utqiaġvik used chemical analysis of harvested bowhead whales to show they can live more than 200 years. Corroborating the chemical evidence, hunters have recovered 19th-century harpoon tips from bowheads taken in modern hunts.

Right whales, which are much more closely related to bowhead whales than any other species, appear to exhibit similar lifespans. Like bowheads, right whales filter feed through baleen and migrate seasonally to give birth. Whalers considered them the "right" whales to hunt due to their thick blubber, which caused them to float when killed.

The current study examined four decades of data collected by photo identification programs tracking individual whales from two species: the Southern right whale, which lives in the oceans south of the equator, and the critically endangered North Atlantic right whale, found along the Atlantic coast of North America. Researchers used the data to construct survivorship curves -- graphs that show the proportion of a population that survives to each age -- similar to those used by insurance companies to calculate human life expectancies.

Analysis revealed that Southern right whales, once thought to live only 70 to 80 years, can exceed lifespans of 130 years, with some individuals possibly reaching 150 years. In contrast, the study found the average lifespan of the North Atlantic right whale is just 22 years, with very few individuals surviving past the age of 50.

According to University of Alaska Fairbanks associate professor Greg Breed, the stark contrast in lifespans between these two closely related species is primarily due to human impacts. Breed is the study's lead author.

"North Atlantic whales have unusually short lifespans compared to other whales, but this isn't because of intrinsic differences in biology, and they should live much longer," he said. "They're frequently tangled in fishing gear or struck by ships, and they suffer from starvation, potentially linked to environmental changes we don't fully understand."

Breed has spent years studying marine mammals, including seals, certain species of which can live up to 50 years, and narwhals, with lifespans of a century or more. He noted that a lack of data on whale aging led to significant underestimations of their lifespans in the past.

"We didn't know how to age baleen whales until 1955, which was the very end of industrial whaling," Breed said. "By the time we figured it out, there weren't many old whales left to study. So we just assumed they didn't live that long."

The study has important implications for conservation efforts. "To attain healthy populations that include old animals, recovery might take hundreds of years," Breed said. "For animals that live to be 100 or 150 and only give birth to a surviving calf every 10 years or so, slow recovery is to be expected."

The study also underscores the importance of cultural knowledge among whale populations.

"There's a growing recognition that recovery isn't just about biomass or the number of individuals. It's about the knowledge these animals pass along to the next generation," Breed said.

"That knowledge isn't just genetic -- it's cultural and behavioral. Older individuals teach survival skills. Younger animals learn by observing and copying the strategies of the older ones."

The loss of older individuals disrupts this critical transfer of knowledge and can impair the survival of the young.

Breed and his colleagues intend to extend their research to other whale populations and predict whether other whale species currently thought to live around 80 years may also have much longer lifespans. They hope to learn more about how whaling affected the number of old individuals in current whale populations and predict when their numbers will recover to pre-whaling levels.