Until now, it was thought that southern right whales and right whales in the North Atlantic could, at most, live to be 70 or 80 years old. They could actually live twice as long ! This is what researchers say in a study published on December 20 in the journal Science Advances.
The researchers modeled the current life expectancy of these species of whales by using photos and data on these cetaceans collected between 1979 and 2021. They concluded that southern right whales currently have a life expectancy of average life of 73.4 years, with 10 % of individuals who had a chance of exceeding 131.8 years of existence.
For North Atlantic right whales, a highly endangered species, the average life expectancy is estimated at just 22 years, the 10 % of oldest individuals over 47 years old.
Such a gap is not normal, however, write the researchers, because the two species are biologically very close. Scientists believe that the low life expectancy of right whales is caused by various anthropogenic pressures and the degraded ecological conditions of their environment (consequences of past mass whaling and current fatal ship collisions, among others). Theoretically, they say, these whales could be capable of living beyond 100 years, or even approaching 150 years, like their southern cousins.
The potential for extreme longevity could be the norm, not the exception. And this, not only for these two species but also for many other cetaceans, emphasize the researchers, which can have serious implications on the fragility of these populations and the importance of preserving them in the long term.
« For animals that can live 100 or 150 years and only have a surviving baby about once every ten years, a slow recovery can be expected. [des populations] »comments Greg Breed, researcher at the University of Alaska (United States) and lead author of the study, in a press release.
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