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https://theconversation.com/whales-can-live-way-longer-than-scientists-had-thought-with-potential-lifespans-as-much-as-double-previous-estimates-245826>
"Southern right whales have lifespans that reach well past 100 years, and 10%
may live past 130 years, according to our new research published in the journal
Science Advances. Some of these whales may live to 150. This lifespan is
almost double the 70-80 years they are conventionally believed to live.
North Atlantic right whales were also thought to have a maximum lifespan of
about 70 years. We found, however, that this critically endangered species’
current average lifespan is only 22 years, and they rarely live past 50.
These two species are very closely related – only 25 years ago they were
considered to be one species – so we’d expect them to have similarly long
lifespans. We attribute the stark difference in longevity in North Atlantic
right whales to human-caused mortality, mostly from entanglements in fishing
gear and ship strikes.
We made these new age estimates using photo identification of individual female
whales over several decades. Individual whales can be recognized year after
year from photographs. When they die, they stop being photographically
“resighted” and disappear. Using these photos, we developed what scientists
call “survivorship curves” by estimating the probability whales would disappear
from the photographic record as they aged. From these survivorship curves, we
could estimate maximum potential lifespans.
Twenty-five years ago, scientists working with Indigenous whale hunters in the
Arctic showed that bowhead whales could live up to and even over 200 years.
Their evidence included finding stone harpoon points that hadn’t been used
since the mid-1800s embedded in the blubber of whales recently killed by
traditional whalers. Analysis of proteins from the eyes of hunted whales
provided further evidence of their long lifespan. Like right whales, before
that analysis, researchers thought bowhead whales lived to about 80 years, and
that humans were the mammals that lived the longest.
In the years following that report, scientists tried to figure out what was
unique about bowhead whales that allowed them to live so long. But our new
analysis of the longevity of two close relatives of bowheads shows that other
whale species also have potentially extremely long lives."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
