New research co-authored by a Griffith University researcher into the lifespans of baleen whales has yielded boom-or-bust results for two well-known species, with one species’ age estimates almost doubling from what was previously thought and the other drastically reduced due to human-driven impacts.
The international research team have given new lifespan estimates to southern right whales and North Atlantic right whales, both of which are baleen (filter feeding) whales whose previous documented ages were, it turns out, estimated low. Centuries of whaling had killed off old whales, leading to an inaccurate picture of how long these whales could live.
The study, led by Dr Greg Breed from the University of Alaska Fairbanks, with Dr Els Vermeulen of the University of Pretoria and Dr Peter Corkeron from Griffith University, used ongoing 40+-year mark-recapture databases from the thriving southern right whale (SRW) and highly endangered North Atlantic right whale (NARW).
The team found the median lifespan for SRW was 73.4 years, with 10% of individuals surviving past 131.8 years. NARW lifespans were likely shortened due to human impacts, with a median lifespan of just 22.3 years, and 10% of individuals living past 47.2 years.
The researchers said using the context of extreme longevity recently documented in another whale species, all balaenid and perhaps most great whales had an “unrecognised potential for great longevity that has been masked by the demographic disruptions of industrial whaling”.
Dr Peter Corkeron, an Adjunct Senior Research Fellow at Griffith’s Centre for Planetary Health and Food Security, said this unrecognised longevity had considerable implications for basic biology and conservation of whales.
“Received wisdom is that the longest that right whales live is into their 70s,” Dr Corkeron said.
“This work shows that they can live to about twice that – models estimate that 10% of them live to over 130, and the tail of the best-fit model stretches out to past 150. “We have better ways of modelling whales’ ages, combined with populations of whales that are recovering after industrial whaling, so we have far more information to assess how long these whales could live.”