Beluga whales and narwhals go through menopause ‘like humans’

Beluga whales and narwhals go through menopause ‘like humans’ because it stops them from having too many young to feed in later life

  • The latest finding means five species are now known to go through menopause
  • Most animal species in the wild continue reproducing until they die 
  • This evolutionary trait helps mothers care for descendants for most of their lives
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Beluga whales and narwhals go through menopause ‘just like humans’, scientists have discovered.

They suggest the trait, which is extremely rare in the animal kingdom, helps cut down competition for food within family groups.

Most species in the wild continue reproducing until they die, but the latest finding means a total of five species are now known to stop reproducing during their lifetime.

Alongside humans, killer whales and short-finned pilot whales were the only other species previously known to experience the menopause.

Understanding how whales evolved the trait may shine light on why our early ancestors developed the trait.

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Beluga whales and narwhals go through menopause ‘just like humans’, scientists have discovered. The Beluga, also known as the white whale (file photo), lives for between 35 and 50 years


Menopause is extremely rare in the animal kingdom, and scientists suggest it may help whales cut down competition for food within family groups. The narwhal (file photo) is famous for its long ‘tusk’, which is actually a tooth that can grow up to 8.8 feet long (2.7 metres) 

Researchers from the University of Exeter, University of York and US Center for Whale Research conducted the new study.

They used data from the dead whales of 16 species and found dormant ovaries in older beluga and narwhal females.

These species may have social structures which mean females live among more and more close relatives as they age, the researchers said.

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They suggest the menopause has evolved independently in three toothed whale species, with beluga whales and narwhals possibly sharing a common ancestor.

Lead author Dr Sam Ellis, from the University of Exeter, said: ‘For menopause to make sense in evolutionary terms, a species needs both a reason to stop reproducing and a reason to live on afterwards.

‘In killer whales, the reason to stop comes because both male and female offspring stay with their mothers for life – so as a female ages, her group contains more and more of her children and grandchildren.


Most species in the wild continue reproducing until they die, but the new study means five species are now known to stop reproducing and continue living after. Along with humans, killer whales (file photo) and short-finned pilot whales go through menopause

‘This increasing relatedness means that, if she keeps having young, they compete with her own direct descendants for resources such as food.

‘The reason to continue living is that older females are of great benefit to their offspring and grand-offspring.

‘For example, their knowledge of where to find food helps groups survive.’

Research into human ancestors suggests they lived among more relatives as they aged. As a result, the menopause may have been favoured as an evolutionary trait to enable older women to impart their wisdom onto younger members of a group – without their time being consumed with their own offspring.

WHY DO SOME SPECIES GO THROUGH MENOPAUSE?

Few animals are known to experience menopause, with most species reproducing until they die.

Alongside humans; killer whales, killer whales, short-finned pilot whales, beluga whales and narwhals have evolved the trait.

Typically, menopause is triggered when animals undergo hormonal changes that cause them to stop being able to reproduce.

Researchers suggest this biological ‘off-switch’ is useful in species who spend most of their lives looking after their descendants.

In killer whales, for example, both male and female offspring stay with their mothers for life, as well as grandchildren.

The mother is responsible for finding food, and if she kept having offspring her direct descendants would have to compete for resources.

Senior author Professor Darren Croft, from the University of Exeter, said: ‘It’s hard to study human behaviour in the modern world because it’s so far removed from the conditions our ancestors lived in.

‘Looking at other species like these toothed whales can help us establish how this unusual reproductive strategy has evolved.’

There has already been extensive research into the existence of the menopause among killer whales.

Detailed observations of live beluga whales and narwhals have not yet been carried out.

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