Female animals who do not all reproduce apart from humans?

[Splodgetastic]

Just that - are there any and what is their role? I know there are insects and whale species who go through menopause and have roles such as guarding the colony, helping younger females and showing where food is, but are there species who do not mate or do not reproduce in all cases? Was thinking about it as I approach menopause as a childless woman (and I’m not going to justify being on Mumsnet!) and Google came up with no answer.

I wasn’t thinking about mice deciding not to, but rather maybe a lack of mates or food or whatever! I think we can’t talk about choice in the same way with animals. What roles do childless females have and are there situations where females are theoretically fertile but don’t reproduce and, if so, what is the role in the pack? The wolf example is good and I wondered what the role was in the pack.

There could be something to that. A quick google suggests that, apart from whales, it’s mainly animals in captivity (including lab rats and mice) that live beyond menopause. It’s not ‘natural’ for most species.

I was going to say meerkats, but see a pp beat me to it!

I remember there being quite a to-do on meerkat manor (ever watch that?) When a female other than the pack leader got pregnant (kicked out of the pack, allowed back in eventually after babies died).

I think many mammal species that live in packs have a sort of collaborative approach to rearing young, where only females of a certain status breed but others in the pack (male and female) help with the youngsters.

I read that there are some insects who go through menopause and two species of whales. The insects guard the colony. The whales help with child rearing and show where food is. Apparently if an older female whale has a calf and her daughter has a calf the outcomes are not as good as there is competition for food etc.

Interesting topic. I always felt I was infertile, but became pregnant and had a child. I've never been pregnant before or since so I feel I'm not fertile (how I ended up with the baby in the first place). My dsis is 34 and a bit proper. She's not yet married, and I worry that by the time she gets married and tries for babies it will be too late. I desperately want her to have babies so that I can say 'see, I told you so!'. She knows fucking everything.

Look up the "grandmother hypothesis". The idea is that a woman can make a serious contribution to the survival of her daughters' children if she can hang around after having her own babies. And it actually helps that she's no longer fertile, because being middle-aged, she wouldn't be around long enough to bring up more of her own children, but the effort to do so would take her away from the grandchildren. Of course over human history, maybe only a minority of women would live long enough to help with their grandchildren, but of those who did, the help might be significant. You know, protect the children from hyenas while their mother was away getting some food for them all?

en.wikipedia.org/wiki/Grandmother_hypothesis

I think the amount of time it takes humans to raise their young to self sufficiency (even in comparison to our longer lifespans) is unusually long for mammals isn't it?
Especially as we don't have big litters, so need a greater proportion of offspring to survive to maintain numbers.

Might explain why the help of grandmothers is relevant to humans, and not to most other mammals?

I wonder if it’s also linked to language? Post-menopausal women, even those so old as to be no physical help in child rearing, are still a source of knowledge that can be passed on and increase the chances of a child surviving to maturity.

The grandmother effect is interesting though because a grandmother would be ensuring the survival of a child who shares only 25% of her genes.

Not quite the same thing, but I've observed moorhens that have more than one batch of chicks in a year... The older chicks help the parents out when the second lot are born.

I assume there must be other bird species that do similar (not ducks, whose parenting skills are far inferior to moorhens and have a higher loss rate).
Collaboration in raising young seems fairly common in the animal kingdom.

It reminds me of the gay hypothesis. (Not a real name) but that adult members of the tribe who do not reproduce are helpful in providing for nieces and nephews. So their combination of genes live on, producing more gay individuals

@TEiTetua, that’s was what I read about whales, but that’s more about the science behind menopause in mammals that live a long time rather than mammals that die without ever reproducing. I would be interested to understand more though as it seems interlinked. For example, horses that have never been bred are harder to breed from as they age than those that have and women in my family that never had children seem to die earlier than those that did. Those that had children when they were older (my DGM on my DM’s side, who had a late addition) lasted longest - until their youngest (childless) child was 53.

@7Days, could be something in that.

Wow, still more hypotheses coming through! Finding this all very interesting, so thanks.

It's definitely not true that we would "naturally" die at around the age of menopause. Yes, life expectancy used to be around 40-50, but that didn't mean everyone dropped dead at 50, it was an average - many children and infants died which brought the average life expectancy down, and people wouldn't have lived into their 90s as commonly as they do today, but if you did live through childhood you could expect 70, 80 or so years.

We don't die at menopause; life expectancy without access to modern vaccines and medicine just happens to coincide with that age.

You could argue that menopause is a protective mechanism that stops older females falling pregnant and so helps keeps them alive.
They are then available to promote the stability of the group, pass on their knowledge, and help look after the young.

Post-menopausal women, even those so old as to be no physical help in child rearing, are still a source of knowledge that can be passed on and increase the chances of a child surviving to maturity.

As long as they don't attempt to pass on their knowledge to a mumsnetter, because that would be beyond the pale and necessitate NC

To be morbid, but I don't think we are really meant to live past menopause, we have intervened to (try to) make us live longer. In a natural state we wouldn't live as long as we do.

But older adults who don't have young children of their own to look after are incredibly useful in helping look after young children and ensuring their survival (whether related to them or not).

Even just doing something like food prep/cooking for a mother of a baby or young child helps the child & mother stay nourished and ultimately survive. It can be tough for a mother without help esp if the child is sick for example, which small children regularly are.

People have lived to old age for a long long time, if conditions were conducive to it.

Human females have been living past the menopause for millennia. Much more so than males who were forced into armed combat from the age of 8 onward.

Birds are fascinating on the subject of reproduction if you wish to go outside humans.

Although humans are mammals, humans are at the top of the food chain. That is important.

In some circumstances (broadly when there are not enough pupae/larvae in the hive) worker bees will start to lay eggs - but because they haven't mated they can only lay drones.

OP might be interested in Richard Dawkins "The Selfish Gene" ...

The trade off between individual behaviour(s) and survival of the species is fascinating and not at all well understood ...

@DGRossetti, thanks for the recommendation. Is it easy to grasp for someone who didn’t do science past GCSE? I assume it’s readable as I’ve heard of it, so it must be quite a popular book.

If you can get a copy from a library, it's worth a try !

It's not a textbook, and Dawkins (who I admire as a scientist and communicator, but who can be a little annoying) is quite a clear writer.

"The Ancestors Tale" is also a good read - more about evolution. The chapter on why race is a load of bollocks is a must-read, in my humble opinion/