Do old female wolves go into "menopause"?

[MochaManiac]

I know wolves don't live very long, especially in the wild, but is it known whether wolves go into some type of menopause once they're getting older? I would understand that old age makes it harder and riskier to have litters and that those litters would be unhealthy and smaller, but that would technically mean the female wolf can still go into heat. So, is menopause really a thing for wolves? I just think it's crazy that a wolf could potentially rear pups if they're 8+ (if they even get to that age!).
I'm open to answers regarding both wild and domestic/captive wolves!

[DaniBeez]

is it known whether wolves go into some type of menopause once they're getting older?

No they do not! This is because menopause is unique to the kind of menstruation some primates (including humans) undergo.

Wolves and many other placental mammals instead have estrous cycles. A key difference between estrous cycles and menstruation is that in the former, the uterine lining is completely reabsorbed by the animal. In menstruation the uterine lining is shed (as those of us who have to deal with this know all too well ).

I just think it's crazy that a wolf could potentially rear pups if they're 8+ (if they even get to that age!).

I think what makes the reproductive pattern of animals with estrous cycles seem crazy to us (humans) is because we subconsciously compare it to our own species. We don't associate 'older women' with pregnancy because of menopause. Then we extend that observation to other species like wolves, even if we don't mean to.

If we use litter size as a measure of reproductive performance: what affects litter size if wolves can go into estrus (and potentially become pregnant) throughout their lives? What contributes to "reproductive senescence", i.e. an age-related decline in reproductive performance? I think that is what you were getting at with menopause, maybe.

Scroll down to Figure 2 in this paper. The study that generated it used a 13-year dataset based on Yellowstone litters to compare litter size against a few factors: mother's age, mother's body mass, total pack size, and population. In short, there are multiple factors affecting litter size in wolves and in different (but sometimes related) ways.

The authors note the following in the Discussion:

Given wolves' relatively short life spans, it is not surprising that age was relatively unimportant to reproduction compared to body mass.

Wild wolves face selection pressure from a short lifespan to reach optimal reproductive performance before they die. This typically happens by age 5-7 from disease, poaching, hunting, intra-species disputes, etc. Earlier research showed that wolf body mass—which we now know to be important for having bigger litters—also peaked around 5 years of age. Not a coincidence!

[-Wolfdog-]

is it known whether wolves go into some type of menopause once they're getting older?

No they do not! This is because menopause is unique to the kind of menstruation some primates (including humans) undergo.

Wolves and many other placental mammals instead have estrous cycles. A key difference between estrous cycles and menstruation is that in the former, the uterine lining is completely reabsorbed by the animal. In menstruation the uterine lining is shed (as those of us who have to deal with this know all too well ).

I just think it's crazy that a wolf could potentially rear pups if they're 8+ (if they even get to that age!).

I think what makes the reproductive pattern of animals with estrous cycles seem crazy to us (humans) is because we subconsciously compare it to our own species. We don't associate 'older women' with pregnancy because of menopause. Then we extend that observation to other species like wolves, even if we don't mean to.

If we use litter size as a measure of reproductive performance: what affects litter size if wolves can go into estrus (and potentially become pregnant) throughout their lives? What contributes to "reproductive senescence", i.e. an age-related decline in reproductive performance? I think that is what you were getting at with menopause, maybe.

Scroll down to Figure 2 in this paper. The study that generated it used a 13-year dataset based on Yellowstone litters to compare litter size against a few factors: mother's age, mother's body mass, total pack size, and population. In short, there are multiple factors affecting litter size in wolves and in different (but sometimes related) ways.

The authors note the following in the Discussion:

Given wolves' relatively short life spans, it is not surprising that age was relatively unimportant to reproduction compared to body mass.

Wild wolves face selection pressure from a short lifespan to reach optimal reproductive performance before they die. This typically happens by age 5-7 from disease, poaching, hunting, intra-species disputes, etc. Earlier research showed that wolf body mass—which we now know to be important for having bigger litters—also peaked around 5 years of age. Not a coincidence!

Let’s say a wolf (or dog) reached the ripe old age of 14. I have heard that, the older a dog is, the less fertile she will be and the harder it is to conceive. Would this be relatively similar to menopause in humans?

[DaniBeez]

Let’s say a wolf (or dog) reached the ripe old age of 14. I have heard that, the older a dog is, the less fertile she will be and the harder it is to conceive. Would this be relatively similar to menopause in humans?

Not similar to menopause (primates), since dogs/canines have estrous cycles. What you described here would be reproductive senescence, which applies to both dogs and humans. Reproductive senescence in general refers to age-related decline in reproductive performance, and the term can be applied across many animal species, whether they menstruate or not. What causes reproductive senescence is not entirely understood. Long-lived species like turtles, naked mole rates, and trees challenge our understanding of biological senescence/aging. Hope that clarifies things!