Why does a mongoose mother synchronize her litter with other mothers
The striped mongoose (Mungos mungo) is a carnivorous mammal with an elongated body, lives in thickets of vegetation and dens, is active day and night and is common in Central and East Asia. The mongoose feeds on rodents, birds, invertebrates and reptiles including poisonous snakes.
Individuals of the striped mongoose species live in mixed groups of 7-40 individuals (on average 20 individuals per group). Group members sleep together in underground dens. The female gives birth to 2-5 cubs (an average litter has 4 cubs). The cubs are kept in the den for several weeks and reach nutritional independence at the age of 3 months.
Four times a year the female mongoose gives birth to her cubs on the exact same night along with over half of all the females in her group. Up to 10 females can give birth at the exact same time.
These little carnivores don't plan a joint birthday party for their offspring. The reason for the synchronized births is to increase the survival chances of births.
The researchers who examined the phenomenon report that a litter of mongooses that is estranged a day or two before the synchronized date has a 30% higher chance of being killed by another adult female mongoose in the group.
The females in the group are not interested in competition between the puppies. To avoid competition and to protect their cubs they kill other cubs while their cubs go out looking for food. However, if all the litters are littered at the same time, all the mothers go out in search of food at the same time and therefore there are no females left who can harm the cubs.
Cubs that are born after the synchronized time also suffer from a survival disadvantage since the cubs have less time to grow, they are more vulnerable when they leave the den and they suffer from competition from more mature and stronger cubs that were born before them.
In their article, entitled "Reproductive Competition and the Evolution of Extreme Birth Synchronization in a Cooperative (Cooperative) Mammal" the researchers claim that reproductive events in cooperative societies often tend to a high degree of temporal clustering, that is, to a high frequency of litters in a short and shared period of time, but the evolutionary reasons for this synchronization are still not clear. In the case of mongooses (Mungos mungo), the researchers suggest that the high synchronization results from selection to avoid the negative effects of competition from other females.
Another hypothesis presented in the article is that similar situations during the development of early human society can explain why (to this day) women who are separated from each other for a long time have the phenomenon of synchronizing their menstrual cycles.
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8 תגובות
In many creatures that live in large groups there is littering / hatching / spawning /
Coordinated: ants and bees, water turtles and fish, caribou, wildebeest and others. The most obvious and logical advantage is the statistical chance of survival, the more there is
Young people each have a higher chance of surviving - a lower chance of being eaten,
The smaller the groups, the smaller the relative statistical advantage,
Therefore, the researchers' attempt to compare the reasons for twin litters in huge herds
With litters in small groups... wrong.
Indeed, in many of the mammals that live in groups, usually family groups,
The smaller the groups, the fewer females that spawn,
In wolves as well as in many mongoose species only one female gives birth,
Only the dominant female (alpha) is "allowed" to give birth,
In the relatives of the striped mongoose - the meerkat, the situation is extreme, even if it is a female
that is not an alpha litter...her cubs will be destroyed.
This situation gives the small (family) group the opportunity to refer the
the most resources to care for young people and thus ensure their survival,
Therefore: the coordinated littering of striped mongooses is an exception,
The described advantage "all the mothers go hunting together" is not true because even if it is
Late or early litters, all the mothers went hunting together.
Therefore, another advantage must be sought.
In baboons that live in herds of up to 150 individuals, there are no twin litters,
This is also the case with those closer to us, the chimpanzees and bonobos,
Since the foundation of human society is a small family group
It is wrong to throw mongooses at women.
There is an interesting dilemma here from an evolutionary point of view and also from a game theory point of view.
First of all, apparently it is possible to reach 100% synchronization (if it is possible to reach 50% synchronization, right?)
But it seems that there are still girls who are born first and then later. And if there is, then they should...
Obviously there is an advantage to giving birth first. He is even described in the article!
And puppies that are born a day late will have a hard time competing with other puppies! From this it follows that a mongoose gave birth the day before (think about it... a day is a lot. They are adults after 3 months! In analogy to humans, a day is like 72 days (I calculated according to the age of 18) in analogy to dogs (let's say you stop being puppies around the age of 18 months) it is 6 Days - almost a week!
Human babies or puppies mature a lot during such a period.
So let's say I'm a mongoose and the strategy facing it
1. Give birth early - 30% chance that the puppy will be killed (from other breeds) but let's assume a double chance that it will become an alpha male. (There is no data on this) Should I give birth early?
Do other females kill males and females at the same rate?
(It makes sense to kill males. They compete for my future offspring. Less advantage to kill females.... Is there a correlation with pack size?)
In fact - if there is a strong choice for early birth, it is possible that despite the risk it is worth giving birth early.
Regarding late birth, I think that either there is some advantage to staying longer in the womb (Are large births stronger and healthier? Is there an effect on the size of the litter? (For example, if I give birth to 5 puppies, we will give birth early; if I give birth to 2, we will keep them as long as possible in the womb. They will come out big more and will be at less risk (when they are small)) or it is "mistakes" (mistakes, later mating, etc.)
In any case, there is a lot of data missing on the study.
The findings do not seem puzzling to me. In fact they are even expected.
There are many possible reasons for the advantage that can be derived from synchronizing births.
One of them is related to the possibility of cooperating in protecting the offspring and freeing up more hands to look for food.
Yigal - As far as I know, the synchronization takes place without a man. The finding of menstrual synchronization in women was discovered in girls' boarding schools, monasteries, etc.
Ami,
The claim is that the menstrual cycle synchronizes in women who live in one subjugation with one man and somehow his presence synchronizes their cycle. This makes sense when thinking about evolutionary competition.
Regarding the synchronized calving in the females living in one herd (or in one herd): if you refer to the moments of calving and the growth period in the first days of the offspring, as times when there is sensitivity in terms of dangers of predation, this synchronization has a logic similar to that of the grouping of herbivores in large herds: the chance of One is less likely to be hurt when in a large group, and perhaps this fact underlies the puzzling findings in the article.
Very reminiscent of the family of undomesticated or 'partially domesticated' cats.
It is strange that they do not belong to the same branch of the family in zoological terms.
Interesting research. The extension regarding the synchronization of the cycle in women seems to me too excessive
interesting and nice,
To the best of my knowledge the species Mungos mungo is widespread in Africa from the east to the south.
in Asia...?