What’s the term that is used to describe the ability of some animals to have a litter of young where there can be multiple fathers, like a litter of mismatched puppies or kittens?
Slut
Polyandry. At least that’s the mating system. As to the term relating to oviparous…hmmm, maybe I’ll let my fingers do the walking over to the library…
I’m looking for the term that would describe the fertilization process that allows a mammal to have its eggs fertilized by more than one male during one reproductive cycle.
This website on canine reproduction Physiology (fertilization)) just calls it “multiple sire matings”.
“Multiple Sire Matings” is so prosaic, but it does make sense.
According to Cat Owner’s Home Veterinary Handbook, First Edition:
“While only one sperm can fertilize each egg, a queen who has mated with a number of different toms could produce a litter of kittens having different fathers. This phenomenon is called superfecundity.”
According to my Webster’s Dictionary: “superfecundation: successive fertilization of two or more ova from the same ovulation esp. by different sires.”
Looks like superfecundity might be the term you are seeking.
Superfecundity sounds better. I think I’ll go with that.
This can happen with humans too. In fact, Cecil has already discussed this here in which he uses the term superfecundation.
Hmmm, I guess this might depend on which type of animal you’re referring to. For birds, this is a (presumed) rarity called “cooperative simultaneous polyandry” according to the “Birder’s Handbook” (1988, P. Ehrlich et. al.). But I think I like how superfecundity rolls off the tongue.
Armed with the word superfecundation, I did a quick search of some medical literature. One author asserted that one of out every 12 sets of fraternal twins was the result of superfecundation. However, this didn’t mean that the mother had sex with two different men. It’s just that it happened on two different coitions. (That sounds so romantic.)
The author later went on to assert that about 1 in 400 sets of fraternal twins are the result of a woman having coitions with two different men. (This figure was for the US.)
brachy, you’re right in that ‘polyandry’ might be used outside of its usual definition when applied specifically to birds. However, I note that my dictionary defines polyandry as “the state or practice of having more than one husband or male mate at one time.” So, polyandry may refer to the actual multiple-male mating situation/process , while superfecundity describes the actual fertilization of the eggs.
Superfecundity is probably pretty common in animals that have multiple births and rather indiscriminate mating practices. I imagine it is much rarer in animals that commonly produce single offspring, or whose mating rituals usually involve pair-bonding of some kind.
Anybody want to know what superfetation is? (It’s in the paragraph following ‘superfecundity’.)
Well, I was thinking more in line of “multiple male matings” (a mating system and perhaps more general term for cooperative simultaneous polyandry in which males actively participate in bringing off broods) in which superfecundity can operate. I think the term that BobT is looking for IS superfecundity.
One thing I’m curious about - superfecundity rang a bell (quite dimly and I had to do a little searching to see why). It’s the term used for illustrate the capacity that animals have for reproducing more than will survive, and one of the tenets for natural selection. Did the term get usurped by medicine - or was the usurption the other way around? I couldn’t tell from the SD article.
Okay, I looked it up and WOW does that bring questions to the mind! Oxford say:
/superfetation/ n.
- [Med.] & [Zool.] a second conception during pregnancy giving rise to embryos of different ages in the uterus.
How different?
-
[Bot.] the fertilization of the same ovule by different kinds of pollen.
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the accretion of one thing on another.
Eeewww. So, Coosa, does your dictionary give any examples to the first definition?
I don’t know, brachy - I would think that the original meaning of the term was ‘super fertility’, which would fit with the definition of producing large numbers of offspring. Since the term would also describe multiple simultaneous pregnancies, I would guess that when this phenomenon was discovered, the term was pre-empted.
Okay, again from the Cat Owner’s Home Veterinary Handbook:
"Although ovulation and pregnancy normally suppress the estrus cycle, about ten percent of queens go back into heat and may be willing to breed. In such circumstances the act of mating again induces ovulation, with the result that a second litter is conceived. The two litters can subsequently be born at the same time (in which cases the second is premature and seldom survives), or the second litter can be born alive a few weeks after the first. This phenomenon is known as superfetation.
Although I don’t have any sort of statistics, judging from what I hear from other cat breeders, this happens fairly often in domestic cats; I don’t know if it occurs in other species as frequently. I’ve not heard from anyone who had a second litter delivered later and survive, but a lot of breeders have had litters born that consists of one or two full-term kittens and a couple of very premature kittens, often confirmed by veterinary examination.
This probably doesn’t happen often in normal circustances. Breeding cats are kept in rather unnatural situations; often a queen is allowed to live with the stud after mating, when in the wild state they would go their separate ways afterwards. Also, queens are usually housed with other queens, and often live within earshot/smell of a stud. Cats are not naturally social animals, so there are some pretty weird responses to the constant proximity of other breeding queens and/or male cats.
My only personal experience involved a pregnant queen who came back into heat and willingly mated with the stud cat about two weeks after her initial mating. I didn’t see any signs of a second litter when she delivered the kittens, so either it didn’t happen in this case or she reabsorbed them.
I don’t know if there is a ‘usual’ age difference; in the cases I’ve heard about from other breeders, the age difference seemed to be from two to three weeks. (Average gestation in a cat is 63-65 days.) I’ve also never heard of the age differences being scattered, with one kitten being full term, another two weeks early, another three weeks, early, etc. I suppose it’s possible, but probably extremely rare. I think it happens because of a glitch in the hormone levels in the first two or three weeks of pregnancy.
My memory of this is sketchy, but it seems I’ve heard of this happening in horses and cattle, but because they usually have single births the double pregnancy results in spontaneous abortion of both fetuses (not enough room in the uterus).
Very interesting Coosa. I’ve been thinking about this since yesterday (or early this morning). I wonder if superfetation may have arisen as the female response to male infanticide or merely as “insurance” against the potential loss of a fetus. But I’m not sure if the timing is right for the female response idea.
I’m thinking of lions, although I understand this can happen with domestic kitties if they are living “free-range,” so to speak.
If a female has cubs, and the former male is disposed of by a new rival, then the cubs by the previous male are often (usually?) killed by the new male. This induces the female into a new heat. How often are females pregnant at this time? They go into heat twice a year, I think (I’ve always spayed my pets and have no experience with this.) I imagine if male takeovers happen frequently enough, then it is in the females best interest to hold onto those fetuses if she can do so and if it is worth it for the energetic investment to date. Morphologically, I would guess cats have a bihorned uterus. Now I’m clueless on the physiological events that take place during fertility inducement, but I would imagine hormornal changes would likely result in abortion. If the uterine horns were differentially sensitive to hormonal changes, then perhaps she could hold onto fetuses within one horn. And I could imagine this sensitivity decreasing in that horn as time-since-previous-fertilization increased (the longer she had them in, the more energy she has invested and thus, the bigger the payoff to hang onto them).
This, of course, is a WAG. But it was fun thinking about it.