Weirdest thing ever - or at least so far...

[DoodlebugMania]

My two oldest female rabbits were bred 1/8/17. Both on same day, each to a different male. A month passes, no babies. Forty days pass, no babies. I figured they must not have taken, and decided I would just wait a bit and then re-breed them. They haven't been re-bred, they aren't adjacent to any males. This evening, I go out to feed and water all the buns, and one of the females has given birth on the wire, 68 days later!? I check them regularly throughout the day, she had no exhibited any unusual behavior, so they couldn't have been more than an hour old. Quickly gathered them up, and made a temporary box, added hay and snuggled the buns in, so hopefully they will survive. She had 9, but only 8 were warm and wiggly. *fingers crossed*

 

[Zass]

Anyone escape during that time?

-- Sat Mar 18, 2017 12:54 am --

I don't think its impossible for does to just "hold onto" kits for longer than their usual cycle though.
I've heard people say they would have some kits born one day, and mysteriously, a few week later, the rest of the litter comes out. Often when it was impossible doe the doe to have been bred twice. I'm pretty sure it's that kit retaining habit that has led to the double pregnancy myths.

 

[Dood]

That's impossible

You cannot slow down growth rate that much, it is genetically fixed, and the kits would come out almost the same size and looking like 4week old kits with eyes open and fully furred

 

[alforddm]

I agree it's extremely unlikely since it would be over twice the normal gestational length. Even if you consider delayed implantation of the embryos that is more than extreme. Could anyone else have had access to your rabbits, even without permission? I've heard of neighborhood kids giving rabbits a "play date". There are just so many odd ways that rabbits can get bred, it's hard to take claims like this seriously.

However, there is a thing called embryonic diapause. That in a 2012 study was found to be conservered to some extent across species. However, they induced some "extreme" conditions that wouldn't normally be found.

Researchers led by Grazyna Ptak, an embryologist at the University of Teramo in Italy, used as their baseline mice, one of the few mammals in which diapause is known to occur. In a mouse that has had its ovaries removed, the uterus is unreceptive and a mouse blastocyst will enter diapause, says Ptak. To this hostile environment, the team introduced blastocysts from sheep, which are not known to enter diapause, and saw the early embryos behave in exactly the same way as their mouse counterparts.

In as-yet unpublished work, the researchers have found that the same goes for rabbits and cows. “This strongly suggests that embryonic diapause has an ancient evolutionary origin,” says Ptak. “As the physiology of the very early embryo is similar in all mammals, it’s extremely likely that all mammalian species can do this.”

The phenomenon is not more widely observed in mammals because it is no longer needed, she suggests. "If the female is living under controlled conditions with food, nice temperature and no overcrowding, she will never go through diapause because it’s not necessary," Ptak says.

http://www.nature.com/news/mammals-put- ... ld-1.10228

and the original paper
http://journals.plos.org/plosone/articl ... e.0033027#

 

[DoodlebugMania]

No one has access to the rabbits, there are no neighborhood kids (we live on 80 acres in middle of national forrest, there isn't a neighborhood at all). No one escaped, no one moved them around, and they were caged well over 2 feet away from any males.
I do keep records, I have cards on each cage stating when they were bred, and with which male.
I just stated the facts as I have seen them play out with my rabbits. I'm not saying it's possible, or impossible, I have no idea how or why things happened the way they did, but my dates are accurate.

 

[MaggieJ]

Please don't take offence, DoodlebugMania. I don't think anyone is doubting your facts. It's just such a very weird thing, so it is natural to look for a rational explanation -- and perhaps to express doubt more forcefully than is usual for our members.

Yours is not the first case where a rabbit has given birth when it should have been impossible.

Sometimes the owner is able to find an explanation (breeding through the wire, an error in record keeping, kids letting them "visit", an escape a family member forgot to mention, etc.), but other times the mystery has gone unsolved.

There may be things we don't know about rabbit reproduction. I once read an account of a female rabbit who had been kept in total isolation from other rabbits giving birth. Unlikely as it seems, the article was not a tabloid special!

 

[Nyctra]

Don't mean to resurrect a zombie, but anyone remember this? postponed-litter-t8284.html :shock:

Anyway, congrats on babies! I hope they're doing well.
Better some than none. Odd things happen. I had a rat once have a case of retained sperm or delayed implantation (forget what it's called) so she had back-to-back litters, having the second without being exposed to the buck rat. Seemed to be happening to a lot of people that year, curiously, and I thought it was a load of bull until it happened to me; there was no one else but me to give them a play-date, either.

 

[DoodlebugMania]

Please don't take offence, DoodlebugMania. I don't think anyone is doubting your facts. It's just such a very weird thing, so it is natural to look for a rational explanation -- and perhaps to express doubt more forcefully than is usual for our members.

Yours is not the first case where a rabbit has given birth when it should have been impossible.

Sometimes the owner is able to find an explanation (breeding through the wire, an error in record keeping, kids letting them "visit", an escape a family member forgot to mention, etc.), but other times the mystery has gone unsolved.

There may be things we don't know about rabbit reproduction. I once read an account of a female rabbit who had been kept in total isolation from other rabbits giving birth. Unlikely as it seems, the article was not a tabloid special!

No offense taken at all Ms Maggie. I was simply stating the facts I had. I have racked my brain trying to explain it, and I cannot. Just found it odd and wanted to share.

 

[MaggieJ]

That's good . . . I wasn't sure.

Did you read the old thread that Nyctra posted? As I said, it's not the first time for this.

 

[DoodlebugMania]

That's good . . . I wasn't sure.

Did you read the old thread that Nyctra posted? As I said, it's not the first time for this.

Yes, I did. Was trying to think if anything might have scared them at the time, but I can't think of anything major. I believe the worst thing that happened was a really nasty thunderstorm came through, but those happen a lot here.

 

[Dood]

best-way-to-kick-start-labor-t31358.html

 

[DoodlebugMania]

http://rabbittalk.com/best-way-to-kick-start-labor-t31358.html

Different rabbit. I have several. <br /><br /> -- Sat Mar 18, 2017 5:47 pm -- <br /><br /> F1 bred Jan 8, just had babies
F2 bred Jan 15, put back with male after due date, still nothing, although she is older rabbit
F3 bred Feb 12, babies on march 12
F4 bred feb 12, babies on march 12
F5 bred Feb 12 babies on march 14

 

[akane]

I have sort of the opposite I never explained. A litter fully developed when they should be too young to survive. I assumed my mistake. I'm terrible with dates but the date I wrote on everyone else happened at the same time when they should have and my rabbits were always quite predictable without any 40 day waits. Not even 35 days. I might have had a 33 day here or there but generally even rabbits from different states so they weren't related went 31-32 days quite predictably. That was before we had to move the rabbits. I was living the middle of nowhere with no neighbors having kids, the rabbits on a locked porch or indoors, and only my husband around who wouldn't have messed up bad enough to let Mocha have access to Twix caged in opposite corners with no other cage touching Twix. Even the occasional repairman couldn't have done it because they repeatedly reported they could not go on my property due to my akita. She probably wouldn't have actually done anything. Probably. Intelligent to not test it. There could be some reason behind various unexplained events but there are times you just can't find an answer that makes any sense. Twix was prone to nesting at 2 weeks or a little later after breeding but never produced kits any other time.

I would not say development is so strictly fixed. This may seem quite extreme to have healthy kits from and delayed births often result in the delayed kits being dead but take a look at the thread or 2 with aborted kits born looking very different in development and size which at the time was said it also could spread the myth of double pregnancy. The occasional larger and more developed than usual kit and the occasional runt kit that still survives with no health issues showing up. Those are less extreme but they are variations in growth even without a sign of health disorder in the specific kit. It's known singletons of many species may over develop and are undesirable in animals that have fair sized litters because of difficulty passing them. Larger litters are known to frequently have several small offspring. Even just the fact we have ranges of gestation shows development is not 100% the same. Again it's usually not very extreme but there are factors that stunt or increase growth in the uterus so it's possible a litter could develop slower. Can something possibly stretch it to that long (or speed it up that much) and not result in serious complications is the better question than whether development times can be altered. Obviously they can be to some point.

 

[Zass]

I agree it's extremely unlikely since it would be over twice the normal gestational length. Even if you consider delayed implantation of the embryos that is more than extreme. Could anyone else have had access to your rabbits, even without permission? I've heard of neighborhood kids giving rabbits a "play date". There are just so many odd ways that rabbits can get bred, it's hard to take claims like this seriously.

However, there is a thing called embryonic diapause. That in a 2012 study was found to be conservered to some extent across species. However, they induced some "extreme" conditions that wouldn't normally be found.

Researchers led by Grazyna Ptak, an embryologist at the University of Teramo in Italy, used as their baseline mice, one of the few mammals in which diapause is known to occur. In a mouse that has had its ovaries removed, the uterus is unreceptive and a mouse blastocyst will enter diapause, says Ptak. To this hostile environment, the team introduced blastocysts from sheep, which are not known to enter diapause, and saw the early embryos behave in exactly the same way as their mouse counterparts.

In as-yet unpublished work, the researchers have found that the same goes for rabbits and cows. “This strongly suggests that embryonic diapause has an ancient evolutionary origin,” says Ptak. “As the physiology of the very early embryo is similar in all mammals, it’s extremely likely that all mammalian species can do this.”

The phenomenon is not more widely observed in mammals because it is no longer needed, she suggests. "If the female is living under controlled conditions with food, nice temperature and no overcrowding, she will never go through diapause because it’s not necessary," Ptak says.

http://www.nature.com/news/mammals-put- ... ld-1.10228

and the original paper
http://journals.plos.org/plosone/articl ... e.0033027#

Yeah, embryonic diapause was what I was thinking of. It isn't something rabbits are known for.

In theory though, it could occur, and if it did, I don't think it would necessarily be the result of extreme conditions.

It seems more likely (to me) that it could occur due to strait up malfunction.

 

[alforddm]

Yeah, embryonic diapause was what I was thinking of. It isn't something rabbits are known for.

In theory though, it could occur, and if it did, I don't think it would necessarily be the result of extreme conditions.

It seems more likely (to me) that it could occur due to strait up malfunction.

That is a very good point and something I hadn't considered. I think the study certainly pointed to the possibility that all mammals were potentially capable of delaying embryo implantation.

That could also so possibly be the cause, of at least some, of the underdeveloped kits that are born with otherwise well developed litters.