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Post by betty on Feb 28, 2015 11:36:02 GMT -8
I often see comments and threads of gerbils living way past 4 years, and I just wondered if any breeders out there have actually been breeding for longevity, or whether it is just more of a freak of nature so to speak - like just the odd gerbil here and there rather than any solid patterns.
I understand it is harder to breed for something that you can't spot until later, but if you have kept any of your own, I'm sure you would soon see a pattern.
None of my gerbils have ever have got to four years old, my oldest (so far) just passed at 39 months, so I am constantly surprised when people quote 5, 6 or even 8 years old. That is basically 3 times longer than my average.
And of course, if we could breed it - or these long-lived gerbils increase naturally - would we want to encourage it? Are such tiny rodents really designed to live that long?
I would love to hear some experienced thoughts here.
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Post by Shooting Star on Mar 1, 2015 15:40:02 GMT -8
It's definitely a factor when I'm considering who's good enough to breed. I like breeding healthy older males, 2-3yo. But older males do undergo reproductive changes, even if they're still capable of siring pups. Basically, there's a higher chance of tiny errors in the sperm that can lead to higher mortality, lower birthweight, etc. And obviously, pregnancies are harder on elderly females.
When you do a lot of line-breeding, as I do, you can generally predict how a gerbil will turn out by looking at its background. So it's more a matter of looking at a gerbil's parents and extended family, and their health and longevity. For example, when deciding whether to breed a 6mo female, is her mom still alive? How long did her grandmother live, or is she still living? Same goes for the males in her family. And did any get ovarian cysts, scent gland tumors, or other health problems as they aged? Living longer isn't necessarily a plus if they spent those extra months sick.
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Post by betty on Mar 1, 2015 22:36:49 GMT -8
Thank you for your comments, and having their parents and grandparents around as markers is something I take to show what I would call a good breeder when I look for new stock. And I would never try to breed older gerbils just because they were still alive, I was more thinking of breeding from further down the lines if longevity was found - just like good health.
However, what is the average age of your stock? Have you ever managed to extend that average life through your breeding methods? I haven't been breeding long enough this time to try to extend life - and I had thought that 'over 3 years' (my oldest so far - original patriarch) was a reasonable age - so hadn't thought it could be extended. But then these stories kept coming up?
Have you ever had one of these long-lived gerbils yourself - and if you found one (that had known and fertile) offspring - would you put this into one of your lines?
Has one of these long-lived gerbils ever come from a breeder or are they all pets only - does breeding do something to shorten their lives?
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Post by Shooting Star on Mar 2, 2015 3:52:40 GMT -8
3 years sounds about right as an average longevity for my crew. (Though I did just introduce girlfriends to two 3.25yo boys -- they're in such good condition I was surprised when I looked up their birthdates!) Extending lifespan hasn't really been one of my major goals. If they live significantly less than 3yrs, or start getting health issues before 3yo, yeah those are big red flags. But I take those factors as part of overall health, rather than specifically longevity. It's something I would certainly like to work on, but my kennel size restrictions make it impractical to keep all the gerbils needed for such a venture. As it is, I often adopt out retired breeders with the understanding that the new owner will keep me updated on their health and eventual demise.
I don't believe I've had a gerbil hit 4yo yet. I'm not sure I'd add a relative unknown into my lines just based on longevity. If it was an otherwise excellent gerbil, yeah, but I'd definitely look at all the other factors before deciding.
I take all the long-lived gerbil stories with a grain of salt. Often these are gerbils that were adopted as "adults", and their birthdate is estimated. Or they've been through a few owners, any one of which might be misremembering. Even I thought for quite a while that one of my boys was half a year older than he really was, because my recordkeeping software uses the dd/mm/yyyy format; what I was seeing as Jan 6th was actually June 1st. It's like the difference between "the world's oldest dog" and "the Guinness World Records' verified oldest dog". I'm not saying there aren't gerbils that live to 5+, just that not all these reports may be accurate.
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Post by betty on Mar 2, 2015 12:00:10 GMT -8
I must admit - I wrote off a lot of the 6+ gerbils as the classic 'parent swapping the poorly/dead pet while kids at school' scenario, and of course people with just one clan of gerbils/less experience this can be easily done as 'all agoutis look the same' to the untrained eye... but do you think 5+ is possible even?
I suppose (as for keeping them all) if you foster out the older ones you can at least keep an average for different lines. I only really have one old line - and my oldest gerbil is currently living with a friend - just wondering if they will top their dads 'grand old age' of 3 and a quarter (only 5 months to go....).
And if you did start to breed for age along with good health of course - do you think it would be the luck of a longevity gene cropping up, or do you think it would be more gradual as your lines were eliminating all the illnesses along the way, so extending life through avoidance of death?
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Post by Shooting Star on Mar 2, 2015 13:52:15 GMT -8
I *think* I've heard one or two verifiable cases of a 5yo gerbil, but I don't exactly keep track. There have certainly been 4-year-olds.
It would be astronomically unlikely for there to be a single "longevity gene". Any extension of lifespan would be gradual, due to improved health, optimal care, and countless tiny genetic nuances (polygenes).
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Post by ninestone on Mar 3, 2015 16:04:45 GMT -8
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