San Francisco Garters in Europe - family tree?

[Snake lover 3-25]

ooooo wow so that's why i got 13 females and 2 males from sooty!!! RIP babies......

[aSnakeLovinBabe]

weird.... I've never really noticed a trend like that before... all my litters have been pretty even and I keep my females very warm during gestation.


having said that, I think all of this stuff is a good idea, except for the part of removing a few SF garter snakes from the wild every few years to replenish captive populations. I don't think that any more should be removed from the wild. The ones that are being squished on the roads are losses enough.

Having said THAT.... I truly believe the SF garter is doomed.

[Conners]

Hi guys,

I read the Chlebowy & Martin Hallmen article - very interesting; the first detailed info I've come across on someone's efforts to tot up the European population. Cheers for the link Stefan.

I'm not sure when it was originally written, but I'm guessing a little while back, as the figures for the captive population will surely have risen since? If I was asked to guess, based on how often animals are offered for sale on sites like reptileforums.co.uk, I'd say there must be at least a few hundred SF garters in the UK and Ireland alone.

If they really are all descended from the original pair which were themselves inbred, we could easily be on something like an F15 generation.

Mine seem very healthy and are growing like weeds on a pink diet, but there's no knowing what deleterious genetic traits they're hiding. I don't known anything about their background beyond that there were born in Holland, but I am planning to pair them. What I want to do if I get a healthy litter is see if my contact can persuade Ian who takes care of the London Zoo animals (and breeds his own) to do a couple of like-for-like swaps.

It's very interesting what Adamanteus said about the surfeit of males. I actually came up against the opposite problem when trying to source a pair. I didn't see the point in taking any tetras off the breeder unless he could give me one of each sex, but he only had a single spare male as against half a dozen or so females, so it may be that the gravid female in question was exposed to high temperatures during gestation. I must admit I wasn't aware of how definitive that was in breeding garters, so cheers for the info guys. Thinking back to when I used to breed parietalis, I always had a thermal gradient available, so I never noticed any imbalance of the sexes in the litters.

Has anyone come across examples of inbreeding problems in tetras? For all I know, half the snakes in every litter might be being born with spinal kinks. On the other hand, maybe no issues have shown up?

From what Vince Russo and other big breeders in the US have discovered from pretty extensive experiments, it seems safe to line breed for at least 6 or 7 generations before you can expect to see any issues. After this however, all bets are off.

[Conners]

It's always nice to welcome a fellow Brit, Paul.
Can you trace the lineage of your tetras very far?
I think it's a great idea that we keep future breedings as 'unrelated' as possible.... but it will be difficult to get some people on board.
I'm up for it though. I think part of the problem is the surfeit of males..... I have a trio, one of which is female. They were already attempting to mate prior to brumation, so I'm hoping for a fruitful year..... but I'd be quite happy to exchange one of my males for a more distantly related male, if that can be figured out.

Cheers for the encouraging words Adamanteus. I guess the problem with my idea of a register of animals is that the meaningful data doesn't come through for a few years, because we start with a list of animals whose relationships aren't known. So it will take time and patience. I do think it would be worth it though. Within just a couple of years we'd have broken the chain of filial generations and could be mating cousin snakes instead of siblings.

I don't know anything about the lineage of my two I'm afraid - quite frustrating, but the chap who who sold them to me didn't ask the Dutch breeder at the time of purchase. He's offered to try and find out more though.

Good luck breeding your guys post brumation!

[adamanteus]

I don't know anything about the lineage of my two I'm afraid - quite frustrating, but the chap who who sold them to me didn't ask the Dutch breeder at the time of purchase.

To be honest, Paul, there's every chance that the original breeder of your tetrataenia is a Thamnophis.com member. We have some of the biggest European Garter keepers on this forum, including some 'leading' Dutch keepers.

[Conners]

To be honest, Paul, there's every chance that the original breeder of your tetrataenia is a Thamnophis.com member. We have some of the biggest European Garter keepers on this forum, including some 'leading' Dutch keepers.

Cool - fingers crossed that will be the case! I'm sure some of those guys must already be doing what I'm proposing in terms of the register. I mean if they've bred SFs a few times I'm sure they themselves will be trying to keep the genes as mixed up as possible. I really hope we hear from someone about it if that's the case.

Cheers James!

Paul

[adamanteus]

Certainly mine came with breeding documents and 'ID numbers' (eg. tst 3-0 "Rotterdam Line"). They are from a Dutch breeder (Gijs & Sabine).