Inbreeding

[toothlessjaws]

Inbreeding is clearly not ideal. However I have just returned from an overseas trip and discovered that in my absence, a pair of my young cordons (and i suspect some ruddies) bred last year seem to have paired up with a sibling and built nests and started laying (A LOT).

I was hoping to get my hands on a second pair or swap some of the birds to make up unrelated pairs before the start of the season but now i'm wondering if its just one generation, is it really going to be a problem?

Obviously mutation breeders must do this all the time, but is that more likely parent to offspring matings, which is far better than full sibling matings?

I suspect my only choice now will be a straight swap of birds. if i buy a second pair and split the sibling pair up with the new bloods, i'm wondering if i risk them not bonding as they will be able to see and hear their sibling "mate" in the aviary next door...

[E Orix]

Whether it will cause a problem in your case is debatable. The important thing is if the general mass of people start thinking that
just once maybe OK then our hobby will be in a very precarious position.
Unless it a specific controlled situation then I am totally against it. There are people breeding birds and using tried methods without
short cuts to try and keep the quality up. If breeders start to think breeding close relatives together without thought or control
what will be the outcome.
It really should be a no brainer!!!!!!!!

[finchbreeder]

Oh dear hear we go again with people ignoring nature. Birds and animals in nature choose what they see as the most suitable available mate. This bird/animal will live in or near their teritory, because they do not travel far. This bird/animal will be the offspring of the neighbouring territory holder. The same as their parent did before them. Hence in mature they are constantly mating with cousins and 2nd cousins. Or in rare seasons when their parents did well and the neighbours failed. With their sibblings. Before you tell me they would all have 2 heads in this case, no because think of the territories as they really are. A big spiderweb style of patches. So each one is going to a differnet neighbour depending on the season and it kind of spirals round. So nature mixes and matches the genes by random selection. Each season is different, and mostly not to siblings.
LML

[jonno0383]

If you swap out the siblings with unrelated bloodlines they should have no issue with bonding. I find cordons have a stronger bond then fires so you would be better off swapping one of the pair for the unrelated so they are no longer in ear shot of each other. Fires are less loyal and splitting them into separate flights should be sufficient. I'd personally swap out for completely unrelated pairs so then you can pair up the young for future pairings without the close bloodlines. This blew up quickly In regards to the natural selection it is true that they are not moderated as to how they are paired but it has a less than significant impact on health as they come from a much wider and diverse genetic stock. In captivity where this diversity is greatly diminished we have to take the lead and try to encourage the out crossing of bloodlines to maintain as much variation as possible. In the wild finches like most prey species are predominately a flock species and are always going to have a higher chance of unrelated pairings as flocks mingle during times of hardship. This natural 'socializing' is what we have to try and replicate if we want the birds to maintain a degree of natural vigor. Having said that Accidents happen and sometimes line breeding is necessary but we shouldn't let it go unchecked.

[finchbreeder]

we have to take the lead and try to encourage the out crossing of bloodlines to maintain as much variation as possible.
100% agree - I was not trying to encourage in breeding. Just to stop the panic. The right and proper thing for the best health of our birds is always to breed as diversly (genetically speaking) as possible. My reaction is due to peoples reaction. I feel that we overreact to accidents. It's just about correcting the situation with new blood as soon as practical, and being completely honest with buyers. So that "Under No Circumstances" do sib to sib offspring go together. That is when funky stuff really can happen. I guess I am a naturalist as well as a breeder, so I look at life with reality tinged glasses. Please anyone who has suitable mates for these birds they would be able to swap contact Toothless so its a one up.
LML

[Tiaris]

I agree that there is no cause for concern - these things happen when young are left in the breeding aviary. I'd just break up the pairs after they rear what they have & treat any of their progeny as the same genes as the original pair's young & outcross at next generation. Cordons & Ruddies are genetically diverse here still so not a major issue.

[toothlessjaws]

Thanks everyone.

I'll continue to look for some birds to swap, but if it gets to the spring and i haven't found a substitute i'll let the sibling pair do what they want and cross the offspring i keep back with some fresh blood next year.

I'd never sell anyone siblings as "pairs" even if i'm prepared to pair some myself.

on a side note I know that intentional inbreeding is incredibly common in the zoo industry to deliberately slow the loss of genetic diversity in small founder populations, as inbreeding depression can usually be immediately corrected by outcrossing to unrelated animals again. until the 1990's all the giraffe in Australia were descendants of just a single pair imported by Taronga! Likewise the zoo's breeding pair of andean condors are full siblings. with no way of importing new stock it will be interesting to see if they choose to inbreed a 2nd generation of these birds or let them (very slowly for such long lived birds) die out.

[finchbreeder]

According to some research the critical population number for a species to survive is 2000. This is why with those species in low numbers it is critical to do the best we can in outcrossing and preserving. And the best way to learn to do this well is with less critical species. This is why I say do not panic over an accident, but correct it as soon as possible and be honest about it. Like Toothless has. Zoos are, due to import restrictions forced to do the impossible with nothing. Perhaps Zoos world wide should lobby their governments for preservation of species? But that is another topic so I will stop there.
LML

[greg4041]

I dont encourage inbreeding as a general practice but the total abhorance some people express is totally unfounded as long as it does not continue for to many generations and if used by a kowledgeable breeder can be used to strengthen a species. I am a trained animal technician and have worked in animal breeding laboratories our work was based on totally inbred lines of animals some strains brother sister mated for over 100 generations the biggest problem is usually a decline in fertility and i admit other genetic problems can occur usually within the first 7 generations but carefull selection is neccesary, now if you have to inbred lines and cross them you get what is known as hybrid vigour the young are extremly fertile usually much healthier with dramatically increased fertility this method is used by pig breeders in europe.

[Craig52]

Thank you for that information Greg, glad to have someone in the know with professional experience. Craig