Aussie Finch Forum

I've raised this topic a few times on a couple of other bird related sites and got some interesting opinions (the majority along the lines of OMG NO!) but I have seen some interesting discussions on here about it and would be really interested to hear peoples opinions and the why's behind them. For the last few years I have been breeding rats and inbreeding is considered very advantageous (as long as it is done correctly). I've seen on here discussions about inbreeding being neccesary for mutations to become established, but a the same time a general NO to it as a general practice. Before I really get into breeding any animal I like to look at these things and get a feel for the best way to go about it (and the most popular is not always the best lol).
SO I was wondering a few things firstly how resistant to inbreeding depression are many of the finch species (rats ae very resistant making inbreeding relatively safe), secondly seeing many of you keep smallish numbers of breeding pairs how do you avoid inbreeding anyway (are you continually adding new stock), if you do inbreed what sort of selection process do you use?
Also I wonder if the same advantages to inbreeding exist in finches as exist in other animals....so are there lots of nasty genetic disorders that occur in finches that need to be bred out (in which case inbreeding is a good tool), what are the biggest problems that need to be addressed in health or any other area that may benefit from inbreeding.

Maybe this is where I should explain why in some cases inbreeding can be a good tool, firstly it enables you to weed out nasty recessive problems problems that may float around in a gene pool having little effect until by chance the gene pops up when 2 carriers reproduce, if you inbreed it only takes a couple of generations to find the carriers and remove them from your breeding, secondly inbreeding allows you to set good traits into your population....as I said ealier if it is done it needs to be done responsibly and caefully....really good records and strict selection procedures need to be in place but if you are determined to make improvements then it is useful.....OK now you can all hate me

In the right hands and for the right reasons then no problem ....

If its just borne of laziness or random experimentation by people with no rhyme or reason then not so good.

Wont debate the subject though , never could win an argument .

Oh to be fair yes accidents do happen but an intelligent person will be certain to not let it happen twice.

Inbreeding or line breeding a specie of bird is for the genetically savvy person. Birds are not like rats as you say or fish for example as inbreeding does not quickly effect the subjects. Variability is different from genetic diversity. I am not expert on this subject but if you search, genetic variability diversity birds, there is plenty of research into this area.
Too many bird species have been lost in Australia by people, good intentions or not, wanting to experiment?? with the limited resources/stock available. On the other hand many finch species have been brought back from the cusp it of extinction due to a few very dedicated and experienced breeders.

Inbreeding with finches I don't do there may have been a couple in past times but now I keep a more closer eye, when my birds seem to be getting a bit to related I will go out and buy some fresh bloodlines just to change it a bit as I don't have very much experience with genetics. With my canaries I have parents to young to produce nice size birds and good whistlers, I haven't come across any problems as of yet but this is as far as inbreeding as I choose to go and with canaries this has been done for many years.

a lot of canary and budgie breeders who strive to improve the quality of their birds use line breeding.....to me this is ok so long as you keep accurate records of your birds. In my view if you have a good feature of a bird that you have identified is similar to it's parentage then line breeding is a good way of continuing to develop this feature....conversely any bad features could also be increased which is why you must have a good understanding of the genetic make up of the bird.....in summary i don't think it is for everyone, but if you understand the genetics of your birds and you are prepared to keep accurate records then why not....i feel if it is part of a long term plan then it could be a good thing...cheers Paul

To answer your question about inbreeding depression; as i understand it, this only occurrs after many generations and in populations that start from a very small source population where no recruitment of unrelated birds occurs.
Exactly how may generations it will take before inbreeding depression sets in will depend on how genetically diverse the source population was to begin with, and the genetic resilience of the species.
Most of our captive species are derived from large and genetically diverse source populations and it would be rare to find a breeder who does not introduce fresh blood to their colonies from time to time, so I would be surprised to see examples of inbreeding depression in any but the rarest species.

After reading some of these posts I wonder if anyone has heard of "The Island Syndrome" where only a couple of birds of a species (Passerines, Doves or any land birds) are blown onto or somehow end up on an island from somewhere else. The birds breed to such an extent that enough numbers exist to create enough genetic diversity, and every one of that species are from those original pair or trio. I started off years ago with three Red-whiskered Bulbuls, all siblings from the same nest and they bred for eight years, no deformities or other problems. I only introduced new birds about two years ago.

Hmnnn just goes to show. Im strive not to inbreed anything but im sure mistakes have been made with my own birds by me. Guess its a bit of peice of mind. Takes the edge off worrying to much.

Ben

maz wrote:(rats are very resistant making inbreeding relatively safe)

This resistance is what makes them so successful in being able to survive in a multitude of climates and habitats.

In similar terms I would think the Zebra would be on a par, resistance wise, so I would think they could probably be quite closely inbred.
I think with inbreeding in the way you described with a less resistant species you would really have to be ok with large scale culling should something nasty pop up.
Granted, it may bring out the best hidden genes in a given flock but you would have to be prepared for the worst too, and have the stomach for the wholesale culling that might have to be done.

Surely the worst aspects could be avoided and the good points enhanced with considered line breeding?

I totally agree that breeding records should be kept, even more detailed in the event of inbreeding or line breeding. Memory just cant be relied upon in this case.
I think parent and youngster pairing is ok, if a specific trait is wanted and other sources had been considered first, as long as the young produced from that pairing will be paired with a bird from a totally different source.
I wouldn't like to do sibling pairings. Bear in mind that my previous frame of reference regarding breeding was the dog show ring and this kind of pairing would have been frowned upon.
But having said that Gregor Mendel, is supposed to have bred mice, brother to sister for 40 generations without any noticeable difference except the increase in size. But, as we all know mice are a resistant species.

In a species that I only have a couple of pairs of.
In my case I start off with two pairs from different breeders/location, this way I can make unrelated pairs so that I have the ability to mix up the youngsters in a later generation. When selling the young I try to have unrelated pairs, even holding onto birds for quite a while till I can get the right pair to sell on. When new blood is needed I buy another pair, hopefully from a different breeder than the original pairs and split them up to pair with the birds I already have.

With my gouldians
This is the species I have the most of. I have birds from several locations acquired over a period of time and this is allowing me to still use the adult birds I have without having to in breed apart, from one instance where I just couldn't get a clear YH headed Gouldian hen to put with a YH cock bird. So that particular pairing was parent and young.

Personal criteria for choosing, keeping.
The criteria I look for depends on the species, but after a healthy looking bird, bright eyes, tight feathers and clean vent, and no clicking or raspy sounds, I then go on to choose based on further personally preferred criteria.

With the gouldians I like a nice rise above the beak, no wing feathers crossing over each other on the back, and wings held up tight and close to the body. Also the tail held out and down, not like a wren carries their tail. With the white chested mutation, I like the white to be just that, white, no patches of blue or other markings. Head colours, I prefer to have no splits. Hens head colour must be clear, not keen on the ones with lots of black mixed in.

Not every clutch works out how I would like to be but where is the challenge if it did? Also those that don't work out are still perfectly acceptable birds, after all beauty is in the eye of the beholder.

In some ways I like the fact that there isn't a "standard" for a lot of birds like the Kennel clubs have imposed on dogs. Even when there is a standard it still boils down to one judges opinion over another judges preference.
These choices when a competition trophy is at stake regardless of the animal or bird being shown make it possible for certain traits to become "over produced" often to the detriment of the creature concerned.
I for one would hate to see that type of "standardisation" enter the bird world.