Victorian Zebra Finch
The Darwin Theory
My take on The Darwin Theory. By Graham PASCOE
I recently watched a program on TV called The Dangerous Darwin Theory.
The three part show went into what the Darwin Theory was, i.e. that every living organism on earth does or will adapt to its environment, and that the best Gene pool to accomplish this will prevail. In other woods there is a predetermination in gene reproduction to keep changing in ways that might be beneficial to the beings ability to maintain its place in the changing environment, these changes will include size, colour, body shape, skin cover, reproduction etc. remember we have had ,ice, flood, fire, famine, and the dinosaurs are not around any more.
The program used the example of Germany & the production of the Super race during the 30s & 40s! As the dangerous way to use The Darwin Theory, the Germans did however prove that the Nordic or Northern Europeans did have an extra A Gene in one chromosome, unlike the Southern races in Africa.
This prompted me to study what of this applies in the bird aviaries. I found quite a few things that I or we do for our birds, which directly impacts on our birds need to adapt to their environment. Firstly the simplest answer, if you want to maintain, So called normals, don’t put them in an aviary, leave them out in their chosen environment, because the changes within their gene selection will take a lot longer out there, even with all the natural predation and the extremes of their environment.
There are obvious things that we do to change our bird’s environments, the number of species in an aviary? Too many species not getting on with one another, and the number of birds of one species, taking over, the species in the adjoining aviary, do they get along or are they causing stress?
I have in my Finch aviary 2 pair of Jacarini’s, only one of the males has coloured up this season, the other one is about 40% coloured, he always gives way to the coloured one, has he learnt to adapt to the environment?
Feeding our birds. How much time & energy do the birds outside your aviaries put into getting food? All day in most cases, compare this with the ones in your aviary, who have it all laid out for them, what change does this produce in our birds? Remember austere diet, when birds are not breeding, moulting, or growing.
The best example I have to explain this is, Grapevines, Does changing the environment and feeding, affect our birds like it does Grapevines? I visited Banroc Station at Kingston On Murray some years ago and learned how they started, and what they did to grow their grapes, they applied for an allocation of water, and produced grapes, not happy with this they went to Palestine, (the dry farming capital of the world), and learnt how to grow grapes with little water, they set up their irrigation lines 3ft from the vine roots on both sides of the vine, and only watered one side at a time for some 3 weeks, then changing to the other side for the next three weeks, this made the nematodes on the root system tell the plant it was under stress, and the vine would set seed i.e.: fruit.
With this system they produced more grapes than ever before with higher acid and higher sugar content, and had only used 30% of their water allocation = the Vines adapting to a change of environment.
Do we make our birds adapt to their environment by over feeding them, do they consider if there is plenty of food, there is no need to breed and reproduce?
A similar line to look at is nesting, how much time and effort does the bird outside your aviary need to put into building and maintaining a nest? Finding and picking up 300 to 500 pieces of material, carting it back to the nest. Compare this with having it placed in the aviary for them, sometimes with nesting material already inside the nest box. Could this cause a change in their need to breed or their ability to breed? Or change any part of the breeding cycle, remember that the start of the breeding cycle is eating higher protein food to switch on the pituitary gland, as well as finding and furbishing the nest.
Do birds need running water to bath in, or just a bowl of water to bath in, or are they like so many of our birds, when expected to breed do not get either just a drinking receptacle, will any of these changes be a good environment for the birds to adapt to.
Other things that birds have trouble adapting to are night frights, (cats, possums, mice, cockroaches, snakes, dogs, owls,) etc.
Then there is Genetics, incorrectly blamed for problems they do not cause or are just not understood. If we find something different in a nest of birds we immediately blame its ancestry, which can be the problem in a lot of cases, but spontaneous mutation is taking place as we speak so be open to the fact that the next mutation might appear in your back yard.
So we are back to The Super Race, because that is what we in the bird world are striving for.
Having discussed The Darwin Theory with a few people recently and received blank stares or the comment you can’t breed too close, I posed the question, (which race of beings on the earth has the worst health record?) the answer of course is Humans. So, how are we being produced? Inbreeding? Line breeding? Or outcrossing?
Most countries in the world require it to be outcrossing, so how good is outcrossing working for us?
Does outcrossing work? Yes if you want to bring in unknown genes, some might be good, but some might be bad, Look at the colour variations and size variations in humans, (Not conforming to the standard I venture).
If you look into the food we eat (all food) you will find a majority of it is produced from Line Bred or inbred strains, meat, grains, fruit & vegetables.
There are many examples in nature where inbreeding is working, for example a pride of Lions, the male mates with his daughters, in fact in the wild usually the strongest male of most species is the only one to mate the females, some of whom are his daughters.
Another example of inbreeding working, Yukumura a native sanctuary, used to be run by Dr. Wolmsley He found the only remaining pair of red necked wallabies left on Kangaroo Island. He placed them in an old dairy on his property unfortunately a fox got in and he found the male dead, but could not find the female or her body, he accepted that they were gone for good. The property used to be a dairy farm it had a wet, and over grown area in a gully, that did not get looked at for some five years, upon cleaning this area out he found 26 redneck wallabies, obviously the female had escaped death and had a male young, the rest as they say is history, but trust me he did mate with his mother and his daughters and his sons did mate with there sisters.
They are still there today some 15 years later, living without any problems from being inbred.
Inbreeding has good points, most breeders that I have talked to do not have any proof of the so called problems; they have been told about them or read it some where.
Unfortunately it does take a lot of work and recording of your results for you to be able to ascertain if you are on the right track with the right gene pool.
There are many more examples of inbred strains working, like the pride of lions in the orangora crater in Africa, they have not had any new blood introduced in recorded history, still going strong still breeding well, another pride lives on an island that is lake locked in south Africa, there only food source is buffalo, these lions have changed in shape, they are much heavier set in the chest wider at the shoulders and have longer coats, changing to there environment,
Cheetah are down in numbers and because of inbreeding, checks are being made annually to find any defects in health and or breeding results, it has been found in spite of inbreeding they have very few genetic illnesses.
The South American Sea Lion population crashed recently and has put them in the spot light, testing has found all existing sea lions are from only two matrilineal lines. Testing has proven the diversity of the gene pool within these lines is good and could be enough to save them from extinction.
A recent study in Iceland by (Decode) a genetic company, and published in the science journal, found that inbreeding as close as third cousins produced more children and grand children so inbreeding is working well for Iceland.
For hundreds of years inbreeding was historically unavoidable in Iceland due to its tiny population.
I spent some time, recently sitting talking to a bird person in Ballarat Vic, he told me about a friend of his that 15 years ago purchased a pair of zebra finches, he has successfully breed them every year since then, not the same pair, but progeny from them, he has not placed any other birds in the aviary, he still sells off some 60 to 70 birds per year, keeps 10 pair, so he is doing alright with inbred birds.
Some people cannot come to terms with the fact that spontaneous mutation and gene linkage mutations are happening all the time, I mean right now in our aviaries, an example of linkage mutation is Tuberous Sclerosis in humans, neither parent has it, and neither parent has the gene for it, but the combination of both their genes can produce the mutation.
What does all this mean? If you mate the wrong 2 birds you could produce problems, but, if you test mate every bird you want to breed from, and study the progeny for any variations, you will avoid the unknowns. And if the gene pool is ok and no problems become evident it is ok to mate, fathers to daughters, mothers to sons, and brothers to sisters etc. There are some other things happening in our world as we speak, like how far does the earth move north every year? The latest figure is 20 mm not much really, but I have been on earth for 70 years in that time it has moved 1.4 metres. And it is still moving. This will eventually change the environment, a study being conducted measuring the earth’s speed of rotation has found it is slowing down.
The tsunami in the Indian Ocean a few years ago actually slowed the rotation even more, this slowing down of the rotation will change the environment, I hope that some thing in this article helps some of you to think more about what you do, and how you do it, for the bird’s benefits.
I have seen David Atenbough’s series on Madagascar, There is an under ground river on the island with only two very small entry points, found by following the Ring Tail lemma’s going for a drink, they found the access to the water and this was through caves, so the water is in the dark, there are fish in the water. The gene pool of these fish have adapted to their environment, they have no colour, they have no eyes, they swim upside down, in the dark you do not need colour, you certainly don’t need eyes there is nothing to see, you swim upside down because all your food comes from above, perfect example of the gene pool adapting to environment.
So do some home work, know what genes you have, don’t just look at colour and type, test mate more, study results more closely, keep good records, have at least 3 lines going at one time for the feature you are trying to improve and cross these lines at the 3rd generation if you see something good go with it, if you see something bad start again.
By G. PASCOE