Head colours?

[Tiaris]

How recent from wild caught are we talking here?

[MadHatter]

Just to be clear, I do not know for sure the origin of Sarah Pryke's colony, I only assume it is decended from more recently wild-caught founders as that makes the most sense from a scientific standpoint.
If I had to guess at their origins, I would think it reasonable to assume that, at the earliest, they may have come from some of the last groups of birds to be legally trapped before it was banned in the late 1980's, but I think it more likely that they may have been obtained under permit some time after that. Perhaps even as recently as the mid to late 90's.
On the other hand, we have been breeding Gouldians in captivity since the late 1800's and, aviculturists being what they are, it stands to reason that their would have been, from the very earliest, a concerted campaign to breed different head colours to one-another - not only in an effort to determine the heredity of the different colours but equally to maximise the production of red-headed and yellow-headed birds, which at that time were far rarer in captivity than they are today.
Admittedly, to begin with, the captive population would have been heavily supplemented with wild-caught stocks but by the time legal commercial trapping ended in the late 80s, the level of recruitment into the population from captive breeding must have far out-stripped that from wild-caught stocks by many factors of magnitude.

Ok, so I'm basing all this on a number of assumptions which, if proven flawed, would invalidate the whole thing, but If I'm right, then I would think this might be an interesting avenue for further study. That is, after all, how science works.

[Tiaris]

I doubt that Sarah Pryke's study Gouldians were sourced from anything more recently wild than yours or mine. I also dispute that there has been any concerted campaign to mix head colours to arrive at head colour heritibility outcomes. I also have considerable doubts that the findings of the head-colour reports are universally valid. I think its great that legitimate scientific work on Gouldians (or any finches for that matter) is being done and this can only add considerably to our overall knowledge of our birds, but as I've said I hold grave reservations as to the findings and underlying rationale behind the head colour conclusions.

[natamambo]

Tiaris, I'm not sure what you mean about studies to investigate head colour inheritances. There were considerable private breeder studies in the 30s (from memory), their results were supported by the scientific studies of Dr H Southern in the Journal of Genetics in 1945.

[Tiaris]

What I mean is that there may have been attempts by individuals to ascertain modes of inheritence, etc in the past but that these did not amount to a concerted campaign across the vast body of captive Gouldians to mix head colours of captive birds over time. My scepticism is primarily directed at the conclusions of the recent head colour mating preferences, sex ratio consequences and juvenile mortality differences between mixed head colour pairings v same head colour pairings. I am sceptical that these conclusions are universally valid and I am even more sceptical of the illogical rationale provided to argue the case for the conclusions. When I first read the paper, I discussed it extensively with several other very experienced breeders and the clear concensus was that the findings were contrary to the experience of each. I'm sure this will be dismissed yet again as merely anecdotal observations of scientifically unqualified plodders, but plodders who have bred thousands of Gouldians over 30 to 60 breeding seasons each and whose collective bird brains I would gladly back.

[Niki_K]

I doubt that Sarah Pryke's study Gouldians were sourced from anything more recently wild than yours or mine.

Why is that? As she is based at a university where the colony would have already been set up, they are likely to have (or have had) permits to take birds from the wild if necessary, as I do. I know that some of the birds are from breeders who specialise in wild-type Gouldians, but I'm not sure if those are kept separately for comparative studies.
The fact that you have such different results is intriguing. Are you breeding wild-type morphs or other colourations? Have you tried breeding females with males of the same head colour and then breeding them with males of a different head colour? Did you find any differences?
Bear in mind that the results of head colour experiments may not be able to be applied to different mutations since all of this work has been carried out on wild-type Gouldians, and would need to be studied further.

[Tiaris]

I know that most (if not all) of the Gouldians used at Mike Fidler's were captive bred birds from the general Australian captive Gouldian population. I haven't heard whether any additional wild-caught birds were obtained for the study & the paper certainly did not indicate that this was the case.
My own Gouldian breeding over many years and that of the few other very experienced breeders I referred to included numerous same to same head colour matings and numerous mixed head colour matings with no noticeable difference in mate's head colour preference in colony aviaries, no difference in clutch sizes reared, no noticeable difference in juvenile mortality & no notable difference in sex ratio of young. This is over many years of breeding over the lifetimes of several highly experienced finch breeders, not one season's results from one flock of captive birds. They were mostly wild-type non mutation birds but in more recent years also included some mutants as well. Our earlier experiences of Gouldian breeding included a high proportion of wild-caught birds and regular influxes of these over time up until legal trapping ceased.

[MadHatter]

Perhaps my choice of words was a little ill-considered. When I wrote of a "concerted campaign" to breed different head colours to one-another to determine inheritance and to maximise production of reds and yellows, I was not referring to any organised group, but rather to a number of aviculturists, each working independantly, but all towards the same goals.

Tiaris, I bow to your greater knowledge in relation to the origins of Ms Pryke's colony. You clearly have read far more of the paper(s) in question than I have. I wonder then, if the experiment were repeated with F1 wild-caught stock, would the conclusions be the same? Or with a mixed group of different colour mutations?
I think we can all agree, the results are fascinating, but further study is needed to fully understand the implications.