Abstract
Fostering - the raising of one species under another - is a controversial but widely practiced techinque. Does it destroy the quality of birds for future generations? Or does it make quality stock available in greater numbers for the future? Is it boon or bane? In the following two articles, two friends - and adversaries - debate the issue, with no holds barred.
Dave Pancoast and his wife Nancy operate Blue Ridge Aviaries. in Lowesville. Va .. where they breed an impressive array of birds. Terry Dunham is the Watchbird' s finches editor. and raises finches at Bird Bay Breeders in St. Petersburg, Fl.
There's the bell. Gentlemen: enter the ring.
ANTI-FOSTERING
by Howard 0. Pancoast
I write as a layman, not as a trained zoologist or agriculturist. I try, as best I can, to relate all knowledge to the whole, so that when I think of captive bird breeding, I think of the emerging nations and their frantic drive to industrialize and to exploit to the fullest their natural resources. When I think of aviculture, I think of overpopulation, pollution, war, and of our desperate need for an ethical commitment to a more meaningful purpose than the raw pursuit of another dollar.
It follows from such habits of thought that I am strongly opposed to the indiscriminate use of any breeding practice which would tend to dilute, or otherwise diminish, the long-range vigor and viability of any captive-bred animal.
Note that I used the word '· indiscriminate". Obviously, when the total population of any species is inadequate in either a natural or captive context, or is not yet amenable to captive breeding, then priority must be given to increasing that population by any means possible. If the imprinting of the resulting offspring is then safeguarded by early introduction of the young to naturally imprinted adult members of its own species, then the use of such artificial breeding practices was beneficial.
But it is my impression that such is rarely the case among those who maintain rows of cages of frustrated Society finches opposite corresponding rows of cages of choosier and more colorful finches.
Quite the contrary: the Society finch devotee will almost invariably brag first and loudest about his production volume. This is usually followed by an oblique reference to the resulting income. Thereafter a discussion of mutation and hybrids is par for course.
A leading practitioner and spokesman of this school recently offered me the following information as an example of his thesis. A friend of his had foster-raised 55 offspring in one year from a single pair of Purple Grenadiers. Far from being an advantage, it is my opinion that this feat of production could prove to have been a delayed-fuse disaster.
It must be conceded that the Purple Grenadier is (or was, until then) a rather rare finch in U.S. aviculture. I will hazard the wild guess that that one pair increased our domestic population by at least 20% - one out of five, all brothers and sisters. One could speculate from now 'til dooms-day about the potential for gene pool pollution since virtually nothing is known about the inherent stamina of the parents or of their breeding and rearing potential if left to their own devices. It would be comforting to know at least something about such super-studs before they become the grandparents, aunt and uncle of every indigenous Purple Grenadier in the United States a few generations hence.
Another, and very real, source of potential gene-pool pollution comes from the simple fact that there is virtually no natural selection process at work here. As long as the offspring have feathers, can fly, see lightning, eat seed and survive in a temperature controlled room, they are salable. Birds which are subtly, probably invisibly, flawed since conception-birds which would not, in an even half-way natural environment, have made it through the first year, or even week, of their lives -are pampered, reared, and shipped out, hopefully to disseminate their genetic inadequacies into an ever-increasing proportion of the species' captive population.
But all that is probably quite academic compared to the vastly more immediate problem of imprinting. The simple logistics of fertilizing and delivering enough eggs to result in the successful foster-rearing of 55 offspring would reasonably seem to preclude the likelihood that parents devoted whatever spare time they had to the task of imprinting this herd. A far safer guess is that the young Grenadiers were removed from their foster-society parents at the earliest possible date and subsequently sold or traded at the first opportunity.
Meanwhile. I assume that this same pair of birds is still hard at work, pumping out more eggs to increase its share of the U.S. Grenadier gene-pool. No doubt there will be some small fraction of this huge generation which will overcome these handicaps of flawed imprinting and/or flawed genetics, and will successfully raise viable young. But my logic tells me that it will be a minute fraction.
It would seem far more predictable that one or more of the following will occur:
1 . The new owner will get fed up waiting for his new finches to get it all together, and will tum to the tried-and-true Society finch.
2. The new owner will inadvertently pair siblings, with God-knows what results for the future.
3. The new owner will go ape trying to figure out (I) why his bird's eggs are always clear, or (2) why the young always die in the nest, or (3) why the parents invariably toss them out, or (4) why they never breed at all, and may decide to cross one of the pair with an over-sexed Violet Eared Waxbill on the companion theories of the Societyists of hybrid vigor and re-cross breeding.
No matter how you cut it, the logical extension of these proceses would have to result, at some not too distant date, in a captive race of Purple zombies resembling their vigorous wild ancestors in color only.
I have belabored the example of the fecund Grenadiers for convenience sake alone. The same straight line logic may be applied to any other species, from thousands of Gouldians to a handful of Peter Twinspots.
Fortunately. however, straight-line logic seldom occurs in reality. Too many variables intervene to throw it off course. In this case. one of those variables is us, and many others like us-the believers in natural breeding and rearing. We, like the Society-ists, brag first and loudest about production volume. but with a difference. We brag not of dozens, but handfuls. We think in terms of nests. and of end results in terms of one through five. The subject of consequent income is usually avoided, or at best expressed with a groan. And for ourselves. at least. a mutation is regrettable. and a hybrid is shameful.