Aussie Finch Forum

I have had a pair of orange breasts for just on 1 year now, they have raised 7 young
and all have been cocks,is this normal.

Seems unusual not to see at least one hen out of the 7, but thats the luck of the draw.

Most of my Painteds, Obreasts and quails turn out male. Doesnt matter where I get em from, males seem to pop out.

something weirds going on.... maybe OBs painteds and quail can do that thing gouldians can do where they can determine the sex of their offspring? has anyone actually looked into other species' ability to do that or have they just focused on gouldians?
all of my quail used to turn out male too

Check the density of birds in your aviary as I reckon that density stress influences the sex of the offspring. Unlike mammals, female birds have prezygotic control over the sex of the young that will emerge from their eggs. The herterogametic sex in birds is female and unlike in spematogenesis where all four products of the initial meiotic division mature only one of the resulting ooitids matures and as Sarah Pryke has demonstrated in Gouldians they can favour the maturation of either an ootid carryiong a W or the Z depending on which outcome is the most advantageous. In a crowded aviary resouces other than food are generally very limit so it's advantageous to a hen's selfish genes not to increase stock density too much by adding more females to the population however more male decendants will increase competion to exclude/outcompete another female's line of decent. Now all I need is a set-up like Mike Fidlers to prove it.

Cool thanks Greg

So maybe you could explain my gouldians in the same aviary produce all females bar 1 for 2011

Sarah Pryke mentioned at the birdnerd day in Cooranbong the other week (the STGF day) that when the supply of foods is absolutely regular, Goudlians tend to produce more hens, and where it is more intermittent/unpredictable, the sex ratio of offspring is skewed more toward males.
I seem to recall reading a paper about how birds and lizards produce relatively more males in resourse-unpredictable environments. They explained this as being due to either (i) territory being the limiting factor, and controlled by males, ergo more males results in better chance at reproduction, or (ii) males having a higher chance than females of producing disproportionately many offspring, thereby more chance of propagating greater numbers of direct descendants of their mother.
Perhaps high aviary-stocking density can cause relative resource unpredictability.

On the other hand, given the random nature of these things, the outcome of only one male in a (presumably large) 2011 crop of Gouldians is not the most likely outcome, but doesn't require any particular explanation. If we knew how many females there were, we could calculate the odds accurately, but for arguments sake, lets say there were 20 females and that getting 20 females to one male had a probability of one in 1000. The 999 aviaries with less remarkable ratios wouldn't notice or report their unremarkable ratios.

Mackstaa, if you do it two or three years in a row, it would definitely require explanation. Otherwise, try feeding them less regularly.

Regarding OBs (and the same seems to be true for blue-faces) there seems to be a connection with provision of fresh half-ripe seed and live food. Without either of these, I I have had the 'too many boys' problem arising. Since providing these ad libitum , I have thrown approximately equal ratios.