So what do I look for / what questions do I ask...

At 12 weeks the comb on the male starts to redden. Check her facilities, are they clean, does she allow her growers to mix with adult stock - this is not a good idea as their immunity takes a while to develop. look at the birds around the place, are they healthy, happy, well fed, fresh water or are they stood around all hunched up.

OK Petal, thanks . When does a bird stop being a 'grower'? I want to integrate my new birds into my existing flock, but they'll obviously be a lot younger...

you can't at 12 weeks, at 20 weeks is ok in my opinion for an araucana- they will realistically lay at 25 weeks. Make a separate enclosure. Have you got a cockerel?

Hmmm OK I'll try. No cockerel no. IF I decide I'd like to try breeding, I'm going to buy a cockerel in a year or so from a different person to try to avoid inbreeding problems.

So - if I can build a small coop and section off part of the existing enclosure for a few weeks, will it be OK to mix them up later by sticking them in the main coop after dark? Or is that likely to cause awful problems since the oldies will have seen the newbies for weeks beforehand and may not be fooled?

As Petal says, check the facilities. I would go for the most active and feistiest looking birds as they are likely to be the most robust. The sexes should be obvious at 12 weeks as Petal says, cocks will have bigger redder combs. Pullets of this age will have little/no comb to speak of and it will be pale in colour.

Ask to handle them and check for obvious things like lice around the vent and evidence of scaly leg mite. I also check eyes (bright and no evidence of foam indicative of myco), beak straight with no crossing, toes (straight, but bent toes are a minor fault and not really an issue unless you want to show them) In France I doubt they will have been wormed but you should worm them as soon as you get them home and louse powder them even if they show no signs of being infested. Try and keep them separated for up to two weeks so if they do show signs of illness in that time (usual incubation time for most common avian bugs) you minimise the risk of it passing to your existing flock. After that if they are still fit and well they can all go together if of a similar size. I would normally keep growers separate until 16 - 18 weeks as they have a separate diet but again in France you may find they all get the same stuff anyway in which case only keep them apart until they are of a similar size. Inevitably the newbies will get picked on but it should all settle down within a week.

Hi RH. You're right about not recognising 'growers' in France - I tried to get growers' pellets for my younger birds when I first got them, and they thought I was bonkers. Re-keeping them separated, I'm actually just as concerned about the young ones catching something from the older ones as the other way around - we seem to have had such a range of things going on since October when I first started keeping them, from the cockerel keeling over for no obvious reason, to his sister whom everyone thought probably had Marek's (but is strangely still going strong), through worms and lice and most recently a respiratory infection which meant they've all had to be dosed with antibiotics... I'm wondering whether it'll ever be truly safe for newcomers! But I suppose this is a risk I'll have to take at some point. And of course there's nothing to say the newbies won't bring something horrible with them from outside, hence the quarantine.

I'm not sure how big aracaunas are, but possibly on the smaller side? So they'll always be smaller than my maran (who'll probably leave them alone if they keep away from her food ), and one of my maran crosses (who's currently bottom of the heap and doesn't appear to attack anyone - yet) - I suspect they'll suffer most from the 2 smaller Shetlands (damaged one and sister) who were horrible to the 2 POLs last time, although have now more or less adopted them as part of their clique.

Good to hear I can mix them after a couple of weeks. In terms of the separate enclosure, will it be OK for this to be within the existing one, or does there need to be more space between them? Because if elsewhere, I can't protect them with the electric netting, and they'll have to sleep outside and not with the added protection of the outbuilding...