Indeed, but people are often constrained by the site available. Our pen is in the shape of a fat L. I have seen numerous others in shapes like truncated triangles, fairly pronounced rectangles and the like.
Except that anybody would have carried out the necessary measurements in order to find out the amount of materials they need.
I'm not doubting the rule of thumb. I just proved that it is wrong. The OP asked a question implying he wanted to know the minimum sensible size.
For one particular size the rule may work, but for every other size it is bound to be wrong. 1000 birds may well have been very happy in a 250x250 pen, but that is not any sort of guidance as to what the maximum sensible density is. Other shoots will have had good results from using fewer or more birds in the same area, and not all have bottomless pockets.I'm not persuaded that your 13 acre pen for 1000 birds isn't unnecessarily large.
Nor is it correct if you decided to have a secondary pen with 500 birds: those birds would have half the amount of space per bird you gave to the others. Had you run a commercial shoot (and I know that a valid answer to that would be that you just wouldn't do it) and wanted to put down 10,000 birds, are you seriously saying you would have used a 1300 acre pen?
All you're saying is that the "doubters" are wrong because in your long experience of putting down birds, you did not put down birds at anything like maximal densities, or that for your particular size of pen it worked fine.
The 1m per bird is just a very basic guide u still require some common sense as well, i'm sure someone else can mind at wot distance they half the meterage rate to 0.5m per bird.
Lets face it if ur on a commercial shoot and u don't know how big ur pen should be for X amount of birds u have got bigger problems, most keepers just make it up with the benefit of experience and trail and error.
For smaller pens/pat time keepers/syndicates the figure is not too far away as a ruff guide
So many other varibles too that will affect the birds aswell as purely pen size, vegetation/ground cover, normal weather, even the ammount of hook billed predators which can seriously stress birds in some circumstances esp with gossy's. How long u keep birds in the pen for
In my area a lot of Sitka Spruce woods and the ammount of pens u see around shoots are just mature SS with almost no groundcover and no sunny areas, a pen like that would need to be larger than a well designed pen with a god mix of sun and low down cover plus roosting trees, a wet area would need a larger pen then a dry area to stop it getting clarted up.
As for shape my old head keeper would never allow u to put any corner sharper than 90 degrees in a pen, he would have kittens if i built a triangle shaped pen.
His theory was if any predators get in they will have a kiling spree in the corner, and i still would never put a 90 degree corner in
Just too many varibles to give a definitive answer
But for smaller sized pens it does give u a half decent ball park figure
Ruger is ur whole pen cover crop?
No roosting trees or open areas?
Just thinking i don't think i've ever had a how big the new pen conversation is with anyone thats used area as the measurement, usually the keeper/shoot captain will say it was X amount of fencing, which still gives u a decent idea of the size/scale of the pen.
Just nice and simple