Selfsufficientish.com

Is there a particular reason why chickens poo so much? It seems disproportionate compared to other small animals.

I have no idea - never noticed!

And they drop them wherever they are, is there anything I can do to make them toilet in a specific area?

No.
But a good plan is to move their run to different places over your garden so they naturally fertilise the soil for you.
Especially good to let them run over your vegetable garden in winter to remove pests and manure the soil equally all over in one go.

Talking of pests, and this didn't happen when I had chickens a few years ago, when these chickens pooed, within ten minutes loads of flies came out of nowhere to work on the droppings in the garden (not in the shed, thankfully). I got four of them on Friday and today is the first day I let them free range so it's not as if it was all out there for ages. Is there a tried and trusted way of repelling flies from a garden - plants, gadgets, anything.

I've been dusting with the diatomaceous earth powder, hopefully will keep problems at bay.

any churkendoose experts out there?
What the hell are these?
black beaks, wattles and combs - grey white and black feathers - chortle rather than cluck and scream if upset

Dunno but they are rather handsome.

Ooh, pretty.

Very unusual. Maybe you can start a new breed?

Thanks, I will keep investigating. I was given these birds third hand - apparently they came from a breeder near Urana a couple of hours West of here (Google it) so no history for them.

Re Chooks pooing so much - the quick answer is that they have a very simple and rapid digestive system that results in more waste than mammals - chemical digestion is basic and supported by the process physical grinding in the gizzard. This is also why chooks need a high nutrient diet and access to grit and "gravel"; they actually have "rocks" in their guts.