I have an ameraucana hen that is displaying broodiness. In laying box for longer than usual, putting straw on her back, growling at me etc. But she isnt staying on the eggs long enough each day and isn't acting broody when she's not sitting. Could it just be early stages of broodiness or am I misreading her?
It takes a hen awhile to build her clutch, chasing off the other hens to prevent interference, while her hormones also build. This is termed the "pre-broody" phase.
Generally they do what you see. Spend longer in the nest, several hours a day, and are very protective of their spot, yet will forage and act normal the rest of the day.
Depending upon the genetics, you should see the hen go into a broody phase within a week or two or even three. Putting a clutch for her to sit upon will help to trigger the necessary hormones (by literally pressing on a point in her breastbone that triggers release from the pituitary gland once enough pressure is applied).
Also make sure she is not disturbed and has a warm, draft free nest. Some less dominant hens do get pushed off of nests, though they growl, which will discourage them from sitting.
That's assuming she has the right genetic make up for a real brood. Unfortunately with a lot of the engineering our domestic breeds have, selecting for production against brooding, many of our large fowl hens simply have enough genetics to make them cranky but not enough to actually effectively brood.
I personally call this "sulking," and it is very annoying, unproductive, and can be harmful for the hen if she doesn't eat and take care of herself.
Again, I think you are on the right track. Put some eggs down. Keep traffic away from that nest. Even put some nice fluffy material (timothy hay you get from the pet store is tempting). Make sure it is quiet, darker, and you may trigger a very nice brood for a hen made up of the right genetics.
I'm not sure if you have a true Ameraucana or an Easter Egger. EE's are known for brooding. Many of the hybrids gain some of those genetics back (not so with the production high lines which have them deselected). If you have a good line Ameraucana, you could have genetics as well. The heritage, breeder quality lines, often have better genetics for brooding too.
Good luck. Let us know how it goes. I can highly recommend the "Old Fashioned Broody Hen" thread or the "Broody Hen" thread for further advice.
LofMc