Factors that affect chicken pasture size

I've posted before about the data I found for how much space chickens need on pasture.  The summary is that semi-industrial pastured chicken farmers plan on around 30 feet per bird, once you factor in rotation.  After watching our chickens on pasture for over a year, I've figured out why solid numbers are so hard to come by --- every pasture is different.

Climate.  Your pasture might be three times as productive as mine if you live in a tropical climate, or a tenth as productive if you live in a desert.  More productivity means you can have a smaller pasture for the same number of birds.

Chicken breed.  If your chickens are the scratching type (like our Golden Comets), you'll need a lot more space than if you're raising sedentary Cornish Cross.  On the other hand, I think our Black Australorps are easier on the pasture than our Golden Comets since they seem to be more inclined to hunt down bugs on the wing and less inclined to scratch up the ground.

Seasons.  Here in the mountains of southwest Virginia, our pasture plants grow fastest between late April and the end of June, then it's a slow decline to total lack of growth in the winter.  (Plants in the forest pasture stop growing earlier since they're shaded by the canopy above.)  Meanwhile, our kitchen scrap supply slowly builds through the early summer until I'm bringing the chickens a gallon of tomato tops, cucumber ends, and corn cobs every day starting in mid July and continuing until cold weather hits.  All of that adds up to being able to cram perhaps twice as many chickens into the May to November pasture compared to the December to April pasture.

Chicken age.  If you're raising chicks instead of just maintaining a laying flock, you need to consider the growth rate of your hatchlings.  Until they're four to six weeks old, chicks seem to make no impact on the pasture at all --- they are eating, but are mostly consuming insects and tiny pieces of leaves.  By six weeks, though, I figure a chick is equivalent to about a third of an adult hen, and those cockerels and pullets have as much impact as any other chicken once they reach three months.

Stay tuned for some number crunching on how many square feet I think our chickens need to stay happy and healthy (while keeping the pastures green.)  And don't forget their fresh water supply ---- our chicken waterer is a must.