A peacock requires a minimum of 100 square feet per bird. The required height for their pen should be at least 8’ tall and perches at least 4’ above the ground to allow for proper hanging of the males trains. A full grown male adults train reaches anywhere from 8 to 10 feet when spread out. Due to this you really want to make the minimal width of their pen 12 feet so he has room to move without damaging the ends of his plumage. For example a pen that is 16 feet long by 16 feet wide and 8 feet tall would be 256 square feet. This would be a good size pen to house 2 full grown peacocks. A pen that is 16 feet wide by say 20 feet long would total 320 square feet which would be a good size pen to house 3 full grown adults. Remember, the bigger the pen the happier the birds will be as they will have more room to move around.
Here is an example of some of FL rules for bare requirements for these specific animals.
I am sure different states have different guidelines.
10. Ratites (e.g., ostrich, rhea, emu, cassowary) a. For one or two birds, a paddock enclosing 500 square feet, six feet high (six feet for ostriches) with an attached shaded, protected area. b. For each additional bird, increase original paddock area by 25 percent. (5) Effective date: All cage and enclosure requirements in this rule shall not take effect until January 1, 2008.
6. Quail (e.g., bob-white quail, scaled quail, button quail, and other species) (exhibit only) a. For a pair, a cage 2 feet by 2 feet, 1 foot high. b. For each additional animal, increase original floor area by 10 percent.
5. Lesser game birds (e.g., pheasants, wild guinea fowl, tragopans, snowcocks, partridge, grouse, chachalacas, guans) (exhibit only) a. For up to five birds, a cage having 100 square feet of floor, 6 feet high, with the perch elevated 30 inches. b. For each additional bird, increase original floor area 10 percent.
4. Large ground-dwelling (e.g., Congo peafowl, Javan peafowl, curassows, wild turkeys, brush turkeys (moundbuilders), large grouse, capricali, and sage hen) (exhibit only) a. For up to five birds, a cage having 144 square feet of floor, 6 feet high, with the perch elevated 4 feet above the floor. b. For each additional bird, increase original floor area by 10 percent.
2. Waterfowl. a. Small to Medium (e.g., green-winged teal, mallard and similar sizes ducks, geese) (I) For up to four birds, a cage with 75 square feet of land area and 7.5 square feet of water area. (II) For each additional adult bird, increase enclosure and pool size by 25 percent. b. Large (e.g., geese, swans, and similar size) (I) For up to four birds, an enclosure with 150 square feet of land and 15 square feet of water area. (II) For each additional adult bird, increase enclosure and pool size by 25 percent.
Pen size for an adult emu pair should be about 1/8 to 1/4 acre. Six-foot fencing is adequate for adult emu, but some sources recommend a 6 1/2 to 7-foot fence with a top rail. Taller is always better as an emu can jump surprisingly high. Alleys between pens (with gates opening into alleys) make it easier to move birds. Exercise pens and large pens for groups of birds usually are long and narrow rather than square to provide more running room. The facility should include an isolation or quarantine area for sick or new birds as far as possible from the remainder of the flock.
Newly hatched chicks cannot regulate their body heat and need a source of warmth until 3 months old if the outside temperature is cold. Maintain temperature at 90 to 95 degrees F for the first 3 days after hatch. Decrease temperature 5 degrees every 2 weeks. In warm weather, use supplemental heat only at night. The heat source should be of adequate size for all chicks to get around it, and the pen area should be large enough so the chicks can get away from the heat to avoid overheating. Brooder boxes for chicks 1 to 3 days old are typically about 1 foot high and 2 x 3 or 3 x 4 feet in area per 10 chicks. Bigger is always better as well if possible. Make sure you use a NON slip flooring for your chicks. Chicks may pile and smother one another. Avoid overcrowding, extremes of heat or cold and sudden frightening of the chicks. Piling generally becomes less of a problem after the first few weeks. The floor of the brooding area must be easy to clean and have good traction. Chicks can be moved to an 8 x 8-foot nursery pen at approximately 70 to 85 degrees F on day four and then into progressively larger pens. Encourage outside exercise periods and sunbathing starting at 5 to 7 days of age, depending on the weather. Separate juvenile groups by age and/or size into large communal pens (50 x 100 feet) or pastures. Grass usually survives well in emu pens except along the fence, where the birds' tendency to fence walk kills it.
Breeding pairs select their mates in large communal pens. The female emu chooses the male and will become quite aggressive toward males she doesn't find suitable. In pens where adults are pairing up, some producers leave the corners loose to provide an escape route for birds being chased off by jealous rivals or angry females. These birds pop through the corner into an alley between the pens. Sometimes aggressive females are penned separately from the males, but with a common fence. Usually birds that settle down together in the evening will successfully pair up. Individual pens and shelters usually are provided for breeding pairs; however, polygamous arrangements have been successful.
Shelters may be made of wood, tin, fiberglass or other materials. Fiberglass is lightweight and easy to move (if self-contained). Fiberglass shelters are quite bright inside because of penetrating sunlight. Shelters with good lighting appear to encourage the emus to nest inside. Bedding, such as straw inside the huts, encourages inside egg laying and makes clean egg collection easier. Adult emus appear to be quite tolerant to cold weather. Normal reproduction (more than 30 eggs per pair) has been reported in North Dakota in barns "heated" to 35 to 40 degrees F with an outside temperature of 10 degrees F.