for anything but parlor pigeons i always say at least 40" x 40" x 40" for cage for breeding pair (remember this size will be for one to two sets of young in with them in this space at a time with one to two nest bowls, as females will lay again about two weeks after first pair of squeakers hatch, then again after second pair of squeakers are about two weeks). especially if they are in there most or all of time (not trained to free fly and recall on command or at certain time), as the standard pair cage of 24" squared basically seems to not be good for them to keep fit and raising babies at all and they burn out after one round of young and need rest to build back up for a season or longer. for parlors only 20" height as adults as they cannot fly and then will go up to top and tumble or roll down possibly injuring selves. for group of six non parlors, you can have something size of or made out of large dresser/small closet (for young birds, fliers, unmated adults/same sexed group or "kit"). ive tried all sorts inside and out, and especially outside these sizes and shapes seem to work optimally for my flying and show birds alike. a 36" x 30" x 16" wire rabbit cage made to either hang free against side of buildings (barns inside or out usually, about four or more feet of ground, or however highest you can reach to get at them to pull down or what not, and hopefully not have pest/pred problems), or to set up in free standing metal rabbit breeding rack, would work ok for a breeding pair let out to stretch their and their youngs wings till weaning, or a group of six young or small birds. if you cannot find pigeon food, which all are not seeming the greatest, besides
manna pro poultry conditioner for racing and showing pigeons also, you can feed (unmedicated preferably) laying pellets (chick feed make mine sick on it as to rich, maybe to much protein maybe also, and usually medicated). even cheapest wild bird seed adding in a grit dish with it containing "grit and gravel" with calcium already in it, can both be found cheap at
wal-mart if your in the states. i like to give mine fresh dandilion greens, that most consider weeds, but some know to be great super leafy green food. mine also love to eat chickweed, spinich, kale, and any bugs they can catch on fly on ground or dig up (they learned from my bantam chickens i think). you can also i found feed them budgie ( most in states call parakeets), food. mine love to pick out the parrot pellets as my budgies never ate them anyway, though then you have to add some form of grit again as not in it like already included in pigeon or chicken feed. scratch feed for chickens will work well im told and i tried breifly, but know pigeons will do fine on peas and/or supposedly wheat alone even, or mixed with split/cracked or small corn. milo, salflowers, small/cut sunflowers, are also great for them, as well as other grains and seeds im sure im forgetting others will chime in with hopefully. corn can be essential for cold weather and prep of if your birds are out in cold not in inclosed barn or coop supposedly. ive had some of mine choose for while to live and nest down by goats dogs, ducks, quail, and chickens, and live mostly off cheap crushed dry dog (ol' roy complete red bag) food. ive kept mine in climate of east TN, and even in up most north eastern WI. in nothing but wire cages with one or up to three sides blocked by wood of walls ect and/or and tarping to block full sun wind and rain, and they seemed to love that more then when i pampered them and closed them in. just make sure always are dry, clean have fresh feed once or twice daily, and fresh clean water once to twice a day. some pigeons like chickens will do also and other poultry or fowl (as well as reptiles, amphibians and some other non mammals), will reguritate into their water undigestable material from their crops and stomachs ect.
