The short answer is they are relatively hardy and generally easy to keep but can be difficult to entice to breed. The most readily available (Chilean) run about $3,000. each when you can find them. There is one species regulated by the USFWS (Greater), they require a special purpose permit, the others do not.
Quote:I am curious why you think that? I have seen Chilean and Lesser flamingos for sale in the past and they are not uncommon in zoos so they are available. Many times zoo stock is released to the different public breeders who are approved for sale or trade when a display changes or they are no longer going to be on display. I know several places in Southern CA where they were on display outside of parks or zoos and up until just a few years ago there were live flamingos on display at a privately owned hotel. I lived in FL for almost 13 years and there are some restrictions there because Caribbean flamingos are sometimes found on the mainland and greater flamingos are restricted, I am not sure if greater flamingos are legal to own anywhere, but I think several others are ok to keep, and I may be wrong but if I remember correctly they can be kept without special permits.
As another poster said, they are hard to breed. I worked with them at an aviary, and ours did produce two young over four years. They do not mate every year though, even in the wild, and it took them a while to get the gist of sitting on the nest. The greater flamingos form sand cones, so you have to provide them with lots of damp sand (so, be prepared to be watering it every day several times a day if you want them to lay!), and it doesn't hurt to help them out the first time by forming one. They injure their legs very easily, and will even get tangled up with each other and injure each other by tripping and stampeding. They are flighty birds, and it takes a lot of training just to get them to not freak out when you feed them in an open enclosure. You have to know how to do a stork type hold with proper leg and beak restraint so as to not injure them when they must be checked over. You'll wan to pinion them or be very, very, very good about clipping their wings or you will have an escaped flamingo running around. Mazuri makes a commercial flamingo specific pelleted diet, and has a breeder diet for them as well. They are messy! They eat messily and you have to soak the pellets. They poop everywhere and often, and clean up is not fun. I do not know if a hand-raised flamingo would be more tame, but you would have to find a commercial flamingo crop milk substitute to do so (it would be very different from the commercial pigeon crop milk substitutes), as both the mom and dad secrete this from their crop lining. I don't even want to think about how hard raising a baby flamingo would be myself.
All that said, they are great fun to watch, and make really lovely noises. Sometimes, when in a flock, they will march up and down in a strict formation. X)
I belive that mud is better then sand for nesting. Also flamingos can get friendly....a bit to friendly ,in breeding season. The hand raised ones are really bad for showing to much "love" for people ,if ya catch my drift
Also they tend to have a hard time breeding if pinioned. I prefer to have them in large netted flights.