Wow, they're both beautiful!! I'm thinking about getting a Cockatiel, but it's between that or a Green Cheeked Conure. How old are they? Is Dante loud?
Here's a information filled response to you, and anyone else with parrots on the forum :)
Dante used to scream every time I left the room, sometimes for longer then 20 minutes. She no longer does this unless I leave my door open because I only came back when she stopped, sometimes I'd walk in and she would scream, so I turned right around and walked back out. The cockatiel has a pleasant trilling call that isn't very loud. Green cheek conures have a slightly louder and harsher call then the cockatiels single clear high pitched scream. And keep in mine all birds will at some point in the day scream, usually around sunrise or sunset. it's just what they do, only on rare occasions do you find a bird who won't scream. I recently found out from bird tricks that by feeding your parrot at night time they will be busy eating and not scream.
Both can live to be 30 years old, and some have lived to be even older. Sadly most pet stores give them a life span of 10-20 years because most people unintentionally neglect their birds. Here's 3 major factors to their life span:
Pet parrots eat seeds, most people know this and feed their birds a all seed diet for their entire lives. Unfortunately this is very wrong information and most of their diet should actually consist of fresh fruits, vegetables, grains, and some nuts depending on the type of bird you have. This should be supplemented with a high quality pellet diet, but not just any pellets will do! Most pellets are colorful and full of sugar and fillers that won't do your bird any good.
Birds who aren't fed properly will have premature organ failure, can develop fatty liver disease, become obese, fatty tumors, contributes to a overgrown beak, feather plucking/ feather chewing, causes a parrot to bite more, and they're feathers won't be as brilliant as a well fed bird.
Just like humans if all a bird does is sit around all day they won't be as healthy as a bird who goes out and gets exercise. Some species of birds, like my Galah, are very prone to obesity and fatty tumors. Because of this I'm letting her primary feathers(the feathers that give lift) grow back in so I can teach her to recall and fly outdoors with her harness on. Clipping your birds wing's isn't a bad thing to do because of all the dangers, but well trained fully flighted bird get lots of exercise. A clipped bird should receive lots of playtime to make up for this.
If droppings and food are left in the cage, they will develop mold and bacteria which can even make their owners sick, plus they will smell. Water dishes should be cleaned with diluted dish soap everyday, if they feel slimy that's bacteria and it should of been cleaned sooner. I clean their dry food dishes once a week, and wet food dishes get cleaned everyday a few hours after given the food so it isn't going bad in their cage. I also clean any food dishes that have been pooped on immediately.
The entire cage should be thoroughly cleaned once a week, and all the perches should be wiped down. Try placing the perches in places where they won't get pooped on. I use Nature's Miracle cage and aviary to clean the cages, some people use diluted vinegar. The dishes should be removed when cleaning the entire cage. For the bottom I layer newspaper so that everyday I just take off the top layer and a fresh one is already there, it saves a lot of time and is way more convenient.
Here is Dante's cage for an example of cage size. Cockatiels have long tails that will be destroyed by a cage that's too small, or misplaced perches(to close to the edge or too high). Green cheek conures don't have as long of tails, but they can still be messed up by improper perch placement.
A 16" x 16" x 18" would be good for a cockatiel or Green Cheek conure, that's what size the cage in the photo is.
Also notice the perches, it's very important to have different textures and widths to prevent sores from developing. Having different types of perches also exercise they're feet, and stretches them. Most bird cages come with perches in either wood or plastic similar to the lowest perch you see in this photo, one is ok since it gives your bird access to both sides of the cage but make sure to give variation.
And here's a awesome treat, the pink perch is a cement perch that actually dulls Dante's nails for me so I don't need to cut them. Only downside is it's rough, so make sure your bird has other options.