it's 30% of recruiting them
All you need to do is get Articuno, Zapdos, and Moltress on your team. Then just talk to Alakazam and then you can go.
After the end credits, you can revisit Mt. Thunder, Mt. Blaze, and Frosty Forest (As long as you have no missions for the place that you're going to.) As you get to the final floor, make sure you've saved in that middle section and you only have one Pokemon on your team. If you cant recruit it on the first try reset the game to the last save, and try again. they each have a 30% recruit ratio. After you recruit one of them you unlock the legendary island friend area.
Of the three original legendary birds, there is Moltres, and of the Johtolegendary birds, there is Ho-Oh.
You just have to keep fighting them, eventually one will ask to join, then the chances of getting the other 2 are increased because you have the island.
Based on raw stats the birds would be better than the dogs.
you get legendary island by recruiting one of the three legendary birds u can not buy it u gotta recruit zapdos moltres or articuno it comes with the recruit i recommend getting the highest level u can cuz the higher level u are the more percent you will recruit a Pokemon & be holding a friend bow while u fight it that helps so good luck!
You can only unlock it by recruiting one of the legendary birds
recruit the legendary birds
You need to recruit one of the legendary birds. The island is automatically unlocked.
After howling forest you have to go recruit all the legendary birds if you didn't.
You have to recruit either zapdos, moltres or articuno to unlock legendary island. Go by yourself and carry a friend recruiting item eg. friend bow. thats how i did it. once you have all three birds it will unlock a side mission. Hope this helps ;D (sorry, have forgotten where you find the friend bow)
All you need to do is get Articuno, Zapdos, and Moltress on your team. Then just talk to Alakazam and then you can go.
Like any other pokemon. Keep defeating them, and their friend area is "Legendary Isle". I don't remember if this area comes with the three legendary birds, if not, keep defeating them and after a while one should ask and you will automatically receive access to the friend area. To get a better chance of recruiting Pokemon, give the leader a Friend Bow to hold.
the legendary birds
I am absolutely positive of this answer, what you do is recruit Articuno, Zapdos and Moltres and then you talk to Alakazam in the Town Square. He will tell you to go to Legendary Island. The Legendary Birds will give you access to the Silver Trench.
You can in Mystery Dungeon Blue and Red. You can get Articuno in Time and Darkness too, if you use wonder mail. From N.S.
You do not have to buy a place for the legendary birds. Once you recruit one of them, you get their friend area.