Can you tame the Wild Dragons from the Dragon Cave?

No. Wild dragons are dragons that used to belong to someone, and they either released them into the wilderness themselves or their scroll was burned and after being dead for two weeks, the dragons were brought back to life in the wild. You may not tame them or adopt them in any way, releasing is just there as a better alternative to killing an adult dragon you don't want. You can look at them, but you cannot otherwise interact with them.

Sometimes when the abandoned page is running low, the wild dragons will breed and some of the eggs will go to the AP, so you can possibly adopt the children of dragons in the wilderness, but there is no way to adopt or tame a frozen hatchling or adult dragon not on your scroll, regardless whether it is wild or not.