If you achieve 100% completion of Super Mario Advance 3: Yoshi’s Island, you will see this screen, where the number filled in the blank is the number of lives you have lost on that save file, plus one. This might imply that whenever Yoshi loses a life, it’s not the same Yoshi that restarts the level, but a new Yoshi to take the old one’s place.
Congratulations! Your blunders have killed over 100 Yoshis
Waiting for Winter 