Ekans Evolves at level 22. To Arbok
Pidgeotto evolves at level 36. To Pidgeot
Pidgeotto evolves at level 36.
Pidgey will evolve twice as on other games, at lvl 18 Pidgey evolves into Pidgeotto, and at lvl 36 Pidgeotto will evolve into Pidgeot.
Level 30.
36
Bayleef evolves into Meganium.
Magneton cannot evolve in Pokémon HeartGold.
Pidgey evolves into pidgeotto somewhere along the 20's and pidgeotto's evolve at some level in the 30's.
Level it up with high friendship
pidgeotto will evolve at level 36
For Nosepass to evolve into a Probopass, it needs to level at Mt. Conoret, so you can't evolve them in HeartGold/SoulSilver, you'll have to trade it to Pearl/Diamond/Platinum.
Raise Pidgeotto to a level 36 to evolve into Pidgeot!
36