You learned the secrets of transmutation.

Benefit(s): Whenever you cast a spell from the transmutation school, its effects manifest at +1 caster level. Additionally, select one of the following transmutation spells: bear's endurance, bull's strength, cat's grace, eagle's splendor, fox's cunning, or owl's wisdom. Once per day when you cast that spell, its duration is doubled. A spell affected by this trait cannot be modified further by the Extend Spell metamagic feat or similar abilities.