Hunter's Focus

You may use your bonus action to heighten your senses toward a creature you can see within 60 feet that is a Favored Enemy or is missing half or more of its maximum HP. Your focus on this creature lasts for 1 hour or until you use a bonus action to use this feature again. While your Hunter's Focus is on a creature, you have advantage on any Wisdom (Perception) or Wisdom (Survival) check you make to find or track it, and whenever you hit it with a weapon attack, you deal an extra 1d6 damage of the weapon's damage type.

The length of time your Hunter's Focus lasts increases when you reach 9th level in Ranger (8 hours) and 17th level in Ranger (24 hours).