Fly Like A Bird
Urki is a side-character that has no impact on the story or gameplay. The character himself is an easter egg of a character named Hurk from Far Cry 4. He even speaks with a weird accent like a modern man trying to speak the Wenja language. His missions are pretty much joke missions.
Head on over to his map marker to start his first mission.
You will find him in a dilemma of wanting to fly like a bird, hence the title. You casually tell him that feathers are the reason he can't fly. He then asks you to help him gather ingredients.
Head to the map marker near Urki's hut to begin collecting. Everything you need for the mission can be found in this area.
The only one of note that is a bit tricky to hunt is the raven. You can shoot it down from the sky if you can, but the shoreline closest to the hut, has two ravens land on it to rest. You can shoot them here to collect their feathers.
After collecting the required items, head to the next marker to find Urki getting ready to launch. He then tells you to watch him fly. Head to the map marker that is close to your current location to watch him.
And here we see an Assassin's Creed easter egg. The way Urki first leaps is similar to the Assassin's Creed leap of faith. He even lands on a conveniently placed haystack just like the ones in Assassin's Creed games.