How did the Yukaghir pictographic tradition use birch bark?

The Yukaghir people utilized a pictographic tradition that involved making incisions on fresh birch bark. This practice served distinct social and functional purposes:1

• Route Maps: Men used the birch bark incisions to create maps for navigation.1
• Expression of Feelings: Young women employed the medium as a public means to express their emotions, specifically regarding themes of love and separation.1

While this tradition functioned as a form of communication, it is not considered a system of true writing.1