Bowtruckle reproduction is also rather interesting. When a Bowtruckle dies, one of their bones remains active instead of collapsing to dust. By active, I mean that cells are still dividing and reproducing. This bone then grows into a new adult Bowtruckle. Bowtruckles will live an average of fifty years, though some in older trees have lived as long as their home tree. The oldest Bowtruckle on record is 400 years old, living in an old pine tree. The Bowtruckle gender does not change from rebirth to rebirth. One thing to note is that the average age is a combination of those that die from natural causes and those that are killed by humans or disease. Tree fungus will bring a Bowtruckle down very quickly, as they do not have advanced immune systems. During the witch trials of Europe, the "moving sticks" seen by Muggles were seen as a sign of witchcraft, and trees were burned, killing massive amounts of the Bowtruckle populations. Burned Bowtruckles cannot regenerate, as none of their bones remain active after being burned.