In it's early years, Scouting and Guiding 'borrowed' from a number of cultures. One thing lifted by some units was 'camp names'.
How and when these were bestowed from unit to unit, but a typical form was that each Guide, at the last campfire of her first camp, would write her given name on a piece of wood and cast it into the fire.
The Leaders would then confirm which name the fellow campers had chosen to replace it. At each camp thereafter, she would be known by this nickname. The names were usually drawn from wildlife, but chosen to indicate either a personality trait, or some incident which had happened during the camp.