Another threat has been caused by the introduction of yellow crazy ants, which decrease habitat quality.
An invasion of the yellow crazy ant poses continued risk for the booby population.
Yellow crazy ants formed supercolonies in the 1990s and spread throughout 28% of the islands forest.
The principal threat comes from yellow crazy ants which were accidentally introduced to the island.
The crazy ants are particularly destructive to the native wildlife, and needed to be eradicated.
In summary, crazy ants kill the fauna, but encourage scale insects.
Over recent decades yellow crazy ants have emerged as one of the worst 100 invasive species in the world.
It is commonly called the crazy ant, for its erratic movement.
It latest management plan (2002) listed control of the yellow crazy ant as its highest priority.