I have been re-reading “Last Chance to See” and there is a section on the Mauritius Kestrel. In 1989, when Douglas Adams and Mark Carwardine visited, there were only about 35 of these kestrels (up from 4 in 1978). I am reading about them now on wikipedia there are currently over 800 living in their natural environment. They are still vulenerable, but the raptors can declare a win on this, I think.