[6] In 1981, it was estimated that the petrel colony, comprising about 2000 breeding pairs, was declining by 33% every year, due to predation by black rats, cats and other introduced species.

[7] Prior to 1984, the residents of Floreana had declared Cerro Pajas a "Protected Area", an initiative led by local conservationist Felipe Cruz.

[6] In the early 1980s, conservationists launched the first programme to control introduced rats at Cerro Pajas, to improve the petrels' breeding success.

[6] This programme was started by Malcolm Coulter, an ornithologist at the Charles Darwin Research Station, and continued in its early years by Felipe Cruz and American naturalist Tina Beach.

[7] Throughout the 1980s, continued rat baiting allowed the petrel colony to maintain high levels of nesting success.