Page "Procellariiformes" Paragraph 18

The other type of philopatry exhibited is site fidelity, where pairs of birds return to the same nesting site for a number of years.

Among the most extreme examples known of this tendency was the fidelity of a ringed Northern Fulmar that returned to the same nest site for 25 years.

The average number of birds returning to the same nest sites is high in all species studied, with figures of around 91 % for Bulwer's Petrels, and 85 % of males and 76 % of females for Cory's Shearwaters ( after a successful breeding attempt ).