Why do many procellariiform pairs remain with the same mate for life?

Many procellariiform pairs remain with the same mate for life primarily because they return each year to the same established breeding site. In these large, crowded colonies, competition for nesting territories is often severe; by remaining faithful to a specific nest site, the male and female also remain faithful to each other.1

This long-term pair bond is reinforced by elaborate greeting ceremonies—such as bill-fencing, cackling, and, in albatrosses, bowing and dancing displays—which help the birds recognize their mates and displace natural aggression or fear. While some albatross pairs may even remain together at sea during the nonbreeding season, other species, such as burrowing shearwaters and petrels, meet only on land at night and rely on voice, touch, and smell for recognition.1

Because these birds often face a slow rate of reproduction and must invest significant time and energy into raising their young, the stability of the pair bond is an important factor in their reproductive success.1