Birds
Slender-billed Prion
Pachyptila belcheri · also called narrow-billed prion
Carrying the narrowest bill of any prion species, a slender-billed prion picks individual planktonic prey from the sea surface rather than filtering in bulk, breeding in burrow colonies across the Falkland Islands that can number in the millions of pairs.
Overview
The slender-billed prion, Pachyptila belcheri, is a Least Concern seabird native to ocean and coastal habitat across the South Atlantic and southern Indian Ocean. Its uniquely narrow bill, pale facial pattern, and enormous Falkland Islands colonies make it one of the more numerically abundant and physically distinctive small seabirds found anywhere in the Southern Ocean.
A different feeding strategy in a familiar shape
While most prions rely on comb-like bill structures to filter huge volumes of seawater for plankton, the slender-billed prion has instead evolved a narrower bill built more for picking out individual prey items, a subtly different foraging strategy hidden inside an otherwise familiar prion body plan.
Status
Least Concern, remaining extremely abundant and generally stable across major breeding sites, particularly the Falkland Islands, though some colonies remain vulnerable wherever introduced predators gain access.
Slender-billed Prion: common questions
What makes the slender-billed prion's bill unusual?
This species has the narrowest, least comb-lined bill of any prion species, an adaptation suited to picking out individual prey items rather than filtering large volumes of seawater like some related prions.
How many slender-billed prions breed together?
This species breeds in extremely large burrow colonies, particularly across the Falkland Islands, with some major sites holding populations numbering in the millions of breeding pairs.
How can you identify a slender-billed prion?
This species has a notably pale face with a more contrasting white eyebrow stripe than most other prion species, along with the characteristic dark M-shaped wing pattern shared across the group.
What threatens slender-billed prion colonies?
This species can suffer severe losses at colonies where introduced rats or cats gain access, since it has little natural defence against mammalian predators introduced to its breeding islands.