Seabird colonies provide rare opportunities to study trophic segregation in an entire bird community. We here present data
on nitrogen and carbon isotope ratios of eight species of seabirds from New Island, Falkland Islands, and compare trophic
levels (TL) and foraging distributions. We included adult feathers representing the interbreeding season, as well as chick
feathers or down representing the breeding season. The stable isotope ratios indicated differences in feeding areas and TLs
between species, consistent with the data of previous conventional diet analyses and observations at sea. We further reviewed
conventional and stable isotope seabird community studies calculating the means and ranges of TLs observed across these studies.
The mean TL (3.7) of the seabird community on New Island was at the lower end of the mean value range (3.5–4.5), but not significantly
different, from the reviewed seabird communities. Seabirds on New Island had a range of 1.3 TLs, which is on the upper end
of ranges within a community (0.4–1.5), indicating strong trophic structuring.
Keywords Stable isotopes - Seabird colonies - Trophic level - Falkland Islands - Dietary segregation