Table 4.
Intra-specific differences in bulk and compound-specific stable isotopic analyses of Thin-billed prions Pachyptila belcheri
| Tissue | n | δ13C (‰) | δ15N (‰) | Trophic position | δ15N [Glx] (‰) | δ15N [Phe] (‰) |
|---|---|---|---|---|---|---|
| Breeding season | ||||||
| Induced feathers | ||||||
| All | 8 | − 18.5 ± 2.6 | 13.0 ± 1.6 | 3.9 ± 0.2 | 21.2 ± 2.4 | 3.3 ± 2.1 |
| Polar | 2 | − 22.5 ± 0.2 | 10.7 ± 1.1 | 3.7 ± 0.1 | 18.4 ± 0.6 | 0.9 ± 0.4 |
| Temperate | 6 | − 17.2 ± 0.9 | 13.7 ± 0.6 | 3.9 ± 0.2 | 22.7 ± 1.5 | 4.1 ± 1.8 |
| Chick blood cells | 5 | − 19.8 ± 0.9 | 12.1 ± 0.4 | 3.5 ± 0.1 | 22.1 ± 1.1 | 5.4 ± 0.4 |
| Chick feathers | 5 | − 18.5 ± 1.0 | 13.7 ± 0.4 | 3.4 ± 0.1 | 21.3 ± 0.7 | 5.6 ± 0.4 |
| Egg membranes | 6 | − 16.4 ± 0.7 | 11.7 ± 0.9 | 3.2 ± 0.4 | 19.8 ± 3.3 | 5.5 ± 0.6 |
| Inter-breeding season (moult, based on tail feathers) | ||||||
| Polar moulting | 5 | − 24.0 ± 0.4 | 7.8 ± 0.4 | 3.2 ± 0.1 | 14.3 ± 1.5 | 0.0 ± 1.8 |
| Temperate moulting | 6 | − 18.2 ± 0.9 | 15.4 ± 1.3 | 3.8 ± 0.3 | 22.1 ± 2.8 | 4.0 ± 1.8 |
Bulk stable isotope values δ13C and δ15N, trophic positions calculated from CSIA-AA and δ15N values of the trophic amino acid Glx (glutamic acid) and the source amino acid Phe (phenylanaline). Means and standard deviations are given