Table 3 Isotopic niche metrics of Gentoo Penguins Pygoscelis papua. Parameters are based on carbon (δ13C) and nitrogen (δ15N) stable isotopes of chick feather samples as a marker of breeding season foraging ecology from two colonies at New Island and two breeding seasons calculated with the SIAR package. SE South End colony, NE North End colony
From: How animals distribute themselves in space: variable energy landscapes
Symbol | Explanation | NE, 2013 | SE, 2013 | NE, 2014 | SE, 2014 |
|---|---|---|---|---|---|
n = 20 | n = 20 | n = 18 | n = 20 | ||
LOC | Location of centroid (mean δ13C, mean δ15N) | −15.73, 14.45 | −15.49, 14.39 | −16.04, 14.75 | −15.94, 14.71 |
SEA | Area of the standard ellipse (isotope niche width) | 0.34 | 0.63 | 0.15 | 0.19 |
SEAc | as above, corrected for sample size | 0.36 | 0.67 | 0.16 | 0.20 |
NR | trophic length (range in δ15N) | 1.46 | 1.74 | 1.40 | 0.99 |
CR | diversity of basal resources (range in δ13C) | 0.96 | 2.19 | 0.82 | 0.99 |
CD | niche width 2 (Mean distance to centroid) | 0.43 | 0.52 | 0.31 | 0.29 |
NND | mean Nearest Neighbour Distance | 0.16 | 0.26 | 0.13 | 0.15 |