How animals distribute themselves in space: energy landscapes of Antarctic avian predators

Table 4 Diet and isotopic niche metrics

	Gentoo female adults	Gentoo male adults	Gentoo first chicks	Gentoo second chicks	Chinstrap adults	Chinstrap chicks
N	10	15	24	24	6	11
δ¹³C	-25.12±0.49^a,b	-24.84±0.40 ^a	-25.43±0.54 ^b,c	-25.48±0.53^b,c	-25.98±0.15 ^c,d	-26.56±0.09 ^d
δ¹⁵N	8.26±0.41^a	8.48±0.65 ^a	8.13±0.64 ^a	8.15±0.66 ^a	7.98±0.10 ^a,b	7.36±0.17 ^b
SEA	0.48	0.74	0.72	0.75	0.04	0.05
SEAc	0.55	0.80	0.75	0.78	0.05	0.06
SEAb	0.51	0.72	0.74	0.77	0.04	0.05
NR	1.65	2.45	2.24	2.64	0.31	0.58
CR	1.48	1.62	1.71	2.00	0.39	0.34
CD	0.55	0.62	0.70	0.70	0.17	0.17
NND	0.33	0.29	0.16	0.20	0.12	0.10

Data correspond to gentoo penguins Pygoscelis papua breeding at Devils Point, Byers Peninsula, Livingston Island, South Shetland Islands, Antarctica, during chick guard (December 2016), and chinstrap penguins Pygoscelis antarcticus breeding at Vapour Col rookery, Deception Island, South Shetland Islands, Antarctica, during chick guard (January 2017)
Dunn tests were used for pairwise comparisons, and homogenous subsets are marked with superscript letters. SEA: area of the standard ellipse (isotope niche width). SEAc: as SEA, corrected for sample size. SEAb: Bayesian standard ellipse area. NR: trophic length (range in δ¹⁵N). CR: diversity of basal resources (range in δ¹³C). CD: niche width 2 (mean distance to centroid). NND: mean nearest neighbour distance

ISSN: 2051-3933