Table 1.

Mean ± s.d. of plasma δ¹³C and δ¹⁵N values of Sabine's gull and Arctic terns in 2008 and 2009, as well as of different food items from the marine and terrestrial food webs collected at Nasaruvaalik Island, Nunavut. Not all possible food items present in the diet of the species were collected.

		n	δ13C (‰)a	δ15N (‰)
2008	Sabine's gull	18	−17.53 ± 2.04	13.52 ± 1.76
	Arctic tern	10	−17.03 ± 0.64	14.71 ± 0.38
2009	Sabine's gull	20	−23.22 ± 0.93	8.84 ± 0.71
	Arctic tern	22	−15.89 ± 0.89	13.72 ± 1.04
marine food webb
	harpacticoid copepod	8	−17.23 ± 1.56	5.97 ± 0.46
	calanoid copepod	8	−15.34 ± 3.66	9.92 ± 1.08
	amphipodc	19	−16.33 ± 2.85	10.41 ± 2.09
	Arctic cod (Boreogadus saida)	16	−20.17 ± 1.36	13.51 ± 0.61
terrestrial food webd
	saxifrage	3	−29.73 ± 1.08	1.55 ± 0.29
	lichen	10	−25.15 ± 1.94	−0.25 ± 2.48
	terrestrial invertebrated	22	−26.73 ± 1.08	6.12 ± 2.15
	moth	4	−28.75 ± 0.71	13.40 ± 2.06

^aThe bird and marine food web δ¹³C values were normalized for lipid content [25] except for Arctic cod samples, which were lipid-extracted.

^bItems were collected in 2008, 2009 and 2011 at Nasaruvaalik Island.

^cAmphipod includes species from the genus Gammarus, Gammaracanthus and Themisto.

^dTerrestrial invertebrate includes chironomids, collembolla and other flies; moths were separated from that group because of their surprisingly high δ¹⁵N values.