Discrimination factors of carbon and nitrogen stable isotopes from diet to hair in captive large Arctic carnivores of conservation concern.

摘要: Rationale Stable isotope analysis is widely used to reconstruct diet, delineate trophic interactions, and determine energy pathways. Such ecological inferences are based on the idea that animals are, isotopically, what they eat but with a predictable difference between isotopic ratio of consumer its coined as discrimination factor. Providing correct estimates diet-consumer in controlled conditions key for robust application stable isotopes technique wild. Methods Using Finnigan Mat Delta Plus isotope-ratio mass spectrometer, we investigated carbon nitrogen ratios (δ13 C δ15 N values) guard hairs four Arctic predators; wolf (n = 7), wolverine 2), grizzly bear polar 3). During 3-month trial, carnivores were fed mixed diet. The δ13 values, (g) diet items, monitored weekly each individual their Total Diet Average ratios. Results Diet-hair (Δx) varied according species, ranging [1.88 ± 0.69‰: 3.2 0.69‰] [1.58 0.17‰: 3.81 0.22‰] values. Adult wolves Δ13 average (2.03 0.7‰) was lower than young (2.60 0.8‰) any other species (combined 2.59 0.28‰), except (2.12 0.23‰). Wolves Δ15 averages (juveniles: 3.51 0.34‰, adults: 3.68 0.28‰) higher those average: 2.50 0.58‰). Conclusions factors values calculated this study could be studies dealing free-ranging animals, implications non-invasive research approaches. As studies, recommend caution applying our when population structure heterogeneous.