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ALCES VOL. 38, 2002 BEN-DAVID ET AL. - STABLE ISOTOPES IN MOOSE AND CARIBOU

219

UTILITY OF STABLE ISOTOPE ANALYSIS IN STUDYING FORAGING

ECOLOGY OF HERBIVORES: EXAMPLES FROM MOOSE AND

CARIBOU [Alces 37(2): 421-434, 2001]

Merav Ben-David1, Einav Shochat2, and Layne G. Adams2

1Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; 2U.S.

Geological Survey, Biological Resources Division, 1011 Tudor Rd., Anchorage, AK 99503, USA

ALCES VOL. 38: 219-220 (2002)

Key words:  Alaska, Alces alces, amino acids, caribou, Denali National Park, moose, Rangifer
tarandus, seasonal diets, δ13C, δ15N

ERRATUM: Due to a problem with the resolution of symbols used in Figures 4 and 5 of the above

paper (p. 427 of Volume 37, Issue Number 2), those figures were not accurately reproduced in all

printed copies of the Alces journal.  Figures 4 and 5 are reprinted below using new symbols.  Please
compare these figures with those published previously for accuracy.

Fig. 4.  Stable isotope ratios of blood cells from moose and caribou collected in Denali National Park

and Preserve, Alaska, USA. Black solid symbols represent late summer-autumn values for caribou

in 1993 and moose in 1998. Light shaded closed symbols represent winter values for caribou in

1993 and moose in 1998. Open circles represent winter values for caribou in 1998. Isotopic ratios

of blood cells from moose and caribou were significantly different from each other in all seasons

(K nearest neighbor randomization test, P < 0.001).  Values of δ15N were not significantly different
between winter and summer for moose (ANOVA, P = 0.4), or caribou (ANOVA, P = 0.06).  In both
species, a significant enrichment of 0.5-0.6‰ in δ13C occurred in winter (ANOVA, P = 0.03 for
moose, and P < 0.001 for caribou).

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δ13C

δ15N

Caribou

Moose



STABLE ISOTOPES IN MOOSE AND CARIBOU - BEN-DAVID ET AL. ALCES VOL. 38, 2002

220

Fig. 5 – Stable isotope ratios of blood cells from moose and caribou collected in Denali National Park

and Preserve, Alaska, USA, in autumn and spring 1993 and 1998, plotted against the range of

predicted isotopic ratios for herbivores (for symbol designations see Figure 4). Stable isotope

ratios of moose and caribou were within the predicted range of values for each herbivore based

on plant isotope ratios and trophic fractionation. Caribou values did not register inside the area

of overlap indicating that trees and shrubs contributed less to the diet of these herbivores than

other components of their diet.

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δ13C

δ15N

Herbivore

feeding

on trees,

shrubs,

 and aquatic

plants

Herbivore

feeding

on herbs,

mushrooms

and lichens

Herbivore

feeding

on herbs

and 50%

lichens