724_Final Report.pdf - North Pacific Research Board

and possibly wintering areas over time, which would provide meaningful information about changes in
relative abundance of prey at these areas over time.
In conclusion, we advise researchers to apply our QFASA results with some caution in that the
captive eider CCs, turnover rates, and FA subsets may require further consideration in application to wild
birds. We stress that further work is required to calculate complete turnover rates of FAs from a natural
diet, investigate the sensitivity of CCs and FA subsets to diets, and of the model to the CCs and FA
subsets used. However, despite this sensitivity our study showed that QFASA accurately estimated Diet 1
and accurately indicated diet switches in captive eiders, and that diets can be estimated over an extended
time period. Thus, our understanding of diet can be back-tracked to more than a month in a feeding eider.
Regardless of model limitations, this study provides an important basis for further validation studies and
interpretation of adipose tissue FA data from wild populations. Applying minimally invasive QFASA
techniques to determine the diets of spectacled and Steller’s eiders during different life history stages will
provide information about their diets and help identify critical habitats to support conservation of these
threatened breeding populations.
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