Isotopic characterization of flight feathers in two pelagic seabirds: Sampling strategies for ecological studies

The Condor
By: , and 

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Abstract

We wish to use stable-isotope analysis of flight feathers to understand the feeding behavior of pelagic seabirds, such as the Hawaiian Petrel (Pterodroma sandwichensis) and Newell’s Shearwater (Puffinus auricularis newelli). Analysis of remiges is particularly informative because the sequence and timing of remex molt are often known. The initial step, reported here, is to obtain accurate isotope values from whole remiges by means of a minimally invasive protocol appropriate for live birds or museum specimens. The high variability observed in D13C and D15N values within a feather precludes the use of a small section of vane. We found the average range within 42 Hawaiian Petrel remiges to be 1.3‰ for both D13C and D15N and that within 10 Newell’s Shearwater remiges to be 1.3‰ and 0.7‰ for D13C and D15N, respectively. The D13C of all 52 feathers increased from tip to base, and the majority of Hawaiian Petrel feathers showed an analogous trend in D15N. Although the average range of DD in 21 Hawaiian Petrel remiges was 11‰, we found no longitudinal trend. We discuss influences of trophic level, foraging location, metabolism, and pigmentation on isotope values and compare three methods of obtaining isotope averages of whole feathers. Our novel barb-sampling protocol requires only 1.0 mg of feather and minimal preparation time. Because it leaves the feather nearly intact, this protocol will likely facilitate obtaining isotope values from remiges of live birds and museum specimens. As a consequence, it will help expand the understanding of historical trends in foraging behavior

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Isotopic characterization of flight feathers in two pelagic seabirds: Sampling strategies for ecological studies
Series title The Condor
DOI 10.1525/cond.2010.090186
Volume 112
Issue 2
Year Published 2010
Language English
Publisher The Cooper Ornithological Society
Contributing office(s) Fort Collins Science Center
Description 9 p.
First page 337
Last page 346
Country United States
State Hawaii
Online Only (Y/N) N
Additional Online Files (Y/N) N