Meeting Abstract

P3.126  Jan. 6  A comparison of methods for collecting exhaled breath from birds for stable isotope analysis HATCH, K.A.; WU, A.C.*; Brigham Young University; Brigham Young University alexwu00@yahoo.com

Stable isotope analysis is becoming a widely used technique in animal physiology and ecology. Usually muscle or liver tissue, hair or feathers are used for diet and trophic level analyses. However, CO₂ in exhailed breath can be analyzed to determine the metabolic substrate used by the animal over the previous few hours. This is a reflection of the portion of the diet used by the animal for energy rather than to build up tissue. We compare two methods for taking and analyzing breath samples from birds to determine the &delta¹³C of the CO₂ in the exhailed breath: (1) placing a bird in a sealed container from which repeated air samples are drawn, analyzed and keeling plots used to determine the &delta¹³C of the breath, and (2) using a mask and balloon to collect a single sample of the breath which is analyzed without the use of keeling plots.