Using Plasma-Lipid Metabolites to Index Changes in Lipid Reserves of Free-Living Lesser Scaup (Aythya Affinis)

• Published in: The Auk Vol. 125; no. 2; p. 354
• Main Authors: Anteau, Michael J, Afton, Alan D
• Format: Journal Article
• Language: English
• Published: Waco American Ornithological Society 01.04.2008
• Subjects: Bird migration; Colleges & universities; Metabolites; Mineral reserves; Natural resources; Plasma; Triglycerides; Wildfowl
• ISSN: 2732-4613
• DOI: 10.1525/auk.2008.06255

Understanding daily lipid-reserve changes in migrating wild birds is important for habitat assessment and species conservation. Plasma-lipid metabolites have been used to estimate rates of lipid accumulation or catabolism in small-bodied wild birds (<75 g), but this has not been validated for larger-bodied wild birds such as waterfowl. We developed an index for detecting whether individual birds accumulate or catabolize lipid reserves by regressing plasma-lipid metabolite levels (triglyceride and β-hydroxybutyrate) and known one-day mass changes (daily mass change) of 22 free-living Lesser Scaup (Aythya affinis ; a larger-bodied species with typical mass range 600-1,000 g). Triglyceride and β-hydroxybutyrate predicted 75% of the variation in daily mass change (F = 28.85, df = 2 and 19, P < 0.001). Triglyceride was positively correlated (P = 0.029) with mass change, and β-hydroxybutyrate was negatively correlated (P < 0.001) with mass change (daily mass change = -54.49 + 11.82 [triglyceride] - 28.65 [β-hydroxybutyratelog ]). Our results indicate that triglyceride and β-hydroxybutyrate can estimate one-day changes in mass of free-living wild Lesser Scaup, which provides an index to daily changes in lipid reserves and should be useful for assessing quality of migration habitat. [PUBLICATION ABSTRACT]