Seasonal and elevational variation in glucose and glycogen in two songbird species

Karen L. Sweazea, Krystal S. Tsosie, Elizabeth J. Beckman, Phred M. Benham, Christopher C. Witt

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Birds naturally maintain high glucose concentrations in the blood and tissues, even when relying on fat to meet the metabolic demands of flight or thermogenesis. One possibility is that high glucose levels might be needed to deal with these metabolic demands. Thus, we hypothesized that birds chronically exposed to colder temperatures and higher elevations have higher circulating glucose and tissue free glucose and glycogen compared to conspecifics living at warmer temperatures and lower elevations. Adult House Sparrows (Passer domesticus) and House Finches (Haemorhous mexicanus) were captured from Phoenix, AZ (340 m elevation), and Albuquerque, NM (1600 m elevation), during the summer and winter months. We measured plasma glucose, as well as free glucose and glycogen from multiple tissues. In general, high elevation and colder temperatures were associated with higher tissue glycogen and higher free glucose concentrations in the brain. These findings indicate that glucose and glycogen are subject to seasonal phenotypic flexibility as well as geographic variations that may relate to local food availability and abundance.

Original languageEnglish (US)
Article number110703
JournalComparative Biochemistry and Physiology -Part A : Molecular and Integrative Physiology
StatePublished - Jul 2020


  • Aves
  • Elevation
  • Glucose
  • Glycogen
  • Seasonality

ASJC Scopus subject areas

  • Biochemistry
  • Physiology
  • Aquatic Science
  • Animal Science and Zoology
  • Molecular Biology


Dive into the research topics of 'Seasonal and elevational variation in glucose and glycogen in two songbird species'. Together they form a unique fingerprint.

Cite this