Document Type
Article
Publication Date
Winter 1-3-1991
Journal Title
Physiological and Biochemical Zoology
Volume Number
64
Issue Number
4
First Page
973
Last Page
984
Version
Publisher PDF: the final published version of the article, with professional formatting and typesetting
Disciplines
Biology | Ecology and Evolutionary Biology | Ornithology | Physiology
Abstract
Contrary to some reviews, total body water (TBW) may fall below the expected value of about 65% in birds if measured as a percentage of total body mass. However, water constitutes a relatively stable proportion (659%-70%) of body composition when measured as a percentage of lean body mass (LBM). We demonstrate this by using data from two migratory phalaropes (Phalaropus tricolor and Phalaropus lobatus), which exhibit inverse relationships between TBW and body mass and between TBW and fat content. As the phalaropes fatten before migration, lipids increase but not at the expense of water, which also increases with gains in lean tissue. The gain in lean dry mass with body size is also correlated with migration. Because absolute water increases with body mass, TBW is a poor measure of hydration; however, because of the inverse relationship between TBW and fat, TBW can predict body fat accurately if a calibration curve is first generated. We provide equations that predict fat content in both species of phalaropes suggest that water normally be reported not as TBW (a percentage of total body mass) but preferably as "lean" body water (LBW, a percentage of lean body mass). In the absence of quantitative estimates off at, we suggest that water be communicated in absolute amount, preferably with some estimate of condition (fat).
Digital USD Citation
Ellis, Hugh I. and Jehl, Joseph R. Jr, "Total Body Water and Body Composition in Phalaropes and Other Birds" (1991). Biology: Faculty Scholarship. 23.
https://digital.sandiego.edu/biology_facpub/23
Included in
Biology Commons, Ecology and Evolutionary Biology Commons, Ornithology Commons, Physiology Commons
Notes
Original publication information:
Ellis, H.I. and J.R. Jehl, Jr. 1991. Total body water and body composition in phalaropes and other birds. Physiol. Zool. 64:973-984.