Total body water (TBW)

Range 1st study [Ruch & Hughes (1975)] 79%: 2nd study [Walter & Hughes (1978)] 88% %
Organism Glaucous-winged Gull Larus glaucescens
Reference Sheila A. Mahoney & Joseph R. Jehl, Jr., Body water content in marine birds, The Condor 86: 208-209, The Cooper Ornithological Society 1984 link p.208 left column top paragraph
Primary Source Ruch FE Jr, Hughes MR. The effects of hypertonic sodium chloride injection on body water distribution in ducks (Anas platyrhynchos), gulls (Larus glaucesens) and roosters (Gallus domesticus). Comp Biochem Physiol A Comp Physiol. 1975 Sep 1 52(1):21-8. AND Anne Walter & Maryanne Robinson Hughes, Total body water volume and turnover rate in fresh water and sea water adapted glaucous-winged gulls, Larus glaucescens, Comparative Biochemistry and Physiology Part A: Physiology, Volume 61, Issue 2, 1978, Pages 233-237, doi:10.1016/0300-9629(78)90103-2 link PubMed ID240552
Method Primary source Walter & Hughes, 1978, abstract: "1.1. Total body water (TBW) volume and TBW turnover rate were measured by tritiated water (THO) disappearance rate in glaucous-winged gulls, Larus glaucescens drinking either fresh water or sea water. These measurements were compared allometrically to values reported for other birds."
Comments P.208 left column top paragraph: "Total body water (TBW) in adult birds averages approximately 60% of body weight, regardless of bird size (Skadhauge 1981:3 BNID 113046). Voluminous data on land and aquatic birds have been obtained using two techniques: oven drying to constant weight and isotope or dye dilution. These techniques yield similar results (Degen et al. 1981). However, Ruch and Hughes (1975, primary source) and Walter and Hughes (1978, primary source), using isotope dilution, found very high values of TBW of 79% and 88%, respectively, in age-unspecified (presumably adult) Glaucous-winged Gulls (Larus glaucescens). They postulated that “the larger TBW volume may be of adaptive significance to marine birds since a larger relative volume would buffer the impact of a salt load on the concentrations of body fluids” (Walter and Hughes 1978, primary source). At that time, with the exception of one tern species (see Table l), their data were apparently the only published values of TBW for marine birds." Please note-there may have been a mix-up, and values from the 1st & 2nd study are 88% & 79%, respectively (as value of 79% appears in abstract of 2nd study, heading 2.2).
Entered by Uri M
ID 113050