Cation content of salt gland secretion and tears in the brolga, Grus rubicundus (Perry) (Aves : Gruidae)

Abstract

This is the first report of salt gland secretion in cranes (Gruidae). The sodium and potassium concentrations of the plasma, tears, salt gland secretion, and urine of the brolga were determined. Tear sodium was equal to plasma sodium; tear plasma was four times as concentrated as plasma potassium. These values were normal for tears. The salt gland secretion sodium concentration (about 300 m-equivll) was lower than that reported for other NaC1-injected birds. This may be due to the diet, small gland size, or to insufficient stress. The salt gland secretion to plasma ratios were the same for sodium and potassium. This is unusual. The urine had a lower sodium concentration than the plasma.