Salt Gland Secretion in Saline-Acclimated Chestnut Teal, and its Relevance to Release Programs

Abstract

Chestnut teal were raised on increasing concentrations of sodium chloride in their drinking and bathing water, and the response to an intravenous salt load compared with that of animals maintained on fresh water. The salt-raised birds had lower body weights, larger nasal glands and higher plasma osmotic and sodium levels than control animals. After infusion of sodium chloride, the rate of salt gland secretion was similar in the two groups, but the salt-acclimated animals produced higher concentrations. These birds also were superior in their ability to concentrate urine. Although acclimation to salt water does induce changes in chestnut teal, they remain inferior to truly marine birds in their ability to handle salt. Their observed feeding in saline environments, and their release into such areas, probably rely on access to fresh water.