Validation of an enzyme immunoassay for measurement of excreted estrogen and testosterone metabolites in the white-crowned sparrow (Zonotrichia leucophrys oriantha)

Over the past few years there has been a growing interest in hormonal analyses, despite the cost and difficulty involved in measuring hormones using radioimmunoassays. Therefore, there is a need for alternate procedures, such as enzyme immunoassays, capable of providing similar data to that provided by radioactive methods. Enzyme immunoassays are a less expensive method of measuring estrone conjugates and testosterone. With further work, the enzyme immunoassay also provides the potential to adapt the enzyme assay for use in the field. The data in this study demonstrate that an enzyme assay can accurately detect both endogenous and exogenous hormonal changes in the droppings of white‐crowned sparrows. © 1995 Wiley‐Liss, Inc.