Progress Report: Productivity Study Of Whistling Swans Wintering In Chesapeake Bay
During the past four winters an effort has been made to devise a satisfactory method of estimating the percent of young among the whistling swan population wintering in the Chesapeake Bay. Work to date indicates that this can be done by use of well distributed 35-mm. aerial color slides. Combining photography with direct visual appraisal was tried in the winter of 1965. The tentative conclusion from this was that use of aerial photos for large, densely packed flocks and visual appraisal for widely dispersed flocks would give accurate results at somewhat less expense than using the...
