Masters Theses

Date of Award


Degree Type


Degree Name

Master of Science



Major Professor

Ralph W. Dimmick

Committee Members

Garland R. Wells, James T. Tanner


One objective of this study was to determine the seasonal abundance and distribution of wood ducks on the Holston River in East Tennessee. A second objective was to evaluate the use of float counts and roost counts as techniques for determining population numbers or trends in this area. Field observations were begun in April, 1967 and concluded in April, 1968. This study was conducted primarily on a 30-mile segment of the Holston River extending from the confluence of the North Fork and South Fork of the Holston River near Kingsport to the upper end of John Sevier Lake near Rogersville, Tennessee. The float count was the technique used to study the abundance and distribution of wood ducks. A motor-propelled canoe was used and the 30-mile segment was floated at bi-weekly intervals. Roosting-flight counts were made at islands by two observers-- one stationed at each end. Counts lasted from 30 minutes before sunset until dark. Wood ducks first arrived on the upper Holston River about February 15, with peak numbers of adults occurring in mid-March. During this period, most of their activity was confined to loafing and feeding along wooded banks and areas with negligible current. Breeding pair density was estimated at about 12 pairs per mile. The peak hatching date was in mid-May. The number of broods seen per mile was 2,6; this occurred on June 19. Abundant, rooted aquatic vegetation was an important food source for wood ducks, and a major attractant for migrating waterfowl in the fall and winter. Flocks of juvenile and adult wood ducks began to congregate about the middle of July. Numbers on the study area reached a peak of 1971 on September 12. Wood ducks roosted on segments of the river where the current was negligible, and near the bank in masses of aquatic vegetation, among leafy branches which drooped into the water, and on partially submerged logs and branches. Wood ducks began to migrate from the Holston River between September 12 and October 2. By the end of November most of the wood ducks were gone. The float count was believed to be a reliable method for determining the number of wood ducks on the study area during early spring and early fall. The night float trip seemed to be the quickest and surest method for locating wood duck roosts. Roosting flight counts were not possible at most roosting sites because the ducks remained there both day and night. At one roost, counts were conducted from August to October. The number of roosting birds reached a peak of 671 September 12 and thereafter decreased. Roost counts made during the peak roosting period in mid-September at Clay Islands may be useful in estimating year to year trends in the abundance of wood ducks on the study area.

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